1 // Copyright (c) 2012 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 CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_ 6 #define CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_ 7 8 #include "base/memory/ref_counted.h" 9 #include "base/memory/scoped_ptr.h" 10 #include "base/time/time.h" 11 #include "content/browser/android/edge_effect.h" 12 #include "ui/gfx/size_f.h" 13 #include "ui/gfx/vector2d_f.h" 14 15 class SkBitmap; 16 17 namespace cc { 18 class Layer; 19 } 20 21 namespace content { 22 23 /* |OverscrollGlow| mirrors its Android counterpart, OverscrollGlow.java. 24 * Conscious tradeoffs were made to align this as closely as possible with the 25 * original Android java version. 26 */ 27 class OverscrollGlow { 28 public: 29 // Create and initialize a new effect with the necessary resources. 30 // If |enabled| is false, the effect will be be deactivated until 31 // SetEnabled(true) is called. 32 // The caller should attach |root_layer| to the desired layer tree. 33 static scoped_ptr<OverscrollGlow> Create(bool enabled); 34 35 // Force loading of any necessary resources. This function is thread-safe. 36 static void EnsureResources(); 37 38 ~OverscrollGlow(); 39 40 // If false, the glow will be deactivated, and subsequent calls to 41 // OnOverscrolled or Animate will have no effect. 42 void SetEnabled(bool enabled); 43 44 // |overscroll| is the accumulated overscroll for the current gesture. 45 // |velocity| is the instantaneous velocity for the overscroll. 46 void OnOverscrolled(base::TimeTicks current_time, 47 gfx::Vector2dF overscroll, 48 gfx::Vector2dF velocity); 49 50 // Triggers glow recession for any active edges. 51 // Note: This does not actually release any resources; the name mirrors that 52 // in Android's OverscrollGlow class. 53 void Release(base::TimeTicks current_time); 54 55 // Returns true if the effect still needs animation ticks. 56 bool Animate(base::TimeTicks current_time); 57 58 // Returns true if the effect needs animation ticks. 59 bool NeedsAnimate() const; 60 61 // The root layer of the effect (not necessarily of the tree). 62 scoped_refptr<cc::Layer> root_layer() const { 63 return root_layer_; 64 } 65 66 // Horizontal overscroll will be ignored when false. 67 void set_horizontal_overscroll_enabled(bool enabled) { 68 horizontal_overscroll_enabled_ = enabled; 69 } 70 // Vertical overscroll will be ignored when false. 71 void set_vertical_overscroll_enabled(bool enabled) { 72 vertical_overscroll_enabled_ = enabled; 73 } 74 // The size of the layer for which edges will be animated. 75 void set_size(gfx::SizeF size) { 76 size_ = size; 77 } 78 79 private: 80 enum Axis { AXIS_X, AXIS_Y }; 81 82 OverscrollGlow(bool enabled, const SkBitmap& edge, const SkBitmap& glow); 83 84 void Pull(base::TimeTicks current_time, 85 gfx::Vector2dF added_overscroll); 86 void Absorb(base::TimeTicks current_time, 87 gfx::Vector2dF velocity, 88 gfx::Vector2dF overscroll, 89 gfx::Vector2dF old_overscroll); 90 91 void ReleaseAxis(Axis axis, base::TimeTicks current_time); 92 93 EdgeEffect* GetOppositeEdge(int edge_index); 94 95 scoped_ptr<EdgeEffect> edge_effects_[EdgeEffect::EDGE_COUNT]; 96 97 bool enabled_; 98 gfx::SizeF size_; 99 gfx::Vector2dF old_overscroll_; 100 gfx::Vector2dF old_velocity_; 101 bool horizontal_overscroll_enabled_; 102 bool vertical_overscroll_enabled_; 103 104 scoped_refptr<cc::Layer> root_layer_; 105 106 DISALLOW_COPY_AND_ASSIGN(OverscrollGlow); 107 }; 108 109 } // namespace content 110 111 #endif // CONTENT_BROWSER_ANDROID_SCROLL_GLOW_H_ 112
