gecko-dev/dom/base/TreeWalker.h

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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
*/
#ifndef mozilla_dom_TreeWalker_h
#define mozilla_dom_TreeWalker_h
#include "nsIDOMTreeWalker.h"
#include "nsTraversal.h"
#include "nsCOMPtr.h"
#include "nsTArray.h"
#include "nsCycleCollectionParticipant.h"
class nsINode;
class nsIDOMNode;
namespace mozilla {
namespace dom {
class TreeWalker MOZ_FINAL : public nsIDOMTreeWalker, public nsTraversal
{
virtual ~TreeWalker();
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_NSIDOMTREEWALKER
TreeWalker(nsINode *aRoot,
uint32_t aWhatToShow,
const NodeFilterHolder &aFilter);
NS_DECL_CYCLE_COLLECTION_CLASS(TreeWalker)
// WebIDL API
nsINode* Root() const
{
return mRoot;
}
uint32_t WhatToShow() const
{
return mWhatToShow;
}
already_AddRefed<NodeFilter> GetFilter()
{
return mFilter.ToWebIDLCallback();
}
nsINode* CurrentNode() const
{
return mCurrentNode;
}
void SetCurrentNode(nsINode& aNode, ErrorResult& aResult);
// All our traversal methods return strong refs because filtering can
// remove nodes from the tree.
already_AddRefed<nsINode> ParentNode(ErrorResult& aResult);
already_AddRefed<nsINode> FirstChild(ErrorResult& aResult);
already_AddRefed<nsINode> LastChild(ErrorResult& aResult);
already_AddRefed<nsINode> PreviousSibling(ErrorResult& aResult);
already_AddRefed<nsINode> NextSibling(ErrorResult& aResult);
already_AddRefed<nsINode> PreviousNode(ErrorResult& aResult);
already_AddRefed<nsINode> NextNode(ErrorResult& aResult);
JSObject* WrapObject(JSContext *cx);
private:
nsCOMPtr<nsINode> mCurrentNode;
/*
* 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> FirstChildInternal(bool aReversed,
ErrorResult& aResult);
/*
* 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> NextSiblingInternal(bool aReversed,
ErrorResult& aResult);
// Implementation for our various XPCOM getters
typedef already_AddRefed<nsINode> (TreeWalker::*NodeGetter)(ErrorResult&);
inline nsresult ImplNodeGetter(NodeGetter aGetter, nsIDOMNode** aRetval)
{
mozilla::ErrorResult rv;
nsCOMPtr<nsINode> node = (this->*aGetter)(rv);
if (rv.Failed()) {
return rv.ErrorCode();
}
*aRetval = node ? node.forget().take()->AsDOMNode() : nullptr;
return NS_OK;
}
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_TreeWalker_h