summaryrefslogtreecommitdiffstats
path: root/accessible/base/SelectionManager.h
blob: d8e6dabbdf0f3b5dc9b9c8e3675e4a4497d5dab8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/* -*- Mode: C++; tab-width: 4; 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_SelectionManager_h__
#define mozilla_a11y_SelectionManager_h__

#include "nsIFrame.h"
#include "nsISelectionListener.h"

class nsIPresShell;

namespace mozilla {

namespace dom {
class Element;
}

namespace a11y {

class AccEvent;
class HyperTextAccessible;

/**
 * This special accessibility class is for the caret and selection management.
 * There is only 1 visible caret per top level window. However, there may be
 * several visible selections.
 *
 * The important selections are the one owned by each document, and the one in
 * the currently focused control.
 *
 * On Windows this class is used to move an invisible system caret that
 * shadows the Mozilla caret. Windows will also automatically map this to
 * the MSAA caret accessible object (via OBJID_CARET) (as opposed to the root
 * accessible tree for a window which is retrieved with OBJID_CLIENT).
 *
 * For ATK and IAccessible2, this class is used to fire caret move and
 * selection change events.
 */

struct SelData;

class SelectionManager : public nsISelectionListener
{
public:
  // nsISupports
  // implemented by derived nsAccessibilityService

  // nsISelectionListener
  NS_DECL_NSISELECTIONLISTENER

  // SelectionManager
  void Shutdown() { ClearControlSelectionListener(); }

  /**
   * Listen to selection events on the focused control.
   *
   * Note: only one control's selection events are listened to at a time. This
   * will remove the previous control's selection listener.
   */
  void SetControlSelectionListener(dom::Element* aFocusedElm);

  /**
   * Stop listening to selection events on the control.
   */
  void ClearControlSelectionListener();

  /**
   * Listen to selection events on the document.
   */
  void AddDocSelectionListener(nsIPresShell* aPresShell);

  /**
   * Stop listening to selection events for a given document
   */
  void RemoveDocSelectionListener(nsIPresShell* aShell);

  /**
   * Process delayed event, results in caret move and text selection change
   * events.
   */
  void ProcessTextSelChangeEvent(AccEvent* aEvent);

  /**
   * Gets the current caret offset/hypertext accessible pair. If there is no
   * current pair, then returns -1 for the offset and a nullptr for the
   * accessible.
   */
  inline HyperTextAccessible* AccessibleWithCaret(int32_t* aCaret)
  {
    if (aCaret)
      *aCaret = mCaretOffset;

    return mAccWithCaret;
  }

  /**
   * Update caret offset when it doesn't go through a caret move event.
   */
  inline void UpdateCaretOffset(HyperTextAccessible* aItem, int32_t aOffset)
  {
    mAccWithCaret = aItem;
    mCaretOffset = aOffset;
  }

  inline void ResetCaretOffset()
  {
    mCaretOffset = -1;
    mAccWithCaret = nullptr;
  }

protected:

  SelectionManager();

  /**
   * Process DOM selection change. Fire selection and caret move events.
   */
  void ProcessSelectionChanged(SelData* aSelData);

private:
  int32_t mCaretOffset;
  HyperTextAccessible* mAccWithCaret;
  // Currently focused controls.
  nsWeakPtr mCurrCtrlNormalSel;
  nsWeakPtr mCurrCtrlSpellSel;
};

} // namespace a11y
} // namespace mozilla

#endif