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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=4 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
/*
* Implementation of DOM Traversal's TreeWalker
*/
#include "mozilla/dom/TreeWalker.h"
#include "nsIContent.h"
#include "nsError.h"
#include "nsINode.h"
#include "nsContentUtils.h"
#include "mozilla/dom/NodeFilterBinding.h"
#include "mozilla/dom/TreeWalkerBinding.h"
namespace mozilla::dom {
/*
* Factories, constructors and destructors
*/
TreeWalker::TreeWalker(nsINode* aRoot, uint32_t aWhatToShow,
NodeFilter* aFilter)
: nsTraversal(aRoot, aWhatToShow, aFilter), mCurrentNode(aRoot) {}
TreeWalker::~TreeWalker() { /* destructor code */
}
/*
* nsISupports and cycle collection stuff
*/
NS_IMPL_CYCLE_COLLECTION(TreeWalker, mFilter, mCurrentNode, mRoot)
// QueryInterface implementation for TreeWalker
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TreeWalker)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
// Have to pass in dom::TreeWalker because a11y has an a11y::TreeWalker that
// passes TreeWalker so refcount logging would get confused on the name
// collision.
NS_IMPL_CYCLE_COLLECTING_ADDREF(dom::TreeWalker)
NS_IMPL_CYCLE_COLLECTING_RELEASE(dom::TreeWalker)
void TreeWalker::SetCurrentNode(nsINode& aNode, ErrorResult& aResult) {
aResult = nsContentUtils::CheckSameOrigin(mRoot, &aNode);
if (aResult.Failed()) {
return;
}
mCurrentNode = &aNode;
}
already_AddRefed<nsINode> TreeWalker::ParentNode(ErrorResult& aResult) {
nsCOMPtr<nsINode> node = mCurrentNode;
while (node && node != mRoot) {
node = node->GetParentNode();
if (node) {
int16_t filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
if (filtered == NodeFilter_Binding::FILTER_ACCEPT) {
mCurrentNode = node;
return node.forget();
}
}
}
return nullptr;
}
already_AddRefed<nsINode> TreeWalker::FirstChild(ErrorResult& aResult) {
return FirstChildInternal(false, aResult);
}
already_AddRefed<nsINode> TreeWalker::LastChild(ErrorResult& aResult) {
return FirstChildInternal(true, aResult);
}
already_AddRefed<nsINode> TreeWalker::PreviousSibling(ErrorResult& aResult) {
return NextSiblingInternal(true, aResult);
}
already_AddRefed<nsINode> TreeWalker::NextSibling(ErrorResult& aResult) {
return NextSiblingInternal(false, aResult);
}
already_AddRefed<nsINode> TreeWalker::PreviousNode(ErrorResult& aResult) {
nsCOMPtr<nsINode> node = mCurrentNode;
while (node != mRoot) {
while (nsINode* previousSibling = node->GetPreviousSibling()) {
node = previousSibling;
int16_t filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
nsINode* lastChild;
while (filtered != NodeFilter_Binding::FILTER_REJECT &&
(lastChild = node->GetLastChild())) {
node = lastChild;
filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
}
if (filtered == NodeFilter_Binding::FILTER_ACCEPT) {
mCurrentNode = node;
return node.forget();
}
}
if (node == mRoot) {
break;
}
node = node->GetParentNode();
if (!node) {
break;
}
int16_t filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
if (filtered == NodeFilter_Binding::FILTER_ACCEPT) {
mCurrentNode = node;
return node.forget();
}
}
return nullptr;
}
already_AddRefed<nsINode> TreeWalker::NextNode(ErrorResult& aResult) {
int16_t filtered =
NodeFilter_Binding::FILTER_ACCEPT; // pre-init for inner loop
nsCOMPtr<nsINode> node = mCurrentNode;
while (1) {
nsINode* firstChild;
while (filtered != NodeFilter_Binding::FILTER_REJECT &&
(firstChild = node->GetFirstChild())) {
node = firstChild;
filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
if (filtered == NodeFilter_Binding::FILTER_ACCEPT) {
// Node found
mCurrentNode = node;
return node.forget();
}
}
nsINode* sibling = nullptr;
nsINode* temp = node;
do {
if (temp == mRoot) break;
sibling = temp->GetNextSibling();
if (sibling) break;
temp = temp->GetParentNode();
} while (temp);
if (!sibling) break;
node = sibling;
// Found a sibling. Either ours or ancestor's
filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
if (filtered == NodeFilter_Binding::FILTER_ACCEPT) {
// Node found
mCurrentNode = node;
return node.forget();
}
}
return nullptr;
}
/*
* TreeWalker helper functions
*/
/*
* Implements FirstChild and LastChild which only vary in which direction
* they search.
* @param aReversed Controls whether we search forwards or backwards
* @param aResult Whether we threw or not.
* @returns The desired node. Null if no child is found
*/
already_AddRefed<nsINode> TreeWalker::FirstChildInternal(bool aReversed,
ErrorResult& aResult) {
nsCOMPtr<nsINode> node =
aReversed ? mCurrentNode->GetLastChild() : mCurrentNode->GetFirstChild();
while (node) {
int16_t filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
switch (filtered) {
case NodeFilter_Binding::FILTER_ACCEPT:
// Node found
mCurrentNode = node;
return node.forget();
case NodeFilter_Binding::FILTER_SKIP: {
nsINode* child =
aReversed ? node->GetLastChild() : node->GetFirstChild();
if (child) {
node = child;
continue;
}
break;
}
case NodeFilter_Binding::FILTER_REJECT:
// Keep searching
break;
}
do {
nsINode* sibling =
aReversed ? node->GetPreviousSibling() : node->GetNextSibling();
if (sibling) {
node = sibling;
break;
}
nsINode* parent = node->GetParentNode();
if (!parent || parent == mRoot || parent == mCurrentNode) {
return nullptr;
}
node = parent;
} while (node);
}
return nullptr;
}
/*
* Implements NextSibling and PreviousSibling which only vary in which
* direction they search.
* @param aReversed Controls whether we search forwards or backwards
* @param aResult Whether we threw or not.
* @returns The desired node. Null if no child is found
*/
already_AddRefed<nsINode> TreeWalker::NextSiblingInternal(
bool aReversed, ErrorResult& aResult) {
nsCOMPtr<nsINode> node = mCurrentNode;
if (node == mRoot) {
return nullptr;
}
while (1) {
nsINode* sibling =
aReversed ? node->GetPreviousSibling() : node->GetNextSibling();
while (sibling) {
node = sibling;
int16_t filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
if (filtered == NodeFilter_Binding::FILTER_ACCEPT) {
// Node found
mCurrentNode = node;
return node.forget();
}
// If rejected or no children, try a sibling
if (filtered == NodeFilter_Binding::FILTER_REJECT ||
!(sibling =
aReversed ? node->GetLastChild() : node->GetFirstChild())) {
sibling =
aReversed ? node->GetPreviousSibling() : node->GetNextSibling();
}
}
node = node->GetParentNode();
if (!node || node == mRoot) {
return nullptr;
}
// Is parent transparent in filtered view?
int16_t filtered = TestNode(node, aResult);
if (aResult.Failed()) {
return nullptr;
}
if (filtered == NodeFilter_Binding::FILTER_ACCEPT) {
return nullptr;
}
}
}
bool TreeWalker::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
JS::MutableHandle<JSObject*> aReflector) {
return TreeWalker_Binding::Wrap(aCx, this, aGivenProto, aReflector);
}
} // namespace mozilla::dom