gecko/content/base/src/TreeWalker.h

/* -*- 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;
class nsIDOMNodeFilter;

namespace mozilla {
namespace dom {

class TreeWalker : public nsIDOMTreeWalker, public nsTraversal
{
public:
    NS_DECL_CYCLE_COLLECTING_ISUPPORTS
    NS_DECL_NSIDOMTREEWALKER

    TreeWalker(nsINode *aRoot,
               uint32_t aWhatToShow,
               const NodeFilterHolder &aFilter);
    virtual ~TreeWalker();

    NS_DECL_CYCLE_COLLECTION_CLASS(TreeWalker)

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 _retval   Returned node. Null if no child is found
     * @returns         Errorcode
     */
    nsresult FirstChildInternal(bool aReversed, nsIDOMNode **_retval);

    /*
     * Implements NextSibling and PreviousSibling which only vary in which
     * direction they search.
     * @param aReversed Controls whether we search forwards or backwards
     * @param _retval   Returned node. Null if no child is found
     * @returns         Errorcode
     */
    nsresult NextSiblingInternal(bool aReversed, nsIDOMNode **_retval);
};

} // namespace dom
} // namespace mozilla

#endif // mozilla_dom_TreeWalker_h