gecko-dev/dom/base/NodeIterator.cpp

243 строки
5.9 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* 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/. */
/*
* Implementation of DOM Traversal's NodeIterator
*/
#include "mozilla/dom/NodeIterator.h"
#include "nsError.h"
#include "nsIContent.h"
#include "nsIDocument.h"
#include "nsContentUtils.h"
#include "nsCOMPtr.h"
#include "mozilla/dom/NodeFilterBinding.h"
#include "mozilla/dom/NodeIteratorBinding.h"
namespace mozilla {
namespace dom {
/*
* NodePointer implementation
*/
NodeIterator::NodePointer::NodePointer(nsINode *aNode, bool aBeforeNode) :
mNode(aNode),
mBeforeNode(aBeforeNode)
{
}
bool NodeIterator::NodePointer::MoveToNext(nsINode *aRoot)
{
if (!mNode)
return false;
if (mBeforeNode) {
mBeforeNode = false;
return true;
}
nsINode* child = mNode->GetFirstChild();
if (child) {
mNode = child;
return true;
}
return MoveForward(aRoot, mNode);
}
bool NodeIterator::NodePointer::MoveToPrevious(nsINode *aRoot)
{
if (!mNode)
return false;
if (!mBeforeNode) {
mBeforeNode = true;
return true;
}
if (mNode == aRoot)
return false;
MoveBackward(mNode->GetParentNode(), mNode->GetPreviousSibling());
return true;
}
void NodeIterator::NodePointer::AdjustAfterRemoval(nsINode *aRoot,
nsINode *aContainer,
nsIContent *aChild,
nsIContent *aPreviousSibling)
{
// If mNode is null or the root there is nothing to do.
if (!mNode || mNode == aRoot)
return;
// check if ancestor was removed
if (!nsContentUtils::ContentIsDescendantOf(mNode, aChild))
return;
if (mBeforeNode) {
// Try the next sibling
nsINode *nextSibling = aPreviousSibling ? aPreviousSibling->GetNextSibling()
: aContainer->GetFirstChild();
if (nextSibling) {
mNode = nextSibling;
return;
}
// Next try siblings of ancestors
if (MoveForward(aRoot, aContainer))
return;
// No suitable node was found so try going backwards
mBeforeNode = false;
}
MoveBackward(aContainer, aPreviousSibling);
}
bool NodeIterator::NodePointer::MoveForward(nsINode *aRoot, nsINode *aNode)
{
while (1) {
if (aNode == aRoot)
break;
nsINode *sibling = aNode->GetNextSibling();
if (sibling) {
mNode = sibling;
return true;
}
aNode = aNode->GetParentNode();
}
return false;
}
void NodeIterator::NodePointer::MoveBackward(nsINode *aParent, nsINode *aNode)
{
if (aNode) {
do {
mNode = aNode;
aNode = aNode->GetLastChild();
} while (aNode);
} else {
mNode = aParent;
}
}
/*
* Factories, constructors and destructors
*/
NodeIterator::NodeIterator(nsINode *aRoot,
uint32_t aWhatToShow,
NodeFilter* aFilter) :
nsTraversal(aRoot, aWhatToShow, aFilter),
mPointer(mRoot, true)
{
aRoot->AddMutationObserver(this);
}
NodeIterator::~NodeIterator()
{
/* destructor code */
if (mRoot)
mRoot->RemoveMutationObserver(this);
}
/*
* nsISupports and cycle collection stuff
*/
NS_IMPL_CYCLE_COLLECTION_CLASS(NodeIterator)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(NodeIterator)
if (tmp->mRoot)
tmp->mRoot->RemoveMutationObserver(tmp);
NS_IMPL_CYCLE_COLLECTION_UNLINK(mRoot)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mFilter)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(NodeIterator)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRoot)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFilter)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
// QueryInterface implementation for NodeIterator
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(NodeIterator)
NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(NodeIterator)
NS_IMPL_CYCLE_COLLECTING_RELEASE(NodeIterator)
already_AddRefed<nsINode>
NodeIterator::NextOrPrevNode(NodePointer::MoveToMethodType aMove,
ErrorResult& aResult)
{
if (mInAcceptNode) {
aResult.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
return nullptr;
}
mWorkingPointer = mPointer;
struct AutoClear {
NodePointer* mPtr;
explicit AutoClear(NodePointer* ptr) : mPtr(ptr) {}
~AutoClear() { mPtr->Clear(); }
} ac(&mWorkingPointer);
while ((mWorkingPointer.*aMove)(mRoot)) {
nsCOMPtr<nsINode> testNode = mWorkingPointer.mNode;
int16_t filtered = TestNode(testNode, aResult);
if (aResult.Failed()) {
return nullptr;
}
if (filtered == NodeFilter_Binding::FILTER_ACCEPT) {
mPointer = mWorkingPointer;
return testNode.forget();
}
}
return nullptr;
}
void
NodeIterator::Detach()
{
if (mRoot) {
mRoot->OwnerDoc()->WarnOnceAbout(nsIDocument::eNodeIteratorDetach);
}
}
/*
* nsIMutationObserver interface
*/
void NodeIterator::ContentRemoved(nsIContent* aChild,
nsIContent* aPreviousSibling)
{
nsINode* container = aChild->GetParentNode();
mPointer.AdjustAfterRemoval(mRoot, container, aChild, aPreviousSibling);
mWorkingPointer.AdjustAfterRemoval(mRoot, container, aChild, aPreviousSibling);
}
bool
NodeIterator::WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto, JS::MutableHandle<JSObject*> aReflector)
{
return NodeIterator_Binding::Wrap(cx, this, aGivenProto, aReflector);
}
} // namespace dom
} // namespace mozilla