import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

dom/base/TreeWalker.cpp

@@ -0,0 +1,449 @@
+/* -*- 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