Implement Chrome OS accessibility features to highlight focus, caret & cursor.

chrome/browser/chromeos/ui/accessibility_focus_ring_controller.h

 // Copyright 2014 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_CHROMEOS_UI_ACCESSIBILITY_FOCUS_RING_CONTROLLER_H_
 #define CHROME_BROWSER_CHROMEOS_UI_ACCESSIBILITY_FOCUS_RING_CONTROLLER_H_
 
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/singleton.h"
 #include "base/time/time.h"
+#include "chrome/browser/chromeos/ui/accessibility_cursor_ring_layer.h"
 #include "chrome/browser/chromeos/ui/accessibility_focus_ring_layer.h"
 #include "ui/compositor/compositor_animation_observer.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace ui {
 class Compositor;
 }
 
 namespace chromeos {
 
-// AccessibilityFocusRingController manages a custom focus ring (or multiple
-// rings) for accessibility.
+// AccessibilityFocusRingController handles drawing custom rings around
+// the focused object, cursor, and/or caret for accessibility.
 class AccessibilityFocusRingController
     : public FocusRingLayerDelegate,
       public ui::CompositorAnimationObserver {
  public:
   // Get the single instance of this class.
   static AccessibilityFocusRingController* GetInstance();
 
   // Draw a focus ring around the given set of rects, in global screen
   // coordinates.
   void SetFocusRing(const std::vector<gfx::Rect>& rects);
 
+  // Draw a ring around the mouse cursor.
+  void SetCursorRing(const gfx::Point& location);
+
+  // Draw a ring around the text caret.
+  void SetCaretRing(const gfx::Point& location);
+
  protected:
   AccessibilityFocusRingController();
   ~AccessibilityFocusRingController() override;
 
   // Given an unordered vector of bounding rectangles that cover everything
   // that currently has focus, populate a vector of one or more
   // AccessibilityFocusRings that surround the rectangles. Adjacent or
   // overlapping rectangles are combined first. This function is protected
   // so it can be unit-tested.
   void RectsToRings(const std::vector<gfx::Rect>& rects,
                     std::vector<AccessibilityFocusRing>* rings) const;
 
   virtual int GetMargin() const;
 
  private:
   // FocusRingLayerDelegate.
   void OnDeviceScaleFactorChanged() override;
 
   // CompositorAnimationObserver.
   void OnAnimationStep(base::TimeTicks timestamp) override;
   void OnCompositingShuttingDown(ui::Compositor* compositor) override;
 
   void Update();
 
+  void AnimateFocusRings(base::TimeTicks timestamp);
+  void AnimateCursorRing(base::TimeTicks timestamp);
+
   AccessibilityFocusRing RingFromSortedRects(
       const std::vector<gfx::Rect>& rects) const;
   void SplitIntoParagraphShape(
       const std::vector<gfx::Rect>& rects,
       gfx::Rect* top,
       gfx::Rect* middle,
       gfx::Rect* bottom) const;
   bool Intersects(const gfx::Rect& r1, const gfx::Rect& r2) const;
+  ui::Compositor* CompositorForBounds(const gfx::Rect& bounds);
+  void RemoveAnimationObservers();
+  void AddAnimationObservers();
 
   std::vector<gfx::Rect> rects_;
   std::vector<AccessibilityFocusRing> previous_rings_;
   std::vector<AccessibilityFocusRing> rings_;
   ScopedVector<AccessibilityFocusRingLayer> layers_;
   base::TimeTicks focus_change_time_;
   ui::Compositor* compositor_;
 
+  base::TimeTicks cursor_start_time_;
+  base::TimeTicks cursor_change_time_;
+  gfx::Point cursor_location_;
+  float cursor_opacity_;
+  scoped_ptr<AccessibilityCursorRingLayer> cursor_layer_;
+  ui::Compositor* cursor_compositor_;
+
+  gfx::Point caret_location_;
+  scoped_ptr<AccessibilityCursorRingLayer> caret_layer_;
+
   friend struct base::DefaultSingletonTraits<AccessibilityFocusRingController>;
 
   DISALLOW_COPY_AND_ASSIGN(AccessibilityFocusRingController);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_UI_ACCESSIBILITY_FOCUS_RING_CONTROLLER_H_