accessible/src/base/TextUpdater.h@97036ab72558
accessible/src/base/TextUpdater.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
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_TextUpdater_h__
7 #define mozilla_a11y_TextUpdater_h__
9 #include "AccEvent.h"
10 #include "HyperTextAccessible.h"
12 namespace mozilla {
13 namespace a11y {
15 /**
16 * Used to find a difference between old and new text and fire text change
17 * events.
18 */
19 class TextUpdater
20 {
21 public:
22 /**
23 * Start text of the text leaf update.
24 */
25 static void Run(DocAccessible* aDocument, TextLeafAccessible* aTextLeaf,
26 const nsAString& aNewText);
28 private:
29 TextUpdater(DocAccessible* aDocument, TextLeafAccessible* aTextLeaf) :
30 mDocument(aDocument), mTextLeaf(aTextLeaf), mHyperText(nullptr),
31 mTextOffset(-1) { }
33 ~TextUpdater()
34 { mDocument = nullptr; mTextLeaf = nullptr; mHyperText = nullptr; }
36 /**
37 * Update text of the text leaf accessible, fire text change and value change
38 * (if applicable) events for its container hypertext accessible.
39 */
40 void DoUpdate(const nsAString& aNewText, const nsAString& aOldText,
41 uint32_t aSkipStart);
43 private:
44 TextUpdater();
45 TextUpdater(const TextUpdater&);
46 TextUpdater& operator=(const TextUpdater&);
48 /**
49 * Fire text change events based on difference between strings.
50 */
51 void ComputeTextChangeEvents(const nsAString& aStr1,
52 const nsAString& aStr2,
53 uint32_t* aEntries,
54 nsTArray<nsRefPtr<AccEvent> >& aEvents);
56 /**
57 * Helper to create text change events for inserted text.
58 */
59 inline void FireInsertEvent(const nsAString& aText, uint32_t aAddlOffset,
60 nsTArray<nsRefPtr<AccEvent> >& aEvents)
61 {
62 nsRefPtr<AccEvent> event =
63 new AccTextChangeEvent(mHyperText, mTextOffset + aAddlOffset,
64 aText, true);
65 aEvents.AppendElement(event);
66 }
68 /**
69 * Helper to create text change events for removed text.
70 */
71 inline void FireDeleteEvent(const nsAString& aText, uint32_t aAddlOffset,
72 nsTArray<nsRefPtr<AccEvent> >& aEvents)
73 {
74 nsRefPtr<AccEvent> event =
75 new AccTextChangeEvent(mHyperText, mTextOffset + aAddlOffset,
76 aText, false);
77 aEvents.AppendElement(event);
78 }
80 /**
81 * The constant used to skip string difference calculation in case of long
82 * strings.
83 */
84 const static uint32_t kMaxStrLen = 1 << 6;
86 private:
87 DocAccessible* mDocument;
88 TextLeafAccessible* mTextLeaf;
89 HyperTextAccessible* mHyperText;
90 int32_t mTextOffset;
91 };
93 } // namespace a11y
94 } // namespace mozilla
96 #endif
