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      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_
    107