Revision 2c61e59a48af27c100c2dd2756b5efad573dbc71 authored by Otto Länd on 28 July 2024, 06:52:26 UTC, committed by Otto Länd on 28 July 2024, 06:52:26 UTC
# ignore-this-changeset
1 parent 65b1e66
ContentIterator.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/. */
#include "ContentIterator.h"
#include "mozilla/Assertions.h"
#include "mozilla/dom/ShadowRoot.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/RangeBoundary.h"
#include "mozilla/RangeUtils.h"
#include "mozilla/Result.h"
#include "nsContentUtils.h"
#include "nsElementTable.h"
#include "nsIContent.h"
#include "nsRange.h"
namespace mozilla {
using namespace dom;
#define NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(aResultType, aMethodName, ...) \
template aResultType ContentIteratorBase<RefPtr<nsINode>>::aMethodName( \
__VA_ARGS__); \
template aResultType ContentIteratorBase<nsINode*>::aMethodName(__VA_ARGS__)
static bool ComparePostMode(const RawRangeBoundary& aStart,
const RawRangeBoundary& aEnd, nsINode& aNode) {
nsINode* parent = aNode.GetParentNode();
if (!parent) {
return false;
}
// aNode should always be content, as we have a parent, but let's just be
// extra careful and check.
nsIContent* content =
NS_WARN_IF(!aNode.IsContent()) ? nullptr : aNode.AsContent();
// Post mode: start < node <= end.
RawRangeBoundary afterNode(parent, content);
const auto isStartLessThanAfterNode = [&]() {
const Maybe<int32_t> startComparedToAfterNode =
nsContentUtils::ComparePoints(aStart, afterNode);
return !NS_WARN_IF(!startComparedToAfterNode) &&
(*startComparedToAfterNode < 0);
};
const auto isAfterNodeLessOrEqualToEnd = [&]() {
const Maybe<int32_t> afterNodeComparedToEnd =
nsContentUtils::ComparePoints(afterNode, aEnd);
return !NS_WARN_IF(!afterNodeComparedToEnd) &&
(*afterNodeComparedToEnd <= 0);
};
return isStartLessThanAfterNode() && isAfterNodeLessOrEqualToEnd();
}
static bool ComparePreMode(const RawRangeBoundary& aStart,
const RawRangeBoundary& aEnd, nsINode& aNode) {
nsINode* parent = aNode.GetParentNode();
if (!parent) {
return false;
}
// Pre mode: start <= node < end.
RawRangeBoundary beforeNode(parent, aNode.GetPreviousSibling());
const auto isStartLessOrEqualToBeforeNode = [&]() {
const Maybe<int32_t> startComparedToBeforeNode =
nsContentUtils::ComparePoints(aStart, beforeNode);
return !NS_WARN_IF(!startComparedToBeforeNode) &&
(*startComparedToBeforeNode <= 0);
};
const auto isBeforeNodeLessThanEndNode = [&]() {
const Maybe<int32_t> beforeNodeComparedToEnd =
nsContentUtils::ComparePoints(beforeNode, aEnd);
return !NS_WARN_IF(!beforeNodeComparedToEnd) &&
(*beforeNodeComparedToEnd < 0);
};
return isStartLessOrEqualToBeforeNode() && isBeforeNodeLessThanEndNode();
}
///////////////////////////////////////////////////////////////////////////
// NodeIsInTraversalRange: returns true if content is visited during
// the traversal of the range in the specified mode.
//
static bool NodeIsInTraversalRange(nsINode* aNode, bool aIsPreMode,
const RawRangeBoundary& aStart,
const RawRangeBoundary& aEnd) {
if (NS_WARN_IF(!aStart.IsSet()) || NS_WARN_IF(!aEnd.IsSet()) ||
NS_WARN_IF(!aNode)) {
return false;
}
// If a leaf node contains an end point of the traversal range, it is
// always in the traversal range.
if (aNode == aStart.Container() || aNode == aEnd.Container()) {
if (aNode->IsCharacterData()) {
return true; // text node or something
}
if (!aNode->HasChildren()) {
MOZ_ASSERT(
aNode != aStart.Container() || aStart.IsStartOfContainer(),
"aStart.Container() doesn't have children and not a data node, "
"aStart should be at the beginning of its container");
MOZ_ASSERT(aNode != aEnd.Container() || aEnd.IsStartOfContainer(),
"aEnd.Container() doesn't have children and not a data node, "
"aEnd should be at the beginning of its container");
return true;
}
}
if (aIsPreMode) {
return ComparePreMode(aStart, aEnd, *aNode);
}
return ComparePostMode(aStart, aEnd, *aNode);
}
void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
PostContentIterator& aField, const char* aName,
uint32_t aFlags = 0) {
ImplCycleCollectionTraverse(
aCallback, static_cast<SafeContentIteratorBase&>(aField), aName, aFlags);
}
void ImplCycleCollectionUnlink(PostContentIterator& aField) {
ImplCycleCollectionUnlink(static_cast<SafeContentIteratorBase&>(aField));
}
void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
PreContentIterator& aField, const char* aName,
uint32_t aFlags = 0) {
ImplCycleCollectionTraverse(
aCallback, static_cast<SafeContentIteratorBase&>(aField), aName, aFlags);
}
void ImplCycleCollectionUnlink(PreContentIterator& aField) {
ImplCycleCollectionUnlink(static_cast<SafeContentIteratorBase&>(aField));
}
void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
ContentSubtreeIterator& aField,
const char* aName, uint32_t aFlags = 0) {
ImplCycleCollectionTraverse(aCallback, aField.mRange, aName, aFlags);
ImplCycleCollectionTraverse(
aCallback, static_cast<SafeContentIteratorBase&>(aField), aName, aFlags);
}
void ImplCycleCollectionUnlink(ContentSubtreeIterator& aField) {
ImplCycleCollectionUnlink(aField.mRange);
ImplCycleCollectionUnlink(static_cast<SafeContentIteratorBase&>(aField));
}
/******************************************************
* ContentIteratorBase
******************************************************/
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(, ContentIteratorBase, Order);
template <typename NodeType>
ContentIteratorBase<NodeType>::ContentIteratorBase(Order aOrder)
: mOrder(aOrder) {}
template ContentIteratorBase<RefPtr<nsINode>>::~ContentIteratorBase();
template ContentIteratorBase<nsINode*>::~ContentIteratorBase();
template <typename NodeType>
ContentIteratorBase<NodeType>::~ContentIteratorBase() {
MOZ_DIAGNOSTIC_ASSERT_IF(mMutationGuard.isSome(),
!mMutationGuard->Mutated(0));
}
/******************************************************
* Init routines
******************************************************/
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(nsresult, Init, nsINode*);
template <typename NodeType>
nsresult ContentIteratorBase<NodeType>::Init(nsINode* aRoot) {
if (NS_WARN_IF(!aRoot)) {
return NS_ERROR_NULL_POINTER;
}
if (mOrder == Order::Pre) {
mFirst = aRoot;
mLast = ContentIteratorBase::GetDeepLastChild(aRoot);
NS_WARNING_ASSERTION(mLast, "GetDeepLastChild returned null");
} else {
mFirst = ContentIteratorBase::GetDeepFirstChild(aRoot);
NS_WARNING_ASSERTION(mFirst, "GetDeepFirstChild returned null");
mLast = aRoot;
}
mClosestCommonInclusiveAncestor = aRoot;
mCurNode = mFirst;
return NS_OK;
}
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(nsresult, Init, AbstractRange*);
template <typename NodeType>
nsresult ContentIteratorBase<NodeType>::Init(AbstractRange* aRange) {
if (NS_WARN_IF(!aRange)) {
return NS_ERROR_INVALID_ARG;
}
if (NS_WARN_IF(!aRange->IsPositioned())) {
return NS_ERROR_INVALID_ARG;
}
return InitInternal(aRange->StartRef().AsRaw(), aRange->EndRef().AsRaw());
}
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(nsresult, Init, nsINode*, uint32_t,
nsINode*, uint32_t);
template <typename NodeType>
nsresult ContentIteratorBase<NodeType>::Init(nsINode* aStartContainer,
uint32_t aStartOffset,
nsINode* aEndContainer,
uint32_t aEndOffset) {
if (NS_WARN_IF(!RangeUtils::IsValidPoints(aStartContainer, aStartOffset,
aEndContainer, aEndOffset))) {
return NS_ERROR_INVALID_ARG;
}
return InitInternal(RawRangeBoundary(aStartContainer, aStartOffset),
RawRangeBoundary(aEndContainer, aEndOffset));
}
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(nsresult, Init, const RawRangeBoundary&,
const RawRangeBoundary&);
template <typename NodeType>
nsresult ContentIteratorBase<NodeType>::Init(const RawRangeBoundary& aStart,
const RawRangeBoundary& aEnd) {
if (NS_WARN_IF(!RangeUtils::IsValidPoints(aStart, aEnd))) {
return NS_ERROR_INVALID_ARG;
}
return InitInternal(aStart, aEnd);
}
template <typename NodeType>
class MOZ_STACK_CLASS ContentIteratorBase<NodeType>::Initializer final {
public:
Initializer(ContentIteratorBase<NodeType>& aIterator,
const RawRangeBoundary& aStart, const RawRangeBoundary& aEnd)
: mIterator{aIterator},
mStart{aStart},
mEnd{aEnd},
mStartIsCharacterData{mStart.Container()->IsCharacterData()} {
MOZ_ASSERT(mStart.IsSetAndValid());
MOZ_ASSERT(mEnd.IsSetAndValid());
}
nsresult Run();
private:
/**
* @return may be nullptr.
*/
nsINode* DetermineFirstNode() const;
/**
* @return may be nullptr.
*/
[[nodiscard]] Result<nsINode*, nsresult> DetermineLastNode() const;
bool IsCollapsedNonCharacterRange() const;
bool IsSingleNodeCharacterRange() const;
ContentIteratorBase& mIterator;
const RawRangeBoundary& mStart;
const RawRangeBoundary& mEnd;
const bool mStartIsCharacterData;
};
template <>
nsresult ContentIteratorBase<RefPtr<nsINode>>::InitInternal(
const RawRangeBoundary& aStart, const RawRangeBoundary& aEnd) {
Initializer initializer{*this, aStart, aEnd};
return initializer.Run();
}
template <>
nsresult ContentIteratorBase<nsINode*>::InitInternal(
const RawRangeBoundary& aStart, const RawRangeBoundary& aEnd) {
Initializer initializer{*this, aStart, aEnd};
nsresult rv = initializer.Run();
if (NS_FAILED(rv)) {
return rv;
}
mMutationGuard.emplace();
mAssertNoGC.emplace();
return NS_OK;
}
template <typename NodeType>
bool ContentIteratorBase<NodeType>::Initializer::IsCollapsedNonCharacterRange()
const {
return !mStartIsCharacterData && mStart == mEnd;
}
template <typename NodeType>
bool ContentIteratorBase<NodeType>::Initializer::IsSingleNodeCharacterRange()
const {
return mStartIsCharacterData && mStart.Container() == mEnd.Container();
}
template <typename NodeType>
nsresult ContentIteratorBase<NodeType>::Initializer::Run() {
// get common content parent
mIterator.mClosestCommonInclusiveAncestor =
nsContentUtils::GetClosestCommonInclusiveAncestor(mStart.Container(),
mEnd.Container());
if (NS_WARN_IF(!mIterator.mClosestCommonInclusiveAncestor)) {
return NS_ERROR_FAILURE;
}
// Check to see if we have a collapsed range, if so, there is nothing to
// iterate over.
//
// XXX: CharacterDataNodes (text nodes) are currently an exception, since
// we always want to be able to iterate text nodes at the end points
// of a range.
if (IsCollapsedNonCharacterRange()) {
mIterator.SetEmpty();
return NS_OK;
}
if (IsSingleNodeCharacterRange()) {
mIterator.mFirst = mStart.Container()->AsContent();
mIterator.mLast = mIterator.mFirst;
mIterator.mCurNode = mIterator.mFirst;
return NS_OK;
}
mIterator.mFirst = DetermineFirstNode();
if (Result<nsINode*, nsresult> lastNode = DetermineLastNode();
NS_WARN_IF(lastNode.isErr())) {
return lastNode.unwrapErr();
} else {
mIterator.mLast = lastNode.unwrap();
}
// If either first or last is null, they both have to be null!
if (!mIterator.mFirst || !mIterator.mLast) {
mIterator.SetEmpty();
}
mIterator.mCurNode = mIterator.mFirst;
return NS_OK;
}
template <typename NodeType>
nsINode* ContentIteratorBase<NodeType>::Initializer::DetermineFirstNode()
const {
nsIContent* cChild = nullptr;
// Try to get the child at our starting point. This might return null if
// mStart is immediately after the last node in mStart.Container().
if (!mStartIsCharacterData) {
cChild = mStart.GetChildAtOffset();
}
if (!cChild) {
// No children (possibly a <br> or text node), or index is after last child.
if (mIterator.mOrder == Order::Pre) {
// XXX: In the future, if start offset is after the last
// character in the cdata node, should we set mFirst to
// the next sibling?
// Normally we would skip the start node because the start node is outside
// of the range in pre mode. However, if aStartOffset == 0, and the node
// is a non-container node (e.g. <br>), we don't skip the node in this
// case in order to address bug 1215798.
bool startIsContainer = true;
if (mStart.Container()->IsHTMLElement()) {
nsAtom* name = mStart.Container()->NodeInfo()->NameAtom();
startIsContainer =
nsHTMLElement::IsContainer(nsHTMLTags::AtomTagToId(name));
}
if (!mStartIsCharacterData &&
(startIsContainer || !mStart.IsStartOfContainer())) {
nsINode* const result =
ContentIteratorBase::GetNextSibling(mStart.Container());
NS_WARNING_ASSERTION(result, "GetNextSibling returned null");
// Does mFirst node really intersect the range? The range could be
// 'degenerate', i.e., not collapsed but still contain no content.
if (result &&
NS_WARN_IF(!NodeIsInTraversalRange(
result, mIterator.mOrder == Order::Pre, mStart, mEnd))) {
return nullptr;
}
return result;
}
return mStart.Container()->AsContent();
}
// post-order
if (NS_WARN_IF(!mStart.Container()->IsContent())) {
// What else can we do?
return nullptr;
}
return mStart.Container()->AsContent();
}
if (mIterator.mOrder == Order::Pre) {
return cChild;
}
// post-order
nsINode* const result = ContentIteratorBase::GetDeepFirstChild(cChild);
NS_WARNING_ASSERTION(result, "GetDeepFirstChild returned null");
// Does mFirst node really intersect the range? The range could be
// 'degenerate', i.e., not collapsed but still contain no content.
if (result && !NodeIsInTraversalRange(result, mIterator.mOrder == Order::Pre,
mStart, mEnd)) {
return nullptr;
}
return result;
}
template <typename NodeType>
Result<nsINode*, nsresult>
ContentIteratorBase<NodeType>::Initializer::DetermineLastNode() const {
const bool endIsCharacterData = mEnd.Container()->IsCharacterData();
if (endIsCharacterData || !mEnd.Container()->HasChildren() ||
mEnd.IsStartOfContainer()) {
if (mIterator.mOrder == Order::Pre) {
if (NS_WARN_IF(!mEnd.Container()->IsContent())) {
// Not much else to do here...
return nullptr;
}
// If the end node is a non-container element and the end offset is 0,
// the last element should be the previous node (i.e., shouldn't
// include the end node in the range).
bool endIsContainer = true;
if (mEnd.Container()->IsHTMLElement()) {
nsAtom* name = mEnd.Container()->NodeInfo()->NameAtom();
endIsContainer =
nsHTMLElement::IsContainer(nsHTMLTags::AtomTagToId(name));
}
if (!endIsCharacterData && !endIsContainer && mEnd.IsStartOfContainer()) {
nsINode* const result = mIterator.PrevNode(mEnd.Container());
NS_WARNING_ASSERTION(result, "PrevNode returned null");
if (result && result != mIterator.mFirst &&
NS_WARN_IF(!NodeIsInTraversalRange(
result, mIterator.mOrder == Order::Pre,
RawRangeBoundary(mIterator.mFirst, 0u), mEnd))) {
return nullptr;
}
return result;
}
return mEnd.Container()->AsContent();
}
// post-order
//
// XXX: In the future, if end offset is before the first character in the
// cdata node, should we set mLast to the prev sibling?
if (!endIsCharacterData) {
nsINode* const result =
ContentIteratorBase::GetPrevSibling(mEnd.Container());
NS_WARNING_ASSERTION(result, "GetPrevSibling returned null");
if (!NodeIsInTraversalRange(result, mIterator.mOrder == Order::Pre,
mStart, mEnd)) {
return nullptr;
}
return result;
}
return mEnd.Container()->AsContent();
}
nsIContent* cChild = mEnd.Ref();
if (NS_WARN_IF(!cChild)) {
// No child at offset!
MOZ_ASSERT_UNREACHABLE("ContentIterator::ContentIterator");
return Err(NS_ERROR_FAILURE);
}
if (mIterator.mOrder == Order::Pre) {
nsINode* const result = ContentIteratorBase::GetDeepLastChild(cChild);
NS_WARNING_ASSERTION(result, "GetDeepLastChild returned null");
if (NS_WARN_IF(!NodeIsInTraversalRange(
result, mIterator.mOrder == Order::Pre, mStart, mEnd))) {
return nullptr;
}
return result;
}
// post-order
return cChild;
}
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(void, SetEmpty);
template <typename NodeType>
void ContentIteratorBase<NodeType>::SetEmpty() {
mCurNode = nullptr;
mFirst = nullptr;
mLast = nullptr;
mClosestCommonInclusiveAncestor = nullptr;
}
// static
template <typename NodeType>
nsINode* ContentIteratorBase<NodeType>::GetDeepFirstChild(nsINode* aRoot) {
if (NS_WARN_IF(!aRoot) || !aRoot->HasChildren()) {
return aRoot;
}
return ContentIteratorBase::GetDeepFirstChild(aRoot->GetFirstChild());
}
// static
template <typename NodeType>
nsIContent* ContentIteratorBase<NodeType>::GetDeepFirstChild(
nsIContent* aRoot, bool aAllowCrossShadowBoundary) {
if (NS_WARN_IF(!aRoot)) {
return nullptr;
}
nsIContent* node = aRoot;
nsIContent* child = nullptr;
if (ShadowRoot* shadowRoot = ShadowDOMSelectionHelpers::GetShadowRoot(
node, aAllowCrossShadowBoundary)) {
// When finding the deepest child of node, if this node has a
// web exposed shadow root, we use this shadow root to find the deepest
// child.
// If the first candidate should be a slotted content,
// shadowRoot->GetFirstChild() should be able to return the <slot> element.
// It's probably correct I think. Then it's up to the caller of this
// iterator to decide whether to use the slot's assigned nodes or not.
MOZ_ASSERT(aAllowCrossShadowBoundary);
child = shadowRoot->GetFirstChild();
} else {
child = node->GetFirstChild();
}
while (child) {
node = child;
if (ShadowRoot* shadowRoot = ShadowDOMSelectionHelpers::GetShadowRoot(
node, aAllowCrossShadowBoundary)) {
// When finding the deepest child of node, if this node has a
// web exposed shadow root, we use this shadow root to find the deepest
// child.
// If the first candidate should be a slotted content,
// shadowRoot->GetFirstChild() should be able to return the <slot>
// element. It's probably correct I think. Then it's up to the caller of
// this iterator to decide whether to use the slot's assigned nodes or
// not.
child = shadowRoot->GetFirstChild();
} else {
child = node->GetFirstChild();
}
}
return node;
}
// static
template <typename NodeType>
nsINode* ContentIteratorBase<NodeType>::GetDeepLastChild(nsINode* aRoot) {
if (NS_WARN_IF(!aRoot) || !aRoot->HasChildren()) {
return aRoot;
}
return ContentIteratorBase::GetDeepLastChild(aRoot->GetLastChild());
}
// static
template <typename NodeType>
nsIContent* ContentIteratorBase<NodeType>::GetDeepLastChild(
nsIContent* aRoot, bool aAllowCrossShadowBoundary) {
if (NS_WARN_IF(!aRoot)) {
return nullptr;
}
nsIContent* node = aRoot;
ShadowRoot* shadowRoot =
ShadowDOMSelectionHelpers::GetShadowRoot(node, aAllowCrossShadowBoundary);
// FIXME(sefeng): This doesn't work with slots / flattened tree.
while (node->HasChildren() || (shadowRoot && shadowRoot->HasChildren())) {
if (node->HasChildren()) {
node = node->GetLastChild();
} else {
MOZ_ASSERT(shadowRoot);
// If this node doesn't have a child, but it's also a shadow host
// that can be selected, we go into this shadow tree.
node = shadowRoot->GetLastChild();
}
shadowRoot = ShadowDOMSelectionHelpers::GetShadowRoot(
node, aAllowCrossShadowBoundary);
}
return node;
}
// Get the next sibling, or parent's next sibling, or shadow host's next
// sibling (when aAllowCrossShadowBoundary is true), or grandpa's next
// sibling...
//
// static
//
template <typename NodeType>
nsIContent* ContentIteratorBase<NodeType>::GetNextSibling(
nsINode* aNode, bool aAllowCrossShadowBoundary) {
if (NS_WARN_IF(!aNode)) {
return nullptr;
}
if (nsIContent* next = aNode->GetNextSibling()) {
return next;
}
nsINode* parent = ShadowDOMSelectionHelpers::GetParentNode(
*aNode, aAllowCrossShadowBoundary);
if (NS_WARN_IF(!parent)) {
return nullptr;
}
if (aAllowCrossShadowBoundary) {
// This is temporary solution.
// For shadow root, instead of getting to the sibling of the parent
// directly, we need to get into the light tree of the parent to handle
// slotted contents.
if (aNode->IsShadowRoot()) {
if (nsIContent* child = parent->GetFirstChild()) {
return child;
}
}
}
return ContentIteratorBase::GetNextSibling(parent, aAllowCrossShadowBoundary);
}
// Get the prev sibling, or parent's prev sibling, or shadow host's prev sibling
// (when aAllowCrossShadowBoundary is true), or grandpa's prev sibling... static
template <typename NodeType>
nsIContent* ContentIteratorBase<NodeType>::GetPrevSibling(
nsINode* aNode, bool aAllowCrossShadowBoundary) {
if (NS_WARN_IF(!aNode)) {
return nullptr;
}
if (nsIContent* prev = aNode->GetPreviousSibling()) {
return prev;
}
nsINode* parent = ShadowDOMSelectionHelpers::GetParentNode(
*aNode, aAllowCrossShadowBoundary);
if (NS_WARN_IF(!parent)) {
return nullptr;
}
return ContentIteratorBase::GetPrevSibling(parent, aAllowCrossShadowBoundary);
}
template <typename NodeType>
nsINode* ContentIteratorBase<NodeType>::NextNode(nsINode* aNode) {
nsINode* node = aNode;
// if we are a Pre-order iterator, use pre-order
if (mOrder == Order::Pre) {
// if it has children then next node is first child
if (node->HasChildren()) {
nsIContent* firstChild = node->GetFirstChild();
MOZ_ASSERT(firstChild);
return firstChild;
}
// else next sibling is next
return ContentIteratorBase::GetNextSibling(node);
}
// post-order
nsINode* parent = node->GetParentNode();
if (NS_WARN_IF(!parent)) {
MOZ_ASSERT(parent, "The node is the root node but not the last node");
mCurNode = nullptr;
return node;
}
if (nsIContent* sibling = node->GetNextSibling()) {
// next node is sibling's "deep left" child
return ContentIteratorBase::GetDeepFirstChild(sibling);
}
return parent;
}
template <typename NodeType>
nsINode* ContentIteratorBase<NodeType>::PrevNode(nsINode* aNode) {
nsINode* node = aNode;
// if we are a Pre-order iterator, use pre-order
if (mOrder == Order::Pre) {
nsINode* parent = node->GetParentNode();
if (NS_WARN_IF(!parent)) {
MOZ_ASSERT(parent, "The node is the root node but not the first node");
mCurNode = nullptr;
return aNode;
}
nsIContent* sibling = node->GetPreviousSibling();
if (sibling) {
return ContentIteratorBase::GetDeepLastChild(sibling);
}
return parent;
}
// post-order
if (node->HasChildren()) {
return node->GetLastChild();
}
// else prev sibling is previous
return ContentIteratorBase::GetPrevSibling(node);
}
/******************************************************
* ContentIteratorBase routines
******************************************************/
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(void, First);
template <typename NodeType>
void ContentIteratorBase<NodeType>::First() {
if (!mFirst) {
MOZ_ASSERT(IsDone());
mCurNode = nullptr;
return;
}
mozilla::DebugOnly<nsresult> rv = PositionAt(mFirst);
NS_ASSERTION(NS_SUCCEEDED(rv), "Failed to position iterator!");
}
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(void, Last);
template <typename NodeType>
void ContentIteratorBase<NodeType>::Last() {
// Note that mLast can be nullptr if SetEmpty() is called in Init()
// since at that time, Init() returns NS_OK.
if (!mLast) {
MOZ_ASSERT(IsDone());
mCurNode = nullptr;
return;
}
mozilla::DebugOnly<nsresult> rv = PositionAt(mLast);
NS_ASSERTION(NS_SUCCEEDED(rv), "Failed to position iterator!");
}
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(void, Next);
template <typename NodeType>
void ContentIteratorBase<NodeType>::Next() {
if (IsDone()) {
return;
}
if (mCurNode == mLast) {
mCurNode = nullptr;
return;
}
mCurNode = NextNode(mCurNode);
}
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(void, Prev);
template <typename NodeType>
void ContentIteratorBase<NodeType>::Prev() {
if (IsDone()) {
return;
}
if (mCurNode == mFirst) {
mCurNode = nullptr;
return;
}
mCurNode = PrevNode(mCurNode);
}
// Keeping arrays of indexes for the stack of nodes makes PositionAt
// interesting...
NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD(nsresult, PositionAt, nsINode*);
template <typename NodeType>
nsresult ContentIteratorBase<NodeType>::PositionAt(nsINode* aCurNode) {
if (NS_WARN_IF(!aCurNode)) {
return NS_ERROR_NULL_POINTER;
}
// take an early out if this doesn't actually change the position
if (mCurNode == aCurNode) {
return NS_OK;
}
mCurNode = aCurNode;
// Check to see if the node falls within the traversal range.
RawRangeBoundary first(mFirst, 0u);
RawRangeBoundary last(mLast, 0u);
if (mFirst && mLast) {
if (mOrder == Order::Pre) {
// In pre we want to record the point immediately before mFirst, which is
// the point immediately after mFirst's previous sibling.
first = {mFirst->GetParentNode(), mFirst->GetPreviousSibling()};
// If mLast has no children, then we want to make sure to include it.
if (!mLast->HasChildren()) {
last = {mLast->GetParentNode(), mLast->AsContent()};
}
} else {
// If the first node has any children, we want to be immediately after the
// last. Otherwise we want to be immediately before mFirst.
if (mFirst->HasChildren()) {
first = {mFirst, mFirst->GetLastChild()};
} else {
first = {mFirst->GetParentNode(), mFirst->GetPreviousSibling()};
}
// Set the last point immediately after the final node.
last = {mLast->GetParentNode(), mLast->AsContent()};
}
}
NS_WARNING_ASSERTION(first.IsSetAndValid(), "first is not valid");
NS_WARNING_ASSERTION(last.IsSetAndValid(), "last is not valid");
// The end positions are always in the range even if it has no parent. We
// need to allow that or 'iter->Init(root)' would assert in Last() or First()
// for example, bug 327694.
if (mFirst != mCurNode && mLast != mCurNode &&
(NS_WARN_IF(!first.IsSet()) || NS_WARN_IF(!last.IsSet()) ||
NS_WARN_IF(!NodeIsInTraversalRange(mCurNode, mOrder == Order::Pre, first,
last)))) {
mCurNode = nullptr;
return NS_ERROR_FAILURE;
}
return NS_OK;
}
/******************************************************
* ContentSubtreeIterator init routines
******************************************************/
nsresult ContentSubtreeIterator::Init(nsINode* aRoot) {
return NS_ERROR_NOT_IMPLEMENTED;
}
nsresult ContentSubtreeIterator::Init(AbstractRange* aRange) {
MOZ_ASSERT(aRange);
if (NS_WARN_IF(!aRange->IsPositioned())) {
return NS_ERROR_INVALID_ARG;
}
mRange = aRange;
return InitWithRange();
}
nsresult ContentSubtreeIterator::Init(nsINode* aStartContainer,
uint32_t aStartOffset,
nsINode* aEndContainer,
uint32_t aEndOffset) {
return Init(RawRangeBoundary(aStartContainer, aStartOffset),
RawRangeBoundary(aEndContainer, aEndOffset));
}
nsresult ContentSubtreeIterator::Init(const RawRangeBoundary& aStartBoundary,
const RawRangeBoundary& aEndBoundary) {
RefPtr<nsRange> range =
nsRange::Create(aStartBoundary, aEndBoundary, IgnoreErrors());
if (NS_WARN_IF(!range) || NS_WARN_IF(!range->IsPositioned())) {
return NS_ERROR_INVALID_ARG;
}
if (NS_WARN_IF(range->StartRef() != aStartBoundary) ||
NS_WARN_IF(range->EndRef() != aEndBoundary)) {
return NS_ERROR_UNEXPECTED;
}
mRange = std::move(range);
return InitWithRange();
}
nsresult ContentSubtreeIterator::InitWithAllowCrossShadowBoundary(
AbstractRange* aRange) {
MOZ_ASSERT(aRange);
if (NS_WARN_IF(!aRange->IsPositioned())) {
return NS_ERROR_INVALID_ARG;
}
mRange = aRange;
mAllowCrossShadowBoundary = AllowRangeCrossShadowBoundary::Yes;
return InitWithRange();
}
void ContentSubtreeIterator::CacheInclusiveAncestorsOfEndContainer() {
mInclusiveAncestorsOfEndContainer.Clear();
nsINode* const endContainer = ShadowDOMSelectionHelpers::GetEndContainer(
mRange, IterAllowCrossShadowBoundary());
nsIContent* endNode =
endContainer->IsContent() ? endContainer->AsContent() : nullptr;
while (endNode) {
mInclusiveAncestorsOfEndContainer.AppendElement(endNode);
// Cross the boundary for contents in shadow tree.
nsINode* parent = ShadowDOMSelectionHelpers::GetParentNode(
*endNode, IterAllowCrossShadowBoundary());
if (!parent || !parent->IsContent()) {
break;
}
endNode = parent->AsContent();
}
}
nsIContent* ContentSubtreeIterator::DetermineCandidateForFirstContent() const {
nsINode* startContainer = ShadowDOMSelectionHelpers::GetStartContainer(
mRange, IterAllowCrossShadowBoundary());
nsIContent* firstCandidate = nullptr;
// find first node in range
nsINode* node = nullptr;
if (!startContainer->GetChildCount()) {
// no children, start at the node itself
node = startContainer;
} else {
nsIContent* child =
IterAllowCrossShadowBoundary()
? mRange->GetMayCrossShadowBoundaryChildAtStartOffset()
: mRange->GetChildAtStartOffset();
MOZ_ASSERT(child == startContainer->GetChildAt_Deprecated(
ShadowDOMSelectionHelpers::StartOffset(
mRange, IterAllowCrossShadowBoundary())));
if (!child) {
// offset after last child
node = startContainer;
} else {
firstCandidate = child;
}
}
if (!firstCandidate) {
// then firstCandidate is next node after node
firstCandidate = ContentIteratorBase::GetNextSibling(
node, IterAllowCrossShadowBoundary());
}
if (firstCandidate) {
firstCandidate = ContentIteratorBase::GetDeepFirstChild(
firstCandidate, IterAllowCrossShadowBoundary());
}
return firstCandidate;
}
nsIContent* ContentSubtreeIterator::DetermineFirstContent() const {
nsIContent* firstCandidate = DetermineCandidateForFirstContent();
if (!firstCandidate) {
return nullptr;
}
// confirm that this first possible contained node is indeed contained. Else
// we have a range that does not fully contain any node.
const Maybe<bool> isNodeContainedInRange =
RangeUtils::IsNodeContainedInRange(*firstCandidate, mRange);
MOZ_ALWAYS_TRUE(isNodeContainedInRange);
if (!isNodeContainedInRange.value()) {
return nullptr;
}
// cool, we have the first node in the range. Now we walk up its ancestors
// to find the most senior that is still in the range. That's the real first
// node.
return GetTopAncestorInRange(firstCandidate);
}
nsIContent* ContentSubtreeIterator::DetermineCandidateForLastContent() const {
nsIContent* lastCandidate{nullptr};
nsINode* endContainer = ShadowDOMSelectionHelpers::GetEndContainer(
mRange, IterAllowCrossShadowBoundary());
// now to find the last node
int32_t offset = ShadowDOMSelectionHelpers::EndOffset(
mRange, IterAllowCrossShadowBoundary());
int32_t numChildren = endContainer->GetChildCount();
nsINode* node = nullptr;
if (offset > numChildren) {
// Can happen for text nodes
offset = numChildren;
}
if (!offset || !numChildren) {
node = endContainer;
} else {
lastCandidate = IterAllowCrossShadowBoundary()
? mRange->MayCrossShadowBoundaryEndRef().Ref()
: mRange->EndRef().Ref();
MOZ_ASSERT(lastCandidate == endContainer->GetChildAt_Deprecated(--offset));
NS_ASSERTION(lastCandidate,
"tree traversal trouble in ContentSubtreeIterator::Init");
}
if (!lastCandidate) {
// then lastCandidate is prev node before node
lastCandidate = ContentIteratorBase::GetPrevSibling(
node, IterAllowCrossShadowBoundary());
}
if (lastCandidate) {
lastCandidate = ContentIteratorBase::GetDeepLastChild(
lastCandidate, IterAllowCrossShadowBoundary());
}
return lastCandidate;
}
nsresult ContentSubtreeIterator::InitWithRange() {
MOZ_ASSERT(mRange);
MOZ_ASSERT(mRange->IsPositioned());
// get the start node and offset, convert to nsINode
mClosestCommonInclusiveAncestor =
mRange->GetClosestCommonInclusiveAncestor(mAllowCrossShadowBoundary);
nsINode* startContainer = ShadowDOMSelectionHelpers::GetStartContainer(
mRange, IterAllowCrossShadowBoundary());
const int32_t startOffset = ShadowDOMSelectionHelpers::StartOffset(
mRange, IterAllowCrossShadowBoundary());
nsINode* endContainer = ShadowDOMSelectionHelpers::GetEndContainer(
mRange, IterAllowCrossShadowBoundary());
const int32_t endOffset = ShadowDOMSelectionHelpers::EndOffset(
mRange, IterAllowCrossShadowBoundary());
MOZ_ASSERT(mClosestCommonInclusiveAncestor && startContainer && endContainer);
// Bug 767169
MOZ_ASSERT(uint32_t(startOffset) <= startContainer->Length() &&
uint32_t(endOffset) <= endContainer->Length());
// short circuit when start node == end node
if (startContainer == endContainer) {
nsINode* child = startContainer->GetFirstChild();
if (!child || startOffset == endOffset) {
// Text node, empty container, or collapsed
SetEmpty();
return NS_OK;
}
}
CacheInclusiveAncestorsOfEndContainer();
mFirst = DetermineFirstContent();
if (!mFirst) {
SetEmpty();
return NS_OK;
}
mLast = DetermineLastContent();
if (!mLast) {
SetEmpty();
return NS_OK;
}
mCurNode = mFirst;
return NS_OK;
}
nsIContent* ContentSubtreeIterator::DetermineLastContent() const {
nsIContent* lastCandidate = DetermineCandidateForLastContent();
if (!lastCandidate) {
return nullptr;
}
// confirm that this last possible contained node is indeed contained. Else
// we have a range that does not fully contain any node.
const Maybe<bool> isNodeContainedInRange =
RangeUtils::IsNodeContainedInRange(*lastCandidate, mRange);
MOZ_ALWAYS_TRUE(isNodeContainedInRange);
if (!isNodeContainedInRange.value()) {
return nullptr;
}
// cool, we have the last node in the range. Now we walk up its ancestors to
// find the most senior that is still in the range. That's the real first
// node.
return GetTopAncestorInRange(lastCandidate);
}
/****************************************************************
* ContentSubtreeIterator overrides of ContentIterator routines
****************************************************************/
// we can't call PositionAt in a subtree iterator...
void ContentSubtreeIterator::First() { mCurNode = mFirst; }
// we can't call PositionAt in a subtree iterator...
void ContentSubtreeIterator::Last() { mCurNode = mLast; }
void ContentSubtreeIterator::Next() {
if (IsDone()) {
return;
}
if (mCurNode == mLast) {
mCurNode = nullptr;
return;
}
nsINode* nextNode = ContentIteratorBase::GetNextSibling(
mCurNode, IterAllowCrossShadowBoundary());
NS_ASSERTION(nextNode, "No next sibling!?! This could mean deadlock!");
int32_t i = mInclusiveAncestorsOfEndContainer.IndexOf(nextNode);
while (i != -1) {
// as long as we are finding ancestors of the endpoint of the range,
// dive down into their children
ShadowRoot* root = ShadowDOMSelectionHelpers::GetShadowRoot(
nextNode, IterAllowCrossShadowBoundary());
if (!root) {
nextNode = nextNode->GetFirstChild();
} else {
// If IterAllowCrossShadowBoundary() returns true, it means we should
// use shadow-including order for this iterator, that means the shadow
// root should always be iterated.
nextNode = IterAllowCrossShadowBoundary() ? root->GetFirstChild()
: nextNode->GetFirstChild();
}
NS_ASSERTION(nextNode, "Iterator error, expected a child node!");
// should be impossible to get a null pointer. If we went all the way
// down the child chain to the bottom without finding an interior node,
// then the previous node should have been the last, which was
// was tested at top of routine.
i = mInclusiveAncestorsOfEndContainer.IndexOf(nextNode);
}
mCurNode = nextNode;
}
void ContentSubtreeIterator::Prev() {
// Prev should be optimized to use the mStartNodes, just as Next
// uses mInclusiveAncestorsOfEndContainer.
if (IsDone()) {
return;
}
if (mCurNode == mFirst) {
mCurNode = nullptr;
return;
}
// If any of these function calls return null, so will all succeeding ones,
// so mCurNode will wind up set to null.
nsINode* prevNode = ContentIteratorBase::GetDeepFirstChild(mCurNode);
prevNode = PrevNode(prevNode);
prevNode = ContentIteratorBase::GetDeepLastChild(prevNode);
mCurNode = GetTopAncestorInRange(prevNode);
}
nsresult ContentSubtreeIterator::PositionAt(nsINode* aCurNode) {
NS_ERROR("Not implemented!");
return NS_ERROR_NOT_IMPLEMENTED;
}
/****************************************************************
* ContentSubtreeIterator helper routines
****************************************************************/
nsIContent* ContentSubtreeIterator::GetTopAncestorInRange(
nsINode* aNode) const {
if (!aNode || !ShadowDOMSelectionHelpers::GetParentNode(
*aNode, IterAllowCrossShadowBoundary())) {
return nullptr;
}
// aNode has a parent, so it must be content.
nsIContent* content = aNode->AsContent();
// sanity check: aNode is itself in the range
Maybe<bool> isNodeContainedInRange =
RangeUtils::IsNodeContainedInRange(*aNode, mRange);
NS_ASSERTION(isNodeContainedInRange && isNodeContainedInRange.value(),
"aNode isn't in mRange, or something else weird happened");
if (!isNodeContainedInRange || !isNodeContainedInRange.value()) {
return nullptr;
}
nsIContent* lastContentInShadowTree = nullptr;
while (content) {
nsINode* parent = ShadowDOMSelectionHelpers::GetParentNode(
*content, IterAllowCrossShadowBoundary());
// content always has a parent. If its parent is the root, however --
// i.e., either it's not content, or it is content but its own parent is
// null -- then we're finished, since we don't go up to the root.
//
// Caveat: If iteration crossing shadow boundary is allowed
// and the root is a shadow root, we keep going up to the
// shadow host and continue.
//
// We have to special-case this because CompareNodeToRange treats the root
// node differently -- see bug 765205.
if (!parent || !ShadowDOMSelectionHelpers::GetParentNode(
*parent, IterAllowCrossShadowBoundary())) {
return content;
}
isNodeContainedInRange =
RangeUtils::IsNodeContainedInRange(*parent, mRange);
MOZ_ALWAYS_TRUE(isNodeContainedInRange);
if (!isNodeContainedInRange.value()) {
if (IterAllowCrossShadowBoundary() && content->IsShadowRoot()) {
MOZ_ASSERT(parent->GetShadowRoot() == content);
// host element is not in range, the last content in tree
// should be the ancestor.
MOZ_ASSERT(lastContentInShadowTree);
return lastContentInShadowTree;
}
return content;
}
// When we cross the boundary, we keep a reference to the
// last content that is in tree, because if we later
// find the shadow host element is not in the range, that means
// the last content in the tree should be top ancestor in range.
//
// Using shadow root doesn't make sense here because it doesn't
// represent a actual content.
if (IterAllowCrossShadowBoundary() && parent->IsShadowRoot()) {
lastContentInShadowTree = content;
}
content = parent->AsContent();
}
MOZ_CRASH("This should only be possible if aNode was null");
}
#undef NS_INSTANTIATE_CONTENT_ITER_BASE_METHOD
} // namespace mozilla
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