ash/accessibility_delegate.h

   1 // Copyright 2013 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 ASH_ACCESSIBILITY_DELEGATE_H_
   6 #define ASH_ACCESSIBILITY_DELEGATE_H_
   7
   8 #include "ash/ash_export.h"
   9 #include "ash/magnifier/magnifier_constants.h"
  10 #include "base/time/time.h"
  11
  12 namespace ash {
  13
  14 enum AccessibilityNotificationVisibility {
  15   A11Y_NOTIFICATION_NONE,
  16   A11Y_NOTIFICATION_SHOW,
  17 };
  18
  19 enum AccessibilityAlert {
  20   A11Y_ALERT_NONE,
  21   A11Y_ALERT_WINDOW_NEEDED,
  22   A11Y_ALERT_WINDOW_OVERVIEW_MODE_ENTERED
  23 };
  24
  25 // A delegate class to control and query accessibility features.
  26 class ASH_EXPORT AccessibilityDelegate {
  27  public:
  28   virtual ~AccessibilityDelegate() {}
  29
  30   // Invoked to toggle spoken feedback for accessibility
  31   virtual void ToggleSpokenFeedback(
  32       AccessibilityNotificationVisibility notify) = 0;
  33
  34   // Returns true if spoken feedback is enabled.
  35   virtual bool IsSpokenFeedbackEnabled() const = 0;
  36
  37   // Invoked to toggle high contrast mode for accessibility.
  38   virtual void ToggleHighContrast() = 0;
  39
  40   // Returns true if high contrast mode is enabled.
  41   virtual bool IsHighContrastEnabled() const = 0;
  42
  43   // Invoked to enable the screen magnifier.
  44   virtual void SetMagnifierEnabled(bool enabled) = 0;
  45
  46   // Invoked to change the type of the screen magnifier.
  47   virtual void SetMagnifierType(MagnifierType type) = 0;
  48
  49   // Returns true if the screen magnifier is enabled.
  50   virtual bool IsMagnifierEnabled() const = 0;
  51
  52   // Returns the current screen magnifier mode.
  53   virtual MagnifierType GetMagnifierType() const = 0;
  54
  55   // Invoked to enable Large Cursor.
  56   virtual void SetLargeCursorEnabled(bool enabled) = 0;
  57
  58   // Returns ture if Large Cursor is enabled.
  59   virtual bool IsLargeCursorEnabled() const = 0;
  60
  61   // Invoked to enable autoclick.
  62   virtual void SetAutoclickEnabled(bool enabled) = 0;
  63
  64   // Returns if autoclick is enabled or not.
  65   virtual bool IsAutoclickEnabled() const = 0;
  66
  67   // Invoked to enable or disable the a11y on-screen keyboard.
  68   virtual void SetVirtualKeyboardEnabled(bool enabled) = 0;
  69
  70   // Returns if the a11y virtual keyboard is enabled.
  71   virtual bool IsVirtualKeyboardEnabled() const = 0;
  72
  73   // Returns true when the accessibility menu should be shown.
  74   virtual bool ShouldShowAccessibilityMenu() const = 0;
  75
  76   // Returns true if a braille display is connected to the system.
  77   virtual bool IsBrailleDisplayConnected() const = 0;
  78
  79   // Cancel all current and queued speech immediately.
  80   virtual void SilenceSpokenFeedback() const = 0;
  81
  82   // Saves the zoom scale of the full screen magnifier.
  83   virtual void SaveScreenMagnifierScale(double scale) = 0;
  84
  85   // Gets a saved value of the zoom scale of full screen magnifier. If a value
  86   // is not saved, return a negative value.
  87   virtual double GetSavedScreenMagnifierScale() = 0;
  88
  89   // Triggers an accessibility alert to give the user feedback.
  90   virtual void TriggerAccessibilityAlert(AccessibilityAlert alert) = 0;
  91
  92   // Gets the last accessibility alert that was triggered.
  93   virtual AccessibilityAlert GetLastAccessibilityAlert() = 0;
  94
  95   // Plays an earcon. Earcons are brief and distinctive sounds that indicate
  96   // when their mapped event has occurred. The sound key enums can be found in
  97   // chromeos/audio/chromeos_sounds.h.
  98   virtual void PlayEarcon(int sound_key) = 0;
  99
 100   // Initiates play of shutdown sound and returns it's duration.
 101   virtual base::TimeDelta PlayShutdownSound() const = 0;
 102 };
 103
 104 }  // namespace ash
 105
 106 #endif  // ASH_ACCESSIBILITY_DELEGATE_H_