The Tor Browser: accessible/src/base/TreeWalker.h@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 #ifndef mozilla_a11y_TreeWalker_h_

     7 #define mozilla_a11y_TreeWalker_h_

     9 #include "mozilla/Attributes.h"

    10 #include <stdint.h>

    12 class nsIContent;

    14 namespace mozilla {

    15 namespace a11y {

    17 class Accessible;

    18 class DocAccessible;

    20 struct WalkState;

    22 /**

    23  * This class is used to walk the DOM tree to create accessible tree.

    24  */

    25 class TreeWalker MOZ_FINAL

    26 {

    27 public:

    28   enum {

    29     // used to walk the existing tree of the given node

    30     eWalkCache = 1,

    31     // used to walk the context tree starting from given node

    32     eWalkContextTree = 2 | eWalkCache

    33   };

    35   /**

    36    * Constructor

    37    *

    38    * @param aContext [in] container accessible for the given node, used to

    39    *                   define accessible context

    40    * @param aNode    [in] the node the search will be prepared relative to

    41    * @param aFlags   [in] flags (see enum above)

    42    */

    43   TreeWalker(Accessible* aContext, nsIContent* aNode, uint32_t aFlags = 0);

    44   ~TreeWalker();

    46   /**

    47    * Return the next child accessible.

    48    *

    49    * @note Returned accessible is bound to the document, if the accessible is

    50    *       rejected during tree creation then the caller should be unbind it

    51    *       from the document.

    52    */

    53   Accessible* NextChild()

    54   {

    55     return NextChildInternal(false);

    56   }

    58 private:

    59   TreeWalker();

    60   TreeWalker(const TreeWalker&);

    61   TreeWalker& operator =(const TreeWalker&);

    63   /**

    64    * Return the next child accessible.

    65    *

    66    * @param  aNoWalkUp  [in] specifies the walk direction, true means we

    67    *                     shouldn't go up through the tree if we failed find

    68    *                     accessible children.

    69    */

    70   Accessible* NextChildInternal(bool aNoWalkUp);

    72   /**

    73    * Create new state for the given node and push it on top of stack.

    74    *

    75    * @note State stack is used to navigate up/down the DOM subtree during

    76    *        accessible children search.

    77    */

    78   void PushState(nsIContent* aNode);

    80   /**

    81    * Pop state from stack.

    82    */

    83   void PopState();

    85   DocAccessible* mDoc;

    86   Accessible* mContext;

    87   int32_t mChildFilter;

    88   uint32_t mFlags;

    89   WalkState* mState;

    90 };

    92 } // namespace a11y

    93 } // namespace mozilla

    95 #endif // mozilla_a11y_TreeWalker_h_

The Tor Browser / file revision

accessible/src/base/TreeWalker.h@97036ab72558

accessible/src/base/TreeWalker.h