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      1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_WIZARD_ACCESSIBILITY_HANDLER_H_
      6 #define CHROME_BROWSER_CHROMEOS_LOGIN_WIZARD_ACCESSIBILITY_HANDLER_H_
      7 #pragma once
      8 
      9 #include <string>
     10 
     11 #include "base/gtest_prod_util.h"
     12 #include "content/common/notification_observer.h"
     13 #include "content/common/notification_source.h"
     14 #include "content/common/notification_type.h"
     15 
     16 class AccessibilityControlInfo;
     17 class AccessibilityTextBoxInfo;
     18 
     19 namespace chromeos {
     20 
     21 enum EarconType {
     22   NO_EARCON,
     23   EARCON_BUTTON,
     24   EARCON_CHECK_OFF,
     25   EARCON_CHECK_ON,
     26   EARCON_ELLIPSES,
     27   EARCON_LINK,
     28   EARCON_LISTBOX,
     29   EARCON_MENU,
     30   EARCON_OBJECT_OPENED,
     31   EARCON_OBJECT_CLOSED,
     32   EARCON_TAB,
     33   EARCON_TEXTBOX,
     34 };
     35 
     36 // Class that handles the accessibility notifications and generates
     37 // appropriate spoken/audio feedback.
     38 class WizardAccessibilityHandler : public NotificationObserver {
     39  public:
     40   WizardAccessibilityHandler() { }
     41 
     42   // Speaks the specified string.
     43   void Speak(const char* speak_str, bool queue, bool interruptible);
     44 
     45  private:
     46   // Override from NotificationObserver.
     47   virtual void Observe(NotificationType type,
     48                        const NotificationSource& source,
     49                        const NotificationDetails& details);
     50 
     51   // Get text to speak and an earcon identifier (which may be NONE) for any
     52   // accessibility event.
     53   void DescribeAccessibilityEvent(NotificationType event_type,
     54                                   const AccessibilityControlInfo* control_info,
     55                                   std::string* out_spoken_description,
     56                                   EarconType* out_earcon);
     57 
     58   // Get text to speak and an optional earcon identifier, specifically for
     59   // a focus or select accessibility event on a control.
     60   void DescribeControl(const AccessibilityControlInfo* control_info,
     61                        bool is_action,
     62                        std::string* out_spoken_description,
     63                        EarconType* out_earcon);
     64 
     65   // Get text to speak when a text control has changed in some way, either
     66   // the contents or selection/cursor.
     67   void DescribeTextChanged(const AccessibilityControlInfo* control_info,
     68                            std::string* out_spoken_description,
     69                            EarconType* out_earcon);
     70 
     71   // Get the text from an AccessibilityTextBoxInfo, obscuring the
     72   // text if it's a password field.
     73   std::string GetTextBoxValue(const AccessibilityTextBoxInfo* textbox_info);
     74 
     75   // Get text to speak when only the selection/cursor has changed.
     76   void DescribeTextSelectionChanged(const std::string& value,
     77                                     int old_start, int old_end,
     78                                     int new_start, int new_end,
     79                                     std::string* out_spoken_description);
     80 
     81   // Get text to speak when the contents of a text control has changed.
     82   void DescribeTextContentsChanged(const std::string& old_value,
     83                                    const std::string& new_value,
     84                                    std::string* out_spoken_description);
     85 
     86   int previous_text_selection_start_;
     87   int previous_text_selection_end_;
     88   std::string previous_text_value_;
     89 
     90   friend class WizardAccessibilityHandlerTest;
     91   FRIEND_TEST_ALL_PREFIXES(WizardAccessibilityHandlerTest, TestFocusEvents);
     92   FRIEND_TEST_ALL_PREFIXES(WizardAccessibilityHandlerTest, TestTextEvents);
     93 
     94   DISALLOW_COPY_AND_ASSIGN(WizardAccessibilityHandler);
     95 };
     96 
     97 }  // namespace chromeos
     98 
     99 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_WIZARD_ACCESSIBILITY_HANDLER_H_
    100