| // Copyright (c) 2010 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef CHROME_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_STATE_H_ |
| #define CHROME_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_STATE_H_ |
| #pragma once |
| |
| #include "base/basictypes.h" |
| |
| template <typename T> struct DefaultSingletonTraits; |
| |
| // The BrowserAccessibilityState class is used to determine if Chrome should be |
| // customized for users with assistive technology, such as screen readers. We |
| // modify the behavior of certain user interfaces to provide a better experience |
| // for screen reader users. The way we detect a screen reader program is |
| // different for each platform. |
| // |
| // Screen Reader Detection |
| // (1) On windows many screen reader detection mechinisms will give false |
| // positives like relying on the SPI_GETSCREENREADER system parameter. In Chrome |
| // we attempt to dynamically detect a MSAA client screen reader by calling |
| // NotifiyWinEvent in WidgetWin with a custom ID and wait to see if the ID |
| // is requested by a subsequent call to WM_GETOBJECT. |
| // (2) On mac we detect if VoiceOver is running. This is stored in a preference |
| // file for Universal Access with the key "voiceOverOnOffKey". |
| class BrowserAccessibilityState { |
| public: |
| // Returns the singleton instance. |
| static BrowserAccessibilityState* GetInstance(); |
| |
| ~BrowserAccessibilityState(); |
| |
| // Called when screen reader client is detected. |
| void OnScreenReaderDetected(); |
| |
| // Returns true if the Chrome browser should be customized for accessibility. |
| bool IsAccessibleBrowser(); |
| |
| private: |
| BrowserAccessibilityState(); |
| friend struct DefaultSingletonTraits<BrowserAccessibilityState>; |
| |
| // Set to true when a screen reader client is detected. |
| bool screen_reader_active_; |
| |
| DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityState); |
| }; |
| |
| #endif // CHROME_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_STATE_H_ |