michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef mozilla_a11y_TreeWalker_h_
michael@0: #define mozilla_a11y_TreeWalker_h_
michael@0: 
michael@0: #include "mozilla/Attributes.h"
michael@0: #include <stdint.h>
michael@0: 
michael@0: class nsIContent;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace a11y {
michael@0: 
michael@0: class Accessible;
michael@0: class DocAccessible;
michael@0: 
michael@0: struct WalkState;
michael@0: 
michael@0: /**
michael@0:  * This class is used to walk the DOM tree to create accessible tree.
michael@0:  */
michael@0: class TreeWalker MOZ_FINAL
michael@0: {
michael@0: public:
michael@0:   enum {
michael@0:     // used to walk the existing tree of the given node
michael@0:     eWalkCache = 1,
michael@0:     // used to walk the context tree starting from given node
michael@0:     eWalkContextTree = 2 | eWalkCache
michael@0:   };
michael@0: 
michael@0:   /**
michael@0:    * Constructor
michael@0:    *
michael@0:    * @param aContext [in] container accessible for the given node, used to
michael@0:    *                   define accessible context
michael@0:    * @param aNode    [in] the node the search will be prepared relative to
michael@0:    * @param aFlags   [in] flags (see enum above)
michael@0:    */
michael@0:   TreeWalker(Accessible* aContext, nsIContent* aNode, uint32_t aFlags = 0);
michael@0:   ~TreeWalker();
michael@0: 
michael@0:   /**
michael@0:    * Return the next child accessible.
michael@0:    *
michael@0:    * @note Returned accessible is bound to the document, if the accessible is
michael@0:    *       rejected during tree creation then the caller should be unbind it
michael@0:    *       from the document.
michael@0:    */
michael@0:   Accessible* NextChild()
michael@0:   {
michael@0:     return NextChildInternal(false);
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   TreeWalker();
michael@0:   TreeWalker(const TreeWalker&);
michael@0:   TreeWalker& operator =(const TreeWalker&);
michael@0: 
michael@0:   /**
michael@0:    * Return the next child accessible.
michael@0:    *
michael@0:    * @param  aNoWalkUp  [in] specifies the walk direction, true means we
michael@0:    *                     shouldn't go up through the tree if we failed find
michael@0:    *                     accessible children.
michael@0:    */
michael@0:   Accessible* NextChildInternal(bool aNoWalkUp);
michael@0: 
michael@0:   /**
michael@0:    * Create new state for the given node and push it on top of stack.
michael@0:    *
michael@0:    * @note State stack is used to navigate up/down the DOM subtree during
michael@0:    *        accessible children search.
michael@0:    */
michael@0:   void PushState(nsIContent* aNode);
michael@0: 
michael@0:   /**
michael@0:    * Pop state from stack.
michael@0:    */
michael@0:   void PopState();
michael@0: 
michael@0:   DocAccessible* mDoc;
michael@0:   Accessible* mContext;
michael@0:   int32_t mChildFilter;
michael@0:   uint32_t mFlags;
michael@0:   WalkState* mState;
michael@0: };
michael@0: 
michael@0: } // namespace a11y
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // mozilla_a11y_TreeWalker_h_