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lightning-sunbird  0.9+nobinonly
nsAccessibleTreeWalker.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.org 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) 2003
00020  * the Initial Developer. All Rights Reserved.
00021  *
00022  * Contributor(s):
00023  *   Original Author: Aaron Leventhal (aaronl@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
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00036  *
00037  * ***** END LICENSE BLOCK ***** */
00038 
00039 #ifndef _nsAccessibleTreeWalker_H_
00040 #define _nsAccessibleTreeWalker_H_
00041 
00042 /* For documentation of the accessibility architecture,  * see http://lxr.mozilla.org/seamonkey/source/accessible/accessible-docs.html
00043  */
00044 
00045 #include "nsCOMPtr.h"
00046 #include "nsIDocument.h"
00047 #include "nsIAccessible.h"
00048 #include "nsIDOMNodeList.h"
00049 #include "nsIAccessibilityService.h"
00050 #include "nsIBindingManager.h"
00051 #include "nsIWeakReference.h"
00052 
00053 enum { eSiblingsUninitialized = -1, eSiblingsWalkFrames = -2 };
00054 
00055 struct WalkState {
00056   nsCOMPtr<nsIAccessible> accessible;
00057   nsCOMPtr<nsIDOMNode> domNode;
00058   nsCOMPtr<nsIDOMNodeList> siblingList;
00059   nsIContent *parentContent; // For walking normal DOM
00060   WalkState *prevState;
00061   nsIFrame *frame;     // Helps avoid GetPrimaryFrameFor() calls
00062   PRInt32 siblingIndex;    // Holds a state flag or an index into the siblingList
00063   PRBool isHidden;         // Don't enter subtree if hidden
00064 };
00065  
00071 class nsAccessibleTreeWalker {
00072 public:
00073   nsAccessibleTreeWalker(nsIWeakReference* aShell, nsIDOMNode* aContent, 
00074     PRBool mWalkAnonymousContent);
00075   virtual ~nsAccessibleTreeWalker();
00076 
00077   NS_IMETHOD GetNextSibling();
00078   NS_IMETHOD GetParent();
00079   NS_IMETHOD GetFirstChild();
00080 
00081   WalkState mState;
00082 
00083 protected:
00084   PRBool GetAccessible();
00085   NS_IMETHOD GetFullTreeParentNode(nsIDOMNode *aChildNode, nsIDOMNode **aParentNodeOut);
00086   void GetKids(nsIDOMNode *aParent);
00087 
00088   void ClearState();
00089   NS_IMETHOD PushState();
00090   NS_IMETHOD PopState();
00091 
00092   void UpdateFrame(PRBool aTryFirstChild);
00093   void GetNextDOMNode();
00094 
00095   nsCOMPtr<nsIWeakReference> mWeakShell;
00096   nsCOMPtr<nsIAccessibilityService> mAccService;
00097   nsCOMPtr<nsIBindingManager> mBindingManager;
00098 };
00099 
00100 #endif