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1 // Copyright 2014 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_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_
6 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_
7 
8 #include "content/browser/renderer_host/input/touch_emulator_client.h"
9 #include "content/common/cursors/webcursor.h"
10 #include "content/common/input/input_event_ack_state.h"
11 #include "third_party/WebKit/public/web/WebInputEvent.h"
12 #include "ui/events/gesture_detection/filtered_gesture_provider.h"
13 #include "ui/gfx/size_f.h"
14 
15 namespace content {
16 
17 // Emulates touch input with mouse and keyboard.
18 class CONTENT_EXPORT TouchEmulator : public ui::GestureProviderClient {
19  public:
20   explicit TouchEmulator(TouchEmulatorClient* client);
21   virtual ~TouchEmulator();
22 
23   void Enable();
24   void Disable();
25 
26   // Note that TouchEmulator should always listen to touch events and their acks
27   // (even in disabled state) to track native stream presence.
enabled()28   bool enabled() const { return enabled_; }
29 
30   // Returns |true| if the event was consumed. Consumed event should not
31   // propagate any further.
32   // TODO(dgozman): maybe pass latency info together with events.
33   bool HandleMouseEvent(const blink::WebMouseEvent& event);
34   bool HandleMouseWheelEvent(const blink::WebMouseWheelEvent& event);
35   bool HandleKeyboardEvent(const blink::WebKeyboardEvent& event);
36   bool HandleTouchEvent(const blink::WebTouchEvent& event);
37 
38   // Returns |true| if the event ack was consumed. Consumed ack should not
39   // propagate any further.
40   bool HandleTouchEventAck(const blink::WebTouchEvent& event,
41                            InputEventAckState ack_result);
42 
43   // Cancel any touches, for example, when focus is lost.
44   void CancelTouch();
45 
46  private:
47   // ui::GestureProviderClient implementation.
48   virtual void OnGestureEvent(const ui::GestureEventData& gesture) OVERRIDE;
49 
50   // Returns cursor size in DIP.
51   gfx::SizeF InitCursorFromResource(
52       WebCursor* cursor, float scale, int resource_id);
53   void ResetState();
54   void UpdateCursor();
55   bool UpdateShiftPressed(bool shift_pressed);
56 
57   // Whether we should convert scrolls into pinches.
58   bool InPinchGestureMode() const;
59 
60   bool FillTouchEventAndPoint(const blink::WebMouseEvent& mouse_event);
61   void FillPinchEvent(const blink::WebInputEvent& event);
62 
63   // The following methods generate and pass gesture events to the renderer.
64   void PinchBegin(const blink::WebGestureEvent& event);
65   void PinchUpdate(const blink::WebGestureEvent& event);
66   void PinchEnd(const blink::WebGestureEvent& event);
67   void ScrollEnd(const blink::WebGestureEvent& event);
68 
69   void ForwardTouchEventToClient();
70 
71   TouchEmulatorClient* const client_;
72   ui::FilteredGestureProvider gesture_provider_;
73 
74   // Disabled emulator does only process touch acks left from previous
75   // emulation. It does not intercept any events.
76   bool enabled_;
77 
78   // While emulation is on, default cursor is touch. Pressing shift changes
79   // cursor to the pinch one.
80   WebCursor pointer_cursor_;
81   WebCursor touch_cursor_;
82   WebCursor pinch_cursor_;
83   gfx::SizeF cursor_size_;
84 
85   // These are used to drop extra mouse move events coming too quickly, so
86   // we don't handle too much touches in gesture provider.
87   bool last_mouse_event_was_move_;
88   double last_mouse_move_timestamp_;
89 
90   bool mouse_pressed_;
91   bool shift_pressed_;
92 
93   blink::WebTouchEvent touch_event_;
94   int emulated_stream_active_sequence_count_;
95   int native_stream_active_sequence_count_;
96 
97   // Whether we should suppress next fling cancel. This may happen when we
98   // did not send fling start in pinch mode.
99   bool suppress_next_fling_cancel_;
100 
101   blink::WebGestureEvent pinch_event_;
102   // Point which does not move while pinch-zooming.
103   gfx::Point pinch_anchor_;
104   // The cumulative scale change from the start of pinch gesture.
105   float pinch_scale_;
106   bool pinch_gesture_active_;
107 
108   DISALLOW_COPY_AND_ASSIGN(TouchEmulator);
109 };
110 
111 }  // namespace content
112 
113 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_
114