nsGfxScrollFrame.cpp
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* rendering object to wrap rendering objects that should be scrollable */
#include "nsGfxScrollFrame.h"
#include "mozilla/layers/LayersTypes.h"
#include "nsIXULRuntime.h"
#include "base/compiler_specific.h"
#include "DisplayItemClip.h"
#include "nsCOMPtr.h"
#include "nsIContentViewer.h"
#include "nsPresContext.h"
#include "nsView.h"
#include "nsViewportInfo.h"
#include "nsContainerFrame.h"
#include "nsGkAtoms.h"
#include "nsNameSpaceManager.h"
#include "mozilla/intl/BidiEmbeddingLevel.h"
#include "mozilla/dom/DocumentInlines.h"
#include "mozilla/gfx/gfxVars.h"
#include "nsFontMetrics.h"
#include "mozilla/dom/NodeInfo.h"
#include "nsScrollbarFrame.h"
#include "nsINode.h"
#include "nsIScrollbarMediator.h"
#include "nsITextControlFrame.h"
#include "nsILayoutHistoryState.h"
#include "nsNodeInfoManager.h"
#include "nsContentCreatorFunctions.h"
#include "nsStyleTransformMatrix.h"
#include "mozilla/PresState.h"
#include "nsContentUtils.h"
#include "nsDisplayList.h"
#include "nsHTMLDocument.h"
#include "nsLayoutUtils.h"
#include "nsBidiPresUtils.h"
#include "nsBidiUtils.h"
#include "nsDocShell.h"
#include "mozilla/ContentEvents.h"
#include "mozilla/DisplayPortUtils.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/Preferences.h"
#include "mozilla/PresShell.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/ScrollbarPreferences.h"
#include "mozilla/ScrollingMetrics.h"
#include "mozilla/StaticPrefs_browser.h"
#include "mozilla/StaticPrefs_toolkit.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/SVGOuterSVGFrame.h"
#include "mozilla/ViewportUtils.h"
#include "mozilla/LookAndFeel.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/HTMLMarqueeElement.h"
#include "mozilla/dom/ScrollTimeline.h"
#include <stdint.h>
#include "mozilla/MathAlgorithms.h"
#include "mozilla/Telemetry.h"
#include "nsSubDocumentFrame.h"
#include "mozilla/Attributes.h"
#include "ScrollbarActivity.h"
#include "nsRefreshDriver.h"
#include "nsStyleConsts.h"
#include "nsIScrollPositionListener.h"
#include "StickyScrollContainer.h"
#include "nsIFrameInlines.h"
#include "gfxPlatform.h"
#include "mozilla/StaticPrefs_apz.h"
#include "mozilla/StaticPrefs_general.h"
#include "mozilla/StaticPrefs_layers.h"
#include "mozilla/StaticPrefs_layout.h"
#include "mozilla/StaticPrefs_mousewheel.h"
#include "mozilla/ToString.h"
#include "ScrollAnimationPhysics.h"
#include "ScrollAnimationBezierPhysics.h"
#include "ScrollAnimationMSDPhysics.h"
#include "ScrollSnap.h"
#include "UnitTransforms.h"
#include "nsSliderFrame.h"
#include "ViewportFrame.h"
#include "mozilla/gfx/gfxVars.h"
#include "mozilla/layers/APZCCallbackHelper.h"
#include "mozilla/layers/APZPublicUtils.h"
#include "mozilla/layers/AxisPhysicsModel.h"
#include "mozilla/layers/AxisPhysicsMSDModel.h"
#include "mozilla/layers/ScrollingInteractionContext.h"
#include "mozilla/layers/ScrollLinkedEffectDetector.h"
#include "mozilla/Unused.h"
#include "MobileViewportManager.h"
#include "VisualViewport.h"
#include "WindowRenderer.h"
#include <algorithm>
#include <cstdlib> // for std::abs(int/long)
#include <cmath> // for std::abs(float/double)
#include <tuple> // for std::tie
static mozilla::LazyLogModule sApzPaintSkipLog("apz.paintskip");
#define PAINT_SKIP_LOG(...) \
MOZ_LOG(sApzPaintSkipLog, LogLevel::Debug, (__VA_ARGS__))
static mozilla::LazyLogModule sScrollRestoreLog("scrollrestore");
#define SCROLLRESTORE_LOG(...) \
MOZ_LOG(sScrollRestoreLog, LogLevel::Debug, (__VA_ARGS__))
static mozilla::LazyLogModule sRootScrollbarsLog("rootscrollbars");
#define ROOT_SCROLLBAR_LOG(...) \
if (mIsRoot) { \
MOZ_LOG(sRootScrollbarsLog, LogLevel::Debug, (__VA_ARGS__)); \
}
static mozilla::LazyLogModule sDisplayportLog("apz.displayport");
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::gfx;
using namespace mozilla::layers;
using namespace mozilla::layout;
using nsStyleTransformMatrix::TransformReferenceBox;
static ScrollDirections GetOverflowChange(const nsRect& aCurScrolledRect,
const nsRect& aPrevScrolledRect) {
ScrollDirections result;
if (aPrevScrolledRect.x != aCurScrolledRect.x ||
aPrevScrolledRect.width != aCurScrolledRect.width) {
result += ScrollDirection::eHorizontal;
}
if (aPrevScrolledRect.y != aCurScrolledRect.y ||
aPrevScrolledRect.height != aCurScrolledRect.height) {
result += ScrollDirection::eVertical;
}
return result;
}
/**
* This class handles the dispatching of scroll events to content.
*
* Scroll events are posted to the refresh driver via
* nsRefreshDriver::PostScrollEvent(), and they are fired during a refresh
* driver tick, after running requestAnimationFrame callbacks but before
* the style flush. This allows rAF callbacks to perform scrolling and have
* that scrolling be reflected on the same refresh driver tick, while at
* the same time allowing scroll event listeners to make style changes and
* have those style changes be reflected on the same refresh driver tick.
*
* ScrollEvents cannot be refresh observers, because none of the existing
* categories of refresh observers (FlushType::Style, FlushType::Layout,
* and FlushType::Display) are run at the desired time in a refresh driver
* tick. They behave similarly to refresh observers in that their presence
* causes the refresh driver to tick.
*
* ScrollEvents are one-shot runnables; the refresh driver drops them after
* running them.
*/
class nsHTMLScrollFrame::ScrollEvent : public Runnable {
public:
NS_DECL_NSIRUNNABLE
explicit ScrollEvent(nsHTMLScrollFrame* aHelper, bool aDelayed);
void Revoke() { mHelper = nullptr; }
private:
nsHTMLScrollFrame* mHelper;
};
class nsHTMLScrollFrame::ScrollEndEvent : public Runnable {
public:
NS_DECL_NSIRUNNABLE
explicit ScrollEndEvent(nsHTMLScrollFrame* aHelper);
void Revoke() { mHelper = nullptr; }
private:
nsHTMLScrollFrame* mHelper;
};
class nsHTMLScrollFrame::AsyncScrollPortEvent : public Runnable {
public:
NS_DECL_NSIRUNNABLE
explicit AsyncScrollPortEvent(nsHTMLScrollFrame* helper)
: Runnable("nsHTMLScrollFrame::AsyncScrollPortEvent"), mHelper(helper) {}
void Revoke() { mHelper = nullptr; }
private:
nsHTMLScrollFrame* mHelper;
};
class nsHTMLScrollFrame::ScrolledAreaEvent : public Runnable {
public:
NS_DECL_NSIRUNNABLE
explicit ScrolledAreaEvent(nsHTMLScrollFrame* helper)
: Runnable("nsHTMLScrollFrame::ScrolledAreaEvent"), mHelper(helper) {}
void Revoke() { mHelper = nullptr; }
private:
nsHTMLScrollFrame* mHelper;
};
//----------------------------------------------------------------------
//----------nsHTMLScrollFrame-------------------------------------------
class ScrollFrameActivityTracker final
: public nsExpirationTracker<nsHTMLScrollFrame, 4> {
public:
// Wait for 3-4s between scrolls before we remove our layers.
// That's 4 generations of 1s each.
enum { TIMEOUT_MS = 1000 };
explicit ScrollFrameActivityTracker(nsIEventTarget* aEventTarget)
: nsExpirationTracker<nsHTMLScrollFrame, 4>(
TIMEOUT_MS, "ScrollFrameActivityTracker", aEventTarget) {}
~ScrollFrameActivityTracker() { AgeAllGenerations(); }
virtual void NotifyExpired(nsHTMLScrollFrame* aObject) override {
RemoveObject(aObject);
aObject->MarkNotRecentlyScrolled();
}
};
static StaticAutoPtr<ScrollFrameActivityTracker> gScrollFrameActivityTracker;
nsHTMLScrollFrame* NS_NewHTMLScrollFrame(PresShell* aPresShell,
ComputedStyle* aStyle, bool aIsRoot) {
return new (aPresShell)
nsHTMLScrollFrame(aStyle, aPresShell->GetPresContext(), aIsRoot);
}
NS_IMPL_FRAMEARENA_HELPERS(nsHTMLScrollFrame)
nsHTMLScrollFrame::nsHTMLScrollFrame(ComputedStyle* aStyle,
nsPresContext* aPresContext,
nsIFrame::ClassID aID, bool aIsRoot)
: nsContainerFrame(aStyle, aPresContext, aID),
mHScrollbarBox(nullptr),
mVScrollbarBox(nullptr),
mScrolledFrame(nullptr),
mScrollCornerBox(nullptr),
mResizerBox(nullptr),
mReferenceFrameDuringPainting(nullptr),
mAsyncScroll(nullptr),
mAsyncSmoothMSDScroll(nullptr),
mLastScrollOrigin(ScrollOrigin::None),
mDestination(0, 0),
mRestorePos(-1, -1),
mLastPos(-1, -1),
mApzScrollPos(0, 0),
mLastUpdateFramesPos(-1, -1),
mDisplayPortAtLastFrameUpdate(),
mScrollParentID(mozilla::layers::ScrollableLayerGuid::NULL_SCROLL_ID),
mAnchor(this),
mCurrentAPZScrollAnimationType(APZScrollAnimationType::No),
mIsFirstScrollableFrameSequenceNumber(Nothing()),
mInScrollingGesture(InScrollingGesture::No),
mAllowScrollOriginDowngrade(false),
mHadDisplayPortAtLastFrameUpdate(false),
mHasVerticalScrollbar(false),
mHasHorizontalScrollbar(false),
mOnlyNeedVScrollbarToScrollVVInsideLV(false),
mOnlyNeedHScrollbarToScrollVVInsideLV(false),
mFrameIsUpdatingScrollbar(false),
mDidHistoryRestore(false),
mIsRoot(aIsRoot),
mSuppressScrollbarUpdate(false),
mSkippedScrollbarLayout(false),
mHadNonInitialReflow(false),
mFirstReflow(true),
mHorizontalOverflow(false),
mVerticalOverflow(false),
mPostedReflowCallback(false),
mMayHaveDirtyFixedChildren(false),
mUpdateScrollbarAttributes(false),
mHasBeenScrolledRecently(false),
mWillBuildScrollableLayer(false),
mIsParentToActiveScrollFrames(false),
mHasBeenScrolled(false),
mIgnoreMomentumScroll(false),
mTransformingByAPZ(false),
mScrollableByAPZ(false),
mZoomableByAPZ(false),
mHasOutOfFlowContentInsideFilter(false),
mSuppressScrollbarRepaints(false),
mIsUsingMinimumScaleSize(false),
mMinimumScaleSizeChanged(false),
mProcessingScrollEvent(false),
mApzAnimationRequested(false),
mApzAnimationTriggeredByScriptRequested(false),
mReclampVVOffsetInReflowFinished(false),
mMayScheduleScrollAnimations(false),
#ifdef MOZ_WIDGET_ANDROID
mHasVerticalOverflowForDynamicToolbar(false),
#endif
mVelocityQueue(PresContext()) {
AppendScrollUpdate(ScrollPositionUpdate::NewScrollframe(nsPoint()));
if (UsesOverlayScrollbars()) {
mScrollbarActivity = new ScrollbarActivity(this);
}
if (mIsRoot) {
mZoomableByAPZ = PresShell()->GetZoomableByAPZ();
}
}
nsHTMLScrollFrame::~nsHTMLScrollFrame() = default;
void nsHTMLScrollFrame::ScrollbarActivityStarted() const {
if (mScrollbarActivity) {
mScrollbarActivity->ActivityStarted();
}
}
void nsHTMLScrollFrame::ScrollbarActivityStopped() const {
if (mScrollbarActivity) {
mScrollbarActivity->ActivityStopped();
}
}
void nsHTMLScrollFrame::DestroyFrom(nsIFrame* aDestructRoot,
PostDestroyData& aPostDestroyData) {
DestroyAbsoluteFrames(aDestructRoot, aPostDestroyData);
if (mIsRoot) {
PresShell()->ResetVisualViewportOffset();
}
mAnchor.Destroy();
if (mScrollbarActivity) {
mScrollbarActivity->Destroy();
mScrollbarActivity = nullptr;
}
// Unbind the content created in CreateAnonymousContent later...
aPostDestroyData.AddAnonymousContent(mHScrollbarContent.forget());
aPostDestroyData.AddAnonymousContent(mVScrollbarContent.forget());
aPostDestroyData.AddAnonymousContent(mScrollCornerContent.forget());
aPostDestroyData.AddAnonymousContent(mResizerContent.forget());
if (mPostedReflowCallback) {
PresShell()->CancelReflowCallback(this);
mPostedReflowCallback = false;
}
if (mDisplayPortExpiryTimer) {
mDisplayPortExpiryTimer->Cancel();
mDisplayPortExpiryTimer = nullptr;
}
if (mActivityExpirationState.IsTracked()) {
gScrollFrameActivityTracker->RemoveObject(this);
}
if (gScrollFrameActivityTracker && gScrollFrameActivityTracker->IsEmpty()) {
gScrollFrameActivityTracker = nullptr;
}
if (mScrollActivityTimer) {
mScrollActivityTimer->Cancel();
mScrollActivityTimer = nullptr;
}
RemoveObservers();
if (mScrollEvent) {
mScrollEvent->Revoke();
}
if (mScrollEndEvent) {
mScrollEndEvent->Revoke();
}
nsContainerFrame::DestroyFrom(aDestructRoot, aPostDestroyData);
}
void nsHTMLScrollFrame::SetInitialChildList(ChildListID aListID,
nsFrameList&& aChildList) {
nsContainerFrame::SetInitialChildList(aListID, std::move(aChildList));
ReloadChildFrames();
}
void nsHTMLScrollFrame::AppendFrames(ChildListID aListID,
nsFrameList&& aFrameList) {
NS_ASSERTION(aListID == FrameChildListID::Principal,
"Only main list supported");
mFrames.AppendFrames(nullptr, std::move(aFrameList));
ReloadChildFrames();
}
void nsHTMLScrollFrame::InsertFrames(ChildListID aListID, nsIFrame* aPrevFrame,
const nsLineList::iterator* aPrevFrameLine,
nsFrameList&& aFrameList) {
NS_ASSERTION(aListID == FrameChildListID::Principal,
"Only main list supported");
NS_ASSERTION(!aPrevFrame || aPrevFrame->GetParent() == this,
"inserting after sibling frame with different parent");
mFrames.InsertFrames(nullptr, aPrevFrame, std::move(aFrameList));
ReloadChildFrames();
}
void nsHTMLScrollFrame::RemoveFrame(ChildListID aListID, nsIFrame* aOldFrame) {
NS_ASSERTION(aListID == FrameChildListID::Principal,
"Only main list supported");
mFrames.DestroyFrame(aOldFrame);
ReloadChildFrames();
}
/**
HTML scrolling implementation
All other things being equal, we prefer layouts with fewer scrollbars showing.
*/
namespace mozilla {
enum class ShowScrollbar : uint8_t {
Auto,
Always,
// Never is a misnomer. We can still get a scrollbar if we need to scroll the
// visual viewport inside the layout viewport. Thus this enum is best thought
// of as value used by layout, which does not know about the visual viewport.
// The visual viewport does not affect any layout sizes, so this is sound.
Never,
};
static ShowScrollbar ShouldShowScrollbar(StyleOverflow aOverflow) {
switch (aOverflow) {
case StyleOverflow::Scroll:
return ShowScrollbar::Always;
case StyleOverflow::Hidden:
return ShowScrollbar::Never;
default:
case StyleOverflow::Auto:
return ShowScrollbar::Auto;
}
}
struct MOZ_STACK_CLASS ScrollReflowInput {
// === Filled in by the constructor. Members in this section shouldn't change
// their values after the constructor. ===
const ReflowInput& mReflowInput;
ShowScrollbar mHScrollbar;
// If the horizontal scrollbar is allowed (even if mHScrollbar ==
// ShowScrollbar::Never) provided that it is for scrolling the visual viewport
// inside the layout viewport only.
bool mHScrollbarAllowedForScrollingVVInsideLV = true;
ShowScrollbar mVScrollbar;
// If the vertical scrollbar is allowed (even if mVScrollbar ==
// ShowScrollbar::Never) provided that it is for scrolling the visual viewport
// inside the layout viewport only.
bool mVScrollbarAllowedForScrollingVVInsideLV = true;
nsMargin mComputedBorder;
// === Filled in by ReflowScrolledFrame ===
OverflowAreas mContentsOverflowAreas;
// The scrollbar gutter sizes used in the most recent reflow of
// mScrolledFrame. The writing-mode is the same as the scroll
// container.
LogicalMargin mScrollbarGutterFromLastReflow;
// True if the most recent reflow of mScrolledFrame is with the
// horizontal scrollbar.
bool mReflowedContentsWithHScrollbar = false;
// True if the most recent reflow of mScrolledFrame is with the
// vertical scrollbar.
bool mReflowedContentsWithVScrollbar = false;
// === Filled in when TryLayout succeeds ===
// The size of the inside-border area
nsSize mInsideBorderSize;
// Whether we decided to show the horizontal scrollbar in the most recent
// TryLayout.
bool mShowHScrollbar = false;
// Whether we decided to show the vertical scrollbar in the most recent
// TryLayout.
bool mShowVScrollbar = false;
// If mShow(H|V)Scrollbar is true then
// mOnlyNeed(V|H)ScrollbarToScrollVVInsideLV indicates if the only reason we
// need that scrollbar is to scroll the visual viewport inside the layout
// viewport. These scrollbars are special in that even if they are layout
// scrollbars they do not take up any layout space.
bool mOnlyNeedHScrollbarToScrollVVInsideLV = false;
bool mOnlyNeedVScrollbarToScrollVVInsideLV = false;
ScrollReflowInput(nsHTMLScrollFrame* aFrame, const ReflowInput& aReflowInput);
nscoord VScrollbarMinHeight() const { return mVScrollbarPrefSize.height; }
nscoord VScrollbarPrefWidth() const { return mVScrollbarPrefSize.width; }
nscoord HScrollbarMinWidth() const { return mHScrollbarPrefSize.width; }
nscoord HScrollbarPrefHeight() const { return mHScrollbarPrefSize.height; }
// Returns the sizes occupied by the scrollbar gutters. If aShowVScroll or
// aShowHScroll is true, the sizes occupied by the scrollbars are also
// included.
nsMargin ScrollbarGutter(bool aShowVScrollbar, bool aShowHScrollbar,
bool aScrollbarOnRight) const {
if (mOverlayScrollbars) {
return mScrollbarGutter;
}
nsMargin gutter = mScrollbarGutter;
if (aShowVScrollbar && gutter.right == 0 && gutter.left == 0) {
const nscoord w = VScrollbarPrefWidth();
if (aScrollbarOnRight) {
gutter.right = w;
} else {
gutter.left = w;
}
}
if (aShowHScrollbar && gutter.bottom == 0) {
// The horizontal scrollbar is always at the bottom side.
gutter.bottom = HScrollbarPrefHeight();
}
return gutter;
}
bool OverlayScrollbars() const { return mOverlayScrollbars; }
private:
// Filled in by the constructor. Put variables here to keep them unchanged
// after initializing them in the constructor.
nsSize mVScrollbarPrefSize;
nsSize mHScrollbarPrefSize;
bool mOverlayScrollbars = false;
// The scrollbar gutter sizes resolved from the scrollbar-gutter and
// scrollbar-width property.
nsMargin mScrollbarGutter;
};
ScrollReflowInput::ScrollReflowInput(nsHTMLScrollFrame* aFrame,
const ReflowInput& aReflowInput)
: mReflowInput(aReflowInput),
mComputedBorder(aReflowInput.ComputedPhysicalBorderPadding() -
aReflowInput.ComputedPhysicalPadding()),
mScrollbarGutterFromLastReflow(aFrame->GetWritingMode()) {
ScrollStyles styles = aFrame->GetScrollStyles();
mHScrollbar = ShouldShowScrollbar(styles.mHorizontal);
mVScrollbar = ShouldShowScrollbar(styles.mVertical);
mOverlayScrollbars = aFrame->UsesOverlayScrollbars();
if (nsScrollbarFrame* scrollbar = aFrame->GetScrollbarBox(false)) {
scrollbar->SetScrollbarMediatorContent(mReflowInput.mFrame->GetContent());
mHScrollbarPrefSize = scrollbar->ScrollbarMinSize();
// A zero minimum size is a bug with non-overlay scrollbars. That means
// we'll always try to place the scrollbar, even if it will ultimately not
// fit, see bug 1809630. XUL collapsing is the exception because the
// front-end uses it.
MOZ_ASSERT(mHScrollbarPrefSize.width && mHScrollbarPrefSize.height,
"Shouldn't have a zero horizontal scrollbar-size");
} else {
mHScrollbar = ShowScrollbar::Never;
mHScrollbarAllowedForScrollingVVInsideLV = false;
}
if (nsScrollbarFrame* scrollbar = aFrame->GetScrollbarBox(true)) {
scrollbar->SetScrollbarMediatorContent(mReflowInput.mFrame->GetContent());
mVScrollbarPrefSize = scrollbar->ScrollbarMinSize();
// See above.
MOZ_ASSERT(mVScrollbarPrefSize.width && mVScrollbarPrefSize.height,
"Shouldn't have a zero vertical scrollbar-size");
} else {
mVScrollbar = ShowScrollbar::Never;
mVScrollbarAllowedForScrollingVVInsideLV = false;
}
const auto* scrollbarStyle =
nsLayoutUtils::StyleForScrollbar(mReflowInput.mFrame);
// Hide the scrollbar when the scrollbar-width is set to none.
//
// Note: In some cases this is unnecessary, because scrollbar-width:none
// makes us suppress scrollbars in CreateAnonymousContent. But if this frame
// initially had a non-'none' scrollbar-width and dynamically changed to
// 'none', then we'll need to handle it here.
if (scrollbarStyle->StyleUIReset()->ScrollbarWidth() ==
StyleScrollbarWidth::None) {
mHScrollbar = ShowScrollbar::Never;
mHScrollbarAllowedForScrollingVVInsideLV = false;
mVScrollbar = ShowScrollbar::Never;
mVScrollbarAllowedForScrollingVVInsideLV = false;
} else if (const auto& scrollbarGutterStyle =
scrollbarStyle->StyleDisplay()->mScrollbarGutter;
scrollbarGutterStyle && !mOverlayScrollbars) {
const auto stable =
bool(scrollbarGutterStyle & StyleScrollbarGutter::STABLE);
const auto bothEdges =
bool(scrollbarGutterStyle & StyleScrollbarGutter::BOTH_EDGES);
if (mReflowInput.GetWritingMode().IsVertical()) {
const nscoord h = HScrollbarPrefHeight();
if (bothEdges) {
mScrollbarGutter.top = mScrollbarGutter.bottom = h;
} else if (stable) {
// The horizontal scrollbar gutter is always at the bottom side.
mScrollbarGutter.bottom = h;
}
} else {
const nscoord w = VScrollbarPrefWidth();
if (bothEdges) {
mScrollbarGutter.left = mScrollbarGutter.right = w;
} else if (stable) {
if (aFrame->IsScrollbarOnRight()) {
mScrollbarGutter.right = w;
} else {
mScrollbarGutter.left = w;
}
}
}
}
}
} // namespace mozilla
// XXXldb Can this go away?
static nsSize ComputeInsideBorderSize(const ScrollReflowInput& aState,
const nsSize& aDesiredInsideBorderSize) {
// aDesiredInsideBorderSize is the frame size; i.e., it includes
// borders and padding (but the scrolled child doesn't have
// borders). The scrolled child has the same padding as us.
nscoord contentWidth = aState.mReflowInput.ComputedWidth();
if (contentWidth == NS_UNCONSTRAINEDSIZE) {
contentWidth = aDesiredInsideBorderSize.width -
aState.mReflowInput.ComputedPhysicalPadding().LeftRight();
}
nscoord contentHeight = aState.mReflowInput.ComputedHeight();
if (contentHeight == NS_UNCONSTRAINEDSIZE) {
contentHeight = aDesiredInsideBorderSize.height -
aState.mReflowInput.ComputedPhysicalPadding().TopBottom();
}
contentWidth = aState.mReflowInput.ApplyMinMaxWidth(contentWidth);
contentHeight = aState.mReflowInput.ApplyMinMaxHeight(contentHeight);
return nsSize(
contentWidth + aState.mReflowInput.ComputedPhysicalPadding().LeftRight(),
contentHeight +
aState.mReflowInput.ComputedPhysicalPadding().TopBottom());
}
/**
* Assuming that we know the metrics for our wrapped frame and
* whether the horizontal and/or vertical scrollbars are present,
* compute the resulting layout and return true if the layout is
* consistent. If the layout is consistent then we fill in the
* computed fields of the ScrollReflowInput.
*
* The layout is consistent when both scrollbars are showing if and only
* if they should be showing. A horizontal scrollbar should be showing if all
* following conditions are met:
* 1) the style is not HIDDEN
* 2) our inside-border height is at least the scrollbar height (i.e., the
* scrollbar fits vertically)
* 3) the style is SCROLL, or the kid's overflow-area XMost is
* greater than the scrollport width
*
* @param aForce if true, then we just assume the layout is consistent.
*/
bool nsHTMLScrollFrame::TryLayout(ScrollReflowInput& aState,
ReflowOutput* aKidMetrics,
bool aAssumeHScroll, bool aAssumeVScroll,
bool aForce) {
if ((aState.mVScrollbar == ShowScrollbar::Never && aAssumeVScroll) ||
(aState.mHScrollbar == ShowScrollbar::Never && aAssumeHScroll)) {
NS_ASSERTION(!aForce, "Shouldn't be forcing a hidden scrollbar to show!");
return false;
}
const auto wm = GetWritingMode();
const nsMargin scrollbarGutter = aState.ScrollbarGutter(
aAssumeVScroll, aAssumeHScroll, IsScrollbarOnRight());
const LogicalMargin logicalScrollbarGutter(wm, scrollbarGutter);
const bool inlineEndsGutterChanged =
aState.mScrollbarGutterFromLastReflow.IStartEnd(wm) !=
logicalScrollbarGutter.IStartEnd(wm);
const bool blockEndsGutterChanged =
aState.mScrollbarGutterFromLastReflow.BStartEnd(wm) !=
logicalScrollbarGutter.BStartEnd(wm);
const bool shouldReflowScrolledFrame =
inlineEndsGutterChanged ||
(blockEndsGutterChanged && ScrolledContentDependsOnBSize(aState));
if (shouldReflowScrolledFrame) {
if (blockEndsGutterChanged) {
nsLayoutUtils::MarkIntrinsicISizesDirtyIfDependentOnBSize(mScrolledFrame);
}
aKidMetrics->mOverflowAreas.Clear();
ROOT_SCROLLBAR_LOG(
"TryLayout reflowing scrolled frame with scrollbars h=%d, v=%d\n",
aAssumeHScroll, aAssumeVScroll);
ReflowScrolledFrame(aState, aAssumeHScroll, aAssumeVScroll, aKidMetrics);
}
const nsSize scrollbarGutterSize(scrollbarGutter.LeftRight(),
scrollbarGutter.TopBottom());
// First, compute our inside-border size and scrollport size
// XXXldb Can we depend more on ComputeSize here?
nsSize kidSize = GetContainSizeAxes().ContainSize(
aKidMetrics->PhysicalSize(), *aState.mReflowInput.mFrame);
const nsSize desiredInsideBorderSize = kidSize + scrollbarGutterSize;
aState.mInsideBorderSize =
ComputeInsideBorderSize(aState, desiredInsideBorderSize);
nsSize layoutSize =
mIsUsingMinimumScaleSize ? mMinimumScaleSize : aState.mInsideBorderSize;
const nsSize scrollPortSize =
Max(nsSize(0, 0), layoutSize - scrollbarGutterSize);
if (mIsUsingMinimumScaleSize) {
mICBSize =
Max(nsSize(0, 0), aState.mInsideBorderSize - scrollbarGutterSize);
}
nsSize visualViewportSize = scrollPortSize;
ROOT_SCROLLBAR_LOG("TryLayout with VV %s\n",
ToString(visualViewportSize).c_str());
mozilla::PresShell* presShell = PresShell();
// Note: we check for a non-null MobileViepwortManager here, but ideally we
// should be able to drop that clause as well. It's just that in some cases
// with extension popups the composition size comes back as stale, because
// the content viewer is only resized after the popup contents are reflowed.
// That case also happens to have no APZ and no MVM, so we use that as a
// way to detect the scenario. Bug 1648669 tracks removing this clause.
if (mIsRoot && presShell->GetMobileViewportManager()) {
visualViewportSize = nsLayoutUtils::CalculateCompositionSizeForFrame(
this, false, &layoutSize);
visualViewportSize =
Max(nsSize(0, 0), visualViewportSize - scrollbarGutterSize);
float resolution = presShell->GetResolution();
visualViewportSize.width /= resolution;
visualViewportSize.height /= resolution;
ROOT_SCROLLBAR_LOG("TryLayout now with VV %s\n",
ToString(visualViewportSize).c_str());
}
nsRect overflowRect = aState.mContentsOverflowAreas.ScrollableOverflow();
// If the content height expanded by the minimum-scale will be taller than
// the scrollable overflow area, we need to expand the area here to tell
// properly whether we need to render the overlay vertical scrollbar.
// NOTE: This expanded size should NOT be used for non-overley scrollbars
// cases since putting the vertical non-overlay scrollbar will make the
// content width narrow a little bit, which in turn the minimum scale value
// becomes a bit bigger than before, then the vertical scrollbar is no longer
// needed, which means the content width becomes the original width, then the
// minimum-scale is changed to the original one, and so forth.
if (UsesOverlayScrollbars() && mIsUsingMinimumScaleSize &&
mMinimumScaleSize.height > overflowRect.YMost()) {
overflowRect.height += mMinimumScaleSize.height - overflowRect.YMost();
}
nsRect scrolledRect =
GetUnsnappedScrolledRectInternal(overflowRect, scrollPortSize);
ROOT_SCROLLBAR_LOG(
"TryLayout scrolledRect:%s overflowRect:%s scrollportSize:%s\n",
ToString(scrolledRect).c_str(), ToString(overflowRect).c_str(),
ToString(scrollPortSize).c_str());
nscoord oneDevPixel = PresContext()->DevPixelsToAppUnits(1);
bool showHScrollbar = aAssumeHScroll;
bool showVScrollbar = aAssumeVScroll;
if (!aForce) {
nsSize sizeToCompare = visualViewportSize;
if (gfxPlatform::UseDesktopZoomingScrollbars()) {
sizeToCompare = scrollPortSize;
}
// No need to compute showHScrollbar if we got ShowScrollbar::Never.
if (aState.mHScrollbar != ShowScrollbar::Never) {
showHScrollbar =
aState.mHScrollbar == ShowScrollbar::Always ||
scrolledRect.XMost() >= sizeToCompare.width + oneDevPixel ||
scrolledRect.x <= -oneDevPixel;
// TODO(emilio): This should probably check this scrollbar's minimum size
// in both axes, for consistency?
if (aState.mHScrollbar == ShowScrollbar::Auto &&
scrollPortSize.width < aState.HScrollbarMinWidth()) {
showHScrollbar = false;
}
ROOT_SCROLLBAR_LOG("TryLayout wants H Scrollbar: %d =? %d\n",
showHScrollbar, aAssumeHScroll);
}
// No need to compute showVScrollbar if we got ShowScrollbar::Never.
if (aState.mVScrollbar != ShowScrollbar::Never) {
showVScrollbar =
aState.mVScrollbar == ShowScrollbar::Always ||
scrolledRect.YMost() >= sizeToCompare.height + oneDevPixel ||
scrolledRect.y <= -oneDevPixel;
// TODO(emilio): This should probably check this scrollbar's minimum size
// in both axes, for consistency?
if (aState.mVScrollbar == ShowScrollbar::Auto &&
scrollPortSize.height < aState.VScrollbarMinHeight()) {
showVScrollbar = false;
}
ROOT_SCROLLBAR_LOG("TryLayout wants V Scrollbar: %d =? %d\n",
showVScrollbar, aAssumeVScroll);
}
if (showHScrollbar != aAssumeHScroll || showVScrollbar != aAssumeVScroll) {
const nsMargin wantedScrollbarGutter = aState.ScrollbarGutter(
showVScrollbar, showHScrollbar, IsScrollbarOnRight());
// We report an inconsistent layout only when the desired visibility of
// the scrollbars can change the size of the scrollbar gutters.
if (scrollbarGutter != wantedScrollbarGutter) {
return false;
}
}
}
// If we reach here, the layout is consistent. Record the desired visibility
// of the scrollbars.
aState.mShowHScrollbar = showHScrollbar;
aState.mShowVScrollbar = showVScrollbar;
const nsPoint scrollPortOrigin(
aState.mComputedBorder.left + scrollbarGutter.left,
aState.mComputedBorder.top + scrollbarGutter.top);
SetScrollPort(nsRect(scrollPortOrigin, scrollPortSize));
if (mIsRoot && gfxPlatform::UseDesktopZoomingScrollbars()) {
bool vvChanged = true;
const bool overlay = aState.OverlayScrollbars();
// This loop can run at most twice since we can only add a scrollbar once.
// At this point we've already decided that this layout is consistent so we
// will return true. Scrollbars added here never take up layout space even
// if they are layout scrollbars so any changes made here will not make us
// return false.
while (vvChanged) {
vvChanged = false;
if (!aState.mShowHScrollbar &&
aState.mHScrollbarAllowedForScrollingVVInsideLV) {
if (ScrollPort().width >= visualViewportSize.width + oneDevPixel &&
(overlay ||
visualViewportSize.width >= aState.HScrollbarMinWidth())) {
vvChanged = true;
if (!overlay) {
visualViewportSize.height -= aState.HScrollbarPrefHeight();
}
aState.mShowHScrollbar = true;
aState.mOnlyNeedHScrollbarToScrollVVInsideLV = true;
ROOT_SCROLLBAR_LOG("TryLayout added H scrollbar for VV, VV now %s\n",
ToString(visualViewportSize).c_str());
}
}
if (!aState.mShowVScrollbar &&
aState.mVScrollbarAllowedForScrollingVVInsideLV) {
if (ScrollPort().height >= visualViewportSize.height + oneDevPixel &&
(overlay ||
visualViewportSize.height >= aState.VScrollbarMinHeight())) {
vvChanged = true;
if (!overlay) {
visualViewportSize.width -= aState.VScrollbarPrefWidth();
}
aState.mShowVScrollbar = true;
aState.mOnlyNeedVScrollbarToScrollVVInsideLV = true;
ROOT_SCROLLBAR_LOG("TryLayout added V scrollbar for VV, VV now %s\n",
ToString(visualViewportSize).c_str());
}
}
}
}
return true;
}
bool nsHTMLScrollFrame::ScrolledContentDependsOnBSize(
const ScrollReflowInput& aState) const {
return mScrolledFrame->HasAnyStateBits(
NS_FRAME_CONTAINS_RELATIVE_BSIZE |
NS_FRAME_DESCENDANT_INTRINSIC_ISIZE_DEPENDS_ON_BSIZE) ||
aState.mReflowInput.ComputedBSize() != NS_UNCONSTRAINEDSIZE ||
aState.mReflowInput.ComputedMinBSize() > 0 ||
aState.mReflowInput.ComputedMaxBSize() != NS_UNCONSTRAINEDSIZE;
}
void nsHTMLScrollFrame::ReflowScrolledFrame(ScrollReflowInput& aState,
bool aAssumeHScroll,
bool aAssumeVScroll,
ReflowOutput* aMetrics) {
const WritingMode wm = GetWritingMode();
// these could be NS_UNCONSTRAINEDSIZE ... std::min arithmetic should
// be OK
LogicalMargin padding = aState.mReflowInput.ComputedLogicalPadding(wm);
nscoord availISize =
aState.mReflowInput.ComputedISize() + padding.IStartEnd(wm);
nscoord computedBSize = aState.mReflowInput.ComputedBSize();
nscoord computedMinBSize = aState.mReflowInput.ComputedMinBSize();
nscoord computedMaxBSize = aState.mReflowInput.ComputedMaxBSize();
if (!ShouldPropagateComputedBSizeToScrolledContent()) {
computedBSize = NS_UNCONSTRAINEDSIZE;
computedMinBSize = 0;
computedMaxBSize = NS_UNCONSTRAINEDSIZE;
}
const LogicalMargin scrollbarGutter(
wm, aState.ScrollbarGutter(aAssumeVScroll, aAssumeHScroll,
IsScrollbarOnRight()));
if (const nscoord inlineEndsGutter = scrollbarGutter.IStartEnd(wm);
inlineEndsGutter > 0) {
availISize = std::max(0, availISize - inlineEndsGutter);
}
if (const nscoord blockEndsGutter = scrollbarGutter.BStartEnd(wm);
blockEndsGutter > 0) {
if (computedBSize != NS_UNCONSTRAINEDSIZE) {
computedBSize = std::max(0, computedBSize - blockEndsGutter);
}
computedMinBSize = std::max(0, computedMinBSize - blockEndsGutter);
if (computedMaxBSize != NS_UNCONSTRAINEDSIZE) {
computedMaxBSize = std::max(0, computedMaxBSize - blockEndsGutter);
}
}
nsPresContext* presContext = PresContext();
// Pass InitFlags::CallerWillInit so we can pass in the correct padding.
ReflowInput kidReflowInput(presContext, aState.mReflowInput, mScrolledFrame,
LogicalSize(wm, availISize, NS_UNCONSTRAINEDSIZE),
Nothing(), ReflowInput::InitFlag::CallerWillInit);
const WritingMode kidWM = kidReflowInput.GetWritingMode();
kidReflowInput.Init(presContext, Nothing(), Nothing(),
Some(padding.ConvertTo(kidWM, wm)));
kidReflowInput.mFlags.mAssumingHScrollbar = aAssumeHScroll;
kidReflowInput.mFlags.mAssumingVScrollbar = aAssumeVScroll;
kidReflowInput.mFlags.mTreatBSizeAsIndefinite =
aState.mReflowInput.mFlags.mTreatBSizeAsIndefinite;
kidReflowInput.SetComputedBSize(computedBSize);
kidReflowInput.SetComputedMinBSize(computedMinBSize);
kidReflowInput.SetComputedMaxBSize(computedMaxBSize);
if (aState.mReflowInput.IsBResizeForWM(kidWM)) {
kidReflowInput.SetBResize(true);
}
if (aState.mReflowInput.IsBResizeForPercentagesForWM(kidWM)) {
kidReflowInput.mFlags.mIsBResizeForPercentages = true;
}
// Temporarily set mHasHorizontalScrollbar/mHasVerticalScrollbar to
// reflect our assumptions while we reflow the child.
bool didHaveHorizontalScrollbar = mHasHorizontalScrollbar;
bool didHaveVerticalScrollbar = mHasVerticalScrollbar;
mHasHorizontalScrollbar = aAssumeHScroll;
mHasVerticalScrollbar = aAssumeVScroll;
nsReflowStatus status;
// No need to pass a true container-size to ReflowChild or
// FinishReflowChild, because it's only used there when positioning
// the frame (i.e. if ReflowChildFlags::NoMoveFrame isn't set)
const nsSize dummyContainerSize;
ReflowChild(mScrolledFrame, presContext, *aMetrics, kidReflowInput, wm,
LogicalPoint(wm), dummyContainerSize,
ReflowChildFlags::NoMoveFrame, status);
mHasHorizontalScrollbar = didHaveHorizontalScrollbar;
mHasVerticalScrollbar = didHaveVerticalScrollbar;
// Don't resize or position the view (if any) because we're going to resize
// it to the correct size anyway in PlaceScrollArea. Allowing it to
// resize here would size it to the natural height of the frame,
// which will usually be different from the scrollport height;
// invalidating the difference will cause unnecessary repainting.
FinishReflowChild(
mScrolledFrame, presContext, *aMetrics, &kidReflowInput, wm,
LogicalPoint(wm), dummyContainerSize,
ReflowChildFlags::NoMoveFrame | ReflowChildFlags::NoSizeView);
if (mScrolledFrame->HasAnyStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE)) {
// Propagate NS_FRAME_CONTAINS_RELATIVE_BSIZE from our inner scrolled frame
// to ourselves so that our containing block is aware of it.
//
// Note: If the scrolled frame has any child whose block-size depends on the
// containing block's block-size, the NS_FRAME_CONTAINS_RELATIVE_BSIZE bit
// is set on the scrolled frame when initializing the child's ReflowInput in
// ReflowInput::InitResizeFlags(). Therefore, we propagate the bit here
// after we reflowed the scrolled frame.
AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
}
// XXX Some frames (e.g. nsFrameFrame, nsTextFrame) don't
// bother setting their mOverflowArea. This is wrong because every frame
// should always set mOverflowArea. In fact nsFrameFrame doesn't
// support the 'outline' property because of this. Rather than fix the
// world right now, just fix up the overflow area if necessary. Note that we
// don't check HasOverflowRect() because it could be set even though the
// overflow area doesn't include the frame bounds.
aMetrics->UnionOverflowAreasWithDesiredBounds();
auto* disp = StyleDisplay();
if (MOZ_UNLIKELY(disp->mOverflowClipBoxInline ==
StyleOverflowClipBox::ContentBox)) {
// The scrolled frame is scrollable in the inline axis with
// `overflow-clip-box:content-box`. To prevent its content from being
// clipped at the scroll container's padding edges, we inflate its
// children's scrollable overflow area with its inline padding, and union
// its scrollable overflow area with its children's inflated scrollable
// overflow area.
OverflowAreas childOverflow;
mScrolledFrame->UnionChildOverflow(childOverflow);
nsRect childScrollableOverflow = childOverflow.ScrollableOverflow();
const LogicalMargin inlinePadding =
padding.ApplySkipSides(LogicalSides(wm, eLogicalSideBitsBBoth));
childScrollableOverflow.Inflate(inlinePadding.GetPhysicalMargin(wm));
nsRect& so = aMetrics->ScrollableOverflow();
so = so.UnionEdges(childScrollableOverflow);
}
aState.mContentsOverflowAreas = aMetrics->mOverflowAreas;
aState.mScrollbarGutterFromLastReflow = scrollbarGutter;
aState.mReflowedContentsWithHScrollbar = aAssumeHScroll;
aState.mReflowedContentsWithVScrollbar = aAssumeVScroll;
}
bool nsHTMLScrollFrame::GuessHScrollbarNeeded(const ScrollReflowInput& aState) {
if (aState.mHScrollbar != ShowScrollbar::Auto) {
// no guessing required
return aState.mHScrollbar == ShowScrollbar::Always;
}
// We only care about scrollbars that might take up space when trying to guess
// if we need a scrollbar, so we ignore scrollbars only created to scroll the
// visual viewport inside the layout viewport because they take up no layout
// space.
return mHasHorizontalScrollbar && !mOnlyNeedHScrollbarToScrollVVInsideLV;
}
bool nsHTMLScrollFrame::GuessVScrollbarNeeded(const ScrollReflowInput& aState) {
if (aState.mVScrollbar != ShowScrollbar::Auto) {
// no guessing required
return aState.mVScrollbar == ShowScrollbar::Always;
}
// If we've had at least one non-initial reflow, then just assume
// the state of the vertical scrollbar will be what we determined
// last time.
if (mHadNonInitialReflow) {
// We only care about scrollbars that might take up space when trying to
// guess if we need a scrollbar, so we ignore scrollbars only created to
// scroll the visual viewport inside the layout viewport because they take
// up no layout space.
return mHasVerticalScrollbar && !mOnlyNeedVScrollbarToScrollVVInsideLV;
}
// If this is the initial reflow, guess false because usually
// we have very little content by then.
if (InInitialReflow()) return false;
if (mIsRoot) {
nsIFrame* f = mScrolledFrame->PrincipalChildList().FirstChild();
if (f && f->IsSVGOuterSVGFrame() &&
static_cast<SVGOuterSVGFrame*>(f)->VerticalScrollbarNotNeeded()) {
// Common SVG case - avoid a bad guess.
return false;
}
// Assume that there will be a scrollbar; it seems to me
// that 'most pages' do have a scrollbar, and anyway, it's cheaper
// to do an extra reflow for the pages that *don't* need a
// scrollbar (because on average they will have less content).
return true;
}
// For non-viewports, just guess that we don't need a scrollbar.
// XXX I wonder if statistically this is the right idea; I'm
// basically guessing that there are a lot of overflow:auto DIVs
// that get their intrinsic size and don't overflow
return false;
}
bool nsHTMLScrollFrame::InInitialReflow() const {
// We're in an initial reflow if NS_FRAME_FIRST_REFLOW is set, unless we're a
// root scrollframe. In that case we want to skip this clause altogether.
// The guess here is that there are lots of overflow:auto divs out there that
// end up auto-sizing so they don't overflow, and that the root basically
// always needs a scrollbar if it did last time we loaded this page (good
// assumption, because our initial reflow is no longer synchronous).
return !mIsRoot && HasAnyStateBits(NS_FRAME_FIRST_REFLOW);
}
void nsHTMLScrollFrame::ReflowContents(ScrollReflowInput& aState,
const ReflowOutput& aDesiredSize) {
const WritingMode desiredWm = aDesiredSize.GetWritingMode();
ReflowOutput kidDesiredSize(desiredWm);
ReflowScrolledFrame(aState, GuessHScrollbarNeeded(aState),
GuessVScrollbarNeeded(aState), &kidDesiredSize);
// There's an important special case ... if the child appears to fit
// in the inside-border rect (but overflows the scrollport), we
// should try laying it out without a vertical scrollbar. It will
// usually fit because making the available-width wider will not
// normally make the child taller. (The only situation I can think
// of is when you have a line containing %-width inline replaced
// elements whose percentages sum to more than 100%, so increasing
// the available width makes the line break where it was fitting
// before.) If we don't treat this case specially, then we will
// decide that showing scrollbars is OK because the content
// overflows when we're showing scrollbars and we won't try to
// remove the vertical scrollbar.
// Detecting when we enter this special case is important for when
// people design layouts that exactly fit the container "most of the
// time".
// XXX Is this check really sufficient to catch all the incremental cases
// where the ideal case doesn't have a scrollbar?
if ((aState.mReflowedContentsWithHScrollbar ||
aState.mReflowedContentsWithVScrollbar) &&
aState.mVScrollbar != ShowScrollbar::Always &&
aState.mHScrollbar != ShowScrollbar::Always) {
nsSize kidSize = GetContainSizeAxes().ContainSize(
kidDesiredSize.PhysicalSize(), *aState.mReflowInput.mFrame);
nsSize insideBorderSize = ComputeInsideBorderSize(aState, kidSize);
nsRect scrolledRect = GetUnsnappedScrolledRectInternal(
kidDesiredSize.ScrollableOverflow(), insideBorderSize);
if (nsRect(nsPoint(0, 0), insideBorderSize).Contains(scrolledRect)) {
// Let's pretend we had no scrollbars coming in here
kidDesiredSize.mOverflowAreas.Clear();
ReflowScrolledFrame(aState, false, false, &kidDesiredSize);
}
}
if (IsRootScrollFrameOfDocument()) {
UpdateMinimumScaleSize(aState.mContentsOverflowAreas.ScrollableOverflow(),
kidDesiredSize.PhysicalSize());
}
// Try vertical scrollbar settings that leave the vertical scrollbar
// unchanged. Do this first because changing the vertical scrollbar setting is
// expensive, forcing a reflow always.
// Try leaving the horizontal scrollbar unchanged first. This will be more
// efficient.
ROOT_SCROLLBAR_LOG("Trying layout1 with %d, %d\n",
aState.mReflowedContentsWithHScrollbar,
aState.mReflowedContentsWithVScrollbar);
if (TryLayout(aState, &kidDesiredSize, aState.mReflowedContentsWithHScrollbar,
aState.mReflowedContentsWithVScrollbar, false)) {
return;
}
ROOT_SCROLLBAR_LOG("Trying layout2 with %d, %d\n",
!aState.mReflowedContentsWithHScrollbar,
aState.mReflowedContentsWithVScrollbar);
if (TryLayout(aState, &kidDesiredSize,
!aState.mReflowedContentsWithHScrollbar,
aState.mReflowedContentsWithVScrollbar, false)) {
return;
}
// OK, now try toggling the vertical scrollbar. The performance advantage
// of trying the status-quo horizontal scrollbar state
// does not exist here (we'll have to reflow due to the vertical scrollbar
// change), so always try no horizontal scrollbar first.
bool newVScrollbarState = !aState.mReflowedContentsWithVScrollbar;
ROOT_SCROLLBAR_LOG("Trying layout3 with %d, %d\n", false, newVScrollbarState);
if (TryLayout(aState, &kidDesiredSize, false, newVScrollbarState, false)) {
return;
}
ROOT_SCROLLBAR_LOG("Trying layout4 with %d, %d\n", true, newVScrollbarState);
if (TryLayout(aState, &kidDesiredSize, true, newVScrollbarState, false)) {
return;
}
// OK, we're out of ideas. Try again enabling whatever scrollbars we can
// enable and force the layout to stick even if it's inconsistent.
// This just happens sometimes.
ROOT_SCROLLBAR_LOG("Giving up, adding both scrollbars...\n");
TryLayout(aState, &kidDesiredSize, aState.mHScrollbar != ShowScrollbar::Never,
aState.mVScrollbar != ShowScrollbar::Never, true);
}
void nsHTMLScrollFrame::PlaceScrollArea(ScrollReflowInput& aState,
const nsPoint& aScrollPosition) {
nsIFrame* scrolledFrame = mScrolledFrame;
// Set the x,y of the scrolled frame to the correct value
scrolledFrame->SetPosition(ScrollPort().TopLeft() - aScrollPosition);
// Recompute our scrollable overflow, taking perspective children into
// account. Note that this only recomputes the overflow areas stored on the
// helper (which are used to compute scrollable length and scrollbar thumb
// sizes) but not the overflow areas stored on the frame. This seems to work
// for now, but it's possible that we may need to update both in the future.
AdjustForPerspective(aState.mContentsOverflowAreas.ScrollableOverflow());
// Preserve the width or height of empty rects
const nsSize portSize = ScrollPort().Size();
nsRect scrolledRect = GetUnsnappedScrolledRectInternal(
aState.mContentsOverflowAreas.ScrollableOverflow(), portSize);
nsRect scrolledArea =
scrolledRect.UnionEdges(nsRect(nsPoint(0, 0), portSize));
// Store the new overflow area. Note that this changes where an outline
// of the scrolled frame would be painted, but scrolled frames can't have
// outlines (the outline would go on this scrollframe instead).
// Using FinishAndStoreOverflow is needed so the overflow rect gets set
// correctly. It also messes with the overflow rect in the 'clip' case, but
// scrolled frames can't have 'overflow' either.
// This needs to happen before SyncFrameViewAfterReflow so
// HasOverflowRect() will return the correct value.
OverflowAreas overflow(scrolledArea, scrolledArea);
scrolledFrame->FinishAndStoreOverflow(overflow, scrolledFrame->GetSize());
// Note that making the view *exactly* the size of the scrolled area
// is critical, since the view scrolling code uses the size of the
// scrolled view to clamp scroll requests.
// Normally the scrolledFrame won't have a view but in some cases it
// might create its own.
nsContainerFrame::SyncFrameViewAfterReflow(
scrolledFrame->PresContext(), scrolledFrame, scrolledFrame->GetView(),
scrolledArea, ReflowChildFlags::Default);
}
nscoord nsHTMLScrollFrame::IntrinsicScrollbarGutterSizeAtInlineEdges(
gfxContext* aRenderingContext) {
const bool isVerticalWM = GetWritingMode().IsVertical();
nsScrollbarFrame* inlineEndScrollbarBox =
isVerticalWM ? mHScrollbarBox : mVScrollbarBox;
if (!inlineEndScrollbarBox) {
// No scrollbar box frame means no intrinsic size.
return 0;
}
if (PresContext()->UseOverlayScrollbars()) {
return 0;
}
const auto* styleForScrollbar = nsLayoutUtils::StyleForScrollbar(this);
if (styleForScrollbar->StyleUIReset()->ScrollbarWidth() ==
StyleScrollbarWidth::None) {
// Scrollbar shouldn't appear at all with "scrollbar-width: none".
return 0;
}
const auto& styleScrollbarGutter =
styleForScrollbar->StyleDisplay()->mScrollbarGutter;
ScrollStyles ss = GetScrollStyles();
const StyleOverflow& inlineEndStyleOverflow =
isVerticalWM ? ss.mHorizontal : ss.mVertical;
// Return the scrollbar-gutter size only if we have "overflow:scroll" or
// non-auto "scrollbar-gutter", so early-return here if the conditions aren't
// satisfied.
if (inlineEndStyleOverflow != StyleOverflow::Scroll &&
styleScrollbarGutter == StyleScrollbarGutter::AUTO) {
return 0;
}
// No need to worry about reflow depth here since it's just for scrollbars.
nsSize scrollbarPrefSize = inlineEndScrollbarBox->ScrollbarMinSize();
const nscoord scrollbarSize =
isVerticalWM ? scrollbarPrefSize.height : scrollbarPrefSize.width;
const auto bothEdges =
bool(styleScrollbarGutter & StyleScrollbarGutter::BOTH_EDGES);
return bothEdges ? scrollbarSize * 2 : scrollbarSize;
}
// Legacy, this sucks!
static bool IsMarqueeScrollbox(const nsIFrame& aScrollFrame) {
if (!aScrollFrame.GetContent()) {
return false;
}
if (MOZ_LIKELY(!aScrollFrame.GetContent()->HasBeenInUAWidget())) {
return false;
}
MOZ_ASSERT(aScrollFrame.GetParent() &&
aScrollFrame.GetParent()->GetContent());
return aScrollFrame.GetParent() &&
HTMLMarqueeElement::FromNodeOrNull(
aScrollFrame.GetParent()->GetContent());
}
/* virtual */
nscoord nsHTMLScrollFrame::GetMinISize(gfxContext* aRenderingContext) {
nscoord result = [&] {
if (const Maybe<nscoord> containISize = ContainIntrinsicISize()) {
return *containISize;
}
if (MOZ_UNLIKELY(IsMarqueeScrollbox(*this))) {
return 0;
}
return mScrolledFrame->GetMinISize(aRenderingContext);
}();
DISPLAY_MIN_INLINE_SIZE(this, result);
return result + IntrinsicScrollbarGutterSizeAtInlineEdges(aRenderingContext);
}
/* virtual */
nscoord nsHTMLScrollFrame::GetPrefISize(gfxContext* aRenderingContext) {
const Maybe<nscoord> containISize = ContainIntrinsicISize();
nscoord result = containISize
? *containISize
: mScrolledFrame->GetPrefISize(aRenderingContext);
DISPLAY_PREF_INLINE_SIZE(this, result);
return NSCoordSaturatingAdd(
result, IntrinsicScrollbarGutterSizeAtInlineEdges(aRenderingContext));
}
// When we have perspective set on the outer scroll frame, and transformed
// children (possibly with preserve-3d) then the effective transform on the
// child depends on the offset to the scroll frame, which changes as we scroll.
// This perspective transform can cause the element to move relative to the
// scrolled inner frame, which would cause the scrollable length changes during
// scrolling if we didn't account for it. Since we don't want scrollHeight/Width
// and the size of scrollbar thumbs to change during scrolling, we compute the
// scrollable overflow by determining the scroll position at which the child
// becomes completely visible within the scrollport rather than using the union
// of the overflow areas at their current position.
static void GetScrollableOverflowForPerspective(
nsIFrame* aScrolledFrame, nsIFrame* aCurrentFrame, const nsRect aScrollPort,
nsPoint aOffset, nsRect& aScrolledFrameOverflowArea) {
// Iterate over all children except pop-ups.
for (const auto& [list, listID] : aCurrentFrame->ChildLists()) {
if (listID == FrameChildListID::Popup) {
continue;
}
for (nsIFrame* child : list) {
nsPoint offset = aOffset;
// When we reach a direct child of the scroll, then we record the offset
// to convert from that frame's coordinate into the scroll frame's
// coordinates. Preserve-3d descendant frames use the same offset as their
// ancestors, since TransformRect already converts us into the coordinate
// space of the preserve-3d root.
if (aScrolledFrame == aCurrentFrame) {
offset = child->GetPosition();
}
if (child->Extend3DContext()) {
// If we're a preserve-3d frame, then recurse and include our
// descendants since overflow of preserve-3d frames is only included
// in the post-transform overflow area of the preserve-3d root frame.
GetScrollableOverflowForPerspective(aScrolledFrame, child, aScrollPort,
offset, aScrolledFrameOverflowArea);
}
// If we're transformed, then we want to consider the possibility that
// this frame might move relative to the scrolled frame when scrolling.
// For preserve-3d, leaf frames have correct overflow rects relative to
// themselves. preserve-3d 'nodes' (intermediate frames and the root) have
// only their untransformed children included in their overflow relative
// to self, which is what we want to include here.
if (child->IsTransformed()) {
// Compute the overflow rect for this leaf transform frame in the
// coordinate space of the scrolled frame.
nsPoint scrollPos = aScrolledFrame->GetPosition();
nsRect preScroll, postScroll;
{
// TODO: Can we reuse the reference box?
TransformReferenceBox refBox(child);
preScroll = nsDisplayTransform::TransformRect(
child->ScrollableOverflowRectRelativeToSelf(), child, refBox);
}
// Temporarily override the scroll position of the scrolled frame by
// 10 CSS pixels, and then recompute what the overflow rect would be.
// This scroll position may not be valid, but that shouldn't matter
// for our calculations.
{
aScrolledFrame->SetPosition(scrollPos + nsPoint(600, 600));
TransformReferenceBox refBox(child);
postScroll = nsDisplayTransform::TransformRect(
child->ScrollableOverflowRectRelativeToSelf(), child, refBox);
aScrolledFrame->SetPosition(scrollPos);
}
// Compute how many app units the overflow rects moves by when we adjust
// the scroll position by 1 app unit.
double rightDelta =
(postScroll.XMost() - preScroll.XMost() + 600.0) / 600.0;
double bottomDelta =
(postScroll.YMost() - preScroll.YMost() + 600.0) / 600.0;
// We can't ever have negative scrolling.
NS_ASSERTION(rightDelta > 0.0f && bottomDelta > 0.0f,
"Scrolling can't be reversed!");
// Move preScroll into the coordinate space of the scrollport.
preScroll += offset + scrollPos;
// For each of the four edges of preScroll, figure out how far they
// extend beyond the scrollport. Ignore negative values since that means
// that side is already scrolled in to view and we don't need to add
// overflow to account for it.
nsMargin overhang(std::max(0, aScrollPort.Y() - preScroll.Y()),
std::max(0, preScroll.XMost() - aScrollPort.XMost()),
std::max(0, preScroll.YMost() - aScrollPort.YMost()),
std::max(0, aScrollPort.X() - preScroll.X()));
// Scale according to rightDelta/bottomDelta to adjust for the different
// scroll rates.
overhang.top = NSCoordSaturatingMultiply(
overhang.top, static_cast<float>(1 / bottomDelta));
overhang.right = NSCoordSaturatingMultiply(
overhang.right, static_cast<float>(1 / rightDelta));
overhang.bottom = NSCoordSaturatingMultiply(
overhang.bottom, static_cast<float>(1 / bottomDelta));
overhang.left = NSCoordSaturatingMultiply(
overhang.left, static_cast<float>(1 / rightDelta));
// Take the minimum overflow rect that would allow the current scroll
// position, using the size of the scroll port and offset by the
// inverse of the scroll position.
nsRect overflow = aScrollPort - scrollPos;
// Expand it by our margins to get an overflow rect that would allow all
// edges of our transformed content to be scrolled into view.
overflow.Inflate(overhang);
// Merge it with the combined overflow
aScrolledFrameOverflowArea.UnionRect(aScrolledFrameOverflowArea,
overflow);
} else if (aCurrentFrame == aScrolledFrame) {
aScrolledFrameOverflowArea.UnionRect(
aScrolledFrameOverflowArea,
child->ScrollableOverflowRectRelativeToParent());
}
}
}
}
BaselineSharingGroup nsHTMLScrollFrame::GetDefaultBaselineSharingGroup() const {
return mScrolledFrame->GetDefaultBaselineSharingGroup();
}
nscoord nsHTMLScrollFrame::SynthesizeFallbackBaseline(
mozilla::WritingMode aWM, BaselineSharingGroup aBaselineGroup) const {
// Marign-end even for central baselines.
if (aWM.IsLineInverted()) {
return -GetLogicalUsedMargin(aWM).BStart(aWM);
}
return aBaselineGroup == BaselineSharingGroup::First
? BSize(aWM) + GetLogicalUsedMargin(aWM).BEnd(aWM)
: -GetLogicalUsedMargin(aWM).BEnd(aWM);
}
Maybe<nscoord> nsHTMLScrollFrame::GetNaturalBaselineBOffset(
WritingMode aWM, BaselineSharingGroup aBaselineGroup,
BaselineExportContext aExportContext) const {
// Block containers that are scrollable always have a last baseline
// that are synthesized from block-end margin edge.
// Note(dshin): This behaviour is really only relevant to `inline-block`
// alignment context. In the context of table/flex/grid alignment, first/last
// baselines are calculated through `GetFirstLineBaseline`, which does
// calculations of its own.
// https://drafts.csswg.org/css-align/#baseline-export
if (aExportContext == BaselineExportContext::LineLayout &&
aBaselineGroup == BaselineSharingGroup::Last &&
mScrolledFrame->IsBlockFrameOrSubclass()) {
return Some(SynthesizeFallbackBaseline(aWM, aBaselineGroup));
}
if (StyleDisplay()->IsContainLayout()) {
return Nothing{};
}
// OK, here's where we defer to our scrolled frame.
return mScrolledFrame
->GetNaturalBaselineBOffset(aWM, aBaselineGroup, aExportContext)
.map([this, aWM](nscoord aBaseline) {
// We have to add our border BStart thickness to whatever it returns, to
// produce an offset in our frame-rect's coordinate system. (We don't
// have to add padding, because the scrolled frame handles our padding.)
LogicalMargin border = GetLogicalUsedBorder(aWM);
const auto bSize = GetLogicalSize(aWM).BSize(aWM);
// Clamp the baseline to the border rect. See bug 1791069.
return std::clamp(border.BStart(aWM) + aBaseline, 0, bSize);
});
}
void nsHTMLScrollFrame::AdjustForPerspective(nsRect& aScrollableOverflow) {
// If we have perspective that is being applied to our children, then
// the effective transform on the child depends on the relative position
// of the child to us and changes during scrolling.
if (!ChildrenHavePerspective()) {
return;
}
aScrollableOverflow.SetEmpty();
GetScrollableOverflowForPerspective(mScrolledFrame, mScrolledFrame,
ScrollPort(), nsPoint(),
aScrollableOverflow);
}
void nsHTMLScrollFrame::Reflow(nsPresContext* aPresContext,
ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus) {
MarkInReflow();
DO_GLOBAL_REFLOW_COUNT("nsHTMLScrollFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
HandleScrollbarStyleSwitching();
ScrollReflowInput state(this, aReflowInput);
//------------ Handle Incremental Reflow -----------------
bool reflowHScrollbar = true;
bool reflowVScrollbar = true;
bool reflowScrollCorner = true;
if (!aReflowInput.ShouldReflowAllKids()) {
auto NeedsReflow = [](const nsIFrame* aFrame) {
return aFrame && aFrame->IsSubtreeDirty();
};
reflowHScrollbar = NeedsReflow(mHScrollbarBox);
reflowVScrollbar = NeedsReflow(mVScrollbarBox);
reflowScrollCorner =
NeedsReflow(mScrollCornerBox) || NeedsReflow(mResizerBox);
}
if (mIsRoot) {
reflowScrollCorner = false;
}
const nsRect oldScrollPort = ScrollPort();
nsRect oldScrolledAreaBounds =
mScrolledFrame->ScrollableOverflowRectRelativeToParent();
nsPoint oldScrollPosition = GetScrollPosition();
ReflowContents(state, aDesiredSize);
nsSize layoutSize =
mIsUsingMinimumScaleSize ? mMinimumScaleSize : state.mInsideBorderSize;
aDesiredSize.Width() = layoutSize.width + state.mComputedBorder.LeftRight();
aDesiredSize.Height() = layoutSize.height + state.mComputedBorder.TopBottom();
// Set the size of the frame now since computing the perspective-correct
// overflow (within PlaceScrollArea) can rely on it.
SetSize(aDesiredSize.GetWritingMode(),
aDesiredSize.Size(aDesiredSize.GetWritingMode()));
// Restore the old scroll position, for now, even if that's not valid anymore
// because we changed size. We'll fix it up in a post-reflow callback, because
// our current size may only be temporary (e.g. we're compute XUL desired
// sizes).
PlaceScrollArea(state, oldScrollPosition);
if (!mPostedReflowCallback) {
// Make sure we'll try scrolling to restored position
PresShell()->PostReflowCallback(this);
mPostedReflowCallback = true;
}
bool didOnlyHScrollbar = mOnlyNeedHScrollbarToScrollVVInsideLV;
bool didOnlyVScrollbar = mOnlyNeedVScrollbarToScrollVVInsideLV;
mOnlyNeedHScrollbarToScrollVVInsideLV =
state.mOnlyNeedHScrollbarToScrollVVInsideLV;
mOnlyNeedVScrollbarToScrollVVInsideLV =
state.mOnlyNeedVScrollbarToScrollVVInsideLV;
bool didHaveHScrollbar = mHasHorizontalScrollbar;
bool didHaveVScrollbar = mHasVerticalScrollbar;
mHasHorizontalScrollbar = state.mShowHScrollbar;
mHasVerticalScrollbar = state.mShowVScrollbar;
const nsRect& newScrollPort = ScrollPort();
nsRect newScrolledAreaBounds =
mScrolledFrame->ScrollableOverflowRectRelativeToParent();
if (mSkippedScrollbarLayout || reflowHScrollbar || reflowVScrollbar ||
reflowScrollCorner || HasAnyStateBits(NS_FRAME_IS_DIRTY) ||
didHaveHScrollbar != state.mShowHScrollbar ||
didHaveVScrollbar != state.mShowVScrollbar ||
didOnlyHScrollbar != mOnlyNeedHScrollbarToScrollVVInsideLV ||
didOnlyVScrollbar != mOnlyNeedVScrollbarToScrollVVInsideLV ||
!oldScrollPort.IsEqualEdges(newScrollPort) ||
!oldScrolledAreaBounds.IsEqualEdges(newScrolledAreaBounds)) {
if (!mSuppressScrollbarUpdate) {
mSkippedScrollbarLayout = false;
nsHTMLScrollFrame::SetScrollbarVisibility(mHScrollbarBox,
state.mShowHScrollbar);
nsHTMLScrollFrame::SetScrollbarVisibility(mVScrollbarBox,
state.mShowVScrollbar);
// place and reflow scrollbars
const nsRect insideBorderArea(
nsPoint(state.mComputedBorder.left, state.mComputedBorder.top),
layoutSize);
LayoutScrollbars(state, insideBorderArea, oldScrollPort);
} else {
mSkippedScrollbarLayout = true;
}
}
if (mIsRoot) {
if (RefPtr<MobileViewportManager> manager =
PresShell()->GetMobileViewportManager()) {
// Note that this runs during layout, and when we get here the root
// scrollframe has already been laid out. It may have added or removed
// scrollbars as a result of that layout, so we need to ensure the
// visual viewport is updated to account for that before we read the
// visual viewport size.
manager->UpdateVisualViewportSizeForPotentialScrollbarChange();
} else if (oldScrollPort.Size() != newScrollPort.Size()) {
// We want to make sure to send a visual viewport resize event if the
// scrollport changed sizes for root scroll frames. The
// MobileViewportManager will do that, but if we don't have one (ie we
// aren't a root content document for example) we have to send one
// ourselves.
if (auto* window = nsGlobalWindowInner::Cast(
aPresContext->Document()->GetInnerWindow())) {
window->VisualViewport()->PostResizeEvent();
}
}
}
// Note that we need to do this after the
// UpdateVisualViewportSizeForPotentialScrollbarChange call above because that
// is what updates the visual viewport size and we need it to be up to date.
if (mIsRoot && !state.OverlayScrollbars() &&
(didHaveHScrollbar != state.mShowHScrollbar ||
didHaveVScrollbar != state.mShowVScrollbar ||
didOnlyHScrollbar != mOnlyNeedHScrollbarToScrollVVInsideLV ||
didOnlyVScrollbar != mOnlyNeedVScrollbarToScrollVVInsideLV) &&
PresShell()->IsVisualViewportOffsetSet()) {
// Removing layout/classic scrollbars can make a previously valid vvoffset
// invalid. For example, if we are zoomed in on an overflow hidden document
// and then zoom back out, when apz reaches the initial resolution (ie 1.0)
// it won't know that we can remove the scrollbars, so the vvoffset can
// validly be upto the width/height of the scrollbars. After we reflow and
// remove the scrollbars the only valid vvoffset is (0,0). We could wait
// until we send the new frame metrics to apz and then have it reply with
// the new corrected vvoffset but having an inconsistent vvoffset causes
// problems so trigger the vvoffset to be re-set and re-clamped in
// ReflowFinished.
mReclampVVOffsetInReflowFinished = true;
}
aDesiredSize.SetOverflowAreasToDesiredBounds();
UpdateSticky();
FinishReflowWithAbsoluteFrames(aPresContext, aDesiredSize, aReflowInput,
aStatus);
if (!InInitialReflow() && !mHadNonInitialReflow) {
mHadNonInitialReflow = true;
}
if (mIsRoot && !oldScrolledAreaBounds.IsEqualEdges(newScrolledAreaBounds)) {
PostScrolledAreaEvent();
}
UpdatePrevScrolledRect();
aStatus.Reset(); // This type of frame can't be split.
PostOverflowEvent();
}
void nsHTMLScrollFrame::DidReflow(nsPresContext* aPresContext,
const ReflowInput* aReflowInput) {
nsContainerFrame::DidReflow(aPresContext, aReflowInput);
if (NeedsResnap()) {
PostPendingResnap();
} else {
PresShell()->PostPendingScrollAnchorAdjustment(Anchor());
}
}
////////////////////////////////////////////////////////////////////////////////
#ifdef DEBUG_FRAME_DUMP
nsresult nsHTMLScrollFrame::GetFrameName(nsAString& aResult) const {
return MakeFrameName(u"HTMLScroll"_ns, aResult);
}
#endif
#ifdef ACCESSIBILITY
a11y::AccType nsHTMLScrollFrame::AccessibleType() {
if (IsTableCaption()) {
return GetRect().IsEmpty() ? a11y::eNoType : a11y::eHTMLCaptionType;
}
// Create an accessible regardless of focusable state because the state can be
// changed during frame life cycle without any notifications to accessibility.
if (mContent->IsRootOfNativeAnonymousSubtree() ||
GetScrollStyles().IsHiddenInBothDirections()) {
return a11y::eNoType;
}
return a11y::eHyperTextType;
}
#endif
NS_QUERYFRAME_HEAD(nsHTMLScrollFrame)
NS_QUERYFRAME_ENTRY(nsIAnonymousContentCreator)
NS_QUERYFRAME_ENTRY(nsIScrollableFrame)
NS_QUERYFRAME_ENTRY(nsIStatefulFrame)
NS_QUERYFRAME_ENTRY(nsIScrollbarMediator)
NS_QUERYFRAME_ENTRY(nsHTMLScrollFrame)
NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
nsMargin nsHTMLScrollFrame::GetDesiredScrollbarSizes() const {
nsPresContext* pc = PresContext();
if (pc->UseOverlayScrollbars()) {
return {};
}
const auto& style = *nsLayoutUtils::StyleForScrollbar(this);
const auto scrollbarWidth = style.StyleUIReset()->ScrollbarWidth();
if (scrollbarWidth == StyleScrollbarWidth::None) {
return {};
}
ScrollStyles styles = GetScrollStyles();
nsMargin result(0, 0, 0, 0);
auto size = pc->DevPixelsToAppUnits(
pc->Theme()->GetScrollbarSize(pc, scrollbarWidth, nsITheme::Overlay::No));
if (styles.mVertical != StyleOverflow::Hidden) {
if (IsScrollbarOnRight())
result.left = size;
else
result.right = size;
}
if (styles.mHorizontal != StyleOverflow::Hidden) {
// We don't currently support any scripts that would require a scrollbar
// at the top. (Are there any?)
result.bottom = size;
}
return result;
}
nscoord nsIScrollableFrame::GetNondisappearingScrollbarWidth(nsPresContext* aPc,
WritingMode aWM) {
// We use this to size the combobox dropdown button. For that, we need to have
// the proper big, non-overlay scrollbar size, regardless of whether we're
// using e.g. scrollbar-width: thin, or overlay scrollbars.
auto size = aPc->Theme()->GetScrollbarSize(aPc, StyleScrollbarWidth::Auto,
nsITheme::Overlay::No);
return aPc->DevPixelsToAppUnits(size);
}
void nsHTMLScrollFrame::HandleScrollbarStyleSwitching() {
// Check if we switched between scrollbar styles.
if (mScrollbarActivity && !UsesOverlayScrollbars()) {
mScrollbarActivity->Destroy();
mScrollbarActivity = nullptr;
} else if (!mScrollbarActivity && UsesOverlayScrollbars()) {
mScrollbarActivity = new ScrollbarActivity(do_QueryFrame(this));
}
}
#if defined(MOZ_WIDGET_ANDROID)
static bool IsFocused(nsIContent* aContent) {
// Some content elements, like the GetContent() of a scroll frame
// for a text input field, are inside anonymous subtrees, but the focus
// manager always reports a non-anonymous element as the focused one, so
// walk up the tree until we reach a non-anonymous element.
while (aContent && aContent->IsInNativeAnonymousSubtree()) {
aContent = aContent->GetParent();
}
return aContent ? nsContentUtils::IsFocusedContent(aContent) : false;
}
#endif
void nsHTMLScrollFrame::SetScrollableByAPZ(bool aScrollable) {
mScrollableByAPZ = aScrollable;
}
void nsHTMLScrollFrame::SetZoomableByAPZ(bool aZoomable) {
if (!nsLayoutUtils::UsesAsyncScrolling(this)) {
// If APZ is disabled on this window, then we're never actually going to
// do any zooming. So we don't need to do any of the setup for it. Note
// that this function gets called from ZoomConstraintsClient even if APZ
// is disabled to indicate the zoomability of content.
aZoomable = false;
}
if (mZoomableByAPZ != aZoomable) {
// We might be changing the result of DecideScrollableLayer() so schedule a
// paint to make sure we pick up the result of that change.
mZoomableByAPZ = aZoomable;
SchedulePaint();
}
}
void nsHTMLScrollFrame::SetHasOutOfFlowContentInsideFilter() {
mHasOutOfFlowContentInsideFilter = true;
}
bool nsHTMLScrollFrame::WantAsyncScroll() const {
ScrollStyles styles = GetScrollStyles();
nscoord oneDevPixel =
GetScrolledFrame()->PresContext()->AppUnitsPerDevPixel();
nsRect scrollRange = GetLayoutScrollRange();
// If the page has a visual viewport size that's different from
// the layout viewport size at the current zoom level, we need to be
// able to scroll the visual viewport inside the layout viewport
// even if the page is not zoomable.
if (!GetVisualScrollRange().IsEqualInterior(scrollRange)) {
return true;
}
bool isVScrollable = (scrollRange.height >= oneDevPixel) &&
(styles.mVertical != StyleOverflow::Hidden);
bool isHScrollable = (scrollRange.width >= oneDevPixel) &&
(styles.mHorizontal != StyleOverflow::Hidden);
#if defined(MOZ_WIDGET_ANDROID)
// Mobile platforms need focus to scroll text inputs.
bool canScrollWithoutScrollbars =
!IsForTextControlWithNoScrollbars() || IsFocused(GetContent());
#else
bool canScrollWithoutScrollbars = true;
#endif
// The check for scroll bars was added in bug 825692 to prevent layerization
// of text inputs for performance reasons.
bool isVAsyncScrollable =
isVScrollable && (mVScrollbarBox || canScrollWithoutScrollbars);
bool isHAsyncScrollable =
isHScrollable && (mHScrollbarBox || canScrollWithoutScrollbars);
return isVAsyncScrollable || isHAsyncScrollable;
}
static nsRect GetOnePixelRangeAroundPoint(const nsPoint& aPoint,
bool aIsHorizontal) {
nsRect allowedRange(aPoint, nsSize());
nscoord halfPixel = nsPresContext::CSSPixelsToAppUnits(0.5f);
if (aIsHorizontal) {
allowedRange.x = aPoint.x - halfPixel;
allowedRange.width = halfPixel * 2 - 1;
} else {
allowedRange.y = aPoint.y - halfPixel;
allowedRange.height = halfPixel * 2 - 1;
}
return allowedRange;
}
void nsHTMLScrollFrame::ScrollByPage(nsScrollbarFrame* aScrollbar,
int32_t aDirection,
ScrollSnapFlags aSnapFlags) {
ScrollByUnit(aScrollbar, ScrollMode::Smooth, aDirection, ScrollUnit::PAGES,
aSnapFlags);
}
void nsHTMLScrollFrame::ScrollByWhole(nsScrollbarFrame* aScrollbar,
int32_t aDirection,
ScrollSnapFlags aSnapFlags) {
ScrollByUnit(aScrollbar, ScrollMode::Instant, aDirection, ScrollUnit::WHOLE,
aSnapFlags);
}
void nsHTMLScrollFrame::ScrollByLine(nsScrollbarFrame* aScrollbar,
int32_t aDirection,
ScrollSnapFlags aSnapFlags) {
bool isHorizontal = aScrollbar->IsHorizontal();
nsIntPoint delta;
if (isHorizontal) {
const double kScrollMultiplier =
StaticPrefs::toolkit_scrollbox_horizontalScrollDistance();
delta.x = aDirection * kScrollMultiplier;
if (GetLineScrollAmount().width * delta.x > GetPageScrollAmount().width) {
// The scroll frame is so small that the delta would be more
// than an entire page. Scroll by one page instead to maintain
// context.
ScrollByPage(aScrollbar, aDirection);
return;
}
} else {
const double kScrollMultiplier =
StaticPrefs::toolkit_scrollbox_verticalScrollDistance();
delta.y = aDirection * kScrollMultiplier;
if (GetLineScrollAmount().height * delta.y > GetPageScrollAmount().height) {
// The scroll frame is so small that the delta would be more
// than an entire page. Scroll by one page instead to maintain
// context.
ScrollByPage(aScrollbar, aDirection);
return;
}
}
nsIntPoint overflow;
ScrollBy(delta, ScrollUnit::LINES, ScrollMode::Smooth, &overflow,
ScrollOrigin::Other, nsIScrollableFrame::NOT_MOMENTUM, aSnapFlags);
}
void nsHTMLScrollFrame::RepeatButtonScroll(nsScrollbarFrame* aScrollbar) {
aScrollbar->MoveToNewPosition(nsScrollbarFrame::ImplementsScrollByUnit::Yes);
}
void nsHTMLScrollFrame::ThumbMoved(nsScrollbarFrame* aScrollbar,
nscoord aOldPos, nscoord aNewPos) {
MOZ_ASSERT(aScrollbar != nullptr);
bool isHorizontal = aScrollbar->IsHorizontal();
nsPoint current = GetScrollPosition();
nsPoint dest = current;
if (isHorizontal) {
dest.x = IsPhysicalLTR() ? aNewPos : aNewPos - GetLayoutScrollRange().width;
} else {
dest.y = aNewPos;
}
nsRect allowedRange = GetOnePixelRangeAroundPoint(dest, isHorizontal);
// Don't try to scroll if we're already at an acceptable place.
// Don't call Contains here since Contains returns false when the point is
// on the bottom or right edge of the rectangle.
if (allowedRange.ClampPoint(current) == current) {
return;
}
ScrollToWithOrigin(
dest, &allowedRange,
ScrollOperationParams{ScrollMode::Instant, ScrollOrigin::Other});
}
void nsHTMLScrollFrame::ScrollbarReleased(nsScrollbarFrame* aScrollbar) {
// Scrollbar scrolling does not result in fling gestures, clear any
// accumulated velocity
mVelocityQueue.Reset();
// Perform scroll snapping, if needed. Scrollbar movement uses the same
// smooth scrolling animation as keyboard scrolling.
ScrollSnap(mDestination, ScrollMode::Smooth);
}
void nsHTMLScrollFrame::ScrollByUnit(nsScrollbarFrame* aScrollbar,
ScrollMode aMode, int32_t aDirection,
ScrollUnit aUnit,
ScrollSnapFlags aSnapFlags) {
MOZ_ASSERT(aScrollbar != nullptr);
bool isHorizontal = aScrollbar->IsHorizontal();
nsIntPoint delta;
if (isHorizontal) {
delta.x = aDirection;
} else {
delta.y = aDirection;
}
nsIntPoint overflow;
ScrollBy(delta, aUnit, aMode, &overflow, ScrollOrigin::Other,
nsIScrollableFrame::NOT_MOMENTUM, aSnapFlags);
}
//-------------------- Helper ----------------------
// AsyncSmoothMSDScroll has ref counting.
class nsHTMLScrollFrame::AsyncSmoothMSDScroll final
: public nsARefreshObserver {
public:
AsyncSmoothMSDScroll(const nsPoint& aInitialPosition,
const nsPoint& aInitialDestination,
const nsSize& aInitialVelocity, const nsRect& aRange,
const mozilla::TimeStamp& aStartTime,
nsPresContext* aPresContext,
UniquePtr<ScrollSnapTargetIds> aSnapTargetIds,
ScrollTriggeredByScript aTriggeredByScript)
: mXAxisModel(aInitialPosition.x, aInitialDestination.x,
aInitialVelocity.width,
StaticPrefs::layout_css_scroll_behavior_spring_constant(),
StaticPrefs::layout_css_scroll_behavior_damping_ratio()),
mYAxisModel(aInitialPosition.y, aInitialDestination.y,
aInitialVelocity.height,
StaticPrefs::layout_css_scroll_behavior_spring_constant(),
StaticPrefs::layout_css_scroll_behavior_damping_ratio()),
mRange(aRange),
mStartPosition(aInitialPosition),
mLastRefreshTime(aStartTime),
mCallee(nullptr),
mOneDevicePixelInAppUnits(aPresContext->DevPixelsToAppUnits(1)),
mSnapTargetIds(std::move(aSnapTargetIds)),
mTriggeredByScript(aTriggeredByScript) {
Telemetry::SetHistogramRecordingEnabled(
Telemetry::FX_REFRESH_DRIVER_SYNC_SCROLL_FRAME_DELAY_MS, true);
}
NS_INLINE_DECL_REFCOUNTING(AsyncSmoothMSDScroll, override)
nsSize GetVelocity() {
// In nscoords per second
return nsSize(mXAxisModel.GetVelocity(), mYAxisModel.GetVelocity());
}
nsPoint GetPosition() {
// In nscoords
return nsPoint(NSToCoordRound(mXAxisModel.GetPosition()),
NSToCoordRound(mYAxisModel.GetPosition()));
}
void SetDestination(const nsPoint& aDestination,
ScrollTriggeredByScript aTriggeredByScript) {
mXAxisModel.SetDestination(static_cast<int32_t>(aDestination.x));
mYAxisModel.SetDestination(static_cast<int32_t>(aDestination.y));
mTriggeredByScript = aTriggeredByScript;
}
void SetRange(const nsRect& aRange) { mRange = aRange; }
nsRect GetRange() { return mRange; }
nsPoint GetStartPosition() { return mStartPosition; }
void Simulate(const TimeDuration& aDeltaTime) {
mXAxisModel.Simulate(aDeltaTime);
mYAxisModel.Simulate(aDeltaTime);
nsPoint desired = GetPosition();
nsPoint clamped = mRange.ClampPoint(desired);
if (desired.x != clamped.x) {
// The scroll has hit the "wall" at the left or right edge of the allowed
// scroll range.
// Absorb the impact to avoid bounceback effect.
mXAxisModel.SetVelocity(0.0);
mXAxisModel.SetPosition(clamped.x);
}
if (desired.y != clamped.y) {
// The scroll has hit the "wall" at the left or right edge of the allowed
// scroll range.
// Absorb the impact to avoid bounceback effect.
mYAxisModel.SetVelocity(0.0);
mYAxisModel.SetPosition(clamped.y);
}
}
bool IsFinished() {
return mXAxisModel.IsFinished(mOneDevicePixelInAppUnits) &&
mYAxisModel.IsFinished(mOneDevicePixelInAppUnits);
}
virtual void WillRefresh(mozilla::TimeStamp aTime) override {
mozilla::TimeDuration deltaTime = aTime - mLastRefreshTime;
mLastRefreshTime = aTime;
// The callback may release "this".
// We don't access members after returning, so no need for KungFuDeathGrip.
nsHTMLScrollFrame::AsyncSmoothMSDScrollCallback(mCallee, deltaTime);
}
/*
* Set a refresh observer for smooth scroll iterations (and start observing).
* Should be used at most once during the lifetime of this object.
*/
void SetRefreshObserver(nsHTMLScrollFrame* aCallee) {
NS_ASSERTION(aCallee && !mCallee,
"AsyncSmoothMSDScroll::SetRefreshObserver - Invalid usage.");
RefreshDriver(aCallee)->AddRefreshObserver(this, FlushType::Style,
"Smooth scroll (MSD) animation");
mCallee = aCallee;
}
/**
* The mCallee holds a strong ref to us since the refresh driver doesn't.
* Our dtor and mCallee's Destroy() method both call RemoveObserver() -
* whichever comes first removes us from the refresh driver.
*/
void RemoveObserver() {
if (mCallee) {
RefreshDriver(mCallee)->RemoveRefreshObserver(this, FlushType::Style);
mCallee = nullptr;
}
}
UniquePtr<ScrollSnapTargetIds> TakeSnapTargetIds() {
return std::move(mSnapTargetIds);
}
bool WasTriggeredByScript() const {
return mTriggeredByScript == ScrollTriggeredByScript::Yes;
}
private:
// Private destructor, to discourage deletion outside of Release():
~AsyncSmoothMSDScroll() {
RemoveObserver();
Telemetry::SetHistogramRecordingEnabled(
Telemetry::FX_REFRESH_DRIVER_SYNC_SCROLL_FRAME_DELAY_MS, false);
}
nsRefreshDriver* RefreshDriver(nsHTMLScrollFrame* aCallee) {
return aCallee->PresContext()->RefreshDriver();
}
mozilla::layers::AxisPhysicsMSDModel mXAxisModel, mYAxisModel;
nsRect mRange;
nsPoint mStartPosition;
mozilla::TimeStamp mLastRefreshTime;
nsHTMLScrollFrame* mCallee;
nscoord mOneDevicePixelInAppUnits;
UniquePtr<ScrollSnapTargetIds> mSnapTargetIds;
ScrollTriggeredByScript mTriggeredByScript;
};
// AsyncScroll has ref counting.
class nsHTMLScrollFrame::AsyncScroll final : public nsARefreshObserver {
public:
typedef mozilla::TimeStamp TimeStamp;
typedef mozilla::TimeDuration TimeDuration;
explicit AsyncScroll(UniquePtr<ScrollSnapTargetIds> aSnapTargetIds,
ScrollTriggeredByScript aTriggeredByScript)
: mOrigin(ScrollOrigin::NotSpecified),
mCallee(nullptr),
mSnapTargetIds(std::move(aSnapTargetIds)),
mTriggeredByScript(aTriggeredByScript) {
Telemetry::SetHistogramRecordingEnabled(
Telemetry::FX_REFRESH_DRIVER_SYNC_SCROLL_FRAME_DELAY_MS, true);
}
private:
// Private destructor, to discourage deletion outside of Release():
~AsyncScroll() {
RemoveObserver();
Telemetry::SetHistogramRecordingEnabled(
Telemetry::FX_REFRESH_DRIVER_SYNC_SCROLL_FRAME_DELAY_MS, false);
}
public:
void InitSmoothScroll(TimeStamp aTime, nsPoint aInitialPosition,
nsPoint aDestination, ScrollOrigin aOrigin,
const nsRect& aRange, const nsSize& aCurrentVelocity);
void Init(nsPoint aInitialPosition, const nsRect& aRange) {
mAnimationPhysics = nullptr;
mRange = aRange;
mStartPosition = aInitialPosition;
}
bool IsSmoothScroll() { return mAnimationPhysics != nullptr; }
bool IsFinished(const TimeStamp& aTime) const {
MOZ_RELEASE_ASSERT(mAnimationPhysics);
return mAnimationPhysics->IsFinished(aTime);
}
nsPoint PositionAt(const TimeStamp& aTime) const {
MOZ_RELEASE_ASSERT(mAnimationPhysics);
return mAnimationPhysics->PositionAt(aTime);
}
nsSize VelocityAt(const TimeStamp& aTime) const {
MOZ_RELEASE_ASSERT(mAnimationPhysics);
return mAnimationPhysics->VelocityAt(aTime);
}
nsPoint GetStartPosition() const { return mStartPosition; }
// Most recent scroll origin.
ScrollOrigin mOrigin;
// Allowed destination positions around mDestination
nsRect mRange;
// Initial position where the async scroll was triggered.
nsPoint mStartPosition;
private:
void InitPreferences(TimeStamp aTime, nsAtom* aOrigin);
UniquePtr<ScrollAnimationPhysics> mAnimationPhysics;
// The next section is observer/callback management
// Bodies of WillRefresh and RefreshDriver contain nsHTMLScrollFrame specific
// code.
public:
NS_INLINE_DECL_REFCOUNTING(AsyncScroll, override)
/*
* Set a refresh observer for smooth scroll iterations (and start observing).
* Should be used at most once during the lifetime of this object.
*/
void SetRefreshObserver(nsHTMLScrollFrame* aCallee) {
NS_ASSERTION(aCallee && !mCallee,
"AsyncScroll::SetRefreshObserver - Invalid usage.");
RefreshDriver(aCallee)->AddRefreshObserver(this, FlushType::Style,
"Smooth scroll animation");
mCallee = aCallee;
auto* presShell = mCallee->PresShell();
MOZ_ASSERT(presShell);
presShell->SuppressDisplayport(true);
}
virtual void WillRefresh(mozilla::TimeStamp aTime) override {
// The callback may release "this".
// We don't access members after returning, so no need for KungFuDeathGrip.
nsHTMLScrollFrame::AsyncScrollCallback(mCallee, aTime);
}
/**
* The mCallee holds a strong ref to us since the refresh driver doesn't.
* Our dtor and mCallee's Destroy() method both call RemoveObserver() -
* whichever comes first removes us from the refresh driver.
*/
void RemoveObserver() {
if (mCallee) {
RefreshDriver(mCallee)->RemoveRefreshObserver(this, FlushType::Style);
auto* presShell = mCallee->PresShell();
MOZ_ASSERT(presShell);
presShell->SuppressDisplayport(false);
mCallee = nullptr;
}
}
UniquePtr<ScrollSnapTargetIds> TakeSnapTargetIds() {
return std::move(mSnapTargetIds);
}
bool WasTriggeredByScript() const {
return mTriggeredByScript == ScrollTriggeredByScript::Yes;
}
private:
nsHTMLScrollFrame* mCallee;
UniquePtr<ScrollSnapTargetIds> mSnapTargetIds;
ScrollTriggeredByScript mTriggeredByScript;
nsRefreshDriver* RefreshDriver(nsHTMLScrollFrame* aCallee) {
return aCallee->PresContext()->RefreshDriver();
}
};
void nsHTMLScrollFrame::AsyncScroll::InitSmoothScroll(
TimeStamp aTime, nsPoint aInitialPosition, nsPoint aDestination,
ScrollOrigin aOrigin, const nsRect& aRange,
const nsSize& aCurrentVelocity) {
switch (aOrigin) {
case ScrollOrigin::NotSpecified:
case ScrollOrigin::Restore:
case ScrollOrigin::Relative:
// We don't have special prefs for "restore", just treat it as "other".
// "restore" scrolls are (for now) always instant anyway so unless
// something changes we should never have aOrigin ==
// ScrollOrigin::Restore here.
aOrigin = ScrollOrigin::Other;
break;
case ScrollOrigin::Apz:
// Likewise we should never get APZ-triggered scrolls here, and if that
// changes something is likely broken somewhere.
MOZ_ASSERT(false);
break;
default:
break;
};
// Read preferences only on first iteration or for a different event origin.
if (!mAnimationPhysics || aOrigin != mOrigin) {
mOrigin = aOrigin;
if (StaticPrefs::general_smoothScroll_msdPhysics_enabled()) {
mAnimationPhysics =
MakeUnique<ScrollAnimationMSDPhysics>(aInitialPosition);
} else {
ScrollAnimationBezierPhysicsSettings settings =
layers::apz::ComputeBezierAnimationSettingsForOrigin(mOrigin);
mAnimationPhysics =
MakeUnique<ScrollAnimationBezierPhysics>(aInitialPosition, settings);
}
}
mStartPosition = aInitialPosition;
mRange = aRange;
mAnimationPhysics->Update(aTime, aDestination, aCurrentVelocity);
}
/*
* Callback function from AsyncSmoothMSDScroll, used in
* nsHTMLScrollFrame::ScrollTo
*/
void nsHTMLScrollFrame::AsyncSmoothMSDScrollCallback(
nsHTMLScrollFrame* aInstance, mozilla::TimeDuration aDeltaTime) {
NS_ASSERTION(aInstance != nullptr, "aInstance must not be null");
NS_ASSERTION(aInstance->mAsyncSmoothMSDScroll,
"Did not expect AsyncSmoothMSDScrollCallback without an active "
"MSD scroll.");
nsRect range = aInstance->mAsyncSmoothMSDScroll->GetRange();
aInstance->mAsyncSmoothMSDScroll->Simulate(aDeltaTime);
if (!aInstance->mAsyncSmoothMSDScroll->IsFinished()) {
nsPoint destination = aInstance->mAsyncSmoothMSDScroll->GetPosition();
// Allow this scroll operation to land on any pixel boundary within the
// allowed scroll range for this frame.
// If the MSD is under-dampened or the destination is changed rapidly,
// it is expected (and desired) that the scrolling may overshoot.
nsRect intermediateRange = nsRect(destination, nsSize()).UnionEdges(range);
aInstance->ScrollToImpl(destination, intermediateRange);
// 'aInstance' might be destroyed here
return;
}
aInstance->CompleteAsyncScroll(
aInstance->mAsyncSmoothMSDScroll->GetStartPosition(), range,
aInstance->mAsyncSmoothMSDScroll->TakeSnapTargetIds());
}
/*
* Callback function from AsyncScroll, used in nsHTMLScrollFrame::ScrollTo
*/
void nsHTMLScrollFrame::AsyncScrollCallback(nsHTMLScrollFrame* aInstance,
mozilla::TimeStamp aTime) {
MOZ_ASSERT(aInstance != nullptr, "aInstance must not be null");
MOZ_ASSERT(
aInstance->mAsyncScroll,
"Did not expect AsyncScrollCallback without an active async scroll.");
if (!aInstance || !aInstance->mAsyncScroll) {
return; // XXX wallpaper bug 1107353 for now.
}
nsRect range = aInstance->mAsyncScroll->mRange;
if (aInstance->mAsyncScroll->IsSmoothScroll()) {
if (!aInstance->mAsyncScroll->IsFinished(aTime)) {
nsPoint destination = aInstance->mAsyncScroll->PositionAt(aTime);
// Allow this scroll operation to land on any pixel boundary between the
// current position and the final allowed range. (We don't want
// intermediate steps to be more constrained than the final step!)
nsRect intermediateRange =
nsRect(aInstance->GetScrollPosition(), nsSize()).UnionEdges(range);
aInstance->ScrollToImpl(destination, intermediateRange);
// 'aInstance' might be destroyed here
return;
}
}
aInstance->CompleteAsyncScroll(aInstance->mAsyncScroll->GetStartPosition(),
range,
aInstance->mAsyncScroll->TakeSnapTargetIds());
}
void nsHTMLScrollFrame::SetTransformingByAPZ(bool aTransforming) {
if (mTransformingByAPZ && !aTransforming) {
PostScrollEndEvent();
}
mTransformingByAPZ = aTransforming;
if (!mozilla::css::TextOverflow::HasClippedTextOverflow(this) ||
mozilla::css::TextOverflow::HasBlockEllipsis(mScrolledFrame)) {
// If the block has some overflow marker stuff we should kick off a paint
// because we have special behaviour for it when APZ scrolling is active.
SchedulePaint();
}
}
void nsHTMLScrollFrame::CompleteAsyncScroll(
const nsPoint& aStartPosition, const nsRect& aRange,
UniquePtr<ScrollSnapTargetIds> aSnapTargetIds, ScrollOrigin aOrigin) {
SetLastSnapTargetIds(std::move(aSnapTargetIds));
bool scrollPositionChanged = mDestination != aStartPosition;
bool isNotHandledByApz =
nsLayoutUtils::CanScrollOriginClobberApz(aOrigin) ||
ScrollAnimationState().contains(AnimationState::MainThread);
// Apply desired destination range since this is the last step of scrolling.
RemoveObservers();
AutoWeakFrame weakFrame(this);
ScrollToImpl(mDestination, aRange, aOrigin);
if (!weakFrame.IsAlive()) {
return;
}
// We are done scrolling, set our destination to wherever we actually ended
// up scrolling to.
mDestination = GetScrollPosition();
// Post a `scrollend` event for scrolling not handled by APZ, including:
//
// - programmatic instant scrolls
// - the end of a smooth scroll animation running on the main thread
//
// For scrolling handled by APZ, the `scrollend` event is posted in
// SetTransformingByAPZ() when the APZC is transitioning from a transforming
// to a non-transforming state (e.g. a transition from PANNING to NOTHING).
// The scrollend event should not be fired for a scroll that does not
// result in a scroll position change.
if (isNotHandledByApz && scrollPositionChanged) {
PostScrollEndEvent();
}
}
bool nsHTMLScrollFrame::HasBgAttachmentLocal() const {
const nsStyleBackground* bg = StyleBackground();
return bg->HasLocalBackground();
}
void nsHTMLScrollFrame::ScrollToInternal(
nsPoint aScrollPosition, ScrollMode aMode, ScrollOrigin aOrigin,
const nsRect* aRange, ScrollSnapFlags aSnapFlags,
ScrollTriggeredByScript aTriggeredByScript) {
if (aOrigin == ScrollOrigin::NotSpecified) {
aOrigin = ScrollOrigin::Other;
}
ScrollToWithOrigin(
aScrollPosition, aRange,
ScrollOperationParams{aMode, aOrigin, aSnapFlags, aTriggeredByScript});
}
void nsHTMLScrollFrame::ScrollToCSSPixels(const CSSIntPoint& aScrollPosition,
ScrollMode aMode) {
CSSIntPoint currentCSSPixels = GetScrollPositionCSSPixels();
// Transmogrify this scroll to a relative one if there's any on-going
// animation in APZ triggered by __user__.
// Bug 1740164: We will apply it for cases there's no animation in APZ.
auto scrollAnimationState = ScrollAnimationState();
bool isScrollAnimating =
scrollAnimationState.contains(AnimationState::MainThread) ||
scrollAnimationState.contains(AnimationState::APZPending) ||
scrollAnimationState.contains(AnimationState::APZRequested);
if (mCurrentAPZScrollAnimationType ==
APZScrollAnimationType::TriggeredByUserInput &&
!isScrollAnimating) {
CSSIntPoint delta = aScrollPosition - currentCSSPixels;
// This transmogrification need to be an intended end position scroll
// operation.
ScrollByCSSPixelsInternal(delta, aMode,
ScrollSnapFlags::IntendedEndPosition);
return;
}
nscoord halfPixel = nsPresContext::CSSPixelsToAppUnits(0.5f);
nsPoint pt = CSSPoint::ToAppUnits(aScrollPosition);
nsRect range(pt.x - halfPixel, pt.y - halfPixel, 2 * halfPixel - 1,
2 * halfPixel - 1);
// XXX I don't think the following blocks are needed anymore, now that
// ScrollToImpl simply tries to scroll an integer number of layer
// pixels from the current position
nsPoint current = GetScrollPosition();
if (currentCSSPixels.x == aScrollPosition.x) {
pt.x = current.x;
range.x = pt.x;
range.width = 0;
}
if (currentCSSPixels.y == aScrollPosition.y) {
pt.y = current.y;
range.y = pt.y;
range.height = 0;
}
ScrollToWithOrigin(
pt, &range,
ScrollOperationParams{
aMode, ScrollOrigin::Other,
// This ScrollToCSSPixels is used for Element.scrollTo,
// Element.scrollTop, Element.scrollLeft and for Window.scrollTo.
ScrollSnapFlags::IntendedEndPosition, ScrollTriggeredByScript::Yes});
// 'this' might be destroyed here
}
void nsHTMLScrollFrame::ScrollToCSSPixelsForApz(
const CSSPoint& aScrollPosition, ScrollSnapTargetIds&& aLastSnapTargetIds) {
nsPoint pt = CSSPoint::ToAppUnits(aScrollPosition);
nscoord halfRange = nsPresContext::CSSPixelsToAppUnits(1000);
nsRect range(pt.x - halfRange, pt.y - halfRange, 2 * halfRange - 1,
2 * halfRange - 1);
ScrollToWithOrigin(
pt, &range,
ScrollOperationParams{ScrollMode::Instant, ScrollOrigin::Apz,
std::move(aLastSnapTargetIds)});
// 'this' might be destroyed here
}
CSSIntPoint nsHTMLScrollFrame::GetScrollPositionCSSPixels() {
return CSSIntPoint::FromAppUnitsRounded(GetScrollPosition());
}
/*
* this method wraps calls to ScrollToImpl(), either in one shot or
* incrementally, based on the setting of the smoothness scroll pref
*/
void nsHTMLScrollFrame::ScrollToWithOrigin(nsPoint aScrollPosition,
const nsRect* aRange,
ScrollOperationParams&& aParams) {
// None is never a valid scroll origin to be passed in.
MOZ_ASSERT(aParams.mOrigin != ScrollOrigin::None);
if (aParams.mOrigin != ScrollOrigin::Restore) {
// If we're doing a non-restore scroll, we don't want to later
// override it by restoring our saved scroll position.
SCROLLRESTORE_LOG("%p: Clearing mRestorePos (cur=%s, dst=%s)\n", this,
ToString(GetScrollPosition()).c_str(),
ToString(aScrollPosition).c_str());
mRestorePos.x = mRestorePos.y = -1;
}
Maybe<SnapTarget> snapTarget;
if (!aParams.IsScrollSnapDisabled()) {
snapTarget = GetSnapPointForDestination(ScrollUnit::DEVICE_PIXELS,
aParams.mSnapFlags, mDestination,
aScrollPosition);
if (snapTarget) {
aScrollPosition = snapTarget->mPosition;
}
}
nsRect scrollRange = GetLayoutScrollRange();
mDestination = scrollRange.ClampPoint(aScrollPosition);
if (mDestination != aScrollPosition &&
aParams.mOrigin == ScrollOrigin::Restore &&
GetPageLoadingState() != LoadingState::Loading) {
// If we're doing a restore but the scroll position is clamped, promote
// the origin from one that APZ can clobber to one that it can't clobber.
aParams.mOrigin = ScrollOrigin::Other;
}
nsRect range = aRange && snapTarget.isNothing()
? *aRange
: nsRect(aScrollPosition, nsSize(0, 0));
UniquePtr<ScrollSnapTargetIds> snapTargetIds;
if (snapTarget) {
snapTargetIds =
MakeUnique<ScrollSnapTargetIds>(std::move(snapTarget->mTargetIds));
} else {
snapTargetIds =
MakeUnique<ScrollSnapTargetIds>(std::move(aParams.mTargetIds));
}
if (aParams.IsInstant()) {
// Asynchronous scrolling is not allowed, so we'll kill any existing
// async-scrolling process and do an instant scroll.
CompleteAsyncScroll(GetScrollPosition(), range, std::move(snapTargetIds),
aParams.mOrigin);
mApzSmoothScrollDestination = Nothing();
return;
}
if (!aParams.IsSmoothMsd()) {
// If we get a non-smooth-scroll, reset the cached APZ scroll destination,
// so that we know to process the next smooth-scroll destined for APZ.
mApzSmoothScrollDestination = Nothing();
}
nsPresContext* presContext = PresContext();
TimeStamp now =
presContext->RefreshDriver()->IsTestControllingRefreshesEnabled()
? presContext->RefreshDriver()->MostRecentRefresh()
: TimeStamp::Now();
nsSize currentVelocity(0, 0);
if (aParams.IsSmoothMsd()) {
mIgnoreMomentumScroll = true;
if (!mAsyncSmoothMSDScroll) {
nsPoint sv = mVelocityQueue.GetVelocity();
currentVelocity.width = sv.x;
currentVelocity.height = sv.y;
if (mAsyncScroll) {
if (mAsyncScroll->IsSmoothScroll()) {
currentVelocity = mAsyncScroll->VelocityAt(now);
}
mAsyncScroll = nullptr;
}
if (nsLayoutUtils::AsyncPanZoomEnabled(this) && WantAsyncScroll() &&
CanApzScrollInTheseDirections(
DirectionsInDelta(mDestination - GetScrollPosition()))) {
ApzSmoothScrollTo(mDestination, aParams.mOrigin,
aParams.mTriggeredByScript, std::move(snapTargetIds));
return;
}
mAsyncSmoothMSDScroll = new AsyncSmoothMSDScroll(
GetScrollPosition(), mDestination, currentVelocity,
GetLayoutScrollRange(), now, presContext, std::move(snapTargetIds),
aParams.mTriggeredByScript);
mAsyncSmoothMSDScroll->SetRefreshObserver(this);
} else {
// A previous smooth MSD scroll is still in progress, so we just need to
// update its range and destination.
mAsyncSmoothMSDScroll->SetRange(GetLayoutScrollRange());
mAsyncSmoothMSDScroll->SetDestination(mDestination,
aParams.mTriggeredByScript);
}
return;
}
if (mAsyncSmoothMSDScroll) {
currentVelocity = mAsyncSmoothMSDScroll->GetVelocity();
mAsyncSmoothMSDScroll = nullptr;
}
if (!mAsyncScroll) {
mAsyncScroll =
new AsyncScroll(std::move(snapTargetIds), aParams.mTriggeredByScript);
mAsyncScroll->SetRefreshObserver(this);
}
const bool isSmoothScroll =
aParams.IsSmooth() && nsLayoutUtils::IsSmoothScrollingEnabled();
if (isSmoothScroll) {
mAsyncScroll->InitSmoothScroll(now, GetScrollPosition(), mDestination,
aParams.mOrigin, range, currentVelocity);
} else {
mAsyncScroll->Init(GetScrollPosition(), range);
}
}
// We can't use nsContainerFrame::PositionChildViews here because
// we don't want to invalidate views that have moved.
static void AdjustViews(nsIFrame* aFrame) {
nsView* view = aFrame->GetView();
if (view) {
nsPoint pt;
aFrame->GetParent()->GetClosestView(&pt);
pt += aFrame->GetPosition();
view->SetPosition(pt.x, pt.y);
return;
}
if (!aFrame->HasAnyStateBits(NS_FRAME_HAS_CHILD_WITH_VIEW)) {
return;
}
// Call AdjustViews recursively for all child frames except the popup list as
// the views for popups are not scrolled.
for (const auto& [list, listID] : aFrame->ChildLists()) {
if (listID == FrameChildListID::Popup) {
continue;
}
for (nsIFrame* child : list) {
AdjustViews(child);
}
}
}
void nsHTMLScrollFrame::MarkScrollbarsDirtyForReflow() const {
auto* presShell = PresShell();
if (mVScrollbarBox) {
presShell->FrameNeedsReflow(mVScrollbarBox,
IntrinsicDirty::FrameAncestorsAndDescendants,
NS_FRAME_IS_DIRTY);
}
if (mHScrollbarBox) {
presShell->FrameNeedsReflow(mHScrollbarBox,
IntrinsicDirty::FrameAncestorsAndDescendants,
NS_FRAME_IS_DIRTY);
}
}
void nsHTMLScrollFrame::InvalidateScrollbars() const {
if (mHScrollbarBox) {
mHScrollbarBox->InvalidateFrameSubtree();
}
if (mVScrollbarBox) {
mVScrollbarBox->InvalidateFrameSubtree();
}
}
bool nsHTMLScrollFrame::IsAlwaysActive() const {
if (nsDisplayItem::ForceActiveLayers()) {
return true;
}
// Unless this is the root scrollframe for a non-chrome document
// which is the direct child of a chrome document, we default to not
// being "active".
if (!(mIsRoot && PresContext()->IsRootContentDocumentCrossProcess())) {
return false;
}
// If we have scrolled before, then we should stay active.
if (mHasBeenScrolled) {
return true;
}
// If we're overflow:hidden, then start as inactive until
// we get scrolled manually.
ScrollStyles styles = GetScrollStyles();
return (styles.mHorizontal != StyleOverflow::Hidden &&
styles.mVertical != StyleOverflow::Hidden);
}
static void RemoveDisplayPortCallback(nsITimer* aTimer, void* aClosure) {
nsHTMLScrollFrame* sf = static_cast<nsHTMLScrollFrame*>(aClosure);
// This function only ever gets called from the expiry timer, so it must
// be non-null here. Set it to null here so that we don't keep resetting
// it unnecessarily in MarkRecentlyScrolled().
MOZ_ASSERT(sf->mDisplayPortExpiryTimer);
sf->mDisplayPortExpiryTimer = nullptr;
if (!sf->AllowDisplayPortExpiration() || sf->mIsParentToActiveScrollFrames) {
// If this is a scroll parent for some other scrollable frame, don't
// expire the displayport because it would break scroll handoff. Once the
// descendant scrollframes have their displayports expired, they will
// trigger the displayport expiration on this scrollframe as well, and
// mIsParentToActiveScrollFrames will presumably be false when that kicks
// in.
return;
}
// Remove the displayport from this scrollframe if it's been a while
// since it's scrolled, except if it needs to be always active. Note that
// there is one scrollframe that doesn't fall under this general rule, and
// that is the one that nsLayoutUtils::MaybeCreateDisplayPort decides to put
// a displayport on (i.e. the first scrollframe that WantAsyncScroll()s).
// If that scrollframe is this one, we remove the displayport anyway, and
// as part of the next paint MaybeCreateDisplayPort will put another
// displayport back on it. Although the displayport will "flicker" off and
// back on, the layer itself should never disappear, because this all
// happens between actual painting. If the displayport is reset to a
// different position that's ok; this scrollframe hasn't been scrolled
// recently and so the reset should be correct.
nsIContent* content = sf->GetContent();
if (nsHTMLScrollFrame::ShouldActivateAllScrollFrames()) {
// If we are activating all scroll frames then we only want to remove the
// regular display port and downgrade to a minimal display port.
MOZ_ASSERT(!content->GetProperty(nsGkAtoms::MinimalDisplayPort));
content->SetProperty(nsGkAtoms::MinimalDisplayPort,
reinterpret_cast<void*>(true));
} else {
content->RemoveProperty(nsGkAtoms::MinimalDisplayPort);
DisplayPortUtils::RemoveDisplayPort(content);
// Be conservative and unflag this this scrollframe as being scrollable by
// APZ. If it is still scrollable this will get flipped back soon enough.
sf->mScrollableByAPZ = false;
}
DisplayPortUtils::ExpireDisplayPortOnAsyncScrollableAncestor(sf);
sf->SchedulePaint();
}
void nsHTMLScrollFrame::MarkEverScrolled() {
// Mark this frame as having been scrolled. If this is the root
// scroll frame of a content document, then IsAlwaysActive()
// will return true from now on and MarkNotRecentlyScrolled() won't
// have any effect.
mHasBeenScrolled = true;
}
void nsHTMLScrollFrame::MarkNotRecentlyScrolled() {
if (!mHasBeenScrolledRecently) return;
mHasBeenScrolledRecently = false;
SchedulePaint();
}
void nsHTMLScrollFrame::MarkRecentlyScrolled() {
mHasBeenScrolledRecently = true;
if (IsAlwaysActive()) {
return;
}
if (mActivityExpirationState.IsTracked()) {
gScrollFrameActivityTracker->MarkUsed(this);
} else {
if (!gScrollFrameActivityTracker) {
gScrollFrameActivityTracker =
new ScrollFrameActivityTracker(GetMainThreadSerialEventTarget());
}
gScrollFrameActivityTracker->AddObject(this);
}
// If we just scrolled and there's a displayport expiry timer in place,
// reset the timer.
ResetDisplayPortExpiryTimer();
}
void nsHTMLScrollFrame::ResetDisplayPortExpiryTimer() {
if (mDisplayPortExpiryTimer) {
mDisplayPortExpiryTimer->InitWithNamedFuncCallback(
RemoveDisplayPortCallback, this,
StaticPrefs::apz_displayport_expiry_ms(), nsITimer::TYPE_ONE_SHOT,
"nsHTMLScrollFrame::ResetDisplayPortExpiryTimer");
}
}
bool nsHTMLScrollFrame::AllowDisplayPortExpiration() {
if (IsAlwaysActive()) {
return false;
}
if (mIsRoot && PresContext()->IsRoot()) {
return false;
}
// If this was the first scrollable frame found, this displayport should
// not expire.
if (IsFirstScrollableFrameSequenceNumber().isSome()) {
return false;
}
if (ShouldActivateAllScrollFrames() &&
GetContent()->GetProperty(nsGkAtoms::MinimalDisplayPort)) {
return false;
}
return true;
}
void nsHTMLScrollFrame::TriggerDisplayPortExpiration() {
if (!AllowDisplayPortExpiration()) {
return;
}
if (!StaticPrefs::apz_displayport_expiry_ms()) {
// a zero time disables the expiry
return;
}
if (!mDisplayPortExpiryTimer) {
mDisplayPortExpiryTimer = NS_NewTimer();
}
ResetDisplayPortExpiryTimer();
}
void nsHTMLScrollFrame::ScrollVisual() {
MarkEverScrolled();
AdjustViews(mScrolledFrame);
// We need to call this after fixing up the view positions
// to be consistent with the frame hierarchy.
MarkRecentlyScrolled();
}
/**
* Clamp desired scroll position aDesired and range [aDestLower, aDestUpper]
* to [aBoundLower, aBoundUpper] and then select the appunit value from among
* aBoundLower, aBoundUpper and those such that (aDesired - aCurrent) *
* aRes/aAppUnitsPerPixel is an integer (or as close as we can get
* modulo rounding to appunits) that is in [aDestLower, aDestUpper] and
* closest to aDesired. If no such value exists, return the nearest in
* [aDestLower, aDestUpper].
*/
static nscoord ClampAndAlignWithPixels(nscoord aDesired, nscoord aBoundLower,
nscoord aBoundUpper, nscoord aDestLower,
nscoord aDestUpper,
nscoord aAppUnitsPerPixel, double aRes,
nscoord aCurrent) {
// Intersect scroll range with allowed range, by clamping the ends
// of aRange to be within bounds
nscoord destLower = clamped(aDestLower, aBoundLower, aBoundUpper);
nscoord destUpper = clamped(aDestUpper, aBoundLower, aBoundUpper);
nscoord desired = clamped(aDesired, destLower, destUpper);
double currentLayerVal = (aRes * aCurrent) / aAppUnitsPerPixel;
double desiredLayerVal = (aRes * desired) / aAppUnitsPerPixel;
double delta = desiredLayerVal - currentLayerVal;
double nearestLayerVal = NS_round(delta) + currentLayerVal;
// Convert back from PaintedLayer space to appunits relative to the top-left
// of the scrolled frame.
nscoord aligned =
aRes == 0.0
? 0.0
: NSToCoordRoundWithClamp(nearestLayerVal * aAppUnitsPerPixel / aRes);
// Use a bound if it is within the allowed range and closer to desired than
// the nearest pixel-aligned value.
if (aBoundUpper == destUpper &&
static_cast<decltype(Abs(desired))>(aBoundUpper - desired) <
Abs(desired - aligned)) {
return aBoundUpper;
}
if (aBoundLower == destLower &&
static_cast<decltype(Abs(desired))>(desired - aBoundLower) <
Abs(aligned - desired)) {
return aBoundLower;
}
// Accept the nearest pixel-aligned value if it is within the allowed range.
if (aligned >= destLower && aligned <= destUpper) {
return aligned;
}
// Check if opposite pixel boundary fits into allowed range.
double oppositeLayerVal =
nearestLayerVal + ((nearestLayerVal < desiredLayerVal) ? 1.0 : -1.0);
nscoord opposite = aRes == 0.0
? 0.0
: NSToCoordRoundWithClamp(oppositeLayerVal *
aAppUnitsPerPixel / aRes);
if (opposite >= destLower && opposite <= destUpper) {
return opposite;
}
// No alignment available.
return desired;
}
/**
* Clamp desired scroll position aPt to aBounds and then snap
* it to the same layer pixel edges as aCurrent, keeping it within aRange
* during snapping. aCurrent is the current scroll position.
*/
static nsPoint ClampAndAlignWithLayerPixels(const nsPoint& aPt,
const nsRect& aBounds,
const nsRect& aRange,
const nsPoint& aCurrent,
nscoord aAppUnitsPerPixel,
const MatrixScales& aScale) {
return nsPoint(
ClampAndAlignWithPixels(aPt.x, aBounds.x, aBounds.XMost(), aRange.x,
aRange.XMost(), aAppUnitsPerPixel, aScale.xScale,
aCurrent.x),
ClampAndAlignWithPixels(aPt.y, aBounds.y, aBounds.YMost(), aRange.y,
aRange.YMost(), aAppUnitsPerPixel, aScale.yScale,
aCurrent.y));
}
/* static */
void nsHTMLScrollFrame::ScrollActivityCallback(nsITimer* aTimer,
void* anInstance) {
nsHTMLScrollFrame* self = static_cast<nsHTMLScrollFrame*>(anInstance);
// Fire the synth mouse move.
self->mScrollActivityTimer->Cancel();
self->mScrollActivityTimer = nullptr;
self->PresShell()->SynthesizeMouseMove(true);
}
void nsHTMLScrollFrame::ScheduleSyntheticMouseMove() {
if (!mScrollActivityTimer) {
mScrollActivityTimer = NS_NewTimer(
PresContext()->Document()->EventTargetFor(TaskCategory::Other));
if (!mScrollActivityTimer) {
return;
}
}
mScrollActivityTimer->InitWithNamedFuncCallback(
ScrollActivityCallback, this, 100, nsITimer::TYPE_ONE_SHOT,
"nsHTMLScrollFrame::ScheduleSyntheticMouseMove");
}
void nsHTMLScrollFrame::NotifyApproximateFrameVisibilityUpdate(
bool aIgnoreDisplayPort) {
mLastUpdateFramesPos = GetScrollPosition();
if (aIgnoreDisplayPort) {
mHadDisplayPortAtLastFrameUpdate = false;
mDisplayPortAtLastFrameUpdate = nsRect();
} else {
mHadDisplayPortAtLastFrameUpdate = DisplayPortUtils::GetDisplayPort(
GetContent(), &mDisplayPortAtLastFrameUpdate);
}
}
bool nsHTMLScrollFrame::GetDisplayPortAtLastApproximateFrameVisibilityUpdate(
nsRect* aDisplayPort) {
if (mHadDisplayPortAtLastFrameUpdate) {
*aDisplayPort = mDisplayPortAtLastFrameUpdate;
}
return mHadDisplayPortAtLastFrameUpdate;
}
MatrixScales GetPaintedLayerScaleForFrame(nsIFrame* aFrame) {
MOZ_ASSERT(aFrame, "need a frame");
nsPresContext* presCtx = aFrame->PresContext()->GetRootPresContext();
if (!presCtx) {
presCtx = aFrame->PresContext();
MOZ_ASSERT(presCtx);
}
ParentLayerToScreenScale2D transformToAncestorScale =
ParentLayerToParentLayerScale(
presCtx->PresShell()->GetCumulativeResolution()) *
nsLayoutUtils::GetTransformToAncestorScaleCrossProcessForFrameMetrics(
aFrame);
return transformToAncestorScale.ToUnknownScale();
}
void nsHTMLScrollFrame::ScrollToImpl(
nsPoint aPt, const nsRect& aRange, ScrollOrigin aOrigin,
ScrollTriggeredByScript aTriggeredByScript) {
// None is never a valid scroll origin to be passed in.
MOZ_ASSERT(aOrigin != ScrollOrigin::None);
// Figure out the effective origin for this scroll request.
if (aOrigin == ScrollOrigin::NotSpecified) {
// If no origin was specified, we still want to set it to something that's
// non-unknown, so that we can use eUnknown to distinguish if the frame was
// scrolled at all. Default it to some generic placeholder.
aOrigin = ScrollOrigin::Other;
}
// If this scroll is |relative|, but we've already had a user scroll that
// was not relative, promote this origin to |other|. This ensures that we
// may only transmit a relative update to APZ if all scrolls since the last
// transaction or repaint request have been relative.
if (aOrigin == ScrollOrigin::Relative &&
(mLastScrollOrigin != ScrollOrigin::None &&
mLastScrollOrigin != ScrollOrigin::NotSpecified &&
mLastScrollOrigin != ScrollOrigin::Relative &&
mLastScrollOrigin != ScrollOrigin::Apz)) {
aOrigin = ScrollOrigin::Other;
}
// If the origin is a downgrade, and downgrades are allowed, process the
// downgrade even if we're going to early-exit because we're already at
// the correct scroll position. This ensures that if there wasn't a main-
// thread scroll update pending before a frame reconstruction (as indicated
// by mAllowScrollOriginDowngrade=true), then after the frame reconstruction
// the origin is downgraded to "restore" even if the layout scroll offset to
// be restored is (0,0) (which will take the early-exit below). This is
// important so that restoration of a *visual* scroll offset (which might be
// to something other than (0,0)) isn't clobbered.
bool isScrollOriginDowngrade =
nsLayoutUtils::CanScrollOriginClobberApz(mLastScrollOrigin) &&
!nsLayoutUtils::CanScrollOriginClobberApz(aOrigin);
bool allowScrollOriginChange =
mAllowScrollOriginDowngrade && isScrollOriginDowngrade;
if (allowScrollOriginChange) {
mLastScrollOrigin = aOrigin;
mAllowScrollOriginDowngrade = false;
}
nsPresContext* presContext = PresContext();
nscoord appUnitsPerDevPixel = presContext->AppUnitsPerDevPixel();
// 'scale' is our estimate of the scale factor that will be applied
// when rendering the scrolled content to its own PaintedLayer.
MatrixScales scale = GetPaintedLayerScaleForFrame(mScrolledFrame);
nsPoint curPos = GetScrollPosition();
// Try to align aPt with curPos so they have an integer number of layer
// pixels between them. This gives us the best chance of scrolling without
// having to invalidate due to changes in subpixel rendering.
// Note that when we actually draw into a PaintedLayer, the coordinates
// that get mapped onto the layer buffer pixels are from the display list,
// which are relative to the display root frame's top-left increasing down,
// whereas here our coordinates are scroll positions which increase upward
// and are relative to the scrollport top-left. This difference doesn't
// actually matter since all we are about is that there be an integer number
// of layer pixels between pt and curPos.
nsPoint pt = ClampAndAlignWithLayerPixels(aPt, GetLayoutScrollRange(), aRange,
curPos, appUnitsPerDevPixel, scale);
if (pt == curPos) {
// Even if we are bailing out due to no-op main-thread scroll position
// change, we might need to cancel an APZ smooth scroll that we already
// kicked off. It might be reasonable to eventually remove the
// mApzSmoothScrollDestination clause from this if statement, as that
// may simplify this a bit and should be fine from the APZ side.
if (mApzSmoothScrollDestination && aOrigin != ScrollOrigin::Clamp) {
if (aOrigin == ScrollOrigin::Relative) {
AppendScrollUpdate(
ScrollPositionUpdate::NewRelativeScroll(mApzScrollPos, pt));
mApzScrollPos = pt;
} else if (aOrigin != ScrollOrigin::Apz) {
ScrollOrigin origin =
(mAllowScrollOriginDowngrade || !isScrollOriginDowngrade)
? aOrigin
: mLastScrollOrigin;
AppendScrollUpdate(ScrollPositionUpdate::NewScroll(origin, pt));
}
}
return;
}
// If we are scrolling the RCD-RSF, and a visual scroll update is pending,
// cancel it; otherwise, it will clobber this scroll.
if (IsRootScrollFrameOfDocument() &&
presContext->IsRootContentDocumentCrossProcess()) {
auto* ps = presContext->GetPresShell();
if (const auto& visualScrollUpdate = ps->GetPendingVisualScrollUpdate()) {
if (visualScrollUpdate->mVisualScrollOffset != aPt) {
// Only clobber if the scroll was originated by the main thread.
// Respect the priority of origins (an "eRestore" layout scroll should
// not clobber an "eMainThread" visual scroll.)
bool shouldClobber =
aOrigin == ScrollOrigin::Other ||
(aOrigin == ScrollOrigin::Restore &&
visualScrollUpdate->mUpdateType == FrameMetrics::eRestore);
if (shouldClobber) {
ps->AcknowledgePendingVisualScrollUpdate();
ps->ClearPendingVisualScrollUpdate();
}
}
}
}
bool needFrameVisibilityUpdate = mLastUpdateFramesPos == nsPoint(-1, -1);
nsPoint dist(std::abs(pt.x - mLastUpdateFramesPos.x),
std::abs(pt.y - mLastUpdateFramesPos.y));
nsSize visualViewportSize = GetVisualViewportSize();
nscoord horzAllowance = std::max(
visualViewportSize.width /
std::max(
StaticPrefs::
layout_framevisibility_amountscrollbeforeupdatehorizontal(),
1),
AppUnitsPerCSSPixel());
nscoord vertAllowance = std::max(
visualViewportSize.height /
std::max(
StaticPrefs::
layout_framevisibility_amountscrollbeforeupdatevertical(),
1),
AppUnitsPerCSSPixel());
if (dist.x >= horzAllowance || dist.y >= vertAllowance) {
needFrameVisibilityUpdate = true;
}
// notify the listeners.
for (uint32_t i = 0; i < mListeners.Length(); i++) {
mListeners[i]->ScrollPositionWillChange(pt.x, pt.y);
}
nsRect oldDisplayPort;
nsIContent* content = GetContent();
DisplayPortUtils::GetDisplayPort(content, &oldDisplayPort);
oldDisplayPort.MoveBy(-mScrolledFrame->GetPosition());
// Update frame position for scrolling
mScrolledFrame->SetPosition(mScrollPort.TopLeft() - pt);
// If |mLastScrollOrigin| is already set to something that can clobber APZ's
// scroll offset, then we don't want to change it to something that can't.
// If we allowed this, then we could end up in a state where APZ ignores
// legitimate scroll offset updates because the origin has been masked by
// a later change within the same refresh driver tick.
allowScrollOriginChange =
(mAllowScrollOriginDowngrade || !isScrollOriginDowngrade);
if (allowScrollOriginChange) {
mLastScrollOrigin = aOrigin;
mAllowScrollOriginDowngrade = false;
}
if (aOrigin == ScrollOrigin::Relative) {
MOZ_ASSERT(!isScrollOriginDowngrade);
MOZ_ASSERT(mLastScrollOrigin == ScrollOrigin::Relative);
AppendScrollUpdate(
ScrollPositionUpdate::NewRelativeScroll(mApzScrollPos, pt));
mApzScrollPos = pt;
} else if (aOrigin != ScrollOrigin::Apz) {
AppendScrollUpdate(ScrollPositionUpdate::NewScroll(mLastScrollOrigin, pt));
}
if (mLastScrollOrigin == ScrollOrigin::Apz) {
mApzScrollPos = GetScrollPosition();
}
ScrollVisual();
mAnchor.UserScrolled();
// Only report user-triggered scrolling interactions
bool jsOnStack = nsContentUtils::GetCurrentJSContext() != nullptr;
bool scrollingToAnchor = ScrollingInteractionContext::IsScrollingToAnchor();
if (!jsOnStack && !scrollingToAnchor) {
nsPoint distanceScrolled(std::abs(pt.x - curPos.x),
std::abs(pt.y - curPos.y));
ScrollingMetrics::OnScrollingInteraction(
CSSPoint::FromAppUnits(distanceScrolled).Length());
}
bool schedulePaint = true;
if (nsLayoutUtils::AsyncPanZoomEnabled(this) &&
!nsLayoutUtils::ShouldDisableApzForElement(content) &&
!content->GetProperty(nsGkAtoms::MinimalDisplayPort) &&
StaticPrefs::apz_paint_skipping_enabled()) {
// If APZ is enabled with paint-skipping, there are certain conditions in
// which we can skip paints:
// 1) If APZ triggered this scroll, and the tile-aligned displayport is
// unchanged.
// 2) If non-APZ triggered this scroll, but we can handle it by just asking
// APZ to update the scroll position. Again we make this conditional on
// the tile-aligned displayport being unchanged.
// We do the displayport check first since it's common to all scenarios,
// and then if the displayport is unchanged, we check if APZ triggered,
// or can handle, this scroll. If so, we set schedulePaint to false and
// skip the paint.
// Because of bug 1264297, we also don't do paint-skipping for elements with
// perspective, because the displayport may not have captured everything
// that needs to be painted. So even if the final tile-aligned displayport
// is the same, we force a repaint for these elements. Bug 1254260 tracks
// fixing this properly.
nsRect displayPort;
bool usingDisplayPort =
DisplayPortUtils::GetDisplayPort(content, &displayPort);
displayPort.MoveBy(-mScrolledFrame->GetPosition());
PAINT_SKIP_LOG(
"New scrollpos %s usingDP %d dpEqual %d scrollableByApz "
"%d perspective %d bglocal %d filter %d\n",
ToString(CSSPoint::FromAppUnits(GetScrollPosition())).c_str(),
usingDisplayPort, displayPort.IsEqualEdges(oldDisplayPort),
mScrollableByAPZ, HasPerspective(), HasBgAttachmentLocal(),
mHasOutOfFlowContentInsideFilter);
if (usingDisplayPort && displayPort.IsEqualEdges(oldDisplayPort) &&
!HasPerspective() && !HasBgAttachmentLocal() &&
!mHasOutOfFlowContentInsideFilter) {
bool haveScrollLinkedEffects =
content->GetComposedDoc()->HasScrollLinkedEffect();
bool apzDisabled = haveScrollLinkedEffects &&
StaticPrefs::apz_disable_for_scroll_linked_effects();
if (!apzDisabled) {
if (LastScrollOrigin() == ScrollOrigin::Apz) {
schedulePaint = false;
PAINT_SKIP_LOG("Skipping due to APZ scroll\n");
} else if (mScrollableByAPZ) {
nsIWidget* widget = presContext->GetNearestWidget();
WindowRenderer* renderer =
widget ? widget->GetWindowRenderer() : nullptr;
if (renderer) {
mozilla::layers::ScrollableLayerGuid::ViewID id;
bool success = nsLayoutUtils::FindIDFor(content, &id);
MOZ_ASSERT(success); // we have a displayport, we better have an ID
// Schedule an empty transaction to carry over the scroll offset
// update, instead of a full transaction. This empty transaction
// might still get squashed into a full transaction if something
// happens to trigger one.
MOZ_ASSERT(!mScrollUpdates.IsEmpty());
success = renderer->AddPendingScrollUpdateForNextTransaction(
id, mScrollUpdates.LastElement());
if (success) {
schedulePaint = false;
SchedulePaint(nsIFrame::PAINT_COMPOSITE_ONLY);
PAINT_SKIP_LOG(
"Skipping due to APZ-forwarded main-thread scroll\n");
} else {
PAINT_SKIP_LOG(
"Failed to set pending scroll update on layer manager\n");
}
}
}
}
}
}
// If the new scroll offset is going to clobber APZ's scroll offset, for
// the RCD-RSF this will have the effect of updating the visual viewport
// offset in a way that keeps the relative offset between the layout and
// visual viewports constant. This will cause APZ to send us a new visual
// viewport offset, but instead of waiting for that, just set the value
// we expect APZ will set ourselves, to minimize the chances of
// inconsistencies from querying a stale value.
if (mIsRoot && nsLayoutUtils::CanScrollOriginClobberApz(aOrigin)) {
AutoWeakFrame weakFrame(this);
AutoScrollbarRepaintSuppression repaintSuppression(this, weakFrame,
!schedulePaint);
nsPoint visualViewportOffset = curPos;
if (presContext->PresShell()->IsVisualViewportOffsetSet()) {
visualViewportOffset =
presContext->PresShell()->GetVisualViewportOffset();
}
nsPoint relativeOffset = visualViewportOffset - curPos;
presContext->PresShell()->SetVisualViewportOffset(pt + relativeOffset,
curPos);
if (!weakFrame.IsAlive()) {
return;
}
}
if (schedulePaint) {
SchedulePaint();
if (needFrameVisibilityUpdate) {
presContext->PresShell()->ScheduleApproximateFrameVisibilityUpdateNow();
}
}
if (ChildrenHavePerspective()) {
// The overflow areas of descendants may depend on the scroll position,
// so ensure they get updated.
// First we recompute the overflow areas of the transformed children
// that use the perspective. FinishAndStoreOverflow only calls this
// if the size changes, so we need to do it manually.
RecomputePerspectiveChildrenOverflow(this);
// Update the overflow for the scrolled frame to take any changes from the
// children into account.
mScrolledFrame->UpdateOverflow();
// Update the overflow for the outer so that we recompute scrollbars.
UpdateOverflow();
}
ScheduleSyntheticMouseMove();
nsAutoScriptBlocker scriptBlocker;
PresShell::AutoAssertNoFlush noFlush(*PresShell());
{ // scope the AutoScrollbarRepaintSuppression
AutoWeakFrame weakFrame(this);
AutoScrollbarRepaintSuppression repaintSuppression(this, weakFrame,
!schedulePaint);
UpdateScrollbarPosition();
if (!weakFrame.IsAlive()) {
return;
}
}
presContext->RecordInteractionTime(
nsPresContext::InteractionType::ScrollInteraction, TimeStamp::Now());
PostScrollEvent();
// If this is a viewport scroll, this could affect the relative offset
// between layout and visual viewport, so we might have to fire a visual
// viewport scroll event as well.
if (mIsRoot) {
if (auto* window = nsGlobalWindowInner::Cast(
PresContext()->Document()->GetInnerWindow())) {
window->VisualViewport()->PostScrollEvent(
presContext->PresShell()->GetVisualViewportOffset(), curPos);
}
}
// Schedule the scroll-timelines linked to its scrollable frame.
// if `pt == curPos`, we early return, so the position must be changed at
// this moment. Therefore, we can schedule scroll animations directly.
ScheduleScrollAnimations();
// notify the listeners.
for (uint32_t i = 0; i < mListeners.Length(); i++) {
mListeners[i]->ScrollPositionDidChange(pt.x, pt.y);
}
if (nsCOMPtr<nsIDocShell> docShell = presContext->GetDocShell()) {
docShell->NotifyScrollObservers();
}
}
// Finds the max z-index of the items in aList that meet the following
// conditions
// 1) have z-index auto or z-index >= 0, and
// 2) aFrame is a proper ancestor of the item's frame.
// Returns Nothing() if there is no such item.
static Maybe<int32_t> MaxZIndexInListOfItemsContainedInFrame(
nsDisplayList* aList, nsIFrame* aFrame) {
Maybe<int32_t> maxZIndex = Nothing();
for (nsDisplayItem* item : *aList) {
int32_t zIndex = item->ZIndex();
if (zIndex < 0 ||
!nsLayoutUtils::IsProperAncestorFrame(aFrame, item->Frame())) {
continue;
}
if (!maxZIndex) {
maxZIndex = Some(zIndex);
} else {
maxZIndex = Some(std::max(maxZIndex.value(), zIndex));
}
}
return maxZIndex;
}
template <class T>
static void AppendInternalItemToTop(const nsDisplayListSet& aLists, T* aItem,
const Maybe<int32_t>& aZIndex) {
if (aZIndex) {
aItem->SetOverrideZIndex(aZIndex.value());
aLists.PositionedDescendants()->AppendToTop(aItem);
} else {
aLists.Content()->AppendToTop(aItem);
}
}
static const uint32_t APPEND_OWN_LAYER = 0x1;
static const uint32_t APPEND_POSITIONED = 0x2;
static const uint32_t APPEND_SCROLLBAR_CONTAINER = 0x4;
static const uint32_t APPEND_OVERLAY = 0x8;
static const uint32_t APPEND_TOP = 0x10;
static void AppendToTop(nsDisplayListBuilder* aBuilder,
const nsDisplayListSet& aLists, nsDisplayList* aSource,
nsIFrame* aSourceFrame, nsIFrame* aScrollFrame,
uint32_t aFlags) {
if (aSource->IsEmpty()) {
return;
}
nsDisplayWrapList* newItem;
const ActiveScrolledRoot* asr = aBuilder->CurrentActiveScrolledRoot();
if (aFlags & APPEND_OWN_LAYER) {
ScrollbarData scrollbarData;
if (aFlags & APPEND_SCROLLBAR_CONTAINER) {
scrollbarData = ScrollbarData::CreateForScrollbarContainer(
aBuilder->GetCurrentScrollbarDirection(),
aBuilder->GetCurrentScrollbarTarget());
// Direction should be set
MOZ_ASSERT(scrollbarData.mDirection.isSome());
}
newItem = MakeDisplayItemWithIndex<nsDisplayOwnLayer>(
aBuilder, aSourceFrame,
/* aIndex = */ nsDisplayOwnLayer::OwnLayerForScrollbar, aSource, asr,
nsDisplayOwnLayerFlags::None, scrollbarData, true, false);
} else {
// Build the wrap list with an index of 1, since the scrollbar frame itself
// might have already built an nsDisplayWrapList.
newItem = MakeDisplayItemWithIndex<nsDisplayWrapper>(
aBuilder, aSourceFrame, 1, aSource, asr, false);
}
if (!newItem) {
return;
}
if (aFlags & APPEND_POSITIONED) {
// We want overlay scrollbars to always be on top of the scrolled content,
// but we don't want them to unnecessarily cover overlapping elements from
// outside our scroll frame.
Maybe<int32_t> zIndex = Nothing();
if (aFlags & APPEND_TOP) {
zIndex = Some(INT32_MAX);
} else if (aFlags & APPEND_OVERLAY) {
zIndex = MaxZIndexInListOfItemsContainedInFrame(
aLists.PositionedDescendants(), aScrollFrame);
} else if (aSourceFrame->StylePosition()->mZIndex.IsInteger()) {
zIndex = Some(aSourceFrame->StylePosition()->mZIndex.integer._0);
}
AppendInternalItemToTop(aLists, newItem, zIndex);
} else {
aLists.BorderBackground()->AppendToTop(newItem);
}
}
struct HoveredStateComparator {
static bool Hovered(const nsIFrame* aFrame) {
return aFrame->GetContent()->IsElement() &&
aFrame->GetContent()->AsElement()->HasAttr(kNameSpaceID_None,
nsGkAtoms::hover);
}
bool Equals(nsIFrame* A, nsIFrame* B) const {
return Hovered(A) == Hovered(B);
}
bool LessThan(nsIFrame* A, nsIFrame* B) const {
return !Hovered(A) && Hovered(B);
}
};
void nsHTMLScrollFrame::AppendScrollPartsTo(nsDisplayListBuilder* aBuilder,
const nsDisplayListSet& aLists,
bool aCreateLayer,
bool aPositioned) {
const bool overlayScrollbars = UsesOverlayScrollbars();
AutoTArray<nsIFrame*, 3> scrollParts;
for (nsIFrame* kid : PrincipalChildList()) {
if (kid == mScrolledFrame ||
(kid->IsAbsPosContainingBlock() || overlayScrollbars) != aPositioned) {
continue;
}
scrollParts.AppendElement(kid);
}
if (scrollParts.IsEmpty()) {
return;
}
// We can't check will-change budget during display list building phase.
// This means that we will build scroll bar layers for out of budget
// will-change: scroll position.
const mozilla::layers::ScrollableLayerGuid::ViewID scrollTargetId =
IsScrollingActive()
? nsLayoutUtils::FindOrCreateIDFor(mScrolledFrame->GetContent())
: mozilla::layers::ScrollableLayerGuid::NULL_SCROLL_ID;
scrollParts.Sort(HoveredStateComparator());
DisplayListClipState::AutoSaveRestore clipState(aBuilder);
// Don't let scrollparts extent outside our frame's border-box, if these are
// viewport scrollbars. They would create layerization problems. This wouldn't
// normally be an issue but themes can add overflow areas to scrollbar parts.
if (mIsRoot) {
nsRect scrollPartsClip(aBuilder->ToReferenceFrame(this),
TrueOuterSize(aBuilder));
clipState.ClipContentDescendants(scrollPartsClip);
}
for (uint32_t i = 0; i < scrollParts.Length(); ++i) {
MOZ_ASSERT(scrollParts[i]);
Maybe<ScrollDirection> scrollDirection;
uint32_t appendToTopFlags = 0;
if (scrollParts[i] == mVScrollbarBox) {
scrollDirection.emplace(ScrollDirection::eVertical);
appendToTopFlags |= APPEND_SCROLLBAR_CONTAINER;
}
if (scrollParts[i] == mHScrollbarBox) {
MOZ_ASSERT(!scrollDirection.isSome());
scrollDirection.emplace(ScrollDirection::eHorizontal);
appendToTopFlags |= APPEND_SCROLLBAR_CONTAINER;
}
// The display port doesn't necessarily include the scrollbars, so just
// include all of the scrollbars if we are in a RCD-RSF. We only do
// this for the root scrollframe of the root content document, which is
// zoomable, and where the scrollbar sizes are bounded by the widget.
const nsRect visible =
mIsRoot && PresContext()->IsRootContentDocumentCrossProcess()
? scrollParts[i]->InkOverflowRectRelativeToParent()
: aBuilder->GetVisibleRect();
if (visible.IsEmpty()) {
continue;
}
const nsRect dirty =
mIsRoot && PresContext()->IsRootContentDocumentCrossProcess()
? scrollParts[i]->InkOverflowRectRelativeToParent()
: aBuilder->GetDirtyRect();
// Always create layers for overlay scrollbars so that we don't create a
// giant layer covering the whole scrollport if both scrollbars are visible.
const bool isOverlayScrollbar =
scrollDirection.isSome() && overlayScrollbars;
const bool createLayer =
aCreateLayer || isOverlayScrollbar ||
StaticPrefs::layout_scrollbars_always_layerize_track();
nsDisplayListCollection partList(aBuilder);
{
nsDisplayListBuilder::AutoBuildingDisplayList buildingForChild(
aBuilder, this, visible, dirty);
nsDisplayListBuilder::AutoCurrentScrollbarInfoSetter infoSetter(
aBuilder, scrollTargetId, scrollDirection, createLayer);
BuildDisplayListForChild(
aBuilder, scrollParts[i], partList,
nsIFrame::DisplayChildFlag::ForceStackingContext);
}
// DisplayChildFlag::ForceStackingContext put everything into
// partList.PositionedDescendants().
if (partList.PositionedDescendants()->IsEmpty()) {
continue;
}
if (createLayer) {
appendToTopFlags |= APPEND_OWN_LAYER;
}
if (aPositioned) {
appendToTopFlags |= APPEND_POSITIONED;
}
if (isOverlayScrollbar || scrollParts[i] == mResizerBox) {
if (isOverlayScrollbar && mIsRoot) {
appendToTopFlags |= APPEND_TOP;
} else {
appendToTopFlags |= APPEND_OVERLAY;
aBuilder->SetDisablePartialUpdates(true);
}
}
{
nsDisplayListBuilder::AutoBuildingDisplayList buildingForChild(
aBuilder, scrollParts[i], visible + GetOffsetTo(scrollParts[i]),
dirty + GetOffsetTo(scrollParts[i]));
if (scrollParts[i]->IsTransformed()) {
nsPoint toOuterReferenceFrame;
const nsIFrame* outerReferenceFrame = aBuilder->FindReferenceFrameFor(
scrollParts[i]->GetParent(), &toOuterReferenceFrame);
toOuterReferenceFrame += scrollParts[i]->GetPosition();
buildingForChild.SetReferenceFrameAndCurrentOffset(
outerReferenceFrame, toOuterReferenceFrame);
}
nsDisplayListBuilder::AutoCurrentScrollbarInfoSetter infoSetter(
aBuilder, scrollTargetId, scrollDirection, createLayer);
::AppendToTop(aBuilder, aLists, partList.PositionedDescendants(),
scrollParts[i], this, appendToTopFlags);
}
}
}
nsRect nsHTMLScrollFrame::ExpandRectToNearlyVisible(const nsRect& aRect) const {
// We don't want to expand a rect in a direction that we can't scroll, so we
// check the scroll range.
nsRect scrollRange = GetLayoutScrollRange();
nsPoint scrollPos = GetScrollPosition();
nsMargin expand(0, 0, 0, 0);
nscoord vertShift =
StaticPrefs::layout_framevisibility_numscrollportheights() * aRect.height;
if (scrollRange.y < scrollPos.y) {
expand.top = vertShift;
}
if (scrollPos.y < scrollRange.YMost()) {
expand.bottom = vertShift;
}
nscoord horzShift =
StaticPrefs::layout_framevisibility_numscrollportwidths() * aRect.width;
if (scrollRange.x < scrollPos.x) {
expand.left = horzShift;
}
if (scrollPos.x < scrollRange.XMost()) {
expand.right = horzShift;
}
nsRect rect = aRect;
rect.Inflate(expand);
return rect;
}
static bool ShouldBeClippedByFrame(nsIFrame* aClipFrame,
nsIFrame* aClippedFrame) {
return nsLayoutUtils::IsProperAncestorFrame(aClipFrame, aClippedFrame);
}
static void ClipItemsExceptCaret(
nsDisplayList* aList, nsDisplayListBuilder* aBuilder, nsIFrame* aClipFrame,
const DisplayItemClipChain* aExtraClip,
nsTHashMap<nsPtrHashKey<const DisplayItemClipChain>,
const DisplayItemClipChain*>& aCache) {
for (nsDisplayItem* i : *aList) {
if (!ShouldBeClippedByFrame(aClipFrame, i->Frame())) {
continue;
}
const DisplayItemType type = i->GetType();
if (type != DisplayItemType::TYPE_CARET &&
type != DisplayItemType::TYPE_CONTAINER) {
const DisplayItemClipChain* clip = i->GetClipChain();
const DisplayItemClipChain* intersection = nullptr;
if (aCache.Get(clip, &intersection)) {
i->SetClipChain(intersection, true);
} else {
i->IntersectClip(aBuilder, aExtraClip, true);
aCache.InsertOrUpdate(clip, i->GetClipChain());
}
}
nsDisplayList* children = i->GetSameCoordinateSystemChildren();
if (children) {
ClipItemsExceptCaret(children, aBuilder, aClipFrame, aExtraClip, aCache);
}
}
}
static void ClipListsExceptCaret(nsDisplayListCollection* aLists,
nsDisplayListBuilder* aBuilder,
nsIFrame* aClipFrame,
const DisplayItemClipChain* aExtraClip) {
nsTHashMap<nsPtrHashKey<const DisplayItemClipChain>,
const DisplayItemClipChain*>
cache;
ClipItemsExceptCaret(aLists->BorderBackground(), aBuilder, aClipFrame,
aExtraClip, cache);
ClipItemsExceptCaret(aLists->BlockBorderBackgrounds(), aBuilder, aClipFrame,
aExtraClip, cache);
ClipItemsExceptCaret(aLists->Floats(), aBuilder, aClipFrame, aExtraClip,
cache);
ClipItemsExceptCaret(aLists->PositionedDescendants(), aBuilder, aClipFrame,
aExtraClip, cache);
ClipItemsExceptCaret(aLists->Outlines(), aBuilder, aClipFrame, aExtraClip,
cache);
ClipItemsExceptCaret(aLists->Content(), aBuilder, aClipFrame, aExtraClip,
cache);
}
// This is similar to a "save-restore" RAII class for
// DisplayListBuilder::ContainsBlendMode(), with a slight enhancement.
// If this class is put on the stack and then unwound, the DL builder's
// ContainsBlendMode flag will be effectively the same as if this class wasn't
// put on the stack. However, if the CaptureContainsBlendMode method is called,
// there will be a difference - the blend mode in the descendant display lists
// will be "captured" and extracted.
// The main goal here is to allow conditionally capturing the flag that
// indicates whether or not a blend mode was encountered in the descendant part
// of the display list.
class MOZ_RAII AutoContainsBlendModeCapturer {
nsDisplayListBuilder& mBuilder;
bool mSavedContainsBlendMode;
public:
explicit AutoContainsBlendModeCapturer(nsDisplayListBuilder& aBuilder)
: mBuilder(aBuilder),
mSavedContainsBlendMode(aBuilder.ContainsBlendMode()) {
mBuilder.SetContainsBlendMode(false);
}
bool CaptureContainsBlendMode() {
// "Capture" the flag by extracting and clearing the ContainsBlendMode flag
// on the builder.
bool capturedBlendMode = mBuilder.ContainsBlendMode();
mBuilder.SetContainsBlendMode(false);
return capturedBlendMode;
}
~AutoContainsBlendModeCapturer() {
// If CaptureContainsBlendMode() was called, the descendant blend mode was
// "captured" and so uncapturedContainsBlendMode will be false. If
// CaptureContainsBlendMode() wasn't called, then no capture occurred, and
// uncapturedContainsBlendMode may be true if there was a descendant blend
// mode. In that case, we set the flag on the DL builder so that we restore
// state to what it would have been without this RAII class on the stack.
bool uncapturedContainsBlendMode = mBuilder.ContainsBlendMode();
mBuilder.SetContainsBlendMode(mSavedContainsBlendMode ||
uncapturedContainsBlendMode);
}
};
void nsHTMLScrollFrame::MaybeCreateTopLayerAndWrapRootItems(
nsDisplayListBuilder* aBuilder, nsDisplayListCollection& aSet,
bool aCreateAsyncZoom,
AutoContainsBlendModeCapturer* aAsyncZoomBlendCapture,
const nsRect& aAsyncZoomClipRect, nscoord* aRadii) {
if (!mIsRoot) {
return;
}
// Create any required items for the 'top layer' and check if they'll be
// opaque over the entire area of the viewport. If they are, then we can
// skip building display items for the rest of the page.
if (ViewportFrame* viewport = do_QueryFrame(GetParent())) {
bool topLayerIsOpaque = false;
if (nsDisplayWrapList* topLayerWrapList =
viewport->BuildDisplayListForTopLayer(aBuilder,
&topLayerIsOpaque)) {
// If the top layer content is opaque, and we're the root content document
// in the process, we can drop the display items behind it. We only
// support doing this for the root content document in the process, since
// the top layer content might have fixed position items that have a
// scrolltarget referencing the APZ data for the document. APZ builds this
// data implicitly for the root content document in the process, but
// subdocuments etc need their display items to generate it, so we can't
// cull those.
if (topLayerIsOpaque && PresContext()->IsRootContentDocumentInProcess()) {
aSet.DeleteAll(aBuilder);
}
aSet.PositionedDescendants()->AppendToTop(topLayerWrapList);
}
}
nsDisplayList rootResultList(aBuilder);
bool serializedList = false;
auto SerializeList = [&] {
if (!serializedList) {
serializedList = true;
aSet.SerializeWithCorrectZOrder(&rootResultList, GetContent());
}
};
if (nsIFrame* rootStyleFrame = GetFrameForStyle()) {
bool usingBackdropFilter =
rootStyleFrame->StyleEffects()->HasBackdropFilters() &&
rootStyleFrame->IsVisibleForPainting();
if (rootStyleFrame->StyleEffects()->HasFilters() &&
!aBuilder->IsForGenerateGlyphMask()) {
SerializeList();
rootResultList.AppendNewToTop<nsDisplayFilters>(
aBuilder, this, &rootResultList, rootStyleFrame, usingBackdropFilter);
}
if (usingBackdropFilter) {
SerializeList();
DisplayListClipState::AutoSaveRestore clipState(aBuilder);
nsRect backdropRect =
GetRectRelativeToSelf() + aBuilder->ToReferenceFrame(this);
rootResultList.AppendNewToTop<nsDisplayBackdropFilters>(
aBuilder, this, &rootResultList, backdropRect, rootStyleFrame);
}
}
if (aCreateAsyncZoom) {
MOZ_ASSERT(mIsRoot);
// Wrap all our scrolled contents in an nsDisplayAsyncZoom. This will be
// the layer that gets scaled for APZ zooming. It does not have the
// scrolled ASR, but it does have the composition bounds clip applied to
// it. The children have the layout viewport clip applied to them (above).
// Effectively we are double clipping to the viewport, at potentially
// different async scales.
SerializeList();
if (aAsyncZoomBlendCapture->CaptureContainsBlendMode()) {
// The async zoom contents contain a mix-blend mode, so let's wrap all
// those contents into a blend container, and then wrap the blend
// container in the async zoom container. Otherwise the blend container
// ends up outside the zoom container which results in blend failure for
// WebRender.
nsDisplayItem* blendContainer =
nsDisplayBlendContainer::CreateForMixBlendMode(
aBuilder, this, &rootResultList,
aBuilder->CurrentActiveScrolledRoot());
rootResultList.AppendToTop(blendContainer);
// Blend containers can be created or omitted during partial updates
// depending on the dirty rect. So we basically can't do partial updates
// if there's a blend container involved. There is equivalent code to this
// in the BuildDisplayListForStackingContext function as well, with a more
// detailed comment explaining things better.
if (aBuilder->IsRetainingDisplayList()) {
if (aBuilder->IsPartialUpdate()) {
aBuilder->SetPartialBuildFailed(true);
} else {
aBuilder->SetDisablePartialUpdates(true);
}
}
}
mozilla::layers::FrameMetrics::ViewID viewID =
nsLayoutUtils::FindOrCreateIDFor(mScrolledFrame->GetContent());
DisplayListClipState::AutoSaveRestore clipState(aBuilder);
clipState.ClipContentDescendants(aAsyncZoomClipRect, aRadii);
rootResultList.AppendNewToTop<nsDisplayAsyncZoom>(
aBuilder, this, &rootResultList, aBuilder->CurrentActiveScrolledRoot(),
viewID);
}
if (serializedList) {
aSet.Content()->AppendToTop(&rootResultList);
}
}
void nsHTMLScrollFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsDisplayListSet& aLists) {
SetAndNullOnExit<const nsIFrame> tmpBuilder(
mReferenceFrameDuringPainting, aBuilder->GetCurrentReferenceFrame());
if (aBuilder->IsForFrameVisibility()) {
NotifyApproximateFrameVisibilityUpdate(false);
}
DisplayBorderBackgroundOutline(aBuilder, aLists);
const bool isRootContent =
mIsRoot && PresContext()->IsRootContentDocumentCrossProcess();
nsRect effectiveScrollPort = mScrollPort;
if (isRootContent && PresContext()->HasDynamicToolbar()) {
// Expand the scroll port to the size including the area covered by dynamic
// toolbar in the case where the dynamic toolbar is being used since
// position:fixed elements attached to this root scroller might be taller
// than its scroll port (e.g 100vh). Even if the dynamic toolbar covers the
// taller area, it doesn't mean the area is clipped by the toolbar because
// the dynamic toolbar is laid out outside of our topmost window and it
// transitions without changing our topmost window size.
effectiveScrollPort.SizeTo(nsLayoutUtils::ExpandHeightForDynamicToolbar(
PresContext(), effectiveScrollPort.Size()));
}
// It's safe to get this value before the DecideScrollableLayer call below
// because that call cannot create a displayport for root scroll frames,
// and hence it cannot create an ignore scroll frame.
const bool ignoringThisScrollFrame = aBuilder->GetIgnoreScrollFrame() == this;
// Overflow clipping can never clip frames outside our subtree, so there
// is no need to worry about whether we are a moving frame that might clip
// non-moving frames.
// Not all our descendants will be clipped by overflow clipping, but all
// the ones that aren't clipped will be out of flow frames that have already
// had dirty rects saved for them by their parent frames calling
// MarkOutOfFlowChildrenForDisplayList, so it's safe to restrict our
// dirty rect here.
nsRect visibleRect = aBuilder->GetVisibleRect();
nsRect dirtyRect = aBuilder->GetDirtyRect();
if (!ignoringThisScrollFrame) {
visibleRect = visibleRect.Intersect(effectiveScrollPort);
dirtyRect = dirtyRect.Intersect(effectiveScrollPort);
}
bool dirtyRectHasBeenOverriden = false;
Unused << DecideScrollableLayer(aBuilder, &visibleRect, &dirtyRect,
/* aSetBase = */ !mIsRoot,
&dirtyRectHasBeenOverriden);
if (aBuilder->IsForFrameVisibility()) {
// We expand the dirty rect to catch frames just outside of the scroll port.
// We use the dirty rect instead of the whole scroll port to prevent
// too much expansion in the presence of very large (bigger than the
// viewport) scroll ports.
dirtyRect = ExpandRectToNearlyVisible(dirtyRect);
visibleRect = dirtyRect;
}
// We put non-overlay scrollbars in their own layers when this is the root
// scroll frame and we are a toplevel content document. In this situation,
// the scrollbar(s) would normally be assigned their own layer anyway, since
// they're not scrolled with the rest of the document. But when both
// scrollbars are visible, the layer's visible rectangle would be the size
// of the viewport, so most layer implementations would create a layer buffer
// that's much larger than necessary. Creating independent layers for each
// scrollbar works around the problem.
const bool createLayersForScrollbars = isRootContent;
nsDisplayListCollection set(aBuilder);
if (ignoringThisScrollFrame) {
// If we are a root scroll frame that has a display port we want to add
// scrollbars, they will be children of the scrollable layer, but they get
// adjusted by the APZC automatically.
bool addScrollBars =
mIsRoot && mWillBuildScrollableLayer && aBuilder->IsPaintingToWindow();
if (addScrollBars) {
// Add classic scrollbars.
AppendScrollPartsTo(aBuilder, set, createLayersForScrollbars, false);
}
{
nsDisplayListBuilder::AutoBuildingDisplayList building(
aBuilder, this, visibleRect, dirtyRect);
// Don't clip the scrolled child, and don't paint scrollbars/scrollcorner.
// The scrolled frame shouldn't have its own background/border, so we
// can just pass aLists directly.
BuildDisplayListForChild(aBuilder, mScrolledFrame, set);
}
MaybeCreateTopLayerAndWrapRootItems(aBuilder, set,
/* aCreateAsyncZoom = */ false, nullptr,
nsRect(), nullptr);
if (addScrollBars) {
// Add overlay scrollbars.
AppendScrollPartsTo(aBuilder, set, createLayersForScrollbars, true);
}
set.MoveTo(aLists);
return;
}
// Whether we might want to build a scrollable layer for this scroll frame
// at some point in the future. This controls whether we add the information
// to the layer tree (a scroll info layer if necessary, and add the right
// area to the dispatch to content layer event regions) necessary to activate
// a scroll frame so it creates a scrollable layer.
const bool couldBuildLayer = [&] {
if (!aBuilder->IsPaintingToWindow()) {
return false;
}
if (mWillBuildScrollableLayer) {
return true;
}
return StyleVisibility()->IsVisible() &&
nsLayoutUtils::AsyncPanZoomEnabled(this) && WantAsyncScroll();
}();
// Now display the scrollbars and scrollcorner. These parts are drawn
// in the border-background layer, on top of our own background and
// borders and underneath borders and backgrounds of later elements
// in the tree.
// Note that this does not apply for overlay scrollbars; those are drawn
// in the positioned-elements layer on top of everything else by the call
// to AppendScrollPartsTo(..., true) further down.
AppendScrollPartsTo(aBuilder, aLists, createLayersForScrollbars, false);
const nsStyleDisplay* disp = StyleDisplay();
if (aBuilder->IsForPainting() &&
disp->mWillChange.bits & StyleWillChangeBits::SCROLL) {
aBuilder->AddToWillChangeBudget(this, GetVisualViewportSize());
}
mScrollParentID = aBuilder->GetCurrentScrollParentId();
Maybe<nsRect> contentBoxClip;
Maybe<const DisplayItemClipChain*> extraContentBoxClipForNonCaretContent;
if (MOZ_UNLIKELY(
disp->mOverflowClipBoxBlock == StyleOverflowClipBox::ContentBox ||
disp->mOverflowClipBoxInline == StyleOverflowClipBox::ContentBox)) {
WritingMode wm = mScrolledFrame->GetWritingMode();
bool cbH = (wm.IsVertical() ? disp->mOverflowClipBoxBlock
: disp->mOverflowClipBoxInline) ==
StyleOverflowClipBox::ContentBox;
bool cbV = (wm.IsVertical() ? disp->mOverflowClipBoxInline
: disp->mOverflowClipBoxBlock) ==
StyleOverflowClipBox::ContentBox;
// We only clip if there is *scrollable* overflow, to avoid clipping
// *ink* overflow unnecessarily.
nsRect clipRect = effectiveScrollPort + aBuilder->ToReferenceFrame(this);
nsMargin padding = GetUsedPadding();
if (!cbH) {
padding.left = padding.right = nscoord(0);
}
if (!cbV) {
padding.top = padding.bottom = nscoord(0);
}
clipRect.Deflate(padding);
nsRect so = mScrolledFrame->ScrollableOverflowRect();
if ((cbH && (clipRect.width != so.width || so.x < 0)) ||
(cbV && (clipRect.height != so.height || so.y < 0))) {
// The non-inflated clip needs to be set on all non-caret items.
// We prepare an extra DisplayItemClipChain here that will be intersected
// with those items after they've been created.
const ActiveScrolledRoot* asr = aBuilder->CurrentActiveScrolledRoot();
DisplayItemClip newClip;
newClip.SetTo(clipRect);
const DisplayItemClipChain* extraClip =
aBuilder->AllocateDisplayItemClipChain(newClip, asr, nullptr);
extraContentBoxClipForNonCaretContent = Some(extraClip);
nsIFrame* caretFrame = aBuilder->GetCaretFrame();
// Avoid clipping it in a zero-height line box (heuristic only).
if (caretFrame && caretFrame->GetRect().height != 0) {
nsRect caretRect = aBuilder->GetCaretRect();
// Allow the caret to stick out of the content box clip by half the
// caret height on the top, and its full width on the right.
nsRect inflatedClip = clipRect;
inflatedClip.Inflate(
nsMargin(caretRect.height / 2, caretRect.width, 0, 0));
contentBoxClip = Some(inflatedClip);
}
}
}
AutoContainsBlendModeCapturer blendCapture(*aBuilder);
const bool willBuildAsyncZoomContainer =
mWillBuildScrollableLayer && aBuilder->ShouldBuildAsyncZoomContainer() &&
isRootContent;
nsRect scrollPortClip =
effectiveScrollPort + aBuilder->ToReferenceFrame(this);
nsRect clipRect = scrollPortClip;
// Our override of GetBorderRadii ensures we never have a radius at
// the corners where we have a scrollbar.
nscoord radii[8];
const bool haveRadii = GetPaddingBoxBorderRadii(radii);
if (mIsRoot) {
clipRect.SizeTo(nsLayoutUtils::CalculateCompositionSizeForFrame(
this, true /* aSubtractScrollbars */,
nullptr /* aOverrideScrollPortSize */,
// With the dynamic toolbar, this CalculateCompositionSizeForFrame call
// basically expands the region being covered up by the dynamic toolbar,
// but if the root scroll container is not scrollable, e.g. the root
// element has `overflow: hidden` or `position: fixed`, the function
// doesn't expand the region since expanding the region in such cases
// will prevent the content from restoring zooming to 1.0 zoom level
// such as bug 1652190. That said, this `clipRect` which will be used
// for the async zoom container needs to be expanded because zoomed-in
// contents can be scrollable __visually__ so that the region under the
// dynamic toolbar area will be revealed.
nsLayoutUtils::IncludeDynamicToolbar::Force));
// The composition size is essentially in visual coordinates.
// If we are hit-testing in layout coordinates, transform the clip rect
// to layout coordinates to match.
if (aBuilder->IsRelativeToLayoutViewport() && isRootContent) {
clipRect = ViewportUtils::VisualToLayout(clipRect, PresShell());
}
}
{
DisplayListClipState::AutoSaveRestore clipState(aBuilder);
// If we're building an async zoom container, clip the contents inside
// to the layout viewport (scrollPortClip). The composition bounds clip
// (clipRect) will be applied to the zoom container itself in
// MaybeCreateTopLayerAndWrapRootItems.
nsRect clipRectForContents =
willBuildAsyncZoomContainer ? scrollPortClip : clipRect;
if (mIsRoot) {
clipState.ClipContentDescendants(clipRectForContents,
haveRadii ? radii : nullptr);
} else {
clipState.ClipContainingBlockDescendants(clipRectForContents,
haveRadii ? radii : nullptr);
}
Maybe<DisplayListClipState::AutoSaveRestore> contentBoxClipState;
if (contentBoxClip) {
contentBoxClipState.emplace(aBuilder);
if (mIsRoot) {
contentBoxClipState->ClipContentDescendants(*contentBoxClip);
} else {
contentBoxClipState->ClipContainingBlockDescendants(*contentBoxClip);
}
}
nsDisplayListBuilder::AutoCurrentActiveScrolledRootSetter asrSetter(
aBuilder);
if (mWillBuildScrollableLayer && aBuilder->IsPaintingToWindow()) {
// If this scroll frame has a first scrollable frame sequence number,
// ensure that it matches the current paint sequence number. If it does
// not, reset it so that we can expire the displayport. The stored
// sequence number will not match that of the current paint if the dom
// was mutated in some way that alters the order of scroll frames.
if (IsFirstScrollableFrameSequenceNumber().isSome() &&
*IsFirstScrollableFrameSequenceNumber() !=
nsDisplayListBuilder::GetPaintSequenceNumber()) {
SetIsFirstScrollableFrameSequenceNumber(Nothing());
}
asrSetter.EnterScrollFrame(this);
}
if (couldBuildLayer && mScrolledFrame->GetContent()) {
asrSetter.SetCurrentScrollParentId(
nsLayoutUtils::FindOrCreateIDFor(mScrolledFrame->GetContent()));
}
if (mWillBuildScrollableLayer && aBuilder->BuildCompositorHitTestInfo()) {
// Create a hit test info item for the scrolled content that's not
// clipped to the displayport. This ensures that within the bounds
// of the scroll frame, the scrolled content is always hit, even
// if we are checkerboarding.
CompositorHitTestInfo info =
mScrolledFrame->GetCompositorHitTestInfo(aBuilder);
if (info != CompositorHitTestInvisibleToHit) {
auto* hitInfo =
MakeDisplayItemWithIndex<nsDisplayCompositorHitTestInfo>(
aBuilder, mScrolledFrame, 1);
if (hitInfo) {
aBuilder->SetCompositorHitTestInfo(info);
set.BorderBackground()->AppendToTop(hitInfo);
}
}
}
{
// Clip our contents to the unsnapped scrolled rect. This makes sure
// that we don't have display items over the subpixel seam at the edge
// of the scrolled area.
DisplayListClipState::AutoSaveRestore scrolledRectClipState(aBuilder);
nsRect scrolledRectClip =
GetUnsnappedScrolledRectInternal(
mScrolledFrame->ScrollableOverflowRect(), mScrollPort.Size()) +
mScrolledFrame->GetPosition();
bool clippedToDisplayPort = false;
if (mWillBuildScrollableLayer && aBuilder->IsPaintingToWindow()) {
// Clip the contents to the display port.
// The dirty rect already acts kind of like a clip, in that
// FrameLayerBuilder intersects item bounds and opaque regions with
// it, but it doesn't have the consistent snapping behavior of a
// true clip.
// For a case where this makes a difference, imagine the following
// scenario: The display port has an edge that falls on a fractional
// layer pixel, and there's an opaque display item that covers the
// whole display port up until that fractional edge, and there is a
// transparent display item that overlaps the edge. We want to prevent
// this transparent item from enlarging the scrolled layer's visible
// region beyond its opaque region. The dirty rect doesn't do that -
// it gets rounded out, whereas a true clip gets rounded to nearest
// pixels.
// If there is no display port, we don't need this because the clip
// from the scroll port is still applied.
scrolledRectClip = scrolledRectClip.Intersect(visibleRect);
clippedToDisplayPort = scrolledRectClip.IsEqualEdges(visibleRect);
}
scrolledRectClipState.ClipContainingBlockDescendants(
scrolledRectClip + aBuilder->ToReferenceFrame(this));
if (clippedToDisplayPort) {
// We have to do this after the ClipContainingBlockDescendants call
// above, otherwise that call will clobber the flag set by this call
// to SetClippedToDisplayPort.
scrolledRectClipState.SetClippedToDisplayPort();
}
nsRect visibleRectForChildren = visibleRect;
nsRect dirtyRectForChildren = dirtyRect;
// If we are entering the RCD-RSF, we are crossing the async zoom
// container boundary, and need to convert from visual to layout
// coordinates.
if (willBuildAsyncZoomContainer && aBuilder->IsForEventDelivery()) {
MOZ_ASSERT(ViewportUtils::IsZoomedContentRoot(mScrolledFrame));
visibleRectForChildren =
ViewportUtils::VisualToLayout(visibleRectForChildren, PresShell());
dirtyRectForChildren =
ViewportUtils::VisualToLayout(dirtyRectForChildren, PresShell());
}
nsDisplayListBuilder::AutoBuildingDisplayList building(
aBuilder, this, visibleRectForChildren, dirtyRectForChildren);
BuildDisplayListForChild(aBuilder, mScrolledFrame, set);
if (dirtyRectHasBeenOverriden &&
StaticPrefs::layout_display_list_show_rebuild_area()) {
nsDisplaySolidColor* color = MakeDisplayItem<nsDisplaySolidColor>(
aBuilder, this,
dirtyRect + aBuilder->GetCurrentFrameOffsetToReferenceFrame(),
NS_RGBA(0, 0, 255, 64), false);
if (color) {
color->SetOverrideZIndex(INT32_MAX);
set.PositionedDescendants()->AppendToTop(color);
}
}
}
if (extraContentBoxClipForNonCaretContent) {
// The items were built while the inflated content box clip was in
// effect, so that the caret wasn't clipped unnecessarily. We apply
// the non-inflated clip to the non-caret items now, by intersecting
// it with their existing clip.
ClipListsExceptCaret(&set, aBuilder, mScrolledFrame,
*extraContentBoxClipForNonCaretContent);
}
if (aBuilder->IsPaintingToWindow()) {
mIsParentToActiveScrollFrames =
ShouldActivateAllScrollFrames()
? asrSetter.GetContainsNonMinimalDisplayPort()
: asrSetter.ShouldForceLayerForScrollParent();
}
if (asrSetter.ShouldForceLayerForScrollParent()) {
// Note that forcing layerization of scroll parents follows the scroll
// handoff chain which is subject to the out-of-flow-frames caveat noted
// above (where the asrSetter variable is created).
MOZ_ASSERT(couldBuildLayer && mScrolledFrame->GetContent() &&
aBuilder->IsPaintingToWindow());
if (!mWillBuildScrollableLayer) {
// Set a displayport so next paint we don't have to force layerization
// after the fact. It's ok to pass DoNotRepaint here, since we've
// already painted the change and we're just optimizing it to be
// detected earlier. We also won't confuse RetainedDisplayLists
// with the silent change, since we explicitly request partial updates
// to be disabled on the next paint.
DisplayPortUtils::SetDisplayPortMargins(
GetContent(), PresShell(), DisplayPortMargins::Empty(GetContent()),
DisplayPortUtils::ClearMinimalDisplayPortProperty::Yes, 0,
DisplayPortUtils::RepaintMode::DoNotRepaint);
// Call DecideScrollableLayer to recompute mWillBuildScrollableLayer
// and recompute the current animated geometry root if needed. It's
// too late to change the dirty rect so pass a copy.
nsRect copyOfDirtyRect = dirtyRect;
nsRect copyOfVisibleRect = visibleRect;
Unused << DecideScrollableLayer(aBuilder, ©OfVisibleRect,
©OfDirtyRect,
/* aSetBase = */ false, nullptr);
if (mWillBuildScrollableLayer) {
asrSetter.InsertScrollFrame(this);
aBuilder->SetDisablePartialUpdates(true);
}
}
}
}
if (mWillBuildScrollableLayer && aBuilder->IsPaintingToWindow()) {
aBuilder->ForceLayerForScrollParent();
}
MaybeCreateTopLayerAndWrapRootItems(
aBuilder, set, willBuildAsyncZoomContainer, &blendCapture, clipRect,
haveRadii ? radii : nullptr);
// We want to call SetContainsNonMinimalDisplayPort if
// mWillBuildScrollableLayer is true for any reason other than having a
// minimal display port.
if (aBuilder->IsPaintingToWindow()) {
if (DisplayPortUtils::HasNonMinimalDisplayPort(GetContent()) ||
mZoomableByAPZ || nsContentUtils::HasScrollgrab(GetContent())) {
aBuilder->SetContainsNonMinimalDisplayPort();
}
}
if (couldBuildLayer) {
CompositorHitTestInfo info(CompositorHitTestFlags::eVisibleToHitTest,
CompositorHitTestFlags::eInactiveScrollframe);
// If the scroll frame has non-default overscroll-behavior, instruct
// APZ to require a target confirmation before processing events that
// hit this scroll frame (that is, to drop the events if a
// confirmation does not arrive within the timeout period). Otherwise,
// APZ's fallback behaviour of scrolling the enclosing scroll frame
// would violate the specified overscroll-behavior.
auto overscroll = GetOverscrollBehaviorInfo();
if (overscroll.mBehaviorX != OverscrollBehavior::Auto ||
overscroll.mBehaviorY != OverscrollBehavior::Auto) {
info += CompositorHitTestFlags::eRequiresTargetConfirmation;
}
nsRect area = effectiveScrollPort + aBuilder->ToReferenceFrame(this);
// Make sure that APZ will dispatch events back to content so we can
// create a displayport for this frame. We'll add the item later on.
if (!mWillBuildScrollableLayer && aBuilder->BuildCompositorHitTestInfo()) {
// Make sure the z-index of the inactive item is at least zero.
// Otherwise, it will end up behind non-positioned items in the scrolled
// content.
int32_t zIndex = MaxZIndexInListOfItemsContainedInFrame(
set.PositionedDescendants(), this)
.valueOr(0);
if (aBuilder->IsPartialUpdate()) {
for (nsDisplayItem* item : mScrolledFrame->DisplayItems()) {
if (item->GetType() ==
DisplayItemType::TYPE_COMPOSITOR_HITTEST_INFO) {
auto* hitTestItem =
static_cast<nsDisplayCompositorHitTestInfo*>(item);
if (hitTestItem->GetHitTestInfo().Info().contains(
CompositorHitTestFlags::eInactiveScrollframe)) {
zIndex = std::max(zIndex, hitTestItem->ZIndex());
item->SetCantBeReused();
}
}
}
}
nsDisplayCompositorHitTestInfo* hitInfo =
MakeDisplayItemWithIndex<nsDisplayCompositorHitTestInfo>(
aBuilder, mScrolledFrame, 1, area, info);
if (hitInfo) {
AppendInternalItemToTop(set, hitInfo, Some(zIndex));
aBuilder->SetCompositorHitTestInfo(info);
}
}
if (aBuilder->ShouldBuildScrollInfoItemsForHoisting()) {
aBuilder->AppendNewScrollInfoItemForHoisting(
MakeDisplayItem<nsDisplayScrollInfoLayer>(aBuilder, mScrolledFrame,
this, info, area));
}
}
// Now display overlay scrollbars and the resizer, if we have one.
AppendScrollPartsTo(aBuilder, set, createLayersForScrollbars, true);
set.MoveTo(aLists);
}
nsRect nsHTMLScrollFrame::RestrictToRootDisplayPort(
const nsRect& aDisplayportBase) {
// This function clips aDisplayportBase so that it is no larger than the
// root frame's displayport (or the root composition bounds, if we can't
// obtain the root frame's displayport). This is useful for ensuring that
// the displayport of a tall scrollframe doesn't gobble up all the memory.
nsPresContext* pc = PresContext();
const nsPresContext* rootPresContext =
pc->GetInProcessRootContentDocumentPresContext();
if (!rootPresContext) {
rootPresContext = pc->GetRootPresContext();
}
if (!rootPresContext) {
return aDisplayportBase;
}
const mozilla::PresShell* const rootPresShell = rootPresContext->PresShell();
nsIFrame* rootFrame = rootPresShell->GetRootScrollFrame();
if (!rootFrame) {
rootFrame = rootPresShell->GetRootFrame();
}
if (!rootFrame) {
return aDisplayportBase;
}
// Make sure we aren't trying to restrict to our own displayport, which is a
// circular dependency.
MOZ_ASSERT(!mIsRoot || rootPresContext != pc);
nsRect rootDisplayPort;
bool hasDisplayPort =
rootFrame->GetContent() && DisplayPortUtils::GetDisplayPort(
rootFrame->GetContent(), &rootDisplayPort);
if (hasDisplayPort) {
// The display port of the root frame already factors in it's callback
// transform, so subtract it out here, the GetCumulativeApzCallbackTransform
// call below will add it back.
MOZ_LOG(sDisplayportLog, LogLevel::Verbose,
("RestrictToRootDisplayPort: Existing root displayport is %s\n",
ToString(rootDisplayPort).c_str()));
if (nsIContent* content = rootFrame->GetContent()) {
if (void* property =
content->GetProperty(nsGkAtoms::apzCallbackTransform)) {
rootDisplayPort -=
CSSPoint::ToAppUnits(*static_cast<CSSPoint*>(property));
}
}
} else {
// If we don't have a display port on the root frame let's fall back to
// the root composition bounds instead.
nsRect rootCompBounds =
nsRect(nsPoint(0, 0),
nsLayoutUtils::CalculateCompositionSizeForFrame(rootFrame));
// If rootFrame is the RCD-RSF then
// CalculateCompositionSizeForFrame did not take the document's
// resolution into account, so we must.
if (rootPresContext->IsRootContentDocumentCrossProcess() &&
rootFrame == rootPresShell->GetRootScrollFrame()) {
MOZ_LOG(
sDisplayportLog, LogLevel::Verbose,
("RestrictToRootDisplayPort: Removing resolution %f from root "
"composition bounds %s\n",
rootPresShell->GetResolution(), ToString(rootCompBounds).c_str()));
rootCompBounds =
rootCompBounds.RemoveResolution(rootPresShell->GetResolution());
}
rootDisplayPort = rootCompBounds;
}
MOZ_LOG(sDisplayportLog, LogLevel::Verbose,
("RestrictToRootDisplayPort: Intermediate root displayport %s\n",
ToString(rootDisplayPort).c_str()));
// We want to convert the root display port from the
// coordinate space of |rootFrame| to the coordinate space of
// |this|. We do that with the TransformRect call below.
// However, since we care about the root display port
// relative to what the user is actually seeing, we also need to
// incorporate the APZ callback transforms into this. Most of the
// time those transforms are negligible, but in some cases (e.g.
// when a zoom is applied on an overflow:hidden document) it is
// not (see bug 1280013).
// XXX: Eventually we may want to create a modified version of
// TransformRect that includes the APZ callback transforms
// directly.
nsLayoutUtils::TransformRect(rootFrame, this, rootDisplayPort);
MOZ_LOG(sDisplayportLog, LogLevel::Verbose,
("RestrictToRootDisplayPort: Transformed root displayport %s\n",
ToString(rootDisplayPort).c_str()));
rootDisplayPort += CSSPoint::ToAppUnits(
nsLayoutUtils::GetCumulativeApzCallbackTransform(this));
MOZ_LOG(sDisplayportLog, LogLevel::Verbose,
("RestrictToRootDisplayPort: Final root displayport %s\n",
ToString(rootDisplayPort).c_str()));
// We want to limit aDisplayportBase to be no larger than
// rootDisplayPort on either axis, but we don't want to just
// blindly intersect the two, because rootDisplayPort might be
// offset from where aDisplayportBase is (see bug 1327095 comment
// 8). Instead, we translate rootDisplayPort so as to maximize the
// overlap with aDisplayportBase, and *then* do the intersection.
if (rootDisplayPort.x > aDisplayportBase.x &&
rootDisplayPort.XMost() > aDisplayportBase.XMost()) {
// rootDisplayPort is at a greater x-position for both left and
// right, so translate it such that the XMost() values are the
// same. This will line up the right edge of the two rects, and
// might mean that rootDisplayPort.x is smaller than
// aDisplayportBase.x. We can avoid that by taking the min of the
// x delta and XMost() delta, but it doesn't really matter
// because the intersection between the two rects below will end
// up the same.
rootDisplayPort.x -= (rootDisplayPort.XMost() - aDisplayportBase.XMost());
} else if (rootDisplayPort.x < aDisplayportBase.x &&
rootDisplayPort.XMost() < aDisplayportBase.XMost()) {
// Analaogous code for when the rootDisplayPort is at a smaller
// x-position.
rootDisplayPort.x = aDisplayportBase.x;
}
// Do the same for y-axis
if (rootDisplayPort.y > aDisplayportBase.y &&
rootDisplayPort.YMost() > aDisplayportBase.YMost()) {
rootDisplayPort.y -= (rootDisplayPort.YMost() - aDisplayportBase.YMost());
} else if (rootDisplayPort.y < aDisplayportBase.y &&
rootDisplayPort.YMost() < aDisplayportBase.YMost()) {
rootDisplayPort.y = aDisplayportBase.y;
}
MOZ_LOG(
sDisplayportLog, LogLevel::Verbose,
("RestrictToRootDisplayPort: Root displayport translated to %s to "
"better enclose %s\n",
ToString(rootDisplayPort).c_str(), ToString(aDisplayportBase).c_str()));
// Now we can do the intersection
return aDisplayportBase.Intersect(rootDisplayPort);
}
/* static */ bool nsHTMLScrollFrame::ShouldActivateAllScrollFrames() {
return (StaticPrefs::apz_wr_activate_all_scroll_frames() ||
(StaticPrefs::apz_wr_activate_all_scroll_frames_when_fission() &&
FissionAutostart()));
}
bool nsHTMLScrollFrame::DecideScrollableLayer(
nsDisplayListBuilder* aBuilder, nsRect* aVisibleRect, nsRect* aDirtyRect,
bool aSetBase, bool* aDirtyRectHasBeenOverriden) {
nsIContent* content = GetContent();
// For hit testing purposes with fission we want to create a
// minimal display port for every scroll frame that could be active. (We only
// do this when aSetBase is true because we only want to do this the first
// time this function is called for the same scroll frame.)
if (ShouldActivateAllScrollFrames() &&
!DisplayPortUtils::HasDisplayPort(content) &&
nsLayoutUtils::AsyncPanZoomEnabled(this) && WantAsyncScroll() &&
aBuilder->IsPaintingToWindow() && aSetBase) {
// SetDisplayPortMargins calls TriggerDisplayPortExpiration which starts a
// display port expiry timer for display ports that do expire. However
// minimal display ports do not expire, so the display port has to be
// marked before the SetDisplayPortMargins call so the expiry timer
// doesn't get started.
content->SetProperty(nsGkAtoms::MinimalDisplayPort,
reinterpret_cast<void*>(true));
DisplayPortUtils::SetDisplayPortMargins(
content, PresShell(), DisplayPortMargins::Empty(content),
DisplayPortUtils::ClearMinimalDisplayPortProperty::No, 0,
DisplayPortUtils::RepaintMode::DoNotRepaint);
}
bool usingDisplayPort = DisplayPortUtils::HasDisplayPort(content);
if (aBuilder->IsPaintingToWindow()) {
if (aSetBase) {
nsRect displayportBase = *aVisibleRect;
nsPresContext* pc = PresContext();
bool isContentRootDoc = pc->IsRootContentDocumentCrossProcess();
bool isChromeRootDoc =
!pc->Document()->IsContentDocument() && !pc->GetParentPresContext();
if (mIsRoot && (isContentRootDoc || isChromeRootDoc)) {
displayportBase =
nsRect(nsPoint(0, 0),
nsLayoutUtils::CalculateCompositionSizeForFrame(this));
} else {
// Make the displayport base equal to the visible rect restricted to
// the scrollport and the root composition bounds, relative to the
// scrollport.
displayportBase = aVisibleRect->Intersect(mScrollPort);
mozilla::layers::ScrollableLayerGuid::ViewID viewID =
mozilla::layers::ScrollableLayerGuid::NULL_SCROLL_ID;
if (MOZ_LOG_TEST(sDisplayportLog, LogLevel::Verbose)) {
nsLayoutUtils::FindIDFor(GetContent(), &viewID);
MOZ_LOG(
sDisplayportLog, LogLevel::Verbose,
("Scroll id %" PRIu64 " has visible rect %s, scroll port %s\n",
viewID, ToString(*aVisibleRect).c_str(),
ToString(mScrollPort).c_str()));
}
// Only restrict to the root displayport bounds if necessary,
// as the required coordinate transformation is expensive.
// And don't call RestrictToRootDisplayPort if we would be trying to
// restrict to our own display port, which doesn't make sense (ie if we
// are a root scroll frame in a process root prescontext).
if (usingDisplayPort && (!mIsRoot || pc->GetParentPresContext())) {
displayportBase = RestrictToRootDisplayPort(displayportBase);
MOZ_LOG(sDisplayportLog, LogLevel::Verbose,
("Scroll id %" PRIu64 " has restricted base %s\n", viewID,
ToString(displayportBase).c_str()));
}
displayportBase -= mScrollPort.TopLeft();
}
DisplayPortUtils::SetDisplayPortBase(GetContent(), displayportBase);
}
// If we don't have aSetBase == true then should have already
// been called with aSetBase == true which should have set a
// displayport base.
MOZ_ASSERT(content->GetProperty(nsGkAtoms::DisplayPortBase));
nsRect displayPort;
usingDisplayPort = DisplayPortUtils::GetDisplayPort(
content, &displayPort,
DisplayPortOptions().With(DisplayportRelativeTo::ScrollFrame));
auto OverrideDirtyRect = [&](const nsRect& aRect) {
*aDirtyRect = aRect;
if (aDirtyRectHasBeenOverriden) {
*aDirtyRectHasBeenOverriden = true;
}
};
if (usingDisplayPort) {
// Override the dirty rectangle if the displayport has been set.
*aVisibleRect = displayPort;
if (aBuilder->IsReusingStackingContextItems() ||
!aBuilder->IsPartialUpdate() || aBuilder->InInvalidSubtree() ||
IsFrameModified()) {
OverrideDirtyRect(displayPort);
} else if (HasOverrideDirtyRegion()) {
nsRect* rect = GetProperty(
nsDisplayListBuilder::DisplayListBuildingDisplayPortRect());
if (rect) {
OverrideDirtyRect(*rect);
}
}
} else if (mIsRoot) {
// The displayPort getter takes care of adjusting for resolution. So if
// we have resolution but no displayPort then we need to adjust for
// resolution here.
auto* presShell = PresShell();
*aVisibleRect =
aVisibleRect->RemoveResolution(presShell->GetResolution());
*aDirtyRect = aDirtyRect->RemoveResolution(presShell->GetResolution());
}
}
// Since making new layers is expensive, only create a scrollable layer
// for some scroll frames.
// When a displayport is being used, force building of a layer so that
// the compositor can find the scrollable layer for async scrolling.
// If the element is marked 'scrollgrab', also force building of a layer
// so that APZ can implement scroll grabbing.
mWillBuildScrollableLayer = usingDisplayPort ||
nsContentUtils::HasScrollgrab(content) ||
mZoomableByAPZ;
return mWillBuildScrollableLayer;
}
void nsHTMLScrollFrame::NotifyApzTransaction() {
mAllowScrollOriginDowngrade = true;
mApzScrollPos = GetScrollPosition();
mApzAnimationRequested = IsLastScrollUpdateAnimating();
mApzAnimationTriggeredByScriptRequested =
IsLastScrollUpdateTriggeredByScriptAnimating();
mScrollUpdates.Clear();
if (mIsRoot) {
PresShell()->SetResolutionUpdated(false);
}
}
Maybe<ScrollMetadata> nsHTMLScrollFrame::ComputeScrollMetadata(
WebRenderLayerManager* aLayerManager, const nsIFrame* aItemFrame,
const nsPoint& aOffsetToReferenceFrame) const {
if (!mWillBuildScrollableLayer) {
return Nothing();
}
bool isRootContent =
mIsRoot && PresContext()->IsRootContentDocumentCrossProcess();
MOZ_ASSERT(mScrolledFrame->GetContent());
return Some(nsLayoutUtils::ComputeScrollMetadata(
mScrolledFrame, this, GetContent(), aItemFrame, aOffsetToReferenceFrame,
aLayerManager, mScrollParentID, mScrollPort.Size(), isRootContent));
}
bool nsHTMLScrollFrame::IsRectNearlyVisible(const nsRect& aRect) const {
// Use the right rect depending on if a display port is set.
nsRect displayPort;
bool usingDisplayport = DisplayPortUtils::GetDisplayPort(
GetContent(), &displayPort,
DisplayPortOptions().With(DisplayportRelativeTo::ScrollFrame));
if (mIsRoot && !usingDisplayport &&
PresContext()->IsRootContentDocumentInProcess() &&
!PresContext()->IsRootContentDocumentCrossProcess()) {
// In the case of the root scroller of OOP iframes, there are cases where
// any display port value isn't set, e.g. the iframe element is out of view
// in the parent document. In such cases we'd consider the iframe is not
// visible.
return false;
}
return aRect.Intersects(
ExpandRectToNearlyVisible(usingDisplayport ? displayPort : mScrollPort));
}
OverscrollBehaviorInfo nsHTMLScrollFrame::GetOverscrollBehaviorInfo() const {
nsIFrame* frame = GetFrameForStyle();
if (!frame) {
return {};
}
auto& disp = *frame->StyleDisplay();
return OverscrollBehaviorInfo::FromStyleConstants(disp.mOverscrollBehaviorX,
disp.mOverscrollBehaviorY);
}
ScrollStyles nsHTMLScrollFrame::GetScrollStyles() const {
nsPresContext* presContext = PresContext();
if (!presContext->IsDynamic() &&
!(mIsRoot && presContext->HasPaginatedScrolling())) {
return ScrollStyles(StyleOverflow::Hidden, StyleOverflow::Hidden);
}
if (!mIsRoot) {
return ScrollStyles(*StyleDisplay(),
ScrollStyles::MapOverflowToValidScrollStyle);
}
ScrollStyles result = presContext->GetViewportScrollStylesOverride();
if (nsDocShell* ds = presContext->GetDocShell()) {
switch (ds->ScrollbarPreference()) {
case ScrollbarPreference::Auto:
break;
case ScrollbarPreference::Never:
result.mHorizontal = result.mVertical = StyleOverflow::Hidden;
break;
}
}
return result;
}
nsRect nsHTMLScrollFrame::GetLayoutScrollRange() const {
return GetScrollRange(mScrollPort.width, mScrollPort.height);
}
nsRect nsHTMLScrollFrame::GetScrollRange(nscoord aWidth,
nscoord aHeight) const {
nsRect range = GetScrolledRect();
range.width = std::max(range.width - aWidth, 0);
range.height = std::max(range.height - aHeight, 0);
return range;
}
nsRect nsHTMLScrollFrame::GetVisualScrollRange() const {
nsSize visualViewportSize = GetVisualViewportSize();
return GetScrollRange(visualViewportSize.width, visualViewportSize.height);
}
nsSize nsHTMLScrollFrame::GetVisualViewportSize() const {
auto* presShell = PresShell();
if (mIsRoot && presShell->IsVisualViewportSizeSet()) {
return presShell->GetVisualViewportSize();
}
return mScrollPort.Size();
}
nsPoint nsHTMLScrollFrame::GetVisualViewportOffset() const {
if (mIsRoot) {
auto* presShell = PresShell();
if (auto pendingUpdate = presShell->GetPendingVisualScrollUpdate()) {
// The pending visual scroll update on the PresShell contains a raw,
// unclamped offset (basically, whatever was passed to ScrollToVisual()).
// It will be clamped on the APZ side, but if we use it as the
// main-thread's visual viewport offset we need to clamp it ourselves.
// Use GetScrollRangeForUserInputEvents() to do the clamping because this
// the scroll range that APZ will use.
return GetScrollRangeForUserInputEvents().ClampPoint(
pendingUpdate->mVisualScrollOffset);
}
return presShell->GetVisualViewportOffset();
}
return GetScrollPosition();
}
bool nsHTMLScrollFrame::SetVisualViewportOffset(const nsPoint& aOffset,
bool aRepaint) {
MOZ_ASSERT(mIsRoot);
AutoWeakFrame weakFrame(this);
AutoScrollbarRepaintSuppression repaintSuppression(this, weakFrame,
!aRepaint);
bool retVal =
PresShell()->SetVisualViewportOffset(aOffset, GetScrollPosition());
if (!weakFrame.IsAlive()) {
return false;
}
return retVal;
}
nsRect nsHTMLScrollFrame::GetVisualOptimalViewingRect() const {
auto* presShell = PresShell();
nsRect rect = mScrollPort;
if (mIsRoot && presShell->IsVisualViewportSizeSet() &&
presShell->IsVisualViewportOffsetSet()) {
rect = nsRect(mScrollPort.TopLeft() - GetScrollPosition() +
presShell->GetVisualViewportOffset(),
presShell->GetVisualViewportSize());
}
// NOTE: We intentionally resolve scroll-padding percentages against the
// scrollport even when the visual viewport is set, see
// https://github.com/w3c/csswg-drafts/issues/4393.
rect.Deflate(GetScrollPadding());
return rect;
}
static void AdjustDestinationForWholeDelta(const nsIntPoint& aDelta,
const nsRect& aScrollRange,
nsPoint& aPoint) {
if (aDelta.x < 0) {
aPoint.x = aScrollRange.X();
} else if (aDelta.x > 0) {
aPoint.x = aScrollRange.XMost();
}
if (aDelta.y < 0) {
aPoint.y = aScrollRange.Y();
} else if (aDelta.y > 0) {
aPoint.y = aScrollRange.YMost();
}
}
/**
* Calculate lower/upper scrollBy range in given direction.
* @param aDelta specifies scrollBy direction, if 0 then range will be 0 size
* @param aPos desired destination in AppUnits
* @param aNeg/PosTolerance defines relative range distance
* below and above of aPos point
* @param aMultiplier used for conversion of tolerance into appUnis
*/
static void CalcRangeForScrollBy(int32_t aDelta, nscoord aPos,
float aNegTolerance, float aPosTolerance,
nscoord aMultiplier, nscoord* aLower,
nscoord* aUpper) {
if (!aDelta) {
*aLower = *aUpper = aPos;
return;
}
*aLower = aPos - NSToCoordRound(aMultiplier *
(aDelta > 0 ? aNegTolerance : aPosTolerance));
*aUpper = aPos + NSToCoordRound(aMultiplier *
(aDelta > 0 ? aPosTolerance : aNegTolerance));
}
void nsHTMLScrollFrame::ScrollBy(nsIntPoint aDelta, ScrollUnit aUnit,
ScrollMode aMode, nsIntPoint* aOverflow,
ScrollOrigin aOrigin,
nsIScrollableFrame::ScrollMomentum aMomentum,
ScrollSnapFlags aSnapFlags) {
// When a smooth scroll is being processed on a frame, mouse wheel and
// trackpad momentum scroll event updates must notcancel the SMOOTH or
// SMOOTH_MSD scroll animations, enabling Javascript that depends on them to
// be responsive without forcing the user to wait for the fling animations to
// completely stop.
switch (aMomentum) {
case nsIScrollableFrame::NOT_MOMENTUM:
mIgnoreMomentumScroll = false;
break;
case nsIScrollableFrame::SYNTHESIZED_MOMENTUM_EVENT:
if (mIgnoreMomentumScroll) {
return;
}
break;
}
if (mAsyncSmoothMSDScroll != nullptr) {
// When CSSOM-View scroll-behavior smooth scrolling is interrupted,
// the scroll is not completed to avoid non-smooth snapping to the
// prior smooth scroll's destination.
mDestination = GetScrollPosition();
}
nsSize deltaMultiplier;
float negativeTolerance;
float positiveTolerance;
if (aOrigin == ScrollOrigin::NotSpecified) {
aOrigin = ScrollOrigin::Other;
}
bool isGenericOrigin = (aOrigin == ScrollOrigin::Other);
bool askApzToDoTheScroll = false;
if ((aSnapFlags == ScrollSnapFlags::Disabled || !NeedsScrollSnap()) &&
gfxPlatform::UseDesktopZoomingScrollbars() &&
nsLayoutUtils::AsyncPanZoomEnabled(this) &&
!nsLayoutUtils::ShouldDisableApzForElement(GetContent()) &&
(WantAsyncScroll() || mZoomableByAPZ) &&
CanApzScrollInTheseDirections(DirectionsInDelta(aDelta))) {
askApzToDoTheScroll = true;
}
switch (aUnit) {
case ScrollUnit::DEVICE_PIXELS: {
nscoord appUnitsPerDevPixel = PresContext()->AppUnitsPerDevPixel();
deltaMultiplier = nsSize(appUnitsPerDevPixel, appUnitsPerDevPixel);
if (isGenericOrigin) {
aOrigin = ScrollOrigin::Pixels;
}
negativeTolerance = positiveTolerance = 0.5f;
break;
}
case ScrollUnit::LINES: {
deltaMultiplier = GetLineScrollAmount();
if (isGenericOrigin) {
aOrigin = ScrollOrigin::Lines;
}
negativeTolerance = positiveTolerance = 0.1f;
break;
}
case ScrollUnit::PAGES: {
deltaMultiplier = GetPageScrollAmount();
if (isGenericOrigin) {
aOrigin = ScrollOrigin::Pages;
}
negativeTolerance = 0.05f;
positiveTolerance = 0;
break;
}
case ScrollUnit::WHOLE: {
if (askApzToDoTheScroll) {
MOZ_ASSERT(aDelta.x >= -1 && aDelta.x <= 1 && aDelta.y >= -1 &&
aDelta.y <= 1);
deltaMultiplier = GetScrollRangeForUserInputEvents().Size();
break;
} else {
nsPoint pos = GetScrollPosition();
AdjustDestinationForWholeDelta(aDelta, GetLayoutScrollRange(), pos);
ScrollToWithOrigin(
pos, nullptr /* range */,
ScrollOperationParams{aMode, ScrollOrigin::Other, aSnapFlags,
ScrollTriggeredByScript::No});
// 'this' might be destroyed here
if (aOverflow) {
*aOverflow = nsIntPoint(0, 0);
}
return;
}
}
default:
NS_ERROR("Invalid scroll mode");
return;
}
if (askApzToDoTheScroll) {
nsPoint delta(
NSCoordSaturatingNonnegativeMultiply(aDelta.x, deltaMultiplier.width),
NSCoordSaturatingNonnegativeMultiply(aDelta.y, deltaMultiplier.height));
AppendScrollUpdate(
ScrollPositionUpdate::NewPureRelativeScroll(aOrigin, aMode, delta));
nsIContent* content = GetContent();
if (!DisplayPortUtils::HasNonMinimalNonZeroDisplayPort(content)) {
if (MOZ_LOG_TEST(sDisplayportLog, LogLevel::Debug)) {
mozilla::layers::ScrollableLayerGuid::ViewID viewID =
mozilla::layers::ScrollableLayerGuid::NULL_SCROLL_ID;
nsLayoutUtils::FindIDFor(content, &viewID);
MOZ_LOG(
sDisplayportLog, LogLevel::Debug,
("ScrollBy setting displayport on scrollId=%" PRIu64 "\n", viewID));
}
DisplayPortUtils::CalculateAndSetDisplayPortMargins(
GetScrollTargetFrame(), DisplayPortUtils::RepaintMode::Repaint);
nsIFrame* frame = do_QueryFrame(GetScrollTargetFrame());
DisplayPortUtils::SetZeroMarginDisplayPortOnAsyncScrollableAncestors(
frame);
}
SchedulePaint();
return;
}
nsPoint newPos(NSCoordSaturatingAdd(mDestination.x,
NSCoordSaturatingNonnegativeMultiply(
aDelta.x, deltaMultiplier.width)),
NSCoordSaturatingAdd(mDestination.y,
NSCoordSaturatingNonnegativeMultiply(
aDelta.y, deltaMultiplier.height)));
Maybe<SnapTarget> snapTarget;
if (aSnapFlags != ScrollSnapFlags::Disabled) {
if (NeedsScrollSnap()) {
nscoord appUnitsPerDevPixel = PresContext()->AppUnitsPerDevPixel();
deltaMultiplier = nsSize(appUnitsPerDevPixel, appUnitsPerDevPixel);
negativeTolerance = 0.1f;
positiveTolerance = 0;
ScrollUnit snapUnit = aUnit;
if (aOrigin == ScrollOrigin::MouseWheel) {
// When using a clicky scroll wheel, snap point selection works the same
// as keyboard up/down/left/right navigation, but with varying amounts
// of scroll delta.
snapUnit = ScrollUnit::LINES;
}
snapTarget = GetSnapPointForDestination(snapUnit, aSnapFlags,
mDestination, newPos);
if (snapTarget) {
newPos = snapTarget->mPosition;
}
}
}
// Calculate desired range values.
nscoord rangeLowerX, rangeUpperX, rangeLowerY, rangeUpperY;
CalcRangeForScrollBy(aDelta.x, newPos.x, negativeTolerance, positiveTolerance,
deltaMultiplier.width, &rangeLowerX, &rangeUpperX);
CalcRangeForScrollBy(aDelta.y, newPos.y, negativeTolerance, positiveTolerance,
deltaMultiplier.height, &rangeLowerY, &rangeUpperY);
nsRect range(rangeLowerX, rangeLowerY, rangeUpperX - rangeLowerX,
rangeUpperY - rangeLowerY);
AutoWeakFrame weakFrame(this);
ScrollToWithOrigin(
newPos, &range,
snapTarget ? ScrollOperationParams{aMode, aOrigin,
std::move(snapTarget->mTargetIds)}
: ScrollOperationParams{aMode, aOrigin});
if (!weakFrame.IsAlive()) {
return;
}
if (aOverflow) {
nsPoint clampAmount = newPos - mDestination;
float appUnitsPerDevPixel = PresContext()->AppUnitsPerDevPixel();
*aOverflow =
nsIntPoint(NSAppUnitsToIntPixels(clampAmount.x, appUnitsPerDevPixel),
NSAppUnitsToIntPixels(clampAmount.y, appUnitsPerDevPixel));
}
if (aUnit == ScrollUnit::DEVICE_PIXELS &&
!nsLayoutUtils::AsyncPanZoomEnabled(this)) {
// When APZ is disabled, we must track the velocity
// on the main thread; otherwise, the APZC will manage this.
mVelocityQueue.Sample(GetScrollPosition());
}
}
void nsHTMLScrollFrame::ScrollByCSSPixelsInternal(const CSSIntPoint& aDelta,
ScrollMode aMode,
ScrollSnapFlags aSnapFlags) {
nsPoint current = GetScrollPosition();
// `current` value above might be a value which was aligned to in
// layer-pixels, so starting from such points will make the difference between
// the given position in script (e.g. scrollTo) and the aligned position
// larger, in the worst case the difference can be observed in CSS pixels.
// To avoid it, we use the current position in CSS pixels as the start
// position. Hopefully it exactly matches the position where it was given by
// the previous scrolling operation, but there may be some edge cases where
// the current position in CSS pixels differs from the given position, the
// cases should be fixed in bug 1556685.
CSSIntPoint currentCSSPixels = GetScrollPositionCSSPixels();
nsPoint pt = CSSPoint::ToAppUnits(currentCSSPixels + aDelta);
nscoord halfPixel = nsPresContext::CSSPixelsToAppUnits(0.5f);
nsRect range(pt.x - halfPixel, pt.y - halfPixel, 2 * halfPixel - 1,
2 * halfPixel - 1);
// XXX I don't think the following blocks are needed anymore, now that
// ScrollToImpl simply tries to scroll an integer number of layer
// pixels from the current position
if (aDelta.x == 0.0f) {
pt.x = current.x;
range.x = pt.x;
range.width = 0;
}
if (aDelta.y == 0.0f) {
pt.y = current.y;
range.y = pt.y;
range.height = 0;
}
ScrollToWithOrigin(
pt, &range,
ScrollOperationParams{aMode, ScrollOrigin::Relative, aSnapFlags,
ScrollTriggeredByScript::Yes});
// 'this' might be destroyed here
}
void nsHTMLScrollFrame::ScrollSnap(ScrollMode aMode) {
float flingSensitivity =
StaticPrefs::layout_css_scroll_snap_prediction_sensitivity();
int maxVelocity =
StaticPrefs::layout_css_scroll_snap_prediction_max_velocity();
maxVelocity = nsPresContext::CSSPixelsToAppUnits(maxVelocity);
int maxOffset = maxVelocity * flingSensitivity;
nsPoint velocity = mVelocityQueue.GetVelocity();
// Multiply each component individually to avoid integer multiply
nsPoint predictedOffset =
nsPoint(velocity.x * flingSensitivity, velocity.y * flingSensitivity);
predictedOffset.Clamp(maxOffset);
nsPoint pos = GetScrollPosition();
nsPoint destinationPos = pos + predictedOffset;
ScrollSnap(destinationPos, aMode);
}
void nsHTMLScrollFrame::ScrollSnap(const nsPoint& aDestination,
ScrollMode aMode) {
nsRect scrollRange = GetLayoutScrollRange();
nsPoint pos = GetScrollPosition();
nsPoint snapDestination = scrollRange.ClampPoint(aDestination);
ScrollSnapFlags snapFlags = ScrollSnapFlags::IntendedEndPosition;
if (mVelocityQueue.GetVelocity() != nsPoint()) {
snapFlags |= ScrollSnapFlags::IntendedDirection;
}
// Bug 1776624 : Consider using mDestination as |aStartPos| argument for this
// GetSnapPointForDestination call, this function call is the only one call
// site using `GetScrollPosition()` as |aStartPos|.
if (auto snapTarget = GetSnapPointForDestination(
ScrollUnit::DEVICE_PIXELS, snapFlags, pos, snapDestination)) {
snapDestination = snapTarget->mPosition;
ScrollToWithOrigin(
snapDestination, nullptr /* range */,
ScrollOperationParams{aMode, ScrollOrigin::Other,
std::move(snapTarget->mTargetIds)});
}
}
nsSize nsHTMLScrollFrame::GetLineScrollAmount() const {
RefPtr<nsFontMetrics> fm =
nsLayoutUtils::GetInflatedFontMetricsForFrame(this);
NS_ASSERTION(fm, "FontMetrics is null, assuming fontHeight == 1 appunit");
int32_t appUnitsPerDevPixel = PresContext()->AppUnitsPerDevPixel();
nscoord minScrollAmountInAppUnits =
std::max(1, StaticPrefs::mousewheel_min_line_scroll_amount()) *
appUnitsPerDevPixel;
nscoord horizontalAmount = fm ? fm->AveCharWidth() : 0;
nscoord verticalAmount = fm ? fm->MaxHeight() : 0;
return nsSize(std::max(horizontalAmount, minScrollAmountInAppUnits),
std::max(verticalAmount, minScrollAmountInAppUnits));
}
/**
* Compute the scrollport size excluding any fixed-pos and sticky-pos (that are
* stuck) headers and footers. A header or footer is an box that spans that
* entire width of the viewport and touches the top (or bottom, respectively) of
* the viewport. We also want to consider fixed/sticky elements that stack or
* overlap to effectively create a larger header or footer. Headers and footers
* that cover more than a third of the the viewport are ignored since they
* probably aren't true headers and footers and we don't want to restrict
* scrolling too much in such cases. This is a bit conservative --- some
* pages use elements as headers or footers that don't span the entire width
* of the viewport --- but it should be a good start.
*
* If aViewportFrame is non-null then the scroll frame is the root scroll
* frame and we should consider fixed-pos items.
*/
struct TopAndBottom {
TopAndBottom(nscoord aTop, nscoord aBottom) : top(aTop), bottom(aBottom) {}
nscoord top, bottom;
};
struct TopComparator {
bool Equals(const TopAndBottom& A, const TopAndBottom& B) const {
return A.top == B.top;
}
bool LessThan(const TopAndBottom& A, const TopAndBottom& B) const {
return A.top < B.top;
}
};
struct ReverseBottomComparator {
bool Equals(const TopAndBottom& A, const TopAndBottom& B) const {
return A.bottom == B.bottom;
}
bool LessThan(const TopAndBottom& A, const TopAndBottom& B) const {
return A.bottom > B.bottom;
}
};
static void AddToListIfHeaderFooter(nsIFrame* aFrame,
nsIFrame* aScrollPortFrame,
const nsRect& aScrollPort,
nsTArray<TopAndBottom>& aList) {
nsRect r = aFrame->GetRectRelativeToSelf();
r = nsLayoutUtils::TransformFrameRectToAncestor(aFrame, r, aScrollPortFrame);
r = r.Intersect(aScrollPort);
if ((r.width >= aScrollPort.width / 2 ||
r.width >= NSIntPixelsToAppUnits(800, AppUnitsPerCSSPixel())) &&
r.height <= aScrollPort.height / 3) {
aList.AppendElement(TopAndBottom(r.y, r.YMost()));
}
}
static nsSize GetScrollPortSizeExcludingHeadersAndFooters(
nsIFrame* aScrollFrame, nsIFrame* aViewportFrame,
const nsRect& aScrollPort) {
AutoTArray<TopAndBottom, 10> list;
if (aViewportFrame) {
for (nsIFrame* f : aViewportFrame->GetChildList(FrameChildListID::Fixed)) {
AddToListIfHeaderFooter(f, aViewportFrame, aScrollPort, list);
}
}
// Add sticky frames that are currently in "fixed" positions
StickyScrollContainer* ssc =
StickyScrollContainer::GetStickyScrollContainerForScrollFrame(
aScrollFrame);
if (ssc) {
const nsTArray<nsIFrame*>& stickyFrames = ssc->GetFrames();
for (nsIFrame* f : stickyFrames) {
// If it's acting like fixed position.
if (ssc->IsStuckInYDirection(f)) {
AddToListIfHeaderFooter(f, aScrollFrame, aScrollPort, list);
}
}
}
list.Sort(TopComparator());
nscoord headerBottom = 0;
for (uint32_t i = 0; i < list.Length(); ++i) {
if (list[i].top <= headerBottom) {
headerBottom = std::max(headerBottom, list[i].bottom);
}
}
list.Sort(ReverseBottomComparator());
nscoord footerTop = aScrollPort.height;
for (uint32_t i = 0; i < list.Length(); ++i) {
if (list[i].bottom >= footerTop) {
footerTop = std::min(footerTop, list[i].top);
}
}
headerBottom = std::min(aScrollPort.height / 3, headerBottom);
footerTop = std::max(aScrollPort.height - aScrollPort.height / 3, footerTop);
return nsSize(aScrollPort.width, footerTop - headerBottom);
}
nsSize nsHTMLScrollFrame::GetPageScrollAmount() const {
nsSize effectiveScrollPortSize;
if (GetVisualViewportSize() != mScrollPort.Size()) {
// We want to use the visual viewport size if one is set.
// The headers/footers adjustment is too complicated to do if there is a
// visual viewport that differs from the layout viewport, this is probably
// okay.
effectiveScrollPortSize = GetVisualViewportSize();
} else {
// Reduce effective scrollport height by the height of any
// fixed-pos/sticky-pos headers or footers
effectiveScrollPortSize = GetScrollPortSizeExcludingHeadersAndFooters(
const_cast<nsHTMLScrollFrame*>(this),
mIsRoot ? PresShell()->GetRootFrame() : nullptr, mScrollPort);
}
nsSize lineScrollAmount = GetLineScrollAmount();
// The page increment is the size of the page, minus the smaller of
// 10% of the size or 2 lines.
return nsSize(effectiveScrollPortSize.width -
std::min(effectiveScrollPortSize.width / 10,
2 * lineScrollAmount.width),
effectiveScrollPortSize.height -
std::min(effectiveScrollPortSize.height / 10,
2 * lineScrollAmount.height));
}
/**
* this code is resposible for restoring the scroll position back to some
* saved position. if the user has not moved the scroll position manually
* we keep scrolling down until we get to our original position. keep in
* mind that content could incrementally be coming in. we only want to stop
* when we reach our new position.
*/
void nsHTMLScrollFrame::ScrollToRestoredPosition() {
if (mRestorePos.y == -1 || mLastPos.x == -1 || mLastPos.y == -1) {
return;
}
// make sure our scroll position did not change for where we last put
// it. if it does then the user must have moved it, and we no longer
// need to restore.
//
// In the RTL case, we check whether the scroll position changed using the
// logical scroll position, but we scroll to the physical scroll position in
// all cases
// The layout offset we want to restore is the same as the visual offset
// (for now, may change in bug 1499210), but clamped to the layout scroll
// range (which can be a subset of the visual scroll range).
// Note that we can't do the clamping when initializing mRestorePos in
// RestoreState(), since the scrollable rect (which the clamping depends
// on) can change over the course of the restoration process.
nsPoint layoutRestorePos = GetLayoutScrollRange().ClampPoint(mRestorePos);
nsPoint visualRestorePos = GetVisualScrollRange().ClampPoint(mRestorePos);
// Continue restoring until both the layout and visual scroll positions
// reach the destination. (Note that the two can only be different for
// the root content document's root scroll frame, and when zoomed in).
// This is necessary to avoid situations where the two offsets get stuck
// at different values and nothing reconciles them (see bug 1519621 comment
// 8).
nsPoint logicalLayoutScrollPos = GetLogicalScrollPosition();
SCROLLRESTORE_LOG(
"%p: ScrollToRestoredPosition (mRestorePos=%s, mLastPos=%s, "
"layoutRestorePos=%s, visualRestorePos=%s, "
"logicalLayoutScrollPos=%s, "
"GetLogicalVisualViewportOffset()=%s)\n",
this, ToString(mRestorePos).c_str(), ToString(mLastPos).c_str(),
ToString(layoutRestorePos).c_str(), ToString(visualRestorePos).c_str(),
ToString(logicalLayoutScrollPos).c_str(),
ToString(GetLogicalVisualViewportOffset()).c_str());
// if we didn't move, we still need to restore
if (GetLogicalVisualViewportOffset() == mLastPos ||
logicalLayoutScrollPos == mLastPos) {
// if our desired position is different to the scroll position, scroll.
// remember that we could be incrementally loading so we may enter
// and scroll many times.
if (mRestorePos != mLastPos /* GetLogicalVisualViewportOffset() */ ||
layoutRestorePos != logicalLayoutScrollPos) {
LoadingState state = GetPageLoadingState();
if (state == LoadingState::Stopped && !IsSubtreeDirty()) {
return;
}
nsPoint visualScrollToPos = visualRestorePos;
nsPoint layoutScrollToPos = layoutRestorePos;
if (!IsPhysicalLTR()) {
// convert from logical to physical scroll position
visualScrollToPos.x -=
(GetVisualViewportSize().width - mScrolledFrame->GetRect().width);
layoutScrollToPos.x -=
(GetVisualViewportSize().width - mScrolledFrame->GetRect().width);
}
AutoWeakFrame weakFrame(this);
// It's very important to pass ScrollOrigin::Restore here, so
// ScrollToWithOrigin won't clear out mRestorePos.
ScrollToWithOrigin(
layoutScrollToPos, nullptr,
ScrollOperationParams{ScrollMode::Instant, ScrollOrigin::Restore});
if (!weakFrame.IsAlive()) {
return;
}
if (mIsRoot) {
PresShell()->ScrollToVisual(visualScrollToPos, FrameMetrics::eRestore,
ScrollMode::Instant);
}
if (state == LoadingState::Loading || IsSubtreeDirty()) {
// If we're trying to do a history scroll restore, then we want to
// keep trying this until we succeed, because the page can be loading
// incrementally. So re-get the scroll position for the next iteration,
// it might not be exactly equal to mRestorePos due to rounding and
// clamping.
mLastPos = GetLogicalVisualViewportOffset();
return;
}
}
// If we get here, either we reached the desired position (mLastPos ==
// mRestorePos) or we're not trying to do a history scroll restore, so
// we can stop after the scroll attempt above.
mRestorePos.y = -1;
mLastPos.x = -1;
mLastPos.y = -1;
} else {
// user moved the position, so we won't need to restore
mLastPos.x = -1;
mLastPos.y = -1;
}
}
auto nsHTMLScrollFrame::GetPageLoadingState() -> LoadingState {
bool loadCompleted = false, stopped = false;
nsCOMPtr<nsIDocShell> ds = GetContent()->GetComposedDoc()->GetDocShell();
if (ds) {
nsCOMPtr<nsIContentViewer> cv;
ds->GetContentViewer(getter_AddRefs(cv));
if (cv) {
loadCompleted = cv->GetLoadCompleted();
stopped = cv->GetIsStopped();
}
}
return loadCompleted
? (stopped ? LoadingState::Stopped : LoadingState::Loaded)
: LoadingState::Loading;
}
nsHTMLScrollFrame::OverflowState nsHTMLScrollFrame::GetOverflowState() const {
nsSize scrollportSize = mScrollPort.Size();
nsSize childSize = GetScrolledRect().Size();
OverflowState result = OverflowState::None;
if (childSize.height > scrollportSize.height) {
result |= OverflowState::Vertical;
}
if (childSize.width > scrollportSize.width) {
result |= OverflowState::Horizontal;
}
return result;
}
nsresult nsHTMLScrollFrame::FireScrollPortEvent() {
mAsyncScrollPortEvent.Forget();
// TODO(emilio): why do we need the whole WillPaintObserver infrastructure and
// can't use AddScriptRunner & co? I guess it made sense when we used
// WillPaintObserver for scroll events too, or when this used to flush.
//
// Should we remove this?
OverflowState overflowState = GetOverflowState();
bool newVerticalOverflow = !!(overflowState & OverflowState::Vertical);
bool vertChanged = mVerticalOverflow != newVerticalOverflow;
bool newHorizontalOverflow = !!(overflowState & OverflowState::Horizontal);
bool horizChanged = mHorizontalOverflow != newHorizontalOverflow;
if (!vertChanged && !horizChanged) {
return NS_OK;
}
// If both either overflowed or underflowed then we dispatch only one
// DOM event.
bool both = vertChanged && horizChanged &&
newVerticalOverflow == newHorizontalOverflow;
InternalScrollPortEvent::OrientType orient;
if (both) {
orient = InternalScrollPortEvent::eBoth;
mHorizontalOverflow = newHorizontalOverflow;
mVerticalOverflow = newVerticalOverflow;
} else if (vertChanged) {
orient = InternalScrollPortEvent::eVertical;
mVerticalOverflow = newVerticalOverflow;
if (horizChanged) {
// We need to dispatch a separate horizontal DOM event. Do that the next
// time around since dispatching the vertical DOM event might destroy
// the frame.
PostOverflowEvent();
}
} else {
orient = InternalScrollPortEvent::eHorizontal;
mHorizontalOverflow = newHorizontalOverflow;
}
InternalScrollPortEvent event(
true,
(orient == InternalScrollPortEvent::eHorizontal ? mHorizontalOverflow
: mVerticalOverflow)
? eScrollPortOverflow
: eScrollPortUnderflow,
nullptr);
event.mOrient = orient;
RefPtr<nsIContent> content = GetContent();
RefPtr<nsPresContext> presContext = PresContext();
return EventDispatcher::Dispatch(content, presContext, &event);
}
void nsHTMLScrollFrame::PostScrollEndEvent() {
if (mScrollEndEvent) {
return;
}
// The ScrollEndEvent constructor registers itself with the refresh driver.
mScrollEndEvent = new ScrollEndEvent(this);
}
void nsHTMLScrollFrame::FireScrollEndEvent() {
MOZ_ASSERT(GetContent());
MOZ_ASSERT(mScrollEndEvent);
RefPtr<nsPresContext> presContext = PresContext();
mScrollEndEvent->Revoke();
mScrollEndEvent = nullptr;
nsEventStatus status = nsEventStatus_eIgnore;
WidgetGUIEvent event(true, eScrollend, nullptr);
event.mFlags.mBubbles = mIsRoot;
event.mFlags.mCancelable = false;
// If apz.scrollend-event.content.enabled is not set, the event should
// only be dispatched to the browser chrome.
event.mFlags.mOnlyChromeDispatch =
!StaticPrefs::apz_scrollend_event_content_enabled();
RefPtr<nsINode> target =
mIsRoot ? static_cast<nsINode*>(presContext->Document()) : GetContent();
EventDispatcher::Dispatch(target, presContext, &event, nullptr, &status);
}
void nsHTMLScrollFrame::ReloadChildFrames() {
mScrolledFrame = nullptr;
mHScrollbarBox = nullptr;
mVScrollbarBox = nullptr;
mScrollCornerBox = nullptr;
mResizerBox = nullptr;
for (nsIFrame* frame : PrincipalChildList()) {
nsIContent* content = frame->GetContent();
if (content == GetContent()) {
NS_ASSERTION(!mScrolledFrame, "Already found the scrolled frame");
mScrolledFrame = frame;
} else {
nsAutoString value;
if (content->IsElement()) {
content->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::orient,
value);
}
if (!value.IsEmpty()) {
// probably a scrollbar then
if (value.LowerCaseEqualsLiteral("horizontal")) {
NS_ASSERTION(!mHScrollbarBox,
"Found multiple horizontal scrollbars?");
mHScrollbarBox = do_QueryFrame(frame);
MOZ_ASSERT(mHScrollbarBox, "Not a scrollbar?");
} else {
NS_ASSERTION(!mVScrollbarBox, "Found multiple vertical scrollbars?");
mVScrollbarBox = do_QueryFrame(frame);
MOZ_ASSERT(mVScrollbarBox, "Not a scrollbar?");
}
} else if (content->IsXULElement(nsGkAtoms::resizer)) {
NS_ASSERTION(!mResizerBox, "Found multiple resizers");
mResizerBox = frame;
} else if (content->IsXULElement(nsGkAtoms::scrollcorner)) {
// probably a scrollcorner
NS_ASSERTION(!mScrollCornerBox, "Found multiple scrollcorners");
mScrollCornerBox = frame;
}
}
}
}
already_AddRefed<Element> nsHTMLScrollFrame::MakeScrollbar(
NodeInfo* aNodeInfo, bool aVertical, AnonymousContentKey& aKey) {
MOZ_ASSERT(aNodeInfo);
MOZ_ASSERT(
aNodeInfo->Equals(nsGkAtoms::scrollbar, nullptr, kNameSpaceID_XUL));
static constexpr nsLiteralString kOrientValues[2] = {
u"horizontal"_ns,
u"vertical"_ns,
};
aKey = AnonymousContentKey::Type_Scrollbar;
if (aVertical) {
aKey |= AnonymousContentKey::Flag_Vertical;
}
RefPtr<Element> e;
NS_TrustedNewXULElement(getter_AddRefs(e), do_AddRef(aNodeInfo));
#ifdef DEBUG
// Scrollbars can get restyled by theme changes. Whether such a restyle
// will actually reconstruct them correctly if it involves a frame
// reconstruct... I don't know. :(
e->SetProperty(nsGkAtoms::restylableAnonymousNode,
reinterpret_cast<void*>(true));
#endif // DEBUG
e->SetAttr(kNameSpaceID_None, nsGkAtoms::orient, kOrientValues[aVertical],
false);
if (mIsRoot) {
e->SetProperty(nsGkAtoms::docLevelNativeAnonymousContent,
reinterpret_cast<void*>(true));
e->SetAttr(kNameSpaceID_None, nsGkAtoms::root_, u"true"_ns, false);
// Don't bother making style caching take [root="true"] styles into account.
aKey = AnonymousContentKey::None;
}
return e.forget();
}
bool nsHTMLScrollFrame::IsForTextControlWithNoScrollbars() const {
// FIXME(emilio): we should probably make the scroller inside <input> an
// internal pseudo-element, and then this would be simpler.
//
// Also, this could just use scrollbar-width these days.
auto* content = GetContent();
if (!content) {
return false;
}
auto* input = content->GetClosestNativeAnonymousSubtreeRootParentOrHost();
return input && input->IsHTMLElement(nsGkAtoms::input);
}
auto nsHTMLScrollFrame::GetCurrentAnonymousContent() const
-> EnumSet<AnonymousContentType> {
EnumSet<AnonymousContentType> result;
if (mHScrollbarContent) {
result += AnonymousContentType::HorizontalScrollbar;
}
if (mVScrollbarContent) {
result += AnonymousContentType::VerticalScrollbar;
}
if (mResizerContent) {
result += AnonymousContentType::Resizer;
}
return result;
}
auto nsHTMLScrollFrame::GetNeededAnonymousContent() const
-> EnumSet<AnonymousContentType> {
nsPresContext* pc = PresContext();
// Don't create scrollbars if we're an SVG document being used as an image,
// or if we're printing/print previewing.
// (In the printing case, we allow scrollbars if this is the child of the
// viewport & paginated scrolling is enabled, because then we must be the
// scroll frame for the print preview window, & that does need scrollbars.)
if (pc->Document()->IsBeingUsedAsImage() ||
(!pc->IsDynamic() && !(mIsRoot && pc->HasPaginatedScrolling()))) {
return {};
}
if (IsForTextControlWithNoScrollbars()) {
return {};
}
EnumSet<AnonymousContentType> result;
// If we're the scrollframe for the root, then we want to construct our
// scrollbar frames no matter what. That way later dynamic changes to
// propagated overflow styles will show or hide scrollbars on the viewport
// without requiring frame reconstruction of the viewport (good!).
//
// TODO(emilio): Figure out if we can remove this special-case now that we
// have more targeted optimizations.
if (mIsRoot) {
result += AnonymousContentType::HorizontalScrollbar;
result += AnonymousContentType::VerticalScrollbar;
// If scrollbar-width is none, don't generate scrollbars.
} else if (StyleUIReset()->ScrollbarWidth() != StyleScrollbarWidth::None) {
ScrollStyles styles = GetScrollStyles();
if (styles.mHorizontal != StyleOverflow::Hidden) {
result += AnonymousContentType::HorizontalScrollbar;
}
if (styles.mVertical != StyleOverflow::Hidden) {
result += AnonymousContentType::VerticalScrollbar;
}
// If we have scrollbar-gutter, construct the scrollbar frames to query its
// size to reserve the gutter space at the inline start or end edges.
if (StyleDisplay()->mScrollbarGutter & StyleScrollbarGutter::STABLE) {
result += GetWritingMode().IsVertical()
? AnonymousContentType::HorizontalScrollbar
: AnonymousContentType::VerticalScrollbar;
}
}
// Check if the frame is resizable. Note:
// "The effect of the resize property on generated content is undefined.
// Implementations should not apply the resize property to generated
// content." [1]
// For info on what is generated content, see [2].
// [1]: https://drafts.csswg.org/css-ui/#resize
// [2]: https://www.w3.org/TR/CSS2/generate.html#content
auto resizeStyle = StyleDisplay()->mResize;
if (resizeStyle != StyleResize::None &&
!HasAnyStateBits(NS_FRAME_GENERATED_CONTENT)) {
result += AnonymousContentType::Resizer;
}
return result;
}
nsresult nsHTMLScrollFrame::CreateAnonymousContent(
nsTArray<nsIAnonymousContentCreator::ContentInfo>& aElements) {
typedef nsIAnonymousContentCreator::ContentInfo ContentInfo;
nsPresContext* presContext = PresContext();
nsNodeInfoManager* nodeInfoManager =
presContext->Document()->NodeInfoManager();
auto neededAnonContent = GetNeededAnonymousContent();
if (neededAnonContent.isEmpty()) {
return NS_OK;
}
{
RefPtr<NodeInfo> nodeInfo = nodeInfoManager->GetNodeInfo(
nsGkAtoms::scrollbar, nullptr, kNameSpaceID_XUL, nsINode::ELEMENT_NODE);
NS_ENSURE_TRUE(nodeInfo, NS_ERROR_OUT_OF_MEMORY);
if (neededAnonContent.contains(AnonymousContentType::HorizontalScrollbar)) {
AnonymousContentKey key;
mHScrollbarContent = MakeScrollbar(nodeInfo, /* aVertical */ false, key);
aElements.AppendElement(ContentInfo(mHScrollbarContent, key));
}
if (neededAnonContent.contains(AnonymousContentType::VerticalScrollbar)) {
AnonymousContentKey key;
mVScrollbarContent = MakeScrollbar(nodeInfo, /* aVertical */ true, key);
aElements.AppendElement(ContentInfo(mVScrollbarContent, key));
}
}
if (neededAnonContent.contains(AnonymousContentType::Resizer)) {
MOZ_ASSERT(!mIsRoot, "Root scroll frame shouldn't be resizable");
RefPtr<NodeInfo> nodeInfo;
nodeInfo = nodeInfoManager->GetNodeInfo(
nsGkAtoms::resizer, nullptr, kNameSpaceID_XUL, nsINode::ELEMENT_NODE);
NS_ENSURE_TRUE(nodeInfo, NS_ERROR_OUT_OF_MEMORY);
NS_TrustedNewXULElement(getter_AddRefs(mResizerContent), nodeInfo.forget());
nsAutoString dir;
switch (StyleDisplay()->mResize) {
case StyleResize::Horizontal:
if (IsScrollbarOnRight()) {
dir.AssignLiteral("right");
} else {
dir.AssignLiteral("left");
}
break;
case StyleResize::Vertical:
dir.AssignLiteral("bottom");
if (!IsScrollbarOnRight()) {
mResizerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::flip, u""_ns,
false);
}
break;
case StyleResize::Both:
if (IsScrollbarOnRight()) {
dir.AssignLiteral("bottomright");
} else {
dir.AssignLiteral("bottomleft");
}
break;
default:
NS_WARNING("only resizable types should have resizers");
}
mResizerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::dir, dir, false);
aElements.AppendElement(mResizerContent);
}
if (neededAnonContent.contains(AnonymousContentType::HorizontalScrollbar) &&
neededAnonContent.contains(AnonymousContentType::VerticalScrollbar)) {
AnonymousContentKey key = AnonymousContentKey::Type_ScrollCorner;
RefPtr<NodeInfo> nodeInfo =
nodeInfoManager->GetNodeInfo(nsGkAtoms::scrollcorner, nullptr,
kNameSpaceID_XUL, nsINode::ELEMENT_NODE);
NS_TrustedNewXULElement(getter_AddRefs(mScrollCornerContent),
nodeInfo.forget());
if (mIsRoot) {
mScrollCornerContent->SetProperty(
nsGkAtoms::docLevelNativeAnonymousContent,
reinterpret_cast<void*>(true));
mScrollCornerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::root_,
u"true"_ns, false);
// Don't bother making style caching take [root="true"] styles into
// account.
key = AnonymousContentKey::None;
}
aElements.AppendElement(ContentInfo(mScrollCornerContent, key));
}
// Don't cache styles if we are a child of a <select> element, since we have
// some UA style sheet rules that depend on the <select>'s attributes.
if (GetContent()->IsHTMLElement(nsGkAtoms::select)) {
for (auto& info : aElements) {
info.mKey = AnonymousContentKey::None;
}
}
return NS_OK;
}
void nsHTMLScrollFrame::AppendAnonymousContentTo(
nsTArray<nsIContent*>& aElements, uint32_t aFilter) {
if (mHScrollbarContent) {
aElements.AppendElement(mHScrollbarContent);
}
if (mVScrollbarContent) {
aElements.AppendElement(mVScrollbarContent);
}
if (mScrollCornerContent) {
aElements.AppendElement(mScrollCornerContent);
}
if (mResizerContent) {
aElements.AppendElement(mResizerContent);
}
}
void nsHTMLScrollFrame::DidSetComputedStyle(ComputedStyle* aOldComputedStyle) {
nsContainerFrame::DidSetComputedStyle(aOldComputedStyle);
if (aOldComputedStyle && !mIsRoot &&
StyleDisplay()->mScrollSnapType !=
aOldComputedStyle->StyleDisplay()->mScrollSnapType) {
PostPendingResnap();
}
}
void nsHTMLScrollFrame::RemoveObservers() {
if (mAsyncScroll) {
mAsyncScroll->RemoveObserver();
mAsyncScroll = nullptr;
}
if (mAsyncSmoothMSDScroll) {
mAsyncSmoothMSDScroll->RemoveObserver();
mAsyncSmoothMSDScroll = nullptr;
}
}
/**
* Called when we want to update the scrollbar position, either because
* scrolling happened or the user moved the scrollbar position and we need to
* undo that (e.g., when the user clicks to scroll and we're using smooth
* scrolling, so we need to put the thumb back to its initial position for the
* start of the smooth sequence).
*/
void nsHTMLScrollFrame::UpdateScrollbarPosition() {
AutoWeakFrame weakFrame(this);
mFrameIsUpdatingScrollbar = true;
nsPoint pt = GetScrollPosition();
nsRect scrollRange = GetVisualScrollRange();
if (gfxPlatform::UseDesktopZoomingScrollbars()) {
pt = GetVisualViewportOffset();
scrollRange = GetScrollRangeForUserInputEvents();
}
if (mVScrollbarBox) {
SetCoordAttribute(mVScrollbarBox->GetContent()->AsElement(),
nsGkAtoms::curpos, pt.y - scrollRange.y);
if (!weakFrame.IsAlive()) {
return;
}
}
if (mHScrollbarBox) {
SetCoordAttribute(mHScrollbarBox->GetContent()->AsElement(),
nsGkAtoms::curpos, pt.x - scrollRange.x);
if (!weakFrame.IsAlive()) {
return;
}
}
mFrameIsUpdatingScrollbar = false;
}
void nsHTMLScrollFrame::CurPosAttributeChangedInternal(nsIContent* aContent,
bool aDoScroll) {
NS_ASSERTION(aContent, "aContent must not be null");
NS_ASSERTION((mHScrollbarBox && mHScrollbarBox->GetContent() == aContent) ||
(mVScrollbarBox && mVScrollbarBox->GetContent() == aContent),
"unexpected child");
MOZ_ASSERT(aContent->IsElement());
// Attribute changes on the scrollbars happen in one of three ways:
// 1) The scrollbar changed the attribute in response to some user event
// 2) We changed the attribute in response to a ScrollPositionDidChange
// callback from the scrolling view
// 3) We changed the attribute to adjust the scrollbars for the start
// of a smooth scroll operation
//
// In cases 2 and 3 we do not need to scroll because we're just
// updating our scrollbar.
if (mFrameIsUpdatingScrollbar) {
return;
}
nsRect scrollRange = GetVisualScrollRange();
nsPoint current = GetScrollPosition() - scrollRange.TopLeft();
if (gfxPlatform::UseDesktopZoomingScrollbars()) {
scrollRange = GetScrollRangeForUserInputEvents();
current = GetVisualViewportOffset() - scrollRange.TopLeft();
}
nsPoint dest;
nsRect allowedRange;
dest.x = GetCoordAttribute(mHScrollbarBox, nsGkAtoms::curpos, current.x,
&allowedRange.x, &allowedRange.width);
dest.y = GetCoordAttribute(mVScrollbarBox, nsGkAtoms::curpos, current.y,
&allowedRange.y, &allowedRange.height);
current += scrollRange.TopLeft();
dest += scrollRange.TopLeft();
allowedRange += scrollRange.TopLeft();
// Don't try to scroll if we're already at an acceptable place.
// Don't call Contains here since Contains returns false when the point is
// on the bottom or right edge of the rectangle.
if (allowedRange.ClampPoint(current) == current) {
return;
}
if (mScrollbarActivity &&
(mHasHorizontalScrollbar || mHasVerticalScrollbar)) {
RefPtr<ScrollbarActivity> scrollbarActivity(mScrollbarActivity);
scrollbarActivity->ActivityOccurred();
}
const bool isSmooth = aContent->AsElement()->HasAttr(nsGkAtoms::smooth);
if (isSmooth) {
// Make sure an attribute-setting callback occurs even if the view
// didn't actually move yet. We need to make sure other listeners
// see that the scroll position is not (yet) what they thought it
// was.
AutoWeakFrame weakFrame(this);
UpdateScrollbarPosition();
if (!weakFrame.IsAlive()) {
return;
}
}
if (aDoScroll) {
ScrollToWithOrigin(dest, &allowedRange,
ScrollOperationParams{
isSmooth ? ScrollMode::Smooth : ScrollMode::Instant,
ScrollOrigin::Scrollbars});
}
// 'this' might be destroyed here
}
/* ============= Scroll events ========== */
nsHTMLScrollFrame::ScrollEvent::ScrollEvent(nsHTMLScrollFrame* aHelper,
bool aDelayed)
: Runnable("nsHTMLScrollFrame::ScrollEvent"), mHelper(aHelper) {
mHelper->PresContext()->RefreshDriver()->PostScrollEvent(this, aDelayed);
}
// TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230, bug 1535398)
MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP
nsHTMLScrollFrame::ScrollEvent::Run() {
if (mHelper) {
mHelper->FireScrollEvent();
}
return NS_OK;
}
nsHTMLScrollFrame::ScrollEndEvent::ScrollEndEvent(nsHTMLScrollFrame* aHelper)
: Runnable("nsHTMLScrollFrame::ScrollEndEvent"), mHelper(aHelper) {
mHelper->PresContext()->RefreshDriver()->PostScrollEvent(this);
}
MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP
nsHTMLScrollFrame::ScrollEndEvent::Run() {
if (mHelper) {
mHelper->FireScrollEndEvent();
}
return NS_OK;
}
void nsHTMLScrollFrame::FireScrollEvent() {
RefPtr<nsIContent> content = GetContent();
RefPtr<nsPresContext> presContext = PresContext();
AUTO_PROFILER_TRACING_MARKER_DOCSHELL("Paint", "FireScrollEvent", GRAPHICS,
presContext->GetDocShell());
MOZ_ASSERT(mScrollEvent);
mScrollEvent->Revoke();
mScrollEvent = nullptr;
// If event handling is suppressed, keep posting the scroll event to the
// refresh driver until it is unsuppressed. The event is marked as delayed so
// that the refresh driver does not continue ticking.
if (content->GetComposedDoc() &&
content->GetComposedDoc()->EventHandlingSuppressed()) {
content->GetComposedDoc()->SetHasDelayedRefreshEvent();
PostScrollEvent(/* aDelayed = */ true);
return;
}
bool oldProcessing = mProcessingScrollEvent;
AutoWeakFrame weakFrame(this);
auto RestoreProcessingScrollEvent = mozilla::MakeScopeExit([&] {
if (weakFrame.IsAlive()) { // Otherwise `this` will be dead too.
mProcessingScrollEvent = oldProcessing;
}
});
mProcessingScrollEvent = true;
WidgetGUIEvent event(true, eScroll, nullptr);
nsEventStatus status = nsEventStatus_eIgnore;
// Fire viewport scroll events at the document (where they
// will bubble to the window)
mozilla::layers::ScrollLinkedEffectDetector detector(
content->GetComposedDoc(),
presContext->RefreshDriver()->MostRecentRefresh());
if (mIsRoot) {
if (RefPtr<Document> doc = content->GetUncomposedDoc()) {
// TODO: Bug 1506441
EventDispatcher::Dispatch(MOZ_KnownLive(ToSupports(doc)), presContext,
&event, nullptr, &status);
}
} else {
// scroll events fired at elements don't bubble (although scroll events
// fired at documents do, to the window)
event.mFlags.mBubbles = false;
EventDispatcher::Dispatch(content, presContext, &event, nullptr, &status);
}
}
void nsHTMLScrollFrame::PostScrollEvent(bool aDelayed) {
if (mScrollEvent) {
return;
}
// The ScrollEvent constructor registers itself with the refresh driver.
mScrollEvent = new ScrollEvent(this, aDelayed);
}
// TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230, bug 1535398)
MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP
nsHTMLScrollFrame::AsyncScrollPortEvent::Run() {
return mHelper ? mHelper->FireScrollPortEvent() : NS_OK;
}
void nsHTMLScrollFrame::PostOverflowEvent() {
if (mAsyncScrollPortEvent.IsPending()) {
return;
}
OverflowState overflowState = GetOverflowState();
bool newVerticalOverflow = !!(overflowState & OverflowState::Vertical);
bool vertChanged = mVerticalOverflow != newVerticalOverflow;
bool newHorizontalOverflow = !!(overflowState & OverflowState::Horizontal);
bool horizChanged = mHorizontalOverflow != newHorizontalOverflow;
if (!vertChanged && !horizChanged) {
return;
}
nsRootPresContext* rpc = PresContext()->GetRootPresContext();
if (!rpc) {
return;
}
mAsyncScrollPortEvent = new AsyncScrollPortEvent(this);
rpc->AddWillPaintObserver(mAsyncScrollPortEvent.get());
}
nsIFrame* nsHTMLScrollFrame::GetFrameForStyle() const {
nsIFrame* styleFrame = nullptr;
if (mIsRoot) {
if (const Element* rootElement =
PresContext()->Document()->GetRootElement()) {
styleFrame = rootElement->GetPrimaryFrame();
}
} else {
styleFrame = const_cast<nsHTMLScrollFrame*>(this);
}
return styleFrame;
}
bool nsHTMLScrollFrame::NeedsScrollSnap() const {
nsIFrame* scrollSnapFrame = GetFrameForStyle();
if (!scrollSnapFrame) {
return false;
}
return scrollSnapFrame->StyleDisplay()->mScrollSnapType.strictness !=
StyleScrollSnapStrictness::None;
}
nsSize nsHTMLScrollFrame::GetSnapportSize() const {
nsRect snapport = GetScrollPortRect();
nsMargin scrollPadding = GetScrollPadding();
snapport.Deflate(scrollPadding);
return snapport.Size();
}
bool nsHTMLScrollFrame::IsScrollbarOnRight() const {
nsPresContext* presContext = PresContext();
// The position of the scrollbar in top-level windows depends on the pref
// layout.scrollbar.side. For non-top-level elements, it depends only on the
// directionaliy of the element (equivalent to a value of "1" for the pref).
if (!mIsRoot) {
return IsPhysicalLTR();
}
switch (presContext->GetCachedIntPref(kPresContext_ScrollbarSide)) {
default:
case 0: // UI directionality
return presContext->GetCachedIntPref(kPresContext_BidiDirection) ==
IBMBIDI_TEXTDIRECTION_LTR;
case 1: // Document / content directionality
return IsPhysicalLTR();
case 2: // Always right
return true;
case 3: // Always left
return false;
}
}
bool nsHTMLScrollFrame::IsScrollingActive() const {
const nsStyleDisplay* disp = StyleDisplay();
if (disp->mWillChange.bits & StyleWillChangeBits::SCROLL) {
return true;
}
nsIContent* content = GetContent();
return mHasBeenScrolledRecently || IsAlwaysActive() ||
DisplayPortUtils::HasDisplayPort(content) ||
nsContentUtils::HasScrollgrab(content);
}
void nsHTMLScrollFrame::FinishReflowForScrollbar(Element* aElement,
nscoord aMinXY, nscoord aMaxXY,
nscoord aCurPosXY,
nscoord aPageIncrement,
nscoord aIncrement) {
// Scrollbars assume zero is the minimum position, so translate for them.
SetCoordAttribute(aElement, nsGkAtoms::curpos, aCurPosXY - aMinXY);
SetScrollbarEnabled(aElement, aMaxXY - aMinXY);
SetCoordAttribute(aElement, nsGkAtoms::maxpos, aMaxXY - aMinXY);
SetCoordAttribute(aElement, nsGkAtoms::pageincrement, aPageIncrement);
SetCoordAttribute(aElement, nsGkAtoms::increment, aIncrement);
}
class MOZ_RAII AutoMinimumScaleSizeChangeDetector final {
public:
explicit AutoMinimumScaleSizeChangeDetector(
nsHTMLScrollFrame* ansHTMLScrollFrame)
: mHelper(ansHTMLScrollFrame) {
MOZ_ASSERT(mHelper);
MOZ_ASSERT(mHelper->mIsRoot);
mPreviousMinimumScaleSize = ansHTMLScrollFrame->mMinimumScaleSize;
mPreviousIsUsingMinimumScaleSize =
ansHTMLScrollFrame->mIsUsingMinimumScaleSize;
}
~AutoMinimumScaleSizeChangeDetector() {
if (mPreviousMinimumScaleSize != mHelper->mMinimumScaleSize ||
mPreviousIsUsingMinimumScaleSize != mHelper->mIsUsingMinimumScaleSize) {
mHelper->mMinimumScaleSizeChanged = true;
}
}
private:
nsHTMLScrollFrame* mHelper;
nsSize mPreviousMinimumScaleSize;
bool mPreviousIsUsingMinimumScaleSize;
};
nsSize nsHTMLScrollFrame::TrueOuterSize(nsDisplayListBuilder* aBuilder) const {
if (!PresShell()->UsesMobileViewportSizing()) {
return GetSize();
}
RefPtr<MobileViewportManager> manager =
PresShell()->GetMobileViewportManager();
MOZ_ASSERT(manager);
LayoutDeviceIntSize displaySize = manager->DisplaySize();
MOZ_ASSERT(aBuilder);
// In case of WebRender, we expand the outer size to include the dynamic
// toolbar area here.
// In case of non WebRender, we expand the size dynamically in
// MoveScrollbarForLayerMargin in AsyncCompositionManager.cpp.
WebRenderLayerManager* layerManager = aBuilder->GetWidgetLayerManager();
if (layerManager) {
displaySize.height += ViewAs<LayoutDevicePixel>(
PresContext()->GetDynamicToolbarMaxHeight(),
PixelCastJustification::LayoutDeviceIsScreenForBounds);
}
return LayoutDeviceSize::ToAppUnits(displaySize,
PresContext()->AppUnitsPerDevPixel());
}
void nsHTMLScrollFrame::UpdateMinimumScaleSize(
const nsRect& aScrollableOverflow, const nsSize& aICBSize) {
MOZ_ASSERT(mIsRoot);
AutoMinimumScaleSizeChangeDetector minimumScaleSizeChangeDetector(this);
mIsUsingMinimumScaleSize = false;
if (!PresShell()->UsesMobileViewportSizing()) {
return;
}
nsPresContext* pc = PresContext();
MOZ_ASSERT(pc->IsRootContentDocumentCrossProcess(),
"The pres context should be for the root content document");
RefPtr<MobileViewportManager> manager =
PresShell()->GetMobileViewportManager();
MOZ_ASSERT(manager);
ScreenIntSize displaySize = ViewAs<ScreenPixel>(
manager->DisplaySize(),
PixelCastJustification::LayoutDeviceIsScreenForBounds);
if (displaySize.width == 0 || displaySize.height == 0) {
return;
}
if (aScrollableOverflow.IsEmpty()) {
// Bail if the scrollable overflow rect is empty, as we're going to be
// dividing by it.
return;
}
Document* doc = pc->Document();
MOZ_ASSERT(doc, "The document should be valid");
if (doc->GetFullscreenElement()) {
// Don't use the minimum scale size in the case of fullscreen state.
// FIXME: 1508177: We will no longer need this.
return;
}
nsViewportInfo viewportInfo = doc->GetViewportInfo(displaySize);
if (!viewportInfo.IsZoomAllowed()) {
// Don't apply the minimum scale size if user-scalable=no is specified.
return;
}
// The intrinsic minimum scale is the scale that fits the entire content
// width into the visual viewport.
CSSToScreenScale intrinsicMinScale(
displaySize.width / CSSRect::FromAppUnits(aScrollableOverflow).XMost());
// The scale used to compute the minimum-scale size is the larger of the
// intrinsic minimum and the min-scale from the meta viewport tag.
CSSToScreenScale minScale =
std::max(intrinsicMinScale, viewportInfo.GetMinZoom());
// The minimum-scale size is the size of the visual viewport when zoomed
// to be the minimum scale.
mMinimumScaleSize = CSSSize::ToAppUnits(ScreenSize(displaySize) / minScale);
// Ensure the minimum-scale size is never smaller than the ICB size.
// That could happen if a page has a meta viewport tag with large explicitly
// specified viewport dimensions (making the ICB large) and also a large
// minimum scale (making the min-scale size small).
mMinimumScaleSize = Max(aICBSize, mMinimumScaleSize);
mIsUsingMinimumScaleSize = true;
}
bool nsHTMLScrollFrame::ReflowFinished() {
mPostedReflowCallback = false;
TryScheduleScrollAnimations();
if (mIsRoot) {
if (mMinimumScaleSizeChanged && PresShell()->UsesMobileViewportSizing() &&
!PresShell()->IsResolutionUpdatedByApz()) {
RefPtr<MobileViewportManager> manager =
PresShell()->GetMobileViewportManager();
MOZ_ASSERT(manager);
manager->ShrinkToDisplaySizeIfNeeded();
mMinimumScaleSizeChanged = false;
}
if (!UsesOverlayScrollbars()) {
// Layout scrollbars may have added or removed during reflow, so let's
// update the visual viewport accordingly. Note that this may be a no-op
// because we might have recomputed the visual viewport size during the
// reflow itself, just before laying out the fixed-pos items. But there
// might be cases where that code doesn't run, so this is a sort of
// backstop to ensure we do that recomputation.
if (RefPtr<MobileViewportManager> manager =
PresShell()->GetMobileViewportManager()) {
manager->UpdateVisualViewportSizeForPotentialScrollbarChange();
}
}
#if defined(MOZ_WIDGET_ANDROID)
const bool hasVerticalOverflow =
GetOverflowState() & OverflowState::Vertical &&
GetScrollStyles().mVertical != StyleOverflow::Hidden;
if (!mFirstReflow && mHasVerticalOverflowForDynamicToolbar &&
!hasVerticalOverflow) {
PresShell()->MaybeNotifyShowDynamicToolbar();
}
mHasVerticalOverflowForDynamicToolbar = hasVerticalOverflow;
#endif // defined(MOZ_WIDGET_ANDROID)
}
bool doScroll = true;
if (IsSubtreeDirty()) {
// We will get another call after the next reflow and scrolling
// later is less janky.
doScroll = false;
}
if (mFirstReflow) {
nsPoint currentScrollPos = GetScrollPosition();
if (!mScrollUpdates.IsEmpty() &&
mScrollUpdates.LastElement().GetOrigin() == ScrollOrigin::None &&
currentScrollPos != nsPoint()) {
// With frame reconstructions, the reconstructed frame may have a nonzero
// scroll position by the end of the reflow, but without going through
// RestoreState. In particular this can happen with RTL XUL scrollframes,
// see https://bugzilla.mozilla.org/show_bug.cgi?id=1664638#c14.
// Upon construction, the nsHTMLScrollFrame constructor will have inserted
// a ScrollPositionUpdate into mScrollUpdates with origin None and a zero
// scroll position, but here we update that to hold the correct scroll
// position. Otherwise APZ may end up resetting the scroll position to
// zero incorrectly. If we ever hit this codepath, it must be on a reflow
// immediately following the scrollframe construction, so there should be
// exactly one ScrollPositionUpdate in mScrollUpdates.
MOZ_ASSERT(mScrollUpdates.Length() == 1);
MOZ_ASSERT(mScrollUpdates.LastElement().GetGeneration() ==
mScrollGeneration);
MOZ_ASSERT(mScrollUpdates.LastElement().GetDestination() == CSSPoint());
SCROLLRESTORE_LOG("%p: updating initial SPU to pos %s\n", this,
ToString(currentScrollPos).c_str());
mScrollUpdates.Clear();
AppendScrollUpdate(
ScrollPositionUpdate::NewScrollframe(currentScrollPos));
}
mFirstReflow = false;
}
nsAutoScriptBlocker scriptBlocker;
if (mReclampVVOffsetInReflowFinished) {
MOZ_ASSERT(mIsRoot && PresShell()->IsVisualViewportOffsetSet());
mReclampVVOffsetInReflowFinished = false;
AutoWeakFrame weakFrame(this);
PresShell()->SetVisualViewportOffset(PresShell()->GetVisualViewportOffset(),
GetScrollPosition());
NS_ENSURE_TRUE(weakFrame.IsAlive(), false);
}
if (doScroll) {
ScrollToRestoredPosition();
// Clamp current scroll position to new bounds. Normally this won't
// do anything.
nsPoint currentScrollPos = GetScrollPosition();
ScrollToImpl(currentScrollPos, nsRect(currentScrollPos, nsSize(0, 0)),
ScrollOrigin::Clamp);
if (ScrollAnimationState().isEmpty()) {
// We need to have mDestination track the current scroll position,
// in case it falls outside the new reflow area. mDestination is used
// by ScrollBy as its starting position.
mDestination = GetScrollPosition();
}
}
if (!mUpdateScrollbarAttributes) {
return false;
}
mUpdateScrollbarAttributes = false;
// Update scrollbar attributes.
if (mMayHaveDirtyFixedChildren) {
mMayHaveDirtyFixedChildren = false;
nsIFrame* parentFrame = GetParent();
for (nsIFrame* fixedChild =
parentFrame->GetChildList(FrameChildListID::Fixed).FirstChild();
fixedChild; fixedChild = fixedChild->GetNextSibling()) {
// force a reflow of the fixed child
PresShell()->FrameNeedsReflow(fixedChild, IntrinsicDirty::None,
NS_FRAME_HAS_DIRTY_CHILDREN);
}
}
// Suppress handling of the curpos attribute changes we make here.
NS_ASSERTION(!mFrameIsUpdatingScrollbar, "We shouldn't be reentering here");
mFrameIsUpdatingScrollbar = true;
// FIXME(emilio): Why this instead of mHScrollbarContent / mVScrollbarContent?
RefPtr<Element> vScroll =
mVScrollbarBox ? mVScrollbarBox->GetContent()->AsElement() : nullptr;
RefPtr<Element> hScroll =
mHScrollbarBox ? mHScrollbarBox->GetContent()->AsElement() : nullptr;
// Note, in some cases this may get deleted while finishing reflow
// for scrollbars. XXXmats is this still true now that we have a script
// blocker in this scope? (if not, remove the weak frame checks below).
if (vScroll || hScroll) {
nsSize visualViewportSize = GetVisualViewportSize();
nsRect scrollRange = GetVisualScrollRange();
nsPoint scrollPos = GetScrollPosition();
nsSize lineScrollAmount = GetLineScrollAmount();
if (gfxPlatform::UseDesktopZoomingScrollbars()) {
scrollRange = GetScrollRangeForUserInputEvents();
scrollPos = GetVisualViewportOffset();
}
// If modifying the logic here, be sure to modify the corresponding
// compositor-side calculation in ScrollThumbUtils::ApplyTransformForAxis().
AutoWeakFrame weakFrame(this);
if (vScroll) {
const double kScrollMultiplier =
StaticPrefs::toolkit_scrollbox_verticalScrollDistance();
nscoord increment = lineScrollAmount.height * kScrollMultiplier;
// We normally use (visualViewportSize.height - increment) for height of
// page scrolling. However, it is too small when increment is very large.
// (If increment is larger than visualViewportSize.height, direction of
// scrolling will be opposite). To avoid it, we use
// (float(visualViewportSize.height) * 0.8) as lower bound value of height
// of page scrolling. (bug 383267)
// XXX shouldn't we use GetPageScrollAmount here?
nscoord pageincrement = nscoord(visualViewportSize.height - increment);
nscoord pageincrementMin =
nscoord(float(visualViewportSize.height) * 0.8);
FinishReflowForScrollbar(
vScroll, scrollRange.y, scrollRange.YMost(), scrollPos.y,
std::max(pageincrement, pageincrementMin), increment);
}
if (hScroll) {
const double kScrollMultiplier =
StaticPrefs::toolkit_scrollbox_horizontalScrollDistance();
nscoord increment = lineScrollAmount.width * kScrollMultiplier;
FinishReflowForScrollbar(
hScroll, scrollRange.x, scrollRange.XMost(), scrollPos.x,
nscoord(float(visualViewportSize.width) * 0.8), increment);
}
NS_ENSURE_TRUE(weakFrame.IsAlive(), false);
}
mFrameIsUpdatingScrollbar = false;
// We used to rely on the curpos attribute changes above to scroll the
// view. However, for scrolling to the left of the viewport, we
// rescale the curpos attribute, which means that operations like
// resizing the window while it is scrolled all the way to the left
// hold the curpos attribute constant at 0 while still requiring
// scrolling. So we suppress the effect of the changes above with
// mFrameIsUpdatingScrollbar and call CurPosAttributeChanged here.
// (It actually even works some of the time without this, thanks to
// nsSliderFrame::AttributeChanged's handling of maxpos, but not when
// we hide the scrollbar on a large size change, such as
// maximization.)
if (!mHScrollbarBox && !mVScrollbarBox) {
return false;
}
CurPosAttributeChangedInternal(
mVScrollbarBox ? mVScrollbarBox->GetContent()->AsElement()
: mHScrollbarBox->GetContent()->AsElement(),
doScroll);
return doScroll;
}
void nsHTMLScrollFrame::ReflowCallbackCanceled() {
mPostedReflowCallback = false;
}
bool nsHTMLScrollFrame::ComputeCustomOverflow(OverflowAreas& aOverflowAreas) {
ScrollStyles ss = GetScrollStyles();
// Reflow when the change in overflow leads to one of our scrollbars
// changing or might require repositioning the scrolled content due to
// reduced extents.
nsRect scrolledRect = GetScrolledRect();
ScrollDirections overflowChange =
GetOverflowChange(scrolledRect, mPrevScrolledRect);
mPrevScrolledRect = scrolledRect;
bool needReflow = false;
nsPoint scrollPosition = GetScrollPosition();
if (overflowChange.contains(ScrollDirection::eHorizontal)) {
if (ss.mHorizontal != StyleOverflow::Hidden || scrollPosition.x) {
needReflow = true;
}
}
if (overflowChange.contains(ScrollDirection::eVertical)) {
if (ss.mVertical != StyleOverflow::Hidden || scrollPosition.y) {
needReflow = true;
}
}
if (needReflow) {
// If there are scrollbars, or we're not at the beginning of the pane,
// the scroll position may change. In this case, mark the frame as
// needing reflow. Don't use NS_FRAME_IS_DIRTY as dirty as that means
// we have to reflow the frame and all its descendants, and we don't
// have to do that here. Only this frame needs to be reflowed.
PresShell()->FrameNeedsReflow(this, IntrinsicDirty::None,
NS_FRAME_HAS_DIRTY_CHILDREN);
// Ensure that next time nsHTMLScrollFrame::Reflow runs, we don't skip
// updating the scrollbars. (Because the overflow area of the scrolled
// frame has probably just been updated, Reflow won't see it change.)
mSkippedScrollbarLayout = true;
return false; // reflowing will update overflow
}
PostOverflowEvent();
return nsContainerFrame::ComputeCustomOverflow(aOverflowAreas);
}
void nsHTMLScrollFrame::UpdateSticky() {
StickyScrollContainer* ssc =
StickyScrollContainer::GetStickyScrollContainerForScrollFrame(this);
if (ssc) {
ssc->UpdatePositions(GetScrollPosition(), this);
}
}
void nsHTMLScrollFrame::UpdatePrevScrolledRect() {
// The layout scroll range is determinated by the scrolled rect and the scroll
// port, so if the scrolled rect is updated, we may have to schedule the
// associated scroll-driven animations' restyles.
nsRect currScrolledRect = GetScrolledRect();
if (!currScrolledRect.IsEqualEdges(mPrevScrolledRect)) {
mMayScheduleScrollAnimations = true;
}
mPrevScrolledRect = currScrolledRect;
}
void nsHTMLScrollFrame::AdjustScrollbarRectForResizer(
nsIFrame* aFrame, nsPresContext* aPresContext, nsRect& aRect,
bool aHasResizer, ScrollDirection aDirection) {
if ((aDirection == ScrollDirection::eVertical ? aRect.width : aRect.height) ==
0) {
return;
}
// if a content resizer is present, use its size. Otherwise, check if the
// widget has a resizer.
nsRect resizerRect;
if (aHasResizer) {
resizerRect = mResizerBox->GetRect();
} else {
nsPoint offset;
nsIWidget* widget = aFrame->GetNearestWidget(offset);
LayoutDeviceIntRect widgetRect;
if (!widget || !widget->ShowsResizeIndicator(&widgetRect)) {
return;
}
resizerRect =
nsRect(aPresContext->DevPixelsToAppUnits(widgetRect.x) - offset.x,
aPresContext->DevPixelsToAppUnits(widgetRect.y) - offset.y,
aPresContext->DevPixelsToAppUnits(widgetRect.width),
aPresContext->DevPixelsToAppUnits(widgetRect.height));
}
if (resizerRect.Contains(aRect.BottomRight() - nsPoint(1, 1))) {
switch (aDirection) {
case ScrollDirection::eVertical:
aRect.height = std::max(0, resizerRect.y - aRect.y);
break;
case ScrollDirection::eHorizontal:
aRect.width = std::max(0, resizerRect.x - aRect.x);
break;
}
} else if (resizerRect.Contains(aRect.BottomLeft() + nsPoint(1, -1))) {
switch (aDirection) {
case ScrollDirection::eVertical:
aRect.height = std::max(0, resizerRect.y - aRect.y);
break;
case ScrollDirection::eHorizontal: {
nscoord xmost = aRect.XMost();
aRect.x = std::max(aRect.x, resizerRect.XMost());
aRect.width = xmost - aRect.x;
break;
}
}
}
}
static void AdjustOverlappingScrollbars(nsRect& aVRect, nsRect& aHRect) {
if (aVRect.IsEmpty() || aHRect.IsEmpty()) return;
const nsRect oldVRect = aVRect;
const nsRect oldHRect = aHRect;
if (oldVRect.Contains(oldHRect.BottomRight() - nsPoint(1, 1))) {
aHRect.width = std::max(0, oldVRect.x - oldHRect.x);
} else if (oldVRect.Contains(oldHRect.BottomLeft() - nsPoint(0, 1))) {
nscoord overlap = std::min(oldHRect.width, oldVRect.XMost() - oldHRect.x);
aHRect.x += overlap;
aHRect.width -= overlap;
}
if (oldHRect.Contains(oldVRect.BottomRight() - nsPoint(1, 1))) {
aVRect.height = std::max(0, oldHRect.y - oldVRect.y);
}
}
void nsHTMLScrollFrame::LayoutScrollbarPartAtRect(
const ScrollReflowInput& aState, ReflowInput& aKidReflowInput,
const nsRect& aRect) {
nsPresContext* pc = PresContext();
nsIFrame* kid = aKidReflowInput.mFrame;
const auto wm = kid->GetWritingMode();
ReflowOutput desiredSize(wm);
MOZ_ASSERT(!wm.IsVertical(),
"Scrollbar parts should have writing-mode: initial");
MOZ_ASSERT(!wm.IsInlineReversed(),
"Scrollbar parts should have writing-mode: initial");
// XXX Maybe get a meaningful container size or something. Shouldn't matter
// given our asserts above.
const nsSize containerSize;
aKidReflowInput.SetComputedISize(aRect.Width());
aKidReflowInput.SetComputedBSize(aRect.Height());
const LogicalPoint pos(wm, aRect.TopLeft(), containerSize);
const auto flags = ReflowChildFlags::Default;
nsReflowStatus status;
ReflowOutput kidDesiredSize(wm);
ReflowChild(kid, pc, kidDesiredSize, aKidReflowInput, wm, pos, containerSize,
flags, status);
FinishReflowChild(kid, pc, kidDesiredSize, &aKidReflowInput, wm, pos,
containerSize, flags);
}
void nsHTMLScrollFrame::LayoutScrollbars(ScrollReflowInput& aState,
const nsRect& aInsideBorderArea,
const nsRect& aOldScrollPort) {
NS_ASSERTION(!mSuppressScrollbarUpdate, "This should have been suppressed");
const bool scrollbarOnLeft = !IsScrollbarOnRight();
const bool overlayScrollbars = UsesOverlayScrollbars();
const bool overlayScrollBarsOnRoot = overlayScrollbars && mIsRoot;
const bool showVScrollbar = mVScrollbarBox && mHasVerticalScrollbar;
const bool showHScrollbar = mHScrollbarBox && mHasHorizontalScrollbar;
nsSize compositionSize = mScrollPort.Size();
if (overlayScrollBarsOnRoot) {
compositionSize = nsLayoutUtils::CalculateCompositionSizeForFrame(
this, false, &compositionSize);
}
nsPresContext* presContext = mScrolledFrame->PresContext();
nsRect vRect;
if (showVScrollbar) {
vRect.height =
overlayScrollBarsOnRoot ? compositionSize.height : mScrollPort.height;
vRect.y = mScrollPort.y;
if (scrollbarOnLeft) {
vRect.width = mScrollPort.x - aInsideBorderArea.x;
vRect.x = aInsideBorderArea.x;
} else {
vRect.width = aInsideBorderArea.XMost() - mScrollPort.XMost();
vRect.x = mScrollPort.x + compositionSize.width;
}
if (overlayScrollbars || mOnlyNeedVScrollbarToScrollVVInsideLV) {
const nscoord width = aState.VScrollbarPrefWidth();
// There is no space reserved for the layout scrollbar, it is currently
// not visible because it is positioned just outside the scrollport. But
// we know that it needs to be made visible so we shift it back in.
vRect.width += width;
if (!scrollbarOnLeft) {
vRect.x -= width;
}
}
}
nsRect hRect;
if (showHScrollbar) {
hRect.width =
overlayScrollBarsOnRoot ? compositionSize.width : mScrollPort.width;
hRect.x = mScrollPort.x;
hRect.height = aInsideBorderArea.YMost() - mScrollPort.YMost();
hRect.y = mScrollPort.y + compositionSize.height;
if (overlayScrollbars || mOnlyNeedHScrollbarToScrollVVInsideLV) {
const nscoord height = aState.HScrollbarPrefHeight();
hRect.height += height;
// There is no space reserved for the layout scrollbar, it is currently
// not visible because it is positioned just outside the scrollport. But
// we know that it needs to be made visible so we shift it back in.
hRect.y -= height;
}
}
const bool hasVisualOnlyScrollbarsOnBothDirections =
!overlayScrollbars && showHScrollbar &&
mOnlyNeedHScrollbarToScrollVVInsideLV && showVScrollbar &&
mOnlyNeedVScrollbarToScrollVVInsideLV;
nsPresContext* pc = PresContext();
// place the scrollcorner
if (mScrollCornerBox) {
nsRect r(0, 0, 0, 0);
if (scrollbarOnLeft) {
// scrollbar (if any) on left
r.width = showVScrollbar ? mScrollPort.x - aInsideBorderArea.x : 0;
r.x = aInsideBorderArea.x;
} else {
// scrollbar (if any) on right
r.width =
showVScrollbar ? aInsideBorderArea.XMost() - mScrollPort.XMost() : 0;
r.x = aInsideBorderArea.XMost() - r.width;
}
NS_ASSERTION(r.width >= 0, "Scroll area should be inside client rect");
if (showHScrollbar) {
// scrollbar (if any) on bottom
// Note we don't support the horizontal scrollbar at the top side.
r.height = aInsideBorderArea.YMost() - mScrollPort.YMost();
NS_ASSERTION(r.height >= 0, "Scroll area should be inside client rect");
}
r.y = aInsideBorderArea.YMost() - r.height;
// If we have layout scrollbars and both scrollbars are present and both are
// only needed to scroll the VV inside the LV then we need a scrollcorner
// but the above calculation will result in an empty rect, so adjust it.
if (r.IsEmpty() && hasVisualOnlyScrollbarsOnBothDirections) {
r.width = vRect.width;
r.height = hRect.height;
r.x = scrollbarOnLeft ? mScrollPort.x : mScrollPort.XMost() - r.width;
r.y = mScrollPort.YMost() - r.height;
}
ReflowInput scrollCornerRI(
pc, aState.mReflowInput, mScrollCornerBox,
LogicalSize(mScrollCornerBox->GetWritingMode(), r.Size()));
LayoutScrollbarPartAtRect(aState, scrollCornerRI, r);
}
if (mResizerBox) {
// If a resizer is present, get its size.
//
// TODO(emilio): Should this really account for scrollbar-width?
auto scrollbarWidth = nsLayoutUtils::StyleForScrollbar(this)
->StyleUIReset()
->ScrollbarWidth();
auto scrollbarSize = pc->Theme()->GetScrollbarSize(pc, scrollbarWidth,
nsITheme::Overlay::No);
ReflowInput resizerRI(pc, aState.mReflowInput, mResizerBox,
LogicalSize(mResizerBox->GetWritingMode()));
nsSize resizerMinSize = {resizerRI.ComputedMinWidth(),
resizerRI.ComputedMinHeight()};
nsRect r;
nscoord vScrollbarWidth = pc->DevPixelsToAppUnits(scrollbarSize);
r.width =
std::max(std::max(r.width, vScrollbarWidth), resizerMinSize.width);
r.x = scrollbarOnLeft ? aInsideBorderArea.x
: aInsideBorderArea.XMost() - r.width;
nscoord hScrollbarHeight = pc->DevPixelsToAppUnits(scrollbarSize);
r.height =
std::max(std::max(r.height, hScrollbarHeight), resizerMinSize.height);
r.y = aInsideBorderArea.YMost() - r.height;
LayoutScrollbarPartAtRect(aState, resizerRI, r);
}
// Note that AdjustScrollbarRectForResizer has to be called after the
// resizer has been laid out immediately above this because it gets the rect
// of the resizer frame.
if (mVScrollbarBox) {
AdjustScrollbarRectForResizer(this, presContext, vRect, mResizerBox,
ScrollDirection::eVertical);
}
if (mHScrollbarBox) {
AdjustScrollbarRectForResizer(this, presContext, hRect, mResizerBox,
ScrollDirection::eHorizontal);
}
// Layout scrollbars can overlap at this point if they are both present and
// both only needed to scroll the VV inside the LV.
if (!LookAndFeel::GetInt(LookAndFeel::IntID::AllowOverlayScrollbarsOverlap) ||
hasVisualOnlyScrollbarsOnBothDirections) {
AdjustOverlappingScrollbars(vRect, hRect);
}
if (mVScrollbarBox) {
ReflowInput vScrollbarRI(
pc, aState.mReflowInput, mVScrollbarBox,
LogicalSize(mVScrollbarBox->GetWritingMode(), vRect.Size()));
LayoutScrollbarPartAtRect(aState, vScrollbarRI, vRect);
}
if (mHScrollbarBox) {
ReflowInput hScrollbarRI(
pc, aState.mReflowInput, mHScrollbarBox,
LogicalSize(mHScrollbarBox->GetWritingMode(), hRect.Size()));
LayoutScrollbarPartAtRect(aState, hScrollbarRI, hRect);
}
// may need to update fixed position children of the viewport,
// if the client area changed size because of an incremental
// reflow of a descendant. (If the outer frame is dirty, the fixed
// children will be re-laid out anyway)
if (aOldScrollPort.Size() != mScrollPort.Size() &&
!HasAnyStateBits(NS_FRAME_IS_DIRTY) && mIsRoot) {
mMayHaveDirtyFixedChildren = true;
}
// post reflow callback to modify scrollbar attributes
mUpdateScrollbarAttributes = true;
if (!mPostedReflowCallback) {
PresShell()->PostReflowCallback(this);
mPostedReflowCallback = true;
}
}
#if DEBUG
static bool ShellIsAlive(nsWeakPtr& aWeakPtr) {
RefPtr<PresShell> presShell = do_QueryReferent(aWeakPtr);
return !!presShell;
}
#endif
void nsHTMLScrollFrame::SetScrollbarEnabled(Element* aElement,
nscoord aMaxPos) {
DebugOnly<nsWeakPtr> weakShell(do_GetWeakReference(PresShell()));
if (aMaxPos) {
aElement->UnsetAttr(kNameSpaceID_None, nsGkAtoms::disabled, true);
} else {
aElement->SetAttr(kNameSpaceID_None, nsGkAtoms::disabled, u"true"_ns, true);
}
MOZ_ASSERT(ShellIsAlive(weakShell), "pres shell was destroyed by scrolling");
}
void nsHTMLScrollFrame::SetCoordAttribute(Element* aElement, nsAtom* aAtom,
nscoord aSize) {
DebugOnly<nsWeakPtr> weakShell(do_GetWeakReference(PresShell()));
// convert to pixels
int32_t pixelSize = nsPresContext::AppUnitsToIntCSSPixels(aSize);
// only set the attribute if it changed.
nsAutoString newValue;
newValue.AppendInt(pixelSize);
if (aElement->AttrValueIs(kNameSpaceID_None, aAtom, newValue, eCaseMatters)) {
return;
}
AutoWeakFrame weakFrame(this);
RefPtr<Element> kungFuDeathGrip = aElement;
aElement->SetAttr(kNameSpaceID_None, aAtom, newValue, true);
MOZ_ASSERT(ShellIsAlive(weakShell), "pres shell was destroyed by scrolling");
if (!weakFrame.IsAlive()) {
return;
}
if (mScrollbarActivity &&
(mHasHorizontalScrollbar || mHasVerticalScrollbar)) {
RefPtr<ScrollbarActivity> scrollbarActivity(mScrollbarActivity);
scrollbarActivity->ActivityOccurred();
}
}
static void ReduceRadii(nscoord aXBorder, nscoord aYBorder, nscoord& aXRadius,
nscoord& aYRadius) {
// In order to ensure that the inside edge of the border has no
// curvature, we need at least one of its radii to be zero.
if (aXRadius <= aXBorder || aYRadius <= aYBorder) return;
// For any corner where we reduce the radii, preserve the corner's shape.
double ratio =
std::max(double(aXBorder) / aXRadius, double(aYBorder) / aYRadius);
aXRadius *= ratio;
aYRadius *= ratio;
}
/**
* Implement an override for nsIFrame::GetBorderRadii to ensure that
* the clipping region for the border radius does not clip the scrollbars.
*
* In other words, we require that the border radius be reduced until the
* inner border radius at the inner edge of the border is 0 wherever we
* have scrollbars.
*/
bool nsHTMLScrollFrame::GetBorderRadii(const nsSize& aFrameSize,
const nsSize& aBorderArea,
Sides aSkipSides,
nscoord aRadii[8]) const {
if (!nsContainerFrame::GetBorderRadii(aFrameSize, aBorderArea, aSkipSides,
aRadii)) {
return false;
}
// Since we can use GetActualScrollbarSizes (rather than
// GetDesiredScrollbarSizes) since this doesn't affect reflow, we
// probably should.
nsMargin sb = GetActualScrollbarSizes();
nsMargin border = GetUsedBorder();
if (sb.left > 0 || sb.top > 0) {
ReduceRadii(border.left, border.top, aRadii[eCornerTopLeftX],
aRadii[eCornerTopLeftY]);
}
if (sb.top > 0 || sb.right > 0) {
ReduceRadii(border.right, border.top, aRadii[eCornerTopRightX],
aRadii[eCornerTopRightY]);
}
if (sb.right > 0 || sb.bottom > 0) {
ReduceRadii(border.right, border.bottom, aRadii[eCornerBottomRightX],
aRadii[eCornerBottomRightY]);
}
if (sb.bottom > 0 || sb.left > 0) {
ReduceRadii(border.left, border.bottom, aRadii[eCornerBottomLeftX],
aRadii[eCornerBottomLeftY]);
}
return true;
}
static nscoord SnapCoord(nscoord aCoord, double aRes,
nscoord aAppUnitsPerPixel) {
double snappedToLayerPixels = NS_round((aRes * aCoord) / aAppUnitsPerPixel);
return NSToCoordRoundWithClamp(snappedToLayerPixels * aAppUnitsPerPixel /
aRes);
}
nsRect nsHTMLScrollFrame::GetScrolledRect() const {
nsRect result = GetUnsnappedScrolledRectInternal(
mScrolledFrame->ScrollableOverflowRect(), mScrollPort.Size());
#if 0
// This happens often enough.
if (result.width < mScrollPort.width || result.height < mScrollPort.height) {
NS_WARNING("Scrolled rect smaller than scrollport?");
}
#endif
// Expand / contract the result by up to half a layer pixel so that scrolling
// to the right / bottom edge does not change the layer pixel alignment of
// the scrolled contents.
if (result.x == 0 && result.y == 0 && result.width == mScrollPort.width &&
result.height == mScrollPort.height) {
// The edges that we would snap are already aligned with the scroll port,
// so we can skip all the work below.
return result;
}
// For that, we first convert the scroll port and the scrolled rect to rects
// relative to the reference frame, since that's the space where painting does
// snapping.
nsSize visualViewportSize = GetVisualViewportSize();
const nsIFrame* referenceFrame =
mReferenceFrameDuringPainting ? mReferenceFrameDuringPainting
: nsLayoutUtils::GetReferenceFrame(
const_cast<nsHTMLScrollFrame*>(this));
nsPoint toReferenceFrame = GetOffsetToCrossDoc(referenceFrame);
nsRect scrollPort(mScrollPort.TopLeft() + toReferenceFrame,
visualViewportSize);
nsRect scrolledRect = result + scrollPort.TopLeft();
if (scrollPort.Overflows() || scrolledRect.Overflows()) {
return result;
}
// Now, snap the bottom right corner of both of these rects.
// We snap to layer pixels, so we need to respect the layer's scale.
nscoord appUnitsPerDevPixel =
mScrolledFrame->PresContext()->AppUnitsPerDevPixel();
MatrixScales scale = GetPaintedLayerScaleForFrame(mScrolledFrame);
if (scale.xScale == 0 || scale.yScale == 0) {
scale = MatrixScales();
}
// Compute bounds for the scroll position, and computed the snapped scrolled
// rect from the scroll position bounds.
nscoord snappedScrolledAreaBottom =
SnapCoord(scrolledRect.YMost(), scale.yScale, appUnitsPerDevPixel);
nscoord snappedScrollPortBottom =
SnapCoord(scrollPort.YMost(), scale.yScale, appUnitsPerDevPixel);
nscoord maximumScrollOffsetY =
snappedScrolledAreaBottom - snappedScrollPortBottom;
result.SetBottomEdge(scrollPort.height + maximumScrollOffsetY);
if (GetScrolledFrameDir() == StyleDirection::Ltr) {
nscoord snappedScrolledAreaRight =
SnapCoord(scrolledRect.XMost(), scale.xScale, appUnitsPerDevPixel);
nscoord snappedScrollPortRight =
SnapCoord(scrollPort.XMost(), scale.xScale, appUnitsPerDevPixel);
nscoord maximumScrollOffsetX =
snappedScrolledAreaRight - snappedScrollPortRight;
result.SetRightEdge(scrollPort.width + maximumScrollOffsetX);
} else {
// In RTL, the scrolled area's right edge is at scrollPort.XMost(),
// and the scrolled area's x position is zero or negative. We want
// the right edge to stay flush with the scroll port, so we snap the
// left edge.
nscoord snappedScrolledAreaLeft =
SnapCoord(scrolledRect.x, scale.xScale, appUnitsPerDevPixel);
nscoord snappedScrollPortLeft =
SnapCoord(scrollPort.x, scale.xScale, appUnitsPerDevPixel);
nscoord minimumScrollOffsetX =
snappedScrolledAreaLeft - snappedScrollPortLeft;
result.SetLeftEdge(minimumScrollOffsetX);
}
return result;
}
StyleDirection nsHTMLScrollFrame::GetScrolledFrameDir() const {
// If the scrolled frame has unicode-bidi: plaintext, the paragraph
// direction set by the text content overrides the direction of the frame
if (mScrolledFrame->StyleTextReset()->mUnicodeBidi ==
StyleUnicodeBidi::Plaintext) {
if (nsIFrame* child = mScrolledFrame->PrincipalChildList().FirstChild()) {
return nsBidiPresUtils::ParagraphDirection(child) ==
mozilla::intl::BidiDirection::LTR
? StyleDirection::Ltr
: StyleDirection::Rtl;
}
}
return IsBidiLTR() ? StyleDirection::Ltr : StyleDirection::Rtl;
}
nsRect nsHTMLScrollFrame::GetUnsnappedScrolledRectInternal(
const nsRect& aScrolledOverflowArea, const nsSize& aScrollPortSize) const {
return nsLayoutUtils::GetScrolledRect(mScrolledFrame, aScrolledOverflowArea,
aScrollPortSize, GetScrolledFrameDir());
}
nsMargin nsHTMLScrollFrame::GetActualScrollbarSizes(
nsIScrollableFrame::ScrollbarSizesOptions
aOptions /* = nsIScrollableFrame::ScrollbarSizesOptions::NONE */)
const {
nsRect r = GetPaddingRectRelativeToSelf();
nsMargin m(mScrollPort.y - r.y, r.XMost() - mScrollPort.XMost(),
r.YMost() - mScrollPort.YMost(), mScrollPort.x - r.x);
if (aOptions == nsIScrollableFrame::ScrollbarSizesOptions::
INCLUDE_VISUAL_VIEWPORT_SCROLLBARS &&
!UsesOverlayScrollbars()) {
// If we are using layout scrollbars and they only exist to scroll the
// visual viewport then they do not take up any layout space (so the
// scrollport is the same as the padding rect) but they do cover everything
// below them so some callers may want to include this special type of
// scrollbars in the returned value.
if (mHScrollbarBox && mHasHorizontalScrollbar &&
mOnlyNeedHScrollbarToScrollVVInsideLV) {
m.bottom += mHScrollbarBox->GetRect().height;
}
if (mVScrollbarBox && mHasVerticalScrollbar &&
mOnlyNeedVScrollbarToScrollVVInsideLV) {
if (IsScrollbarOnRight()) {
m.right += mVScrollbarBox->GetRect().width;
} else {
m.left += mVScrollbarBox->GetRect().width;
}
}
}
return m;
}
void nsHTMLScrollFrame::SetScrollbarVisibility(nsIFrame* aScrollbar,
bool aVisible) {
nsScrollbarFrame* scrollbar = do_QueryFrame(aScrollbar);
if (scrollbar) {
// See if we have a mediator.
nsIScrollbarMediator* mediator = scrollbar->GetScrollbarMediator();
if (mediator) {
// Inform the mediator of the visibility change.
mediator->VisibilityChanged(aVisible);
}
}
}
nscoord nsHTMLScrollFrame::GetCoordAttribute(nsIFrame* aBox, nsAtom* aAtom,
nscoord aDefaultValue,
nscoord* aRangeStart,
nscoord* aRangeLength) {
if (aBox) {
nsIContent* content = aBox->GetContent();
nsAutoString value;
if (content->IsElement()) {
content->AsElement()->GetAttr(kNameSpaceID_None, aAtom, value);
}
if (!value.IsEmpty()) {
nsresult error;
// convert it to appunits
nscoord result =
nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
nscoord halfPixel = nsPresContext::CSSPixelsToAppUnits(0.5f);
// Any nscoord value that would round to the attribute value when
// converted to CSS pixels is allowed.
*aRangeStart = result - halfPixel;
*aRangeLength = halfPixel * 2 - 1;
return result;
}
}
// Only this exact default value is allowed.
*aRangeStart = aDefaultValue;
*aRangeLength = 0;
return aDefaultValue;
}
bool nsHTMLScrollFrame::IsLastScrollUpdateAnimating() const {
if (!mScrollUpdates.IsEmpty()) {
switch (mScrollUpdates.LastElement().GetMode()) {
case ScrollMode::Smooth:
case ScrollMode::SmoothMsd:
return true;
case ScrollMode::Instant:
case ScrollMode::Normal:
break;
}
}
return false;
}
bool nsHTMLScrollFrame::IsLastScrollUpdateTriggeredByScriptAnimating() const {
if (!mScrollUpdates.IsEmpty()) {
const ScrollPositionUpdate& lastUpdate = mScrollUpdates.LastElement();
if (lastUpdate.WasTriggeredByScript() &&
(mScrollUpdates.LastElement().GetMode() == ScrollMode::Smooth ||
mScrollUpdates.LastElement().GetMode() == ScrollMode::SmoothMsd)) {
return true;
}
}
return false;
}
using AnimationState = nsIScrollableFrame::AnimationState;
EnumSet<AnimationState> nsHTMLScrollFrame::ScrollAnimationState() const {
EnumSet<AnimationState> retval;
if (IsApzAnimationInProgress()) {
retval += AnimationState::APZInProgress;
if (mCurrentAPZScrollAnimationType ==
APZScrollAnimationType::TriggeredByScript) {
retval += AnimationState::TriggeredByScript;
}
}
if (mApzAnimationRequested) {
retval += AnimationState::APZRequested;
if (mApzAnimationTriggeredByScriptRequested) {
retval += AnimationState::TriggeredByScript;
}
}
if (IsLastScrollUpdateAnimating()) {
retval += AnimationState::APZPending;
if (IsLastScrollUpdateTriggeredByScriptAnimating()) {
retval += AnimationState::TriggeredByScript;
}
}
if (mAsyncScroll) {
retval += AnimationState::MainThread;
if (mAsyncScroll->WasTriggeredByScript()) {
retval += AnimationState::TriggeredByScript;
}
}
if (mAsyncSmoothMSDScroll) {
retval += AnimationState::MainThread;
if (mAsyncSmoothMSDScroll->WasTriggeredByScript()) {
retval += AnimationState::TriggeredByScript;
}
}
return retval;
}
void nsHTMLScrollFrame::ResetScrollInfoIfNeeded(
const MainThreadScrollGeneration& aGeneration,
const APZScrollGeneration& aGenerationOnApz,
APZScrollAnimationType aAPZScrollAnimationType,
InScrollingGesture aInScrollingGesture) {
if (aGeneration == mScrollGeneration) {
mLastScrollOrigin = ScrollOrigin::None;
mApzAnimationRequested = false;
mApzAnimationTriggeredByScriptRequested = false;
}
mScrollGenerationOnApz = aGenerationOnApz;
// We can reset this regardless of scroll generation, as this is only set
// here, as a response to APZ requesting a repaint.
mCurrentAPZScrollAnimationType = aAPZScrollAnimationType;
mInScrollingGesture = aInScrollingGesture;
}
UniquePtr<PresState> nsHTMLScrollFrame::SaveState() {
nsIScrollbarMediator* mediator = do_QueryFrame(GetScrolledFrame());
if (mediator) {
// child handles its own scroll state, so don't bother saving state here
return nullptr;
}
// Don't store a scroll state if we never have been scrolled or restored
// a previous scroll state, and we're not in the middle of a smooth scroll.
auto scrollAnimationState = ScrollAnimationState();
bool isScrollAnimating =
scrollAnimationState.contains(AnimationState::MainThread) ||
scrollAnimationState.contains(AnimationState::APZPending) ||
scrollAnimationState.contains(AnimationState::APZRequested);
if (!mHasBeenScrolled && !mDidHistoryRestore && !isScrollAnimating) {
return nullptr;
}
UniquePtr<PresState> state = NewPresState();
bool allowScrollOriginDowngrade =
!nsLayoutUtils::CanScrollOriginClobberApz(mLastScrollOrigin) ||
mAllowScrollOriginDowngrade;
// Save mRestorePos instead of our actual current scroll position, if it's
// valid and we haven't moved since the last update of mLastPos (same check
// that ScrollToRestoredPosition uses). This ensures if a reframe occurs
// while we're in the process of loading content to scroll to a restored
// position, we'll keep trying after the reframe. Similarly, if we're in the
// middle of a smooth scroll, store the destination so that when we restore
// we'll jump straight to the end of the scroll animation, rather than
// effectively dropping it. Note that the mRestorePos will override the
// smooth scroll destination if both are present.
nsPoint pt = GetLogicalVisualViewportOffset();
if (isScrollAnimating) {
pt = mDestination;
allowScrollOriginDowngrade = false;
}
SCROLLRESTORE_LOG("%p: SaveState, pt=%s, mLastPos=%s, mRestorePos=%s\n", this,
ToString(pt).c_str(), ToString(mLastPos).c_str(),
ToString(mRestorePos).c_str());
if (mRestorePos.y != -1 && pt == mLastPos) {
pt = mRestorePos;
}
state->scrollState() = pt;
state->allowScrollOriginDowngrade() = allowScrollOriginDowngrade;
if (mIsRoot) {
// Only save resolution properties for root scroll frames
state->resolution() = PresShell()->GetResolution();
}
return state;
}
NS_IMETHODIMP nsHTMLScrollFrame::RestoreState(PresState* aState) {
mRestorePos = aState->scrollState();
MOZ_ASSERT(mLastScrollOrigin == ScrollOrigin::None);
mAllowScrollOriginDowngrade = aState->allowScrollOriginDowngrade();
// When restoring state, we promote mLastScrollOrigin to a stronger value
// from the default of eNone, to restore the behaviour that existed when
// the state was saved. If mLastScrollOrigin was a weaker value previously,
// then mAllowScrollOriginDowngrade will be true, and so the combination of
// mAllowScrollOriginDowngrade and the stronger mLastScrollOrigin will allow
// the same types of scrolls as before. It might be possible to also just
// save and restore the mAllowScrollOriginDowngrade and mLastScrollOrigin
// values directly without this sort of fiddling. Something to try in the
// future or if we tinker with this code more.
mLastScrollOrigin = ScrollOrigin::Other;
mDidHistoryRestore = true;
mLastPos = mScrolledFrame ? GetLogicalVisualViewportOffset() : nsPoint(0, 0);
SCROLLRESTORE_LOG("%p: RestoreState, set mRestorePos=%s mLastPos=%s\n", this,
ToString(mRestorePos).c_str(), ToString(mLastPos).c_str());
// Resolution properties should only exist on root scroll frames.
MOZ_ASSERT(mIsRoot || aState->resolution() == 1.0);
if (mIsRoot) {
PresShell()->SetResolutionAndScaleTo(
aState->resolution(), ResolutionChangeOrigin::MainThreadRestore);
}
return NS_OK;
}
void nsHTMLScrollFrame::PostScrolledAreaEvent() {
if (mScrolledAreaEvent.IsPending()) {
return;
}
mScrolledAreaEvent = new ScrolledAreaEvent(this);
nsContentUtils::AddScriptRunner(mScrolledAreaEvent.get());
}
////////////////////////////////////////////////////////////////////////////////
// ScrolledArea change event dispatch
// TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230, bug 1535398)
MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP
nsHTMLScrollFrame::ScrolledAreaEvent::Run() {
if (mHelper) {
mHelper->FireScrolledAreaEvent();
}
return NS_OK;
}
void nsHTMLScrollFrame::FireScrolledAreaEvent() {
mScrolledAreaEvent.Forget();
InternalScrollAreaEvent event(true, eScrolledAreaChanged, nullptr);
RefPtr<nsPresContext> presContext = PresContext();
nsIContent* content = GetContent();
event.mArea = mScrolledFrame->ScrollableOverflowRectRelativeToParent();
if (RefPtr<Document> doc = content->GetUncomposedDoc()) {
// TODO: Bug 1506441
EventDispatcher::Dispatch(MOZ_KnownLive(ToSupports(doc)), presContext,
&event, nullptr);
}
}
ScrollDirections nsIScrollableFrame::GetAvailableScrollingDirections() const {
nscoord oneDevPixel =
GetScrolledFrame()->PresContext()->AppUnitsPerDevPixel();
ScrollDirections directions;
nsRect scrollRange = GetScrollRange();
if (scrollRange.width >= oneDevPixel) {
directions += ScrollDirection::eHorizontal;
}
if (scrollRange.height >= oneDevPixel) {
directions += ScrollDirection::eVertical;
}
return directions;
}
nsRect nsHTMLScrollFrame::GetScrollRangeForUserInputEvents() const {
// This function computes a scroll range based on a scrolled rect and scroll
// port defined as follows:
// scrollable rect = overflow:hidden ? layout viewport : scrollable rect
// scroll port = have visual viewport ? visual viewport : layout viewport
// The results in the same notion of scroll range that APZ uses (the combined
// effect of FrameMetrics::CalculateScrollRange() and
// nsLayoutUtils::CalculateScrollableRectForFrame).
ScrollStyles ss = GetScrollStyles();
nsPoint scrollPos = GetScrollPosition();
nsRect scrolledRect = GetScrolledRect();
if (StyleOverflow::Hidden == ss.mHorizontal) {
scrolledRect.width = mScrollPort.width;
scrolledRect.x = scrollPos.x;
}
if (StyleOverflow::Hidden == ss.mVertical) {
scrolledRect.height = mScrollPort.height;
scrolledRect.y = scrollPos.y;
}
nsSize scrollPort = GetVisualViewportSize();
nsRect scrollRange = scrolledRect;
scrollRange.width = std::max(scrolledRect.width - scrollPort.width, 0);
scrollRange.height = std::max(scrolledRect.height - scrollPort.height, 0);
return scrollRange;
}
ScrollDirections
nsHTMLScrollFrame::GetAvailableScrollingDirectionsForUserInputEvents() const {
nsRect scrollRange = GetScrollRangeForUserInputEvents();
// We check if there is at least one half of a screen pixel of scroll range to
// roughly match what apz does when it checks if the change in scroll position
// in screen pixels round to zero or not.
// (https://searchfox.org/mozilla-central/rev/2f09184ec781a2667feec87499d4b81b32b6c48e/gfx/layers/apz/src/AsyncPanZoomController.cpp#3210)
// This isn't quite half a screen pixel, it doesn't take into account CSS
// transforms, but should be good enough.
float halfScreenPixel =
GetScrolledFrame()->PresContext()->AppUnitsPerDevPixel() /
(PresShell()->GetCumulativeResolution() * 2.f);
ScrollDirections directions;
if (scrollRange.width >= halfScreenPixel) {
directions += ScrollDirection::eHorizontal;
}
if (scrollRange.height >= halfScreenPixel) {
directions += ScrollDirection::eVertical;
}
return directions;
}
/**
* Append scroll positions for valid snap positions into |aSnapInfo| if
* applicable.
*/
static void AppendScrollPositionsForSnap(
const nsIFrame* aFrame, const nsIFrame* aScrolledFrame,
const nsRect& aScrolledRect, const nsMargin& aScrollPadding,
const nsRect& aScrollRange, WritingMode aWritingModeOnScroller,
ScrollSnapInfo& aSnapInfo, nsHTMLScrollFrame::SnapTargetSet* aSnapTargets) {
ScrollSnapTargetId targetId = ScrollSnapUtils::GetTargetIdFor(aFrame);
nsRect snapArea =
ScrollSnapUtils::GetSnapAreaFor(aFrame, aScrolledFrame, aScrolledRect);
// Use the writing-mode on the target element if the snap area is larger than
// the snapport.
// https://drafts.csswg.org/css-scroll-snap/#snap-scope
WritingMode writingMode = ScrollSnapUtils::NeedsToRespectTargetWritingMode(
snapArea.Size(), aSnapInfo.mSnapportSize)
? aFrame->GetWritingMode()
: aWritingModeOnScroller;
// These snap range shouldn't be involved with scroll-margin since we just
// need the visible range of the target element.
if (snapArea.width > aSnapInfo.mSnapportSize.width) {
aSnapInfo.mXRangeWiderThanSnapport.AppendElement(
ScrollSnapInfo::ScrollSnapRange(snapArea.X(), snapArea.XMost(),
targetId));
}
if (snapArea.height > aSnapInfo.mSnapportSize.height) {
aSnapInfo.mYRangeWiderThanSnapport.AppendElement(
ScrollSnapInfo::ScrollSnapRange(snapArea.Y(), snapArea.YMost(),
targetId));
}
// Shift target rect position by the scroll padding to get the padded
// position thus we don't need to take account scroll-padding values in
// ScrollSnapUtils::GetSnapPointForDestination() when it gets called from
// the compositor thread.
snapArea.y -= aScrollPadding.top;
snapArea.x -= aScrollPadding.left;
LogicalRect logicalTargetRect(writingMode, snapArea, aSnapInfo.mSnapportSize);
LogicalSize logicalSnapportRect(writingMode, aSnapInfo.mSnapportSize);
LogicalRect logicalScrollRange(aWritingModeOnScroller, aScrollRange,
// The origin of this logical coordinate system
// what we need here is (0, 0), so we use an
// empty size.
nsSize());
Maybe<nscoord> blockDirectionPosition;
const nsStyleDisplay* styleDisplay = aFrame->StyleDisplay();
nscoord containerBSize = logicalSnapportRect.BSize(writingMode);
switch (styleDisplay->mScrollSnapAlign.block) {
case StyleScrollSnapAlignKeyword::None:
break;
case StyleScrollSnapAlignKeyword::Start:
blockDirectionPosition.emplace(
writingMode.IsVerticalRL() ? -logicalTargetRect.BStart(writingMode)
: logicalTargetRect.BStart(writingMode));
break;
case StyleScrollSnapAlignKeyword::End: {
nscoord candidate = std::clamp(
// What we need here is the scroll position instead of the snap
// position itself, so we need, for example, the top edge of the
// scroll port on horizontal-tb when the frame is positioned at
// the bottom edge of the scroll port. For this reason we subtract
// containerBSize from BEnd of the target and clamp it inside the
// scrollable range.
logicalTargetRect.BEnd(writingMode) - containerBSize,
logicalScrollRange.BStart(writingMode),
logicalScrollRange.BEnd(writingMode));
blockDirectionPosition.emplace(writingMode.IsVerticalRL() ? -candidate
: candidate);
break;
}
case StyleScrollSnapAlignKeyword::Center: {
nscoord targetCenter = (logicalTargetRect.BStart(writingMode) +
logicalTargetRect.BEnd(writingMode)) /
2;
nscoord halfSnapportSize = containerBSize / 2;
// Get the center of the target to align with the center of the snapport
// depending on direction.
nscoord candidate = std::clamp(targetCenter - halfSnapportSize,
logicalScrollRange.BStart(writingMode),
logicalScrollRange.BEnd(writingMode));
blockDirectionPosition.emplace(writingMode.IsVerticalRL() ? -candidate
: candidate);
break;
}
}
Maybe<nscoord> inlineDirectionPosition;
nscoord containerISize = logicalSnapportRect.ISize(writingMode);
switch (styleDisplay->mScrollSnapAlign.inline_) {
case StyleScrollSnapAlignKeyword::None:
break;
case StyleScrollSnapAlignKeyword::Start:
inlineDirectionPosition.emplace(
writingMode.IsInlineReversed()
? -logicalTargetRect.IStart(writingMode)
: logicalTargetRect.IStart(writingMode));
break;
case StyleScrollSnapAlignKeyword::End: {
nscoord candidate = std::clamp(
// Same as above BEnd case, we subtract containerISize.
//
// Note that the logical scroll range is mapped to [0, x] range even
// if it's in RTL contents. So for example, if the physical range is
// [-200, 0], it's mapped to [0, 200], i.e. IStart() is 0, IEnd() is
// 200. So we can just use std::clamp with the same arguments in both
// RTL/LTR cases.
logicalTargetRect.IEnd(writingMode) - containerISize,
logicalScrollRange.IStart(writingMode),
logicalScrollRange.IEnd(writingMode));
inlineDirectionPosition.emplace(
writingMode.IsInlineReversed() ? -candidate : candidate);
break;
}
case StyleScrollSnapAlignKeyword::Center: {
nscoord targetCenter = (logicalTargetRect.IStart(writingMode) +
logicalTargetRect.IEnd(writingMode)) /
2;
nscoord halfSnapportSize = containerISize / 2;
// Get the center of the target to align with the center of the snapport
// depending on direction.
nscoord candidate = std::clamp(targetCenter - halfSnapportSize,
logicalScrollRange.IStart(writingMode),
logicalScrollRange.IEnd(writingMode));
inlineDirectionPosition.emplace(
writingMode.IsInlineReversed() ? -candidate : candidate);
break;
}
}
if (blockDirectionPosition || inlineDirectionPosition) {
aSnapInfo.mSnapTargets.AppendElement(
writingMode.IsVertical()
? ScrollSnapInfo::SnapTarget(
std::move(blockDirectionPosition),
std::move(inlineDirectionPosition), std::move(snapArea),
styleDisplay->mScrollSnapStop, targetId)
: ScrollSnapInfo::SnapTarget(
std::move(inlineDirectionPosition),
std::move(blockDirectionPosition), std::move(snapArea),
styleDisplay->mScrollSnapStop, targetId));
if (aSnapTargets) {
aSnapTargets->EnsureInserted(aFrame->GetContent());
}
}
}
/**
* Collect the scroll positions corresponding to snap positions of frames in the
* subtree rooted at |aFrame|, relative to |aScrolledFrame|, into |aSnapInfo|.
*/
static void CollectScrollPositionsForSnap(
nsIFrame* aFrame, nsIFrame* aScrolledFrame, const nsRect& aScrolledRect,
const nsMargin& aScrollPadding, const nsRect& aScrollRange,
WritingMode aWritingModeOnScroller, ScrollSnapInfo& aSnapInfo,
nsHTMLScrollFrame::SnapTargetSet* aSnapTargets) {
// Snap positions only affect the nearest ancestor scroll container on the
// element's containing block chain.
nsIScrollableFrame* sf = do_QueryFrame(aFrame);
if (sf) {
return;
}
for (const auto& childList : aFrame->ChildLists()) {
for (nsIFrame* f : childList.mList) {
const nsStyleDisplay* styleDisplay = f->StyleDisplay();
if (styleDisplay->mScrollSnapAlign.inline_ !=
StyleScrollSnapAlignKeyword::None ||
styleDisplay->mScrollSnapAlign.block !=
StyleScrollSnapAlignKeyword::None) {
AppendScrollPositionsForSnap(
f, aScrolledFrame, aScrolledRect, aScrollPadding, aScrollRange,
aWritingModeOnScroller, aSnapInfo, aSnapTargets);
}
CollectScrollPositionsForSnap(
f, aScrolledFrame, aScrolledRect, aScrollPadding, aScrollRange,
aWritingModeOnScroller, aSnapInfo, aSnapTargets);
}
}
}
static nscoord ResolveScrollPaddingStyleValue(
const StyleRect<mozilla::NonNegativeLengthPercentageOrAuto>&
aScrollPaddingStyle,
Side aSide, const nsSize& aScrollPortSize) {
if (aScrollPaddingStyle.Get(aSide).IsAuto()) {
// https://drafts.csswg.org/css-scroll-snap-1/#valdef-scroll-padding-auto
return 0;
}
nscoord percentageBasis;
switch (aSide) {
case eSideTop:
case eSideBottom:
percentageBasis = aScrollPortSize.height;
break;
case eSideLeft:
case eSideRight:
percentageBasis = aScrollPortSize.width;
break;
}
return aScrollPaddingStyle.Get(aSide).AsLengthPercentage().Resolve(
percentageBasis);
}
static nsMargin ResolveScrollPaddingStyle(
const StyleRect<mozilla::NonNegativeLengthPercentageOrAuto>&
aScrollPaddingStyle,
const nsSize& aScrollPortSize) {
return nsMargin(ResolveScrollPaddingStyleValue(aScrollPaddingStyle, eSideTop,
aScrollPortSize),
ResolveScrollPaddingStyleValue(aScrollPaddingStyle,
eSideRight, aScrollPortSize),
ResolveScrollPaddingStyleValue(aScrollPaddingStyle,
eSideBottom, aScrollPortSize),
ResolveScrollPaddingStyleValue(aScrollPaddingStyle, eSideLeft,
aScrollPortSize));
}
nsMargin nsHTMLScrollFrame::GetScrollPadding() const {
nsIFrame* styleFrame = GetFrameForStyle();
if (!styleFrame) {
return nsMargin();
}
// The spec says percentage values are relative to the scroll port size.
// https://drafts.csswg.org/css-scroll-snap-1/#scroll-padding
return ResolveScrollPaddingStyle(styleFrame->StylePadding()->mScrollPadding,
GetScrollPortRect().Size());
}
layers::ScrollSnapInfo nsHTMLScrollFrame::ComputeScrollSnapInfo() {
ScrollSnapInfo result;
nsIFrame* scrollSnapFrame = GetFrameForStyle();
if (!scrollSnapFrame) {
return result;
}
const nsStyleDisplay* disp = scrollSnapFrame->StyleDisplay();
if (disp->mScrollSnapType.strictness == StyleScrollSnapStrictness::None) {
// We won't be snapping, short-circuit the computation.
return result;
}
WritingMode writingMode = GetWritingMode();
result.InitializeScrollSnapStrictness(writingMode, disp);
result.mSnapportSize = GetSnapportSize();
CollectScrollPositionsForSnap(
mScrolledFrame, mScrolledFrame, GetScrolledRect(), GetScrollPadding(),
GetLayoutScrollRange(), writingMode, result, &mSnapTargets);
return result;
}
layers::ScrollSnapInfo nsHTMLScrollFrame::GetScrollSnapInfo() {
// TODO(botond): Should we cache it?
return ComputeScrollSnapInfo();
}
Maybe<SnapTarget> nsHTMLScrollFrame::GetSnapPointForDestination(
ScrollUnit aUnit, ScrollSnapFlags aFlags, const nsPoint& aStartPos,
const nsPoint& aDestination) {
// We can release the strong references for the previous snap target
// elements here since calling this ComputeScrollSnapInfo means we are going
// to evaluate new snap points, thus there's no chance to generating
// nsIContent instances in between this function call and the function call
// for the (re-)evaluation.
mSnapTargets.Clear();
return ScrollSnapUtils::GetSnapPointForDestination(
ComputeScrollSnapInfo(), aUnit, aFlags, GetLayoutScrollRange(), aStartPos,
aDestination);
}
Maybe<SnapTarget> nsHTMLScrollFrame::GetSnapPointForResnap() {
// Same as in GetSnapPointForDestination, We can release the strong references
// for the previous snap targets here.
mSnapTargets.Clear();
nsIContent* focusedContent =
GetContent()->GetComposedDoc()->GetUnretargetedFocusedContent();
return ScrollSnapUtils::GetSnapPointForResnap(
ComputeScrollSnapInfo(), GetLayoutScrollRange(), GetScrollPosition(),
mLastSnapTargetIds, focusedContent);
}
bool nsHTMLScrollFrame::NeedsResnap() {
nsIContent* focusedContent =
GetContent()->GetComposedDoc()->GetUnretargetedFocusedContent();
return ScrollSnapUtils::GetSnapPointForResnap(
ComputeScrollSnapInfo(), GetLayoutScrollRange(),
GetScrollPosition(), mLastSnapTargetIds, focusedContent)
.isSome();
}
void nsHTMLScrollFrame::SetLastSnapTargetIds(
UniquePtr<ScrollSnapTargetIds> aIds) {
if (!aIds) {
mLastSnapTargetIds = nullptr;
return;
}
// This SetLastSnapTargetIds gets called asynchronously so that there's a race
// condition something like;
// 1) an async scroll operation triggered snapping to a point on an element
// 2) during the async scroll operation, the element got removed from this
// scroll container
// 3) re-snapping triggered
// 4) this SetLastSnapTargetIds got called
// In such case |aIds| are stale, we shouldn't use it.
for (const auto* idList : {&aIds->mIdsOnX, &aIds->mIdsOnY}) {
for (const auto id : *idList) {
if (!mSnapTargets.Contains(reinterpret_cast<nsIContent*>(id))) {
mLastSnapTargetIds = nullptr;
return;
}
}
}
mLastSnapTargetIds = std::move(aIds);
}
bool nsHTMLScrollFrame::IsLastSnappedTarget(const nsIFrame* aFrame) const {
ScrollSnapTargetId id = ScrollSnapUtils::GetTargetIdFor(aFrame);
MOZ_ASSERT(id != ScrollSnapTargetId::None,
"This function is supposed to be called for contents");
if (!mLastSnapTargetIds) {
return false;
}
return mLastSnapTargetIds->mIdsOnX.Contains(id) ||
mLastSnapTargetIds->mIdsOnY.Contains(id);
}
void nsHTMLScrollFrame::TryResnap() {
// If there's any async scroll is running or we are processing pan/touch
// gestures or scroll thumb dragging, don't clobber the scroll.
if (!ScrollAnimationState().isEmpty() ||
mInScrollingGesture == InScrollingGesture::Yes) {
return;
}
if (auto snapTarget = GetSnapPointForResnap()) {
// We are going to re-snap so that we need to clobber scroll anchoring.
mAnchor.UserScrolled();
// Snap to the nearest snap position if exists.
ScrollToWithOrigin(
snapTarget->mPosition, nullptr /* range */,
ScrollOperationParams{
IsSmoothScroll(ScrollBehavior::Auto) ? ScrollMode::SmoothMsd
: ScrollMode::Instant,
ScrollOrigin::Other, std::move(snapTarget->mTargetIds)});
}
}
void nsHTMLScrollFrame::PostPendingResnapIfNeeded(const nsIFrame* aFrame) {
if (!IsLastSnappedTarget(aFrame)) {
return;
}
PostPendingResnap();
}
void nsHTMLScrollFrame::PostPendingResnap() {
PresShell()->PostPendingScrollResnap(this);
}
nsIScrollableFrame::PhysicalScrollSnapAlign
nsHTMLScrollFrame::GetScrollSnapAlignFor(const nsIFrame* aFrame) const {
StyleScrollSnapAlignKeyword alignForY = StyleScrollSnapAlignKeyword::None;
StyleScrollSnapAlignKeyword alignForX = StyleScrollSnapAlignKeyword::None;
nsIFrame* styleFrame = GetFrameForStyle();
if (!styleFrame) {
return {alignForX, alignForY};
}
if (styleFrame->StyleDisplay()->mScrollSnapType.strictness ==
StyleScrollSnapStrictness::None) {
return {alignForX, alignForY};
}
const nsStyleDisplay* styleDisplay = aFrame->StyleDisplay();
if (styleDisplay->mScrollSnapAlign.inline_ ==
StyleScrollSnapAlignKeyword::None &&
styleDisplay->mScrollSnapAlign.block ==
StyleScrollSnapAlignKeyword::None) {
return {alignForX, alignForY};
}
nsSize snapAreaSize =
ScrollSnapUtils::GetSnapAreaFor(aFrame, mScrolledFrame, GetScrolledRect())
.Size();
const WritingMode writingMode =
ScrollSnapUtils::NeedsToRespectTargetWritingMode(snapAreaSize,
GetSnapportSize())
? aFrame->GetWritingMode()
: styleFrame->GetWritingMode();
switch (styleFrame->StyleDisplay()->mScrollSnapType.axis) {
case StyleScrollSnapAxis::X:
alignForX = writingMode.IsVertical()
? styleDisplay->mScrollSnapAlign.block
: styleDisplay->mScrollSnapAlign.inline_;
break;
case StyleScrollSnapAxis::Y:
alignForY = writingMode.IsVertical()
? styleDisplay->mScrollSnapAlign.inline_
: styleDisplay->mScrollSnapAlign.block;
break;
case StyleScrollSnapAxis::Block:
if (writingMode.IsVertical()) {
alignForX = styleDisplay->mScrollSnapAlign.block;
} else {
alignForY = styleDisplay->mScrollSnapAlign.block;
}
break;
case StyleScrollSnapAxis::Inline:
if (writingMode.IsVertical()) {
alignForY = styleDisplay->mScrollSnapAlign.inline_;
} else {
alignForX = styleDisplay->mScrollSnapAlign.inline_;
}
break;
case StyleScrollSnapAxis::Both:
if (writingMode.IsVertical()) {
alignForX = styleDisplay->mScrollSnapAlign.block;
alignForY = styleDisplay->mScrollSnapAlign.inline_;
} else {
alignForX = styleDisplay->mScrollSnapAlign.inline_;
alignForY = styleDisplay->mScrollSnapAlign.block;
}
break;
}
return {alignForX, alignForY};
}
bool nsHTMLScrollFrame::UsesOverlayScrollbars() const {
return PresContext()->UseOverlayScrollbars();
}
bool nsHTMLScrollFrame::DragScroll(WidgetEvent* aEvent) {
// Dragging is allowed while within a 20 pixel border. Note that device pixels
// are used so that the same margin is used even when zoomed in or out.
nscoord margin = 20 * PresContext()->AppUnitsPerDevPixel();
// Don't drag scroll for small scrollareas.
if (mScrollPort.width < margin * 2 || mScrollPort.height < margin * 2) {
return false;
}
// If willScroll is computed as false, then the frame is already scrolled as
// far as it can go in both directions. Return false so that an ancestor
// scrollframe can scroll instead.
bool willScroll = false;
nsPoint pnt =
nsLayoutUtils::GetEventCoordinatesRelativeTo(aEvent, RelativeTo{this});
nsPoint scrollPoint = GetScrollPosition();
nsRect rangeRect = GetLayoutScrollRange();
// Only drag scroll when a scrollbar is present.
nsPoint offset;
if (mHasHorizontalScrollbar) {
if (pnt.x >= mScrollPort.x && pnt.x <= mScrollPort.x + margin) {
offset.x = -margin;
if (scrollPoint.x > 0) {
willScroll = true;
}
} else if (pnt.x >= mScrollPort.XMost() - margin &&
pnt.x <= mScrollPort.XMost()) {
offset.x = margin;
if (scrollPoint.x < rangeRect.width) {
willScroll = true;
}
}
}
if (mHasVerticalScrollbar) {
if (pnt.y >= mScrollPort.y && pnt.y <= mScrollPort.y + margin) {
offset.y = -margin;
if (scrollPoint.y > 0) {
willScroll = true;
}
} else if (pnt.y >= mScrollPort.YMost() - margin &&
pnt.y <= mScrollPort.YMost()) {
offset.y = margin;
if (scrollPoint.y < rangeRect.height) {
willScroll = true;
}
}
}
if (offset.x || offset.y) {
ScrollToWithOrigin(
GetScrollPosition() + offset, nullptr /* range */,
ScrollOperationParams{ScrollMode::Normal, ScrollOrigin::Other});
}
return willScroll;
}
static nsSliderFrame* GetSliderFrame(nsIFrame* aScrollbarFrame) {
if (!aScrollbarFrame) {
return nullptr;
}
for (const auto& childList : aScrollbarFrame->ChildLists()) {
for (nsIFrame* frame : childList.mList) {
if (nsSliderFrame* sliderFrame = do_QueryFrame(frame)) {
return sliderFrame;
}
}
}
return nullptr;
}
static void AsyncScrollbarDragInitiated(uint64_t aDragBlockId,
nsIFrame* aScrollbar) {
if (nsSliderFrame* sliderFrame = GetSliderFrame(aScrollbar)) {
sliderFrame->AsyncScrollbarDragInitiated(aDragBlockId);
}
}
void nsHTMLScrollFrame::AsyncScrollbarDragInitiated(
uint64_t aDragBlockId, ScrollDirection aDirection) {
switch (aDirection) {
case ScrollDirection::eVertical:
::AsyncScrollbarDragInitiated(aDragBlockId, mVScrollbarBox);
break;
case ScrollDirection::eHorizontal:
::AsyncScrollbarDragInitiated(aDragBlockId, mHScrollbarBox);
break;
}
}
static void AsyncScrollbarDragRejected(nsIFrame* aScrollbar) {
if (nsSliderFrame* sliderFrame = GetSliderFrame(aScrollbar)) {
sliderFrame->AsyncScrollbarDragRejected();
}
}
void nsHTMLScrollFrame::AsyncScrollbarDragRejected() {
// We don't get told which scrollbar requested the async drag,
// so we notify both.
::AsyncScrollbarDragRejected(mHScrollbarBox);
::AsyncScrollbarDragRejected(mVScrollbarBox);
}
void nsHTMLScrollFrame::ApzSmoothScrollTo(
const nsPoint& aDestination, ScrollOrigin aOrigin,
ScrollTriggeredByScript aTriggeredByScript,
UniquePtr<ScrollSnapTargetIds> aSnapTargetIds) {
if (mApzSmoothScrollDestination == Some(aDestination)) {
// If we already sent APZ a smooth-scroll request to this
// destination (i.e. it was the last request
// we sent), then don't send another one because it is redundant.
// This is to avoid a scenario where pages do repeated scrollBy
// calls, incrementing the generation counter, and blocking APZ from
// syncing the scroll offset back to the main thread.
// Note that if we get two smooth-scroll requests to the same
// destination with some other scroll in between,
// mApzSmoothScrollDestination will get reset to Nothing() and so
// we shouldn't have the problem where this check discards a
// legitimate smooth-scroll.
return;
}
// The animation will be handled in the compositor, pass the
// information needed to start the animation and skip the main-thread
// animation for this scroll.
MOZ_ASSERT(aOrigin != ScrollOrigin::None);
mApzSmoothScrollDestination = Some(aDestination);
AppendScrollUpdate(ScrollPositionUpdate::NewSmoothScroll(
aOrigin, aDestination, aTriggeredByScript, std::move(aSnapTargetIds)));
nsIContent* content = GetContent();
if (!DisplayPortUtils::HasNonMinimalNonZeroDisplayPort(content)) {
// If this frame doesn't have a displayport then there won't be an
// APZC instance for it and so there won't be anything to process
// this smooth scroll request. We should set a displayport on this
// frame to force an APZC which can handle the request.
if (MOZ_LOG_TEST(sDisplayportLog, LogLevel::Debug)) {
mozilla::layers::ScrollableLayerGuid::ViewID viewID =
mozilla::layers::ScrollableLayerGuid::NULL_SCROLL_ID;
nsLayoutUtils::FindIDFor(content, &viewID);
MOZ_LOG(
sDisplayportLog, LogLevel::Debug,
("ApzSmoothScrollTo setting displayport on scrollId=%" PRIu64 "\n",
viewID));
}
DisplayPortUtils::CalculateAndSetDisplayPortMargins(
GetScrollTargetFrame(), DisplayPortUtils::RepaintMode::Repaint);
nsIFrame* frame = do_QueryFrame(GetScrollTargetFrame());
DisplayPortUtils::SetZeroMarginDisplayPortOnAsyncScrollableAncestors(frame);
}
// Schedule a paint to ensure that the frame metrics get updated on
// the compositor thread.
SchedulePaint();
}
bool nsHTMLScrollFrame::CanApzScrollInTheseDirections(
ScrollDirections aDirections) {
ScrollStyles styles = GetScrollStyles();
if (aDirections.contains(ScrollDirection::eHorizontal) &&
styles.mHorizontal == StyleOverflow::Hidden)
return false;
if (aDirections.contains(ScrollDirection::eVertical) &&
styles.mVertical == StyleOverflow::Hidden)
return false;
return true;
}
bool nsHTMLScrollFrame::SmoothScrollVisual(
const nsPoint& aVisualViewportOffset,
FrameMetrics::ScrollOffsetUpdateType aUpdateType) {
bool canDoApzSmoothScroll =
nsLayoutUtils::AsyncPanZoomEnabled(this) && WantAsyncScroll();
if (!canDoApzSmoothScroll) {
return false;
}
// Clamp the destination to the visual scroll range.
// There is a potential issue here, where |mDestination| is usually
// clamped to the layout scroll range, and so e.g. a subsequent
// window.scrollBy() may have an undesired effect. However, as this function
// is only called internally, this should not be a problem in practice.
// If it turns out to be, the fix would be:
// - add a new "destination" field that doesn't have to be clamped to
// the layout scroll range
// - clamp mDestination to the layout scroll range here
// - make sure ComputeScrollMetadata() picks up the former as the
// smooth scroll destination to send to APZ.
mDestination = GetVisualScrollRange().ClampPoint(aVisualViewportOffset);
UniquePtr<ScrollSnapTargetIds> snapTargetIds;
// Perform the scroll.
ApzSmoothScrollTo(mDestination,
aUpdateType == FrameMetrics::eRestore
? ScrollOrigin::Restore
: ScrollOrigin::Other,
ScrollTriggeredByScript::No, std::move(snapTargetIds));
return true;
}
bool nsHTMLScrollFrame::IsSmoothScroll(dom::ScrollBehavior aBehavior) const {
// The user smooth scrolling preference should be honored for any requested
// smooth scrolls. A requested smooth scroll when smooth scrolling is
// disabled should be equivalent to an instant scroll.
if (aBehavior == dom::ScrollBehavior::Instant ||
!nsLayoutUtils::IsSmoothScrollingEnabled()) {
return false;
}
if (aBehavior == dom::ScrollBehavior::Smooth) {
return true;
}
nsIFrame* styleFrame = GetFrameForStyle();
if (!styleFrame) {
return false;
}
return (aBehavior == dom::ScrollBehavior::Auto &&
styleFrame->StyleDisplay()->mScrollBehavior ==
StyleScrollBehavior::Smooth);
}
nsTArray<ScrollPositionUpdate> nsHTMLScrollFrame::GetScrollUpdates() const {
return mScrollUpdates.Clone();
}
void nsHTMLScrollFrame::AppendScrollUpdate(
const ScrollPositionUpdate& aUpdate) {
mScrollGeneration = aUpdate.GetGeneration();
mScrollUpdates.AppendElement(aUpdate);
}
void nsHTMLScrollFrame::ScheduleScrollAnimations() {
nsIContent* content = GetContent();
MOZ_ASSERT(content && content->IsElement(),
"The nsIScrollableFrame should have the element.");
const Element* elementOrPseudo = content->AsElement();
PseudoStyleType pseudo = elementOrPseudo->GetPseudoElementType();
if (pseudo != PseudoStyleType::NotPseudo &&
!AnimationUtils::IsSupportedPseudoForAnimations(pseudo)) {
// This is not an animatable pseudo element, and so we don't generate
// scroll-timeline for it.
return;
}
const auto [element, type] =
AnimationUtils::GetElementPseudoPair(elementOrPseudo);
const auto* scheduler = ProgressTimelineScheduler::Get(element, type);
if (!scheduler) {
// We don't have scroll timelines associated with this frame.
return;
}
scheduler->ScheduleAnimations();
}
