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 class CC_EXPORT InputHandlerClient { 28 public: ~InputHandlerClient()29 virtual ~InputHandlerClient() {} 30 31 virtual void WillShutdown() = 0; 32 virtual void Animate(base::TimeTicks time) = 0; 33 virtual void MainThreadHasStoppedFlinging() = 0; 34 35 // Called when scroll deltas reaching the root scrolling layer go unused. 36 // The accumulated overscroll is scoped by the most recent call to 37 // InputHandler::ScrollBegin. 38 virtual void DidOverscroll(const gfx::Vector2dF& accumulated_overscroll, 39 const gfx::Vector2dF& latest_overscroll_delta) = 0; 40 41 protected: InputHandlerClient()42 InputHandlerClient() {} 43 44 private: 45 DISALLOW_COPY_AND_ASSIGN(InputHandlerClient); 46 }; 47 48 // The InputHandler is a way for the embedders to interact with the impl thread 49 // side of the compositor implementation. There is one InputHandler per 50 // LayerTreeHost. To use the input handler, implement the InputHanderClient 51 // interface and bind it to the handler on the compositor thread. 52 class CC_EXPORT InputHandler { 53 public: 54 // Note these are used in a histogram. Do not reorder or delete existing 55 // entries. 56 enum ScrollStatus { 57 ScrollOnMainThread = 0, 58 ScrollStarted, 59 ScrollIgnored, 60 ScrollUnknown, 61 // This must be the last entry. 62 ScrollStatusCount 63 }; 64 enum ScrollInputType { Gesture, Wheel, NonBubblingGesture }; 65 66 // Binds a client to this handler to receive notifications. Only one client 67 // can be bound to an InputHandler. The client must live at least until the 68 // handler calls WillShutdown() on the client. 69 virtual void BindToClient(InputHandlerClient* client) = 0; 70 71 // Selects a layer to be scrolled at a given point in viewport (logical 72 // pixel) coordinates. Returns ScrollStarted if the layer at the coordinates 73 // can be scrolled, ScrollOnMainThread if the scroll event should instead be 74 // delegated to the main thread, or ScrollIgnored if there is nothing to be 75 // scrolled at the given coordinates. 76 virtual ScrollStatus ScrollBegin(const gfx::Point& viewport_point, 77 ScrollInputType type) = 0; 78 79 // Scroll the selected layer starting at the given position. If the scroll 80 // type given to ScrollBegin was a gesture, then the scroll point and delta 81 // should be in viewport (logical pixel) coordinates. Otherwise they are in 82 // scrolling layer's (logical pixel) space. If there is no room to move the 83 // layer in the requested direction, its first ancestor layer that can be 84 // scrolled will be moved instead. If no layer can be moved in the requested 85 // direction at all, then false is returned. If any layer is moved, then 86 // true is returned. 87 // If the scroll delta hits the root layer, and the layer can no longer move, 88 // the root overscroll accumulated within this ScrollBegin() scope is reported 89 // to the client. 90 // Should only be called if ScrollBegin() returned ScrollStarted. 91 virtual bool ScrollBy(const gfx::Point& viewport_point, 92 const gfx::Vector2dF& scroll_delta) = 0; 93 94 virtual bool ScrollVerticallyByPage(const gfx::Point& viewport_point, 95 ScrollDirection direction) = 0; 96 97 // Returns ScrollStarted if a layer was being actively being scrolled, 98 // ScrollIgnored if not. 99 virtual ScrollStatus FlingScrollBegin() = 0; 100 101 virtual void MouseMoveAt(const gfx::Point& mouse_position) = 0; 102 103 // Stop scrolling the selected layer. Should only be called if ScrollBegin() 104 // returned ScrollStarted. 105 virtual void ScrollEnd() = 0; 106 107 virtual void SetRootLayerScrollOffsetDelegate( 108 LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate) = 0; 109 110 // Called when the value returned by 111 // LayerScrollOffsetDelegate.GetTotalScrollOffset has changed for reasons 112 // other than a SetTotalScrollOffset call. 113 // NOTE: This should only called after a valid delegate was set via a call to 114 // SetRootLayerScrollOffsetDelegate. 115 virtual void OnRootLayerDelegatedScrollOffsetChanged() = 0; 116 117 virtual void PinchGestureBegin() = 0; 118 virtual void PinchGestureUpdate(float magnify_delta, 119 const gfx::Point& anchor) = 0; 120 virtual void PinchGestureEnd() = 0; 121 122 virtual void StartPageScaleAnimation(const gfx::Vector2d& target_offset, 123 bool anchor_point, 124 float page_scale, 125 base::TimeDelta duration) = 0; 126 127 // Request another callback to InputHandlerClient::Animate(). 128 virtual void SetNeedsAnimate() = 0; 129 130 // Whether the layer under |viewport_point| is the currently scrolling layer. 131 virtual bool IsCurrentlyScrollingLayerAt(const gfx::Point& viewport_point, 132 ScrollInputType type) = 0; 133 134 virtual bool HaveTouchEventHandlersAt(const gfx::Point& viewport_point) = 0; 135 136 // Calling CreateLatencyInfoSwapPromiseMonitor() to get a scoped 137 // LatencyInfoSwapPromiseMonitor. During the life time of the 138 // LatencyInfoSwapPromiseMonitor, if SetNeedsRedraw() or SetNeedsRedrawRect() 139 // is called on LayerTreeHostImpl, the original latency info will be turned 140 // into a LatencyInfoSwapPromise. 141 virtual scoped_ptr<SwapPromiseMonitor> CreateLatencyInfoSwapPromiseMonitor( 142 ui::LatencyInfo* latency) = 0; 143 144 protected: InputHandler()145 InputHandler() {} ~InputHandler()146 virtual ~InputHandler() {} 147 148 private: 149 DISALLOW_COPY_AND_ASSIGN(InputHandler); 150 }; 151 152 } // namespace cc 153 154 #endif // CC_INPUT_INPUT_HANDLER_H_ 155