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-rw-r--r--dom/base/TreeWalker.cpp329
1 files changed, 329 insertions, 0 deletions
diff --git a/dom/base/TreeWalker.cpp b/dom/base/TreeWalker.cpp
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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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * 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
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-01 17:48:24 +0000