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lightning-sunbird  0.9+nobinonly
nsRuleWalker.h
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00001 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
00002 /* ***** BEGIN LICENSE BLOCK *****
00003  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
00004  *
00005  * The contents of this file are subject to the Mozilla Public License Version
00006  * 1.1 (the "License"); you may not use this file except in compliance with
00007  * the License. You may obtain a copy of the License at
00008  * http://www.mozilla.org/MPL/
00009  *
00010  * Software distributed under the License is distributed on an "AS IS" basis,
00011  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
00012  * for the specific language governing rights and limitations under the
00013  * License.
00014  *
00015  * The Original Code is Mozilla Communicator client code.
00016  *
00017  * The Initial Developer of the Original Code is
00018  * Netscape Communications Corporation.
00019  * Portions created by the Initial Developer are Copyright (C) 1998
00020  * the Initial Developer. All Rights Reserved.
00021  *
00022  * Contributor(s):
00023  *   Original Author: David W. Hyatt (hyatt@netscape.com)
00024  *
00025  * Alternatively, the contents of this file may be used under the terms of
00026  * either of the GNU General Public License Version 2 or later (the "GPL"),
00027  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
00028  * in which case the provisions of the GPL or the LGPL are applicable instead
00029  * of those above. If you wish to allow use of your version of this file only
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00034  * the provisions above, a recipient may use your version of this file under
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00036  *
00037  * ***** END LICENSE BLOCK ***** */
00038 
00039 #include "nsRuleNode.h"
00040 
00041 class nsRuleWalker {
00042 public:
00043   nsRuleNode* GetCurrentNode() { return mCurrent; }
00044   void SetCurrentNode(nsRuleNode* aNode) { mCurrent = aNode; }
00045 
00046   void Forward(nsIStyleRule* aRule) { 
00047     nsRuleNode* next;
00048     mCurrent->Transition(aRule, &next);
00049     mCurrent = next;
00050   }
00051 
00052   void Back() {
00053     if (mCurrent != mRoot)
00054       mCurrent = mCurrent->GetParent();
00055   }
00056 
00057   void Reset() { mCurrent = mRoot; }
00058 
00059   PRBool AtRoot() { return mCurrent == mRoot; }
00060 
00061 private:
00062   nsRuleNode* mCurrent; // Our current position.
00063   nsRuleNode* mRoot; // The root of the tree we're walking.
00064 
00065 public:
00066   nsRuleWalker(nsRuleNode* aRoot) :mCurrent(aRoot), mRoot(aRoot) { MOZ_COUNT_CTOR(nsRuleWalker); };
00067   ~nsRuleWalker() { MOZ_COUNT_DTOR(nsRuleWalker); };
00068 };