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