ReflowOutput.h
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/* struct containing the output from nsIFrame::Reflow */
#ifndef mozilla_ReflowOutput_h
#define mozilla_ReflowOutput_h
#include "mozilla/WritingModes.h"
#include "nsBoundingMetrics.h"
#include "nsRect.h"
//----------------------------------------------------------------------
namespace mozilla {
struct ReflowInput;
} // namespace mozilla
// Option flags
#define NS_REFLOW_CALC_BOUNDING_METRICS 0x0001
/**
* When we store overflow areas as an array of scrollable and visual
* overflow, we use these indices.
*
* eOverflowType_LENGTH is needed (for gcc 4.5.*, at least) to ensure
* that 2 is a valid value of nsOverflowType for use in
* NS_FOR_FRAME_OVERFLOW_TYPES.
*/
enum nsOverflowType { eVisualOverflow, eScrollableOverflow,
eOverflowType_LENGTH };
#define NS_FOR_FRAME_OVERFLOW_TYPES(var_) \
for (nsOverflowType var_ = nsOverflowType(0); var_ < 2; \
var_ = nsOverflowType(var_ + 1))
struct nsOverflowAreas {
private:
nsRect mRects[2];
public:
nsRect& Overflow(size_t aIndex) {
NS_ASSERTION(aIndex < 2, "index out of range");
return mRects[aIndex];
}
const nsRect& Overflow(size_t aIndex) const {
NS_ASSERTION(aIndex < 2, "index out of range");
return mRects[aIndex];
}
nsRect& VisualOverflow() { return mRects[eVisualOverflow]; }
const nsRect& VisualOverflow() const { return mRects[eVisualOverflow]; }
nsRect& ScrollableOverflow() { return mRects[eScrollableOverflow]; }
const nsRect& ScrollableOverflow() const { return mRects[eScrollableOverflow]; }
nsOverflowAreas() {
// default-initializes to zero due to nsRect's default constructor
}
nsOverflowAreas(const nsRect& aVisualOverflow,
const nsRect& aScrollableOverflow)
{
mRects[eVisualOverflow] = aVisualOverflow;
mRects[eScrollableOverflow] = aScrollableOverflow;
}
nsOverflowAreas(const nsOverflowAreas& aOther) {
*this = aOther;
}
nsOverflowAreas& operator=(const nsOverflowAreas& aOther) {
mRects[0] = aOther.mRects[0];
mRects[1] = aOther.mRects[1];
return *this;
}
bool operator==(const nsOverflowAreas& aOther) const {
// Scrollable overflow is a point-set rectangle and visual overflow
// is a pixel-set rectangle.
return VisualOverflow().IsEqualInterior(aOther.VisualOverflow()) &&
ScrollableOverflow().IsEqualEdges(aOther.ScrollableOverflow());
}
bool operator!=(const nsOverflowAreas& aOther) const {
return !(*this == aOther);
}
nsOverflowAreas operator+(const nsPoint& aPoint) const {
nsOverflowAreas result(*this);
result += aPoint;
return result;
}
nsOverflowAreas& operator+=(const nsPoint& aPoint) {
mRects[0] += aPoint;
mRects[1] += aPoint;
return *this;
}
void Clear() {
mRects[0].SetRect(0, 0, 0, 0);
mRects[1].SetRect(0, 0, 0, 0);
}
// Mutates |this| by unioning both overflow areas with |aOther|.
void UnionWith(const nsOverflowAreas& aOther);
// Mutates |this| by unioning both overflow areas with |aRect|.
void UnionAllWith(const nsRect& aRect);
// Mutates |this| by setting both overflow areas to |aRect|.
void SetAllTo(const nsRect& aRect);
};
/**
* An nsCollapsingMargin represents a vertical collapsing margin between
* blocks as described in section 8.3.1 of CSS2,
* <URL: http://www.w3.org/TR/REC-CSS2/box.html#collapsing-margins >.
*
* All adjacent vertical margins collapse, and the resulting margin is
* the sum of the largest positive margin included and the smallest (most
* negative) negative margin included.
*/
struct nsCollapsingMargin {
private:
nscoord mMostPos; // the largest positive margin included
nscoord mMostNeg; // the smallest negative margin included
public:
nsCollapsingMargin()
: mMostPos(0),
mMostNeg(0)
{
}
nsCollapsingMargin(const nsCollapsingMargin& aOther)
: mMostPos(aOther.mMostPos),
mMostNeg(aOther.mMostNeg)
{
}
bool operator==(const nsCollapsingMargin& aOther)
{
return mMostPos == aOther.mMostPos &&
mMostNeg == aOther.mMostNeg;
}
bool operator!=(const nsCollapsingMargin& aOther)
{
return !(*this == aOther);
}
nsCollapsingMargin& operator=(const nsCollapsingMargin& aOther)
{
mMostPos = aOther.mMostPos;
mMostNeg = aOther.mMostNeg;
return *this;
}
void Include(nscoord aCoord)
{
if (aCoord > mMostPos)
mMostPos = aCoord;
else if (aCoord < mMostNeg)
mMostNeg = aCoord;
}
void Include(const nsCollapsingMargin& aOther)
{
if (aOther.mMostPos > mMostPos)
mMostPos = aOther.mMostPos;
if (aOther.mMostNeg < mMostNeg)
mMostNeg = aOther.mMostNeg;
}
void Zero()
{
mMostPos = 0;
mMostNeg = 0;
}
bool IsZero() const
{
return (mMostPos == 0) && (mMostNeg == 0);
}
nscoord get() const
{
return mMostPos + mMostNeg;
}
};
namespace mozilla {
/**
* Reflow metrics used to return the frame's desired size and alignment
* information.
*
* @see #Reflow()
*/
class ReflowOutput {
public:
// XXXldb Should |aFlags| generally be passed from parent to child?
// Some places do it, and some don't. |aFlags| should perhaps go away
// entirely.
// XXX width/height/ascent are OUT parameters and so they shouldn't
// have to be initialized, but there are some bad frame classes that
// aren't properly setting them when returning from Reflow()...
explicit ReflowOutput(mozilla::WritingMode aWritingMode, uint32_t aFlags = 0)
: mISize(0)
, mBSize(0)
, mBlockStartAscent(ASK_FOR_BASELINE)
, mFlags(aFlags)
, mWritingMode(aWritingMode)
{}
explicit ReflowOutput(const ReflowInput& aState, uint32_t aFlags = 0);
// ISize and BSize are logical-coordinate dimensions:
// ISize is the size in the writing mode's inline direction (which equates to
// width in horizontal writing modes, height in vertical ones), and BSize is
// the size in the block-progression direction.
nscoord ISize(mozilla::WritingMode aWritingMode) const {
NS_ASSERTION(!aWritingMode.IsOrthogonalTo(mWritingMode),
"mismatched writing mode");
return mISize;
}
nscoord BSize(mozilla::WritingMode aWritingMode) const {
NS_ASSERTION(!aWritingMode.IsOrthogonalTo(mWritingMode),
"mismatched writing mode");
return mBSize;
}
mozilla::LogicalSize Size(mozilla::WritingMode aWritingMode) const {
NS_ASSERTION(!aWritingMode.IsOrthogonalTo(mWritingMode),
"mismatched writing mode");
return mozilla::LogicalSize(aWritingMode, mISize, mBSize);
}
nscoord& ISize(mozilla::WritingMode aWritingMode) {
NS_ASSERTION(!aWritingMode.IsOrthogonalTo(mWritingMode),
"mismatched writing mode");
return mISize;
}
nscoord& BSize(mozilla::WritingMode aWritingMode) {
NS_ASSERTION(!aWritingMode.IsOrthogonalTo(mWritingMode),
"mismatched writing mode");
return mBSize;
}
// Set inline and block size from a LogicalSize, converting to our
// writing mode as necessary.
void SetSize(mozilla::WritingMode aWM, mozilla::LogicalSize aSize)
{
mozilla::LogicalSize convertedSize = aSize.ConvertTo(mWritingMode, aWM);
mBSize = convertedSize.BSize(mWritingMode);
mISize = convertedSize.ISize(mWritingMode);
}
// Set both inline and block size to zero -- no need for a writing mode!
void ClearSize()
{
mISize = mBSize = 0;
}
// Width and Height are physical dimensions, independent of writing mode.
// Accessing these is slightly more expensive than accessing the logical
// dimensions (once vertical writing mode support is enabled); as far as
// possible, client code should work purely with logical dimensions.
nscoord Width() const { return mWritingMode.IsVertical() ? mBSize : mISize; }
nscoord Height() const { return mWritingMode.IsVertical() ? mISize : mBSize; }
// It's only meaningful to consider "ascent" on the block-start side of the
// frame, so no need to pass a writing mode argument
nscoord BlockStartAscent() const
{
return mBlockStartAscent;
}
nscoord& Width() { return mWritingMode.IsVertical() ? mBSize : mISize; }
nscoord& Height() { return mWritingMode.IsVertical() ? mISize : mBSize; }
nsSize PhysicalSize()
{
return Size(mWritingMode).GetPhysicalSize(mWritingMode);
}
void SetBlockStartAscent(nscoord aAscent)
{
mBlockStartAscent = aAscent;
}
enum { ASK_FOR_BASELINE = nscoord_MAX };
// Metrics that _exactly_ enclose the text to allow precise MathML placements.
// If the NS_REFLOW_CALC_BOUNDING_METRICS flag is set, then the caller is
// requesting that you also compute additional details about your inner
// bounding box and italic correction. For example, the bounding box of
// msup is the smallest rectangle that _exactly_ encloses both the text
// of the base and the text of the superscript.
nsBoundingMetrics mBoundingMetrics; // [OUT]
// Carried out block-end margin values. This is the collapsed
// (generational) block-end margin value.
nsCollapsingMargin mCarriedOutBEndMargin;
// For frames that have content that overflow their content area
// (HasOverflowAreas() is true) these rectangles represent the total
// area of the frame including visible overflow, i.e., don't include
// overflowing content that is hidden. The rects are in the local
// coordinate space of the frame, and should be at least as big as the
// desired size. If there is no content that overflows, then the
// overflow area is identical to the desired size and should be {0, 0,
// width, height}.
nsOverflowAreas mOverflowAreas;
nsRect& VisualOverflow()
{ return mOverflowAreas.VisualOverflow(); }
const nsRect& VisualOverflow() const
{ return mOverflowAreas.VisualOverflow(); }
nsRect& ScrollableOverflow()
{ return mOverflowAreas.ScrollableOverflow(); }
const nsRect& ScrollableOverflow() const
{ return mOverflowAreas.ScrollableOverflow(); }
// Set all of mOverflowAreas to (0, 0, width, height).
void SetOverflowAreasToDesiredBounds();
// Union all of mOverflowAreas with (0, 0, width, height).
void UnionOverflowAreasWithDesiredBounds();
mozilla::WritingMode GetWritingMode() const { return mWritingMode; }
private:
nscoord mISize, mBSize; // [OUT] desired width and height (border-box)
nscoord mBlockStartAscent; // [OUT] baseline (in Block direction), or ASK_FOR_BASELINE
public:
uint32_t mFlags;
private:
mozilla::WritingMode mWritingMode;
};
} // mozilla namespace
#endif // mozilla_ReflowOutput_h
