1 // Copyright 2011 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 CC_INPUT_INPUT_HANDLER_H_ 6 #define CC_INPUT_INPUT_HANDLER_H_ 7 8 #include "base/basictypes.h" 9 #include "base/time/time.h" 10 #include "cc/base/cc_export.h" 11 #include "cc/base/swap_promise_monitor.h" 12 #include "cc/input/scrollbar.h" 13 14 namespace gfx { 15 class Point; 16 class PointF; 17 class Vector2d; 18 class Vector2dF; 19 } 20 21 namespace ui { struct LatencyInfo; } 22 23 namespace cc { 24 25 class LayerScrollOffsetDelegate; 26 27 struct DidOverscrollParams { 28 gfx::Vector2dF accumulated_overscroll; 29 gfx::Vector2dF latest_overscroll_delta; 30 gfx::Vector2dF current_fling_velocity; 31 }; 32 33 class CC_EXPORT InputHandlerClient { 34 public: ~InputHandlerClient()35 virtual ~InputHandlerClient() {} 36 37 virtual void WillShutdown() = 0; 38 virtual void Animate(base::TimeTicks time) = 0; 39 virtual void MainThreadHasStoppedFlinging() = 0; 40 41 // Called when scroll deltas reaching the root scrolling layer go unused. 42 // The accumulated overscroll is scoped by the most recent call to 43 // InputHandler::ScrollBegin. 44 virtual void DidOverscroll(const DidOverscrollParams& params) = 0; 45 46 protected: InputHandlerClient()47 InputHandlerClient() {} 48 49 private: 50 DISALLOW_COPY_AND_ASSIGN(InputHandlerClient); 51 }; 52 53 // The InputHandler is a way for the embedders to interact with the impl thread 54 // side of the compositor implementation. There is one InputHandler per 55 // LayerTreeHost. To use the input handler, implement the InputHanderClient 56 // interface and bind it to the handler on the compositor thread. 57 class CC_EXPORT InputHandler { 58 public: 59 enum ScrollStatus { ScrollOnMainThread, ScrollStarted, ScrollIgnored }; 60 enum ScrollInputType { Gesture, Wheel, NonBubblingGesture }; 61 62 // Binds a client to this handler to receive notifications. Only one client 63 // can be bound to an InputHandler. The client must live at least until the 64 // handler calls WillShutdown() on the client. 65 virtual void BindToClient(InputHandlerClient* client) = 0; 66 67 // Selects a layer to be scrolled at a given point in viewport (logical 68 // pixel) coordinates. Returns ScrollStarted if the layer at the coordinates 69 // can be scrolled, ScrollOnMainThread if the scroll event should instead be 70 // delegated to the main thread, or ScrollIgnored if there is nothing to be 71 // scrolled at the given coordinates. 72 virtual ScrollStatus ScrollBegin(gfx::Point viewport_point, 73 ScrollInputType type) = 0; 74 75 // Scroll the selected layer starting at the given position. If the scroll 76 // type given to ScrollBegin was a gesture, then the scroll point and delta 77 // should be in viewport (logical pixel) coordinates. Otherwise they are in 78 // scrolling layer's (logical pixel) space. If there is no room to move the 79 // layer in the requested direction, its first ancestor layer that can be 80 // scrolled will be moved instead. If no layer can be moved in the requested 81 // direction at all, then false is returned. If any layer is moved, then 82 // true is returned. 83 // If the scroll delta hits the root layer, and the layer can no longer move, 84 // the root overscroll accumulated within this ScrollBegin() scope is reported 85 // to the client. 86 // Should only be called if ScrollBegin() returned ScrollStarted. 87 virtual bool ScrollBy(gfx::Point viewport_point, 88 gfx::Vector2dF scroll_delta) = 0; 89 90 virtual bool ScrollVerticallyByPage( 91 gfx::Point viewport_point, 92 ScrollDirection direction) = 0; 93 94 // Returns ScrollStarted if a layer was being actively being scrolled, 95 // ScrollIgnored if not. 96 virtual ScrollStatus FlingScrollBegin() = 0; 97 98 virtual void NotifyCurrentFlingVelocity(gfx::Vector2dF velocity) = 0; 99 100 virtual void MouseMoveAt(gfx::Point mouse_position) = 0; 101 102 // Stop scrolling the selected layer. Should only be called if ScrollBegin() 103 // returned ScrollStarted. 104 virtual void ScrollEnd() = 0; 105 106 virtual void SetRootLayerScrollOffsetDelegate( 107 LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate) = 0; 108 109 // Called when the value returned by 110 // LayerScrollOffsetDelegate.GetTotalScrollOffset has changed for reasons 111 // other than a SetTotalScrollOffset call. 112 // NOTE: This should only called after a valid delegate was set via a call to 113 // SetRootLayerScrollOffsetDelegate. 114 virtual void OnRootLayerDelegatedScrollOffsetChanged() = 0; 115 116 virtual void PinchGestureBegin() = 0; 117 virtual void PinchGestureUpdate(float magnify_delta, gfx::Point anchor) = 0; 118 virtual void PinchGestureEnd() = 0; 119 120 virtual void StartPageScaleAnimation(gfx::Vector2d target_offset, 121 bool anchor_point, 122 float page_scale, 123 base::TimeDelta duration) = 0; 124 125 // Request another callback to InputHandlerClient::Animate(). 126 virtual void ScheduleAnimation() = 0; 127 128 virtual bool HaveTouchEventHandlersAt(gfx::Point viewport_point) = 0; 129 130 // Calling CreateLatencyInfoSwapPromiseMonitor() to get a scoped 131 // LatencyInfoSwapPromiseMonitor. During the life time of the 132 // LatencyInfoSwapPromiseMonitor, if SetNeedsRedraw() or SetNeedsRedrawRect() 133 // is called on LayerTreeHostImpl, the original latency info will be turned 134 // into a LatencyInfoSwapPromise. 135 virtual scoped_ptr<SwapPromiseMonitor> CreateLatencyInfoSwapPromiseMonitor( 136 ui::LatencyInfo* latency) = 0; 137 138 protected: InputHandler()139 InputHandler() {} ~InputHandler()140 virtual ~InputHandler() {} 141 142 private: 143 DISALLOW_COPY_AND_ASSIGN(InputHandler); 144 }; 145 146 } // namespace cc 147 148 #endif // CC_INPUT_INPUT_HANDLER_H_ 149