gecko/layout/style/nsRuleWalker.h

74 lines
2.6 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Original Author: David W. Hyatt (hyatt@netscape.com)
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* a class that walks the lexicographic tree of rule nodes as style
* rules are matched
*/
#include "nsRuleNode.h"
class nsRuleWalker {
public:
nsRuleNode* GetCurrentNode() { return mCurrent; }
void SetCurrentNode(nsRuleNode* aNode) { mCurrent = aNode; }
void Forward(nsIStyleRule* aRule) {
nsRuleNode* next;
mCurrent->Transition(aRule, &next);
mCurrent = next;
}
void Back() {
if (mCurrent != mRoot)
mCurrent = mCurrent->GetParent();
}
void Reset() { mCurrent = mRoot; }
PRBool AtRoot() { return mCurrent == mRoot; }
private:
nsRuleNode* mCurrent; // Our current position.
nsRuleNode* mRoot; // The root of the tree we're walking.
public:
nsRuleWalker(nsRuleNode* aRoot) :mCurrent(aRoot), mRoot(aRoot) { MOZ_COUNT_CTOR(nsRuleWalker); }
~nsRuleWalker() { MOZ_COUNT_DTOR(nsRuleWalker); }
};