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/* -*- Mode: C++; tab-width: 4; 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/. */
/*
* Implementation of DOM Traversal's NodeIterator
*/
#include "mozilla/dom/NodeIterator.h"
#include "nsError.h"
#include "nsIContent.h"
#include "mozilla/dom/Document.h"
#include "nsContentUtils.h"
#include "nsCOMPtr.h"
#include "mozilla/dom/NodeFilterBinding.h"
#include "mozilla/dom/NodeIteratorBinding.h"
namespace mozilla::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 (!mNode->IsInclusiveDescendantOf(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;
int16_t filtered = TestNode(mWorkingPointer.mNode, aResult, &testNode);
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(DeprecatedOperations::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 mozilla::dom
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