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 a new effect. If |enabled| is false, the effect will remain 30 // deactivated until explicitly enabled. 31 // Note: No resources will be allocated until the effect is both 32 // enabled and an overscroll event has occurred. 33 static scoped_ptr<OverscrollGlow> Create(bool enabled); 34 35 ~OverscrollGlow(); 36 37 // Enable the effect. If the effect was previously disabled, it will remain 38 // dormant until subsequent calls to |OnOverscrolled()|. 39 void Enable(); 40 41 // Deactivate and detach the effect. Subsequent calls to |OnOverscrolled()| or 42 // |Animate()| will have no effect. 43 void Disable(); 44 45 // Effect layers will be attached to |overscrolling_layer| if necessary. 46 // |accumulated_overscroll| and |overscroll_delta| are in device pixels, while 47 // |velocity| is in device pixels / second. 48 // Returns true if the effect still needs animation ticks. 49 bool OnOverscrolled(cc::Layer* overscrolling_layer, 50 base::TimeTicks current_time, 51 gfx::Vector2dF accumulated_overscroll, 52 gfx::Vector2dF overscroll_delta, 53 gfx::Vector2dF velocity); 54 55 // Returns true if the effect still needs animation ticks. 56 // Note: The effect will detach itself when no further animation is required. 57 bool Animate(base::TimeTicks current_time); 58 59 // Update the effect according to the most recent display parameters, 60 // Note: All dimensions are in device pixels. 61 struct DisplayParameters { 62 DisplayParameters(); 63 gfx::SizeF size; 64 float edge_offsets[EdgeEffect::EDGE_COUNT]; 65 float device_scale_factor; 66 }; 67 void UpdateDisplayParameters(const DisplayParameters& params); 68 69 70 private: 71 enum Axis { AXIS_X, AXIS_Y }; 72 73 OverscrollGlow(bool enabled); 74 75 // Returns whether the effect is initialized. 76 bool InitializeIfNecessary(); 77 bool NeedsAnimate() const; 78 void UpdateLayerAttachment(cc::Layer* parent); 79 void Detach(); 80 void Pull(base::TimeTicks current_time, gfx::Vector2dF overscroll_delta); 81 void Absorb(base::TimeTicks current_time, 82 gfx::Vector2dF velocity, 83 bool x_overscroll_started, 84 bool y_overscroll_started); 85 void Release(base::TimeTicks current_time); 86 void ReleaseAxis(Axis axis, base::TimeTicks current_time); 87 88 EdgeEffect* GetOppositeEdge(int edge_index); 89 90 scoped_ptr<EdgeEffect> edge_effects_[EdgeEffect::EDGE_COUNT]; 91 92 DisplayParameters display_params_; 93 bool enabled_; 94 bool initialized_; 95 96 scoped_refptr<cc::Layer> root_layer_; 97 98 DISALLOW_COPY_AND_ASSIGN(OverscrollGlow); 99 }; 100 101 } // namespace content 102 103 #endif // CONTENT_BROWSER_ANDROID_SCROLL_GLOW_H_ 104