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      1 // Copyright 2014 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_STICKY_KEYS_STICKY_KEYS_OVERLAY_H_
      6 #define ASH_STICKY_KEYS_STICKY_KEYS_OVERLAY_H_
      7 
      8 #include "ash/ash_export.h"
      9 #include "ash/sticky_keys/sticky_keys_state.h"
     10 #include "base/memory/scoped_ptr.h"
     11 #include "ui/compositor/layer_animation_observer.h"
     12 #include "ui/events/event_constants.h"
     13 #include "ui/gfx/geometry/size.h"
     14 
     15 namespace gfx {
     16 class Rect;
     17 }
     18 
     19 namespace views {
     20 class Widget;
     21 }
     22 
     23 namespace ash {
     24 
     25 class StickyKeysOverlayView;
     26 
     27 // Controls the overlay UI for sticky keys, an accessibility feature allowing
     28 // use of modifier keys without holding them down. This overlay will appear as
     29 // a transparent window on the top left of the screen, showing the state of
     30 // each sticky key modifier.
     31 class ASH_EXPORT StickyKeysOverlay : public ui::LayerAnimationObserver {
     32  public:
     33   StickyKeysOverlay();
     34   virtual ~StickyKeysOverlay();
     35 
     36   // Shows or hides the overlay.
     37   void Show(bool visible);
     38 
     39   void SetModifierVisible(ui::EventFlags modifier, bool visible);
     40 
     41   bool GetModifierVisible(ui::EventFlags modifier);
     42 
     43   // Updates the overlay with the current state of a sticky key modifier.
     44   void SetModifierKeyState(ui::EventFlags modifier,
     45                            StickyKeyState state);
     46 
     47   // Get the current state of the sticky key modifier in the overlay.
     48   StickyKeyState GetModifierKeyState(ui::EventFlags modifier);
     49 
     50   // Returns true if the overlay is currently visible. If the overlay is
     51   // animating, the returned value is the target of the animation.
     52   bool is_visible() { return is_visible_; }
     53 
     54  private:
     55   // Returns the current bounds of the overlay, which is based on visibility.
     56   gfx::Rect CalculateOverlayBounds();
     57 
     58   // gfx::LayerAnimationObserver overrides:
     59   virtual void OnLayerAnimationEnded(
     60       ui::LayerAnimationSequence* sequence) OVERRIDE;
     61   virtual void OnLayerAnimationAborted(
     62       ui::LayerAnimationSequence* sequence) OVERRIDE;
     63   virtual void OnLayerAnimationScheduled(
     64       ui::LayerAnimationSequence* sequence) OVERRIDE;
     65 
     66   bool is_visible_;
     67   scoped_ptr<views::Widget> overlay_widget_;
     68   // Ownership of |overlay_view_| is passed to the view heirarchy.
     69   StickyKeysOverlayView* overlay_view_;
     70   gfx::Size widget_size_;
     71 };
     72 
     73 }  // namespace ash
     74 
     75 #endif  // ASH_STICKY_KEYS_STICKY_KEYS_OVERLAY_H_
     76