/src/mozilla-central/accessible/base/TreeWalker.h

Source (jump to first uncovered line)
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_a11y_TreeWalker_h_
#define mozilla_a11y_TreeWalker_h_

#include "mozilla/Attributes.h"
#include <stdint.h>
#include "mozilla/dom/ChildIterator.h"
#include "nsCOMPtr.h"

class nsIContent;

namespace mozilla {
namespace a11y {

class Accessible;
class DocAccessible;

/**
 * This class is used to walk the DOM tree to create accessible tree.
 */
class TreeWalker final
{
public:
  enum {
    // used to walk the existing tree of the given node
    eWalkCache = 1,
    // used to walk the context tree starting from given node
    eWalkContextTree = 2 | eWalkCache,
    eScoped = 4
  };

  /**
   * Used to navigate and create if needed the accessible children.
   */
  explicit TreeWalker(Accessible* aContext);

  /**
   * Used to navigate the accessible children relative to the anchor.
   *
   * @param aContext [in] container accessible for the given node, used to
   *                   define accessible context
   * @param aAnchorNode [in] the node the search will be prepared relative to
   * @param aFlags   [in] flags (see enum above)
   */
  TreeWalker(Accessible* aContext, nsIContent* aAnchorNode, uint32_t aFlags = eWalkCache);

  /**
   * Navigates the accessible children within the anchor node subtree.
   */
  TreeWalker(DocAccessible* aDocument, nsIContent* aAnchorNode);

  ~TreeWalker();

  /**
   * Resets the walker state, and sets the given node as an anchor. Returns a
   * first accessible element within the node including the node itself.
   */
  Accessible* Scope(nsIContent* aAnchorNode);

  /**
   * Resets the walker state.
   */
  void Reset()
  {
    mPhase = eAtStart;
    mStateStack.Clear();
    mARIAOwnsIdx = 0;
  }

  /**
   * Sets the walker state to the given child node if it's within the anchor.
   */
  bool Seek(nsIContent* aChildNode);

  /**
   * Return the next/prev accessible.
   *
   * @note Returned accessible is bound to the document, if the accessible is
   *       rejected during tree creation then the caller should be unbind it
   *       from the document.
   */
  Accessible* Next();
  Accessible* Prev();

  Accessible* Context() const { return mContext; }
  DocAccessible* Document() const { return mDoc; }

private:
  TreeWalker();
  TreeWalker(const TreeWalker&);
  TreeWalker& operator =(const TreeWalker&);

  /**
   * Return an accessible for the given node if any.
   */
  Accessible* AccessibleFor(nsIContent* aNode, uint32_t aFlags,
                            bool* aSkipSubtree);

  /**
   * Create new state for the given node and push it on top of stack / at bottom
   * of stack.
   *
   * @note State stack is used to navigate up/down the DOM subtree during
   *        accessible children search.
   */
  dom::AllChildrenIterator* PushState(nsIContent* aContent,
                                      bool aStartAtBeginning)
  {
    return mStateStack.AppendElement(
      dom::AllChildrenIterator(aContent, mChildFilter, aStartAtBeginning));
  }
  dom::AllChildrenIterator* PrependState(nsIContent* aContent,
                                         bool aStartAtBeginning)
  {
    return mStateStack.InsertElementAt(0,
      dom::AllChildrenIterator(aContent, mChildFilter, aStartAtBeginning));
  }

  /**
   * Pop state from stack.
   */
  dom::AllChildrenIterator* PopState();

  DocAccessible* mDoc;
  Accessible* mContext;
  nsIContent* mAnchorNode;

  AutoTArray<dom::AllChildrenIterator, 20> mStateStack;
  uint32_t mARIAOwnsIdx;

  int32_t mChildFilter;
  uint32_t mFlags;

  enum Phase {
    eAtStart,
    eAtDOM,
    eAtARIAOwns,
    eAtEnd
  };
  Phase mPhase;
};

} // namespace a11y
} // namespace mozilla

#endif // mozilla_a11y_TreeWalker_h_

Line	Count	Source (jump to first uncovered line)
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/. */
5
6		#ifndef mozilla_a11y_TreeWalker_h_
7		#define mozilla_a11y_TreeWalker_h_
8
9		#include "mozilla/Attributes.h"
10		#include <stdint.h>
11		#include "mozilla/dom/ChildIterator.h"
12		#include "nsCOMPtr.h"
13
14		class nsIContent;
15
16		namespace mozilla {
17		namespace a11y {
18
19		class Accessible;
20		class DocAccessible;
21
22		/**
23		* This class is used to walk the DOM tree to create accessible tree.
24		*/
25		class TreeWalker 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		eScoped = 4
34		};
35
36		/**
37		* Used to navigate and create if needed the accessible children.
38		*/
39		explicit TreeWalker(Accessible* aContext);
40
41		/**
42		* Used to navigate the accessible children relative to the anchor.
43		*
44		* @param aContext [in] container accessible for the given node, used to
45		* define accessible context
46		* @param aAnchorNode [in] the node the search will be prepared relative to
47		* @param aFlags [in] flags (see enum above)
48		*/
49		TreeWalker(Accessible* aContext, nsIContent* aAnchorNode, uint32_t aFlags = eWalkCache);
50
51		/**
52		* Navigates the accessible children within the anchor node subtree.
53		*/
54		TreeWalker(DocAccessible* aDocument, nsIContent* aAnchorNode);
55
56		~TreeWalker();
57
58		/**
59		* Resets the walker state, and sets the given node as an anchor. Returns a
60		* first accessible element within the node including the node itself.
61		*/
62		Accessible* Scope(nsIContent* aAnchorNode);
63
64		/**
65		* Resets the walker state.
66		*/
67		void Reset()
68	0	{
69	0	mPhase = eAtStart;
70	0	mStateStack.Clear();
71	0	mARIAOwnsIdx = 0;
72	0	}
73
74		/**
75		* Sets the walker state to the given child node if it's within the anchor.
76		*/
77		bool Seek(nsIContent* aChildNode);
78
79		/**
80		* Return the next/prev accessible.
81		*
82		* @note Returned accessible is bound to the document, if the accessible is
83		* rejected during tree creation then the caller should be unbind it
84		* from the document.
85		*/
86		Accessible* Next();
87		Accessible* Prev();
88
89	0	Accessible* Context() const { return mContext; }
90	0	DocAccessible* Document() const { return mDoc; }
91
92		private:
93		TreeWalker();
94		TreeWalker(const TreeWalker&);
95		TreeWalker& operator =(const TreeWalker&);
96
97		/**
98		* Return an accessible for the given node if any.
99		*/
100		Accessible* AccessibleFor(nsIContent* aNode, uint32_t aFlags,
101		bool* aSkipSubtree);
102
103		/**
104		* Create new state for the given node and push it on top of stack / at bottom
105		* of stack.
106		*
107		* @note State stack is used to navigate up/down the DOM subtree during
108		* accessible children search.
109		*/
110		dom::AllChildrenIterator* PushState(nsIContent* aContent,
111		bool aStartAtBeginning)
112	0	{
113	0	return mStateStack.AppendElement(
114	0	dom::AllChildrenIterator(aContent, mChildFilter, aStartAtBeginning));
115	0	}
116		dom::AllChildrenIterator* PrependState(nsIContent* aContent,
117		bool aStartAtBeginning)
118	0	{
119	0	return mStateStack.InsertElementAt(0,
120	0	dom::AllChildrenIterator(aContent, mChildFilter, aStartAtBeginning));
121	0	}
122
123		/**
124		* Pop state from stack.
125		*/
126		dom::AllChildrenIterator* PopState();
127
128		DocAccessible* mDoc;
129		Accessible* mContext;
130		nsIContent* mAnchorNode;
131
132		AutoTArray<dom::AllChildrenIterator, 20> mStateStack;
133		uint32_t mARIAOwnsIdx;
134
135		int32_t mChildFilter;
136		uint32_t mFlags;
137
138		enum Phase {
139		eAtStart,
140		eAtDOM,
141		eAtARIAOwns,
142		eAtEnd
143		};
144		Phase mPhase;
145		};
146
147		} // namespace a11y
148		} // namespace mozilla
149
150		#endif // mozilla_a11y_TreeWalker_h_

Coverage Report

Created: 2018-09-25 14:53