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-rw-r--r--dom/base/TreeWalker.cpp449
1 files changed, 449 insertions, 0 deletions
diff --git a/dom/base/TreeWalker.cpp b/dom/base/TreeWalker.cpp
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+++ b/dom/base/TreeWalker.cpp
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim: set ts=4 et sw=4 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/. */
+
+/*
+ * Implementation of DOM Traversal's nsIDOMTreeWalker
+ */
+
+#include "mozilla/dom/TreeWalker.h"
+
+#include "nsIContent.h"
+#include "nsIDOMNode.h"
+#include "nsError.h"
+#include "nsINode.h"
+#include "nsContentUtils.h"
+#include "mozilla/dom/TreeWalkerBinding.h"
+
+namespace mozilla {
+namespace dom {
+
+/*
+ * Factories, constructors and destructors
+ */
+
+TreeWalker::TreeWalker(nsINode *aRoot,
+ uint32_t aWhatToShow,
+ NodeFilterHolder aFilter) :
+ nsTraversal(aRoot, aWhatToShow, Move(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(nsIDOMTreeWalker)
+ NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMTreeWalker)
+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)
+
+
+
+/*
+ * nsIDOMTreeWalker Getters/Setters
+ */
+
+NS_IMETHODIMP TreeWalker::GetRoot(nsIDOMNode * *aRoot)
+{
+ NS_ADDREF(*aRoot = Root()->AsDOMNode());
+ return NS_OK;
+}
+
+NS_IMETHODIMP TreeWalker::GetWhatToShow(uint32_t *aWhatToShow)
+{
+ *aWhatToShow = WhatToShow();
+ return NS_OK;
+}
+
+NS_IMETHODIMP TreeWalker::GetFilter(nsIDOMNodeFilter * *aFilter)
+{
+ NS_ENSURE_ARG_POINTER(aFilter);
+
+ *aFilter = mFilter.ToXPCOMCallback().take();
+
+ return NS_OK;
+}
+
+NS_IMETHODIMP TreeWalker::GetCurrentNode(nsIDOMNode * *aCurrentNode)
+{
+ if (mCurrentNode) {
+ return CallQueryInterface(mCurrentNode, aCurrentNode);
+ }
+
+ *aCurrentNode = nullptr;
+
+ return NS_OK;
+}
+NS_IMETHODIMP TreeWalker::SetCurrentNode(nsIDOMNode * aCurrentNode)
+{
+ NS_ENSURE_TRUE(aCurrentNode, NS_ERROR_DOM_NOT_SUPPORTED_ERR);
+ NS_ENSURE_TRUE(mRoot, NS_ERROR_UNEXPECTED);
+
+ nsCOMPtr<nsINode> node = do_QueryInterface(aCurrentNode);
+ NS_ENSURE_TRUE(node, NS_ERROR_UNEXPECTED);
+
+ ErrorResult rv;
+ SetCurrentNode(*node, rv);
+ return rv.StealNSResult();
+}
+
+void
+TreeWalker::SetCurrentNode(nsINode& aNode, ErrorResult& aResult)
+{
+ aResult = nsContentUtils::CheckSameOrigin(mRoot, &aNode);
+ if (aResult.Failed()) {
+ return;
+ }
+
+ mCurrentNode = &aNode;
+}
+
+/*
+ * nsIDOMTreeWalker functions
+ */
+
+NS_IMETHODIMP TreeWalker::ParentNode(nsIDOMNode **_retval)
+{
+ return ImplNodeGetter(&TreeWalker::ParentNode, _retval);
+}
+
+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 == nsIDOMNodeFilter::FILTER_ACCEPT) {
+ mCurrentNode = node;
+ return node.forget();
+ }
+ }
+ }
+
+ return nullptr;
+}
+
+NS_IMETHODIMP TreeWalker::FirstChild(nsIDOMNode **_retval)
+{
+ return ImplNodeGetter(&TreeWalker::FirstChild, _retval);
+}
+
+already_AddRefed<nsINode>
+TreeWalker::FirstChild(ErrorResult& aResult)
+{
+ return FirstChildInternal(false, aResult);
+}
+
+NS_IMETHODIMP TreeWalker::LastChild(nsIDOMNode **_retval)
+{
+ return ImplNodeGetter(&TreeWalker::LastChild, _retval);
+}
+
+already_AddRefed<nsINode>
+TreeWalker::LastChild(ErrorResult& aResult)
+{
+ return FirstChildInternal(true, aResult);
+}
+
+NS_IMETHODIMP TreeWalker::PreviousSibling(nsIDOMNode **_retval)
+{
+ return ImplNodeGetter(&TreeWalker::PreviousSibling, _retval);
+}
+
+already_AddRefed<nsINode>
+TreeWalker::PreviousSibling(ErrorResult& aResult)
+{
+ return NextSiblingInternal(true, aResult);
+}
+
+NS_IMETHODIMP TreeWalker::NextSibling(nsIDOMNode **_retval)
+{
+ return ImplNodeGetter(&TreeWalker::NextSibling, _retval);
+}
+
+already_AddRefed<nsINode>
+TreeWalker::NextSibling(ErrorResult& aResult)
+{
+ return NextSiblingInternal(false, aResult);
+}
+
+NS_IMETHODIMP TreeWalker::PreviousNode(nsIDOMNode **_retval)
+{
+ return ImplNodeGetter(&TreeWalker::PreviousNode, _retval);
+}
+
+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 != nsIDOMNodeFilter::FILTER_REJECT &&
+ (lastChild = node->GetLastChild())) {
+ node = lastChild;
+ filtered = TestNode(node, aResult);
+ if (aResult.Failed()) {
+ return nullptr;
+ }
+ }
+
+ if (filtered == nsIDOMNodeFilter::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 == nsIDOMNodeFilter::FILTER_ACCEPT) {
+ mCurrentNode = node;
+ return node.forget();
+ }
+ }
+
+ return nullptr;
+}
+
+NS_IMETHODIMP TreeWalker::NextNode(nsIDOMNode **_retval)
+{
+ return ImplNodeGetter(&TreeWalker::NextNode, _retval);
+}
+
+already_AddRefed<nsINode>
+TreeWalker::NextNode(ErrorResult& aResult)
+{
+ int16_t filtered = nsIDOMNodeFilter::FILTER_ACCEPT; // pre-init for inner loop
+
+ nsCOMPtr<nsINode> node = mCurrentNode;
+
+ while (1) {
+
+ nsINode *firstChild;
+ while (filtered != nsIDOMNodeFilter::FILTER_REJECT &&
+ (firstChild = node->GetFirstChild())) {
+ node = firstChild;
+
+ filtered = TestNode(node, aResult);
+ if (aResult.Failed()) {
+ return nullptr;
+ }
+
+ if (filtered == nsIDOMNodeFilter::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 == nsIDOMNodeFilter::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 nsIDOMNodeFilter::FILTER_ACCEPT:
+ // Node found
+ mCurrentNode = node;
+ return node.forget();
+ case nsIDOMNodeFilter::FILTER_SKIP: {
+ nsINode *child = aReversed ? node->GetLastChild()
+ : node->GetFirstChild();
+ if (child) {
+ node = child;
+ continue;
+ }
+ break;
+ }
+ case nsIDOMNodeFilter::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 == nsIDOMNodeFilter::FILTER_ACCEPT) {
+ // Node found
+ mCurrentNode = node;
+ return node.forget();
+ }
+
+ // If rejected or no children, try a sibling
+ if (filtered == nsIDOMNodeFilter::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 == nsIDOMNodeFilter::FILTER_ACCEPT) {
+ return nullptr;
+ }
+ }
+}
+
+bool
+TreeWalker::WrapObject(JSContext *aCx, JS::Handle<JSObject*> aGivenProto, JS::MutableHandle<JSObject*> aReflector)
+{
+ return TreeWalkerBinding::Wrap(aCx, this, aGivenProto, aReflector);
+}
+
+} // namespace dom
+} // namespace mozilla