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.
5 #ifndef CC_INPUT_INPUT_HANDLER_H_
6 #define CC_INPUT_INPUT_HANDLER_H_
8 #include "base/basictypes.h"
9 #include "base/memory/scoped_ptr.h"
10 #include "base/time/time.h"
11 #include "cc/base/cc_export.h"
12 #include "cc/base/swap_promise_monitor.h"
13 #include "cc/input/scrollbar.h"
22 namespace ui { struct LatencyInfo; }
26 class LayerScrollOffsetDelegate;
28 struct CC_EXPORT InputHandlerScrollResult {
29 InputHandlerScrollResult();
30 // Did any layer scroll as a result this ScrollBy call?
32 // Was any of the scroll delta argument to this ScrollBy call not used?
33 bool did_overscroll_root;
34 // The total overscroll that has been accumulated by all ScrollBy calls that
35 // have had overscroll since the last ScrollBegin call. This resets upon a
36 // ScrollBy with no overscroll.
37 gfx::Vector2dF accumulated_root_overscroll;
38 // The amount of the scroll delta argument to this ScrollBy call that was not
39 // used for scrolling.
40 gfx::Vector2dF unused_scroll_delta;
43 class CC_EXPORT InputHandlerClient {
45 virtual ~InputHandlerClient() {}
47 virtual void WillShutdown() = 0;
48 virtual void Animate(base::TimeTicks time) = 0;
49 virtual void MainThreadHasStoppedFlinging() = 0;
52 InputHandlerClient() {}
55 DISALLOW_COPY_AND_ASSIGN(InputHandlerClient);
58 // The InputHandler is a way for the embedders to interact with the impl thread
59 // side of the compositor implementation. There is one InputHandler per
60 // LayerTreeHost. To use the input handler, implement the InputHanderClient
61 // interface and bind it to the handler on the compositor thread.
62 class CC_EXPORT InputHandler {
64 // Note these are used in a histogram. Do not reorder or delete existing
67 ScrollOnMainThread = 0,
71 // This must be the last entry.
74 enum ScrollInputType { Gesture, Wheel, NonBubblingGesture };
76 // Binds a client to this handler to receive notifications. Only one client
77 // can be bound to an InputHandler. The client must live at least until the
78 // handler calls WillShutdown() on the client.
79 virtual void BindToClient(InputHandlerClient* client) = 0;
81 // Selects a layer to be scrolled at a given point in viewport (logical
82 // pixel) coordinates. Returns ScrollStarted if the layer at the coordinates
83 // can be scrolled, ScrollOnMainThread if the scroll event should instead be
84 // delegated to the main thread, or ScrollIgnored if there is nothing to be
85 // scrolled at the given coordinates.
86 virtual ScrollStatus ScrollBegin(const gfx::Point& viewport_point,
87 ScrollInputType type) = 0;
89 virtual ScrollStatus ScrollAnimated(const gfx::Point& viewport_point,
90 const gfx::Vector2dF& scroll_delta) = 0;
92 // Scroll the selected layer starting at the given position. If the scroll
93 // type given to ScrollBegin was a gesture, then the scroll point and delta
94 // should be in viewport (logical pixel) coordinates. Otherwise they are in
95 // scrolling layer's (logical pixel) space. If there is no room to move the
96 // layer in the requested direction, its first ancestor layer that can be
97 // scrolled will be moved instead. The return value's |did_scroll| field is
98 // set to false if no layer can be moved in the requested direction at all,
99 // and set to true if any layer is moved.
100 // If the scroll delta hits the root layer, and the layer can no longer move,
101 // the root overscroll accumulated within this ScrollBegin() scope is reported
102 // in the return value's |accumulated_overscroll| field.
103 // Should only be called if ScrollBegin() returned ScrollStarted.
104 virtual InputHandlerScrollResult ScrollBy(
105 const gfx::Point& viewport_point,
106 const gfx::Vector2dF& scroll_delta) = 0;
108 virtual bool ScrollVerticallyByPage(const gfx::Point& viewport_point,
109 ScrollDirection direction) = 0;
111 // Returns ScrollStarted if a layer was being actively being scrolled,
112 // ScrollIgnored if not.
113 virtual ScrollStatus FlingScrollBegin() = 0;
115 virtual void MouseMoveAt(const gfx::Point& mouse_position) = 0;
117 // Stop scrolling the selected layer. Should only be called if ScrollBegin()
118 // returned ScrollStarted.
119 virtual void ScrollEnd() = 0;
121 virtual void SetRootLayerScrollOffsetDelegate(
122 LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate) = 0;
124 // Called when the value returned by
125 // LayerScrollOffsetDelegate.GetTotalScrollOffset has changed for reasons
126 // other than a SetTotalScrollOffset call.
127 // NOTE: This should only called after a valid delegate was set via a call to
128 // SetRootLayerScrollOffsetDelegate.
129 virtual void OnRootLayerDelegatedScrollOffsetChanged() = 0;
131 virtual void PinchGestureBegin() = 0;
132 virtual void PinchGestureUpdate(float magnify_delta,
133 const gfx::Point& anchor) = 0;
134 virtual void PinchGestureEnd() = 0;
136 // Request another callback to InputHandlerClient::Animate().
137 virtual void SetNeedsAnimate() = 0;
139 // Whether the layer under |viewport_point| is the currently scrolling layer.
140 virtual bool IsCurrentlyScrollingLayerAt(const gfx::Point& viewport_point,
141 ScrollInputType type) = 0;
143 virtual bool HaveTouchEventHandlersAt(const gfx::Point& viewport_point) = 0;
145 // Calling CreateLatencyInfoSwapPromiseMonitor() to get a scoped
146 // LatencyInfoSwapPromiseMonitor. During the life time of the
147 // LatencyInfoSwapPromiseMonitor, if SetNeedsRedraw() or SetNeedsRedrawRect()
148 // is called on LayerTreeHostImpl, the original latency info will be turned
149 // into a LatencyInfoSwapPromise.
150 virtual scoped_ptr<SwapPromiseMonitor> CreateLatencyInfoSwapPromiseMonitor(
151 ui::LatencyInfo* latency) = 0;
155 virtual ~InputHandler() {}
158 DISALLOW_COPY_AND_ASSIGN(InputHandler);
163 #endif // CC_INPUT_INPUT_HANDLER_H_