chrome/browser/chromeos/ui/accessibility_focus_ring_controller.h

   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 CHROME_BROWSER_CHROMEOS_UI_ACCESSIBILITY_FOCUS_RING_CONTROLLER_H_
   6 #define CHROME_BROWSER_CHROMEOS_UI_ACCESSIBILITY_FOCUS_RING_CONTROLLER_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/scoped_vector.h"
  12 #include "base/memory/singleton.h"
  13 #include "base/time/time.h"
  14 #include "chrome/browser/chromeos/ui/accessibility_focus_ring_layer.h"
  15 #include "ui/compositor/compositor_animation_observer.h"
  16 #include "ui/gfx/geometry/rect.h"
  17
  18 namespace ui {
  19 class Compositor;
  20 }
  21
  22 namespace chromeos {
  23
  24 // AccessibilityFocusRingController manages a custom focus ring (or multiple
  25 // rings) for accessibility.
  26 class AccessibilityFocusRingController
  27     : public FocusRingLayerDelegate,
  28       public ui::CompositorAnimationObserver {
  29  public:
  30   // Get the single instance of this class.
  31   static AccessibilityFocusRingController* GetInstance();
  32
  33   // Draw a focus ring around the given set of rects, in global screen
  34   // coordinates.
  35   void SetFocusRing(const std::vector<gfx::Rect>& rects);
  36
  37  protected:
  38   AccessibilityFocusRingController();
  39   ~AccessibilityFocusRingController() override;
  40
  41   // Given an unordered vector of bounding rectangles that cover everything
  42   // that currently has focus, populate a vector of one or more
  43   // AccessibilityFocusRings that surround the rectangles. Adjacent or
  44   // overlapping rectangles are combined first. This function is protected
  45   // so it can be unit-tested.
  46   void RectsToRings(const std::vector<gfx::Rect>& rects,
  47                     std::vector<AccessibilityFocusRing>* rings) const;
  48
  49   virtual int GetMargin() const;
  50
  51  private:
  52   // FocusRingLayerDelegate.
  53   void OnDeviceScaleFactorChanged() override;
  54
  55   // CompositorAnimationObserver.
  56   void OnAnimationStep(base::TimeTicks timestamp) override;
  57   void OnCompositingShuttingDown(ui::Compositor* compositor) override;
  58
  59   void Update();
  60
  61   AccessibilityFocusRing RingFromSortedRects(
  62       const std::vector<gfx::Rect>& rects) const;
  63   void SplitIntoParagraphShape(
  64       const std::vector<gfx::Rect>& rects,
  65       gfx::Rect* top,
  66       gfx::Rect* middle,
  67       gfx::Rect* bottom) const;
  68   bool Intersects(const gfx::Rect& r1, const gfx::Rect& r2) const;
  69
  70   std::vector<gfx::Rect> rects_;
  71   std::vector<AccessibilityFocusRing> previous_rings_;
  72   std::vector<AccessibilityFocusRing> rings_;
  73   ScopedVector<AccessibilityFocusRingLayer> layers_;
  74   base::TimeTicks focus_change_time_;
  75   ui::Compositor* compositor_;
  76
  77   friend struct base::DefaultSingletonTraits<AccessibilityFocusRingController>;
  78
  79   DISALLOW_COPY_AND_ASSIGN(AccessibilityFocusRingController);
  80 };
  81
  82 }  // namespace chromeos
  83
  84 #endif  // CHROME_BROWSER_CHROMEOS_UI_ACCESSIBILITY_FOCUS_RING_CONTROLLER_H_