gesture_provider.h revision 5c02ac1a9c1b504631c0a3d2b6e737b5d738bae1 
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 UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_
6#define UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_
7
8#include "base/basictypes.h"
9#include "base/memory/scoped_ptr.h"
10#include "ui/events/gesture_detection/gesture_detection_export.h"
11#include "ui/events/gesture_detection/gesture_detector.h"
12#include "ui/events/gesture_detection/scale_gesture_detector.h"
13#include "ui/events/gesture_detection/snap_scroll_controller.h"
14#include "ui/gfx/display.h"
15
16namespace ui {
17
18struct GestureEventData;
19
20class GESTURE_DETECTION_EXPORT GestureProviderClient {
21 public:
22  virtual ~GestureProviderClient() {}
23  virtual void OnGestureEvent(const GestureEventData& gesture) = 0;
24};
25
26// Given a stream of |MotionEvent|'s, provides gesture detection and gesture
27// event dispatch.
28class GESTURE_DETECTION_EXPORT GestureProvider {
29 public:
30  struct GESTURE_DETECTION_EXPORT Config {
31    Config();
32    ~Config();
33    gfx::Display display;
34    GestureDetector::Config gesture_detector_config;
35    ScaleGestureDetector::Config scale_gesture_detector_config;
36
37    // If |disable_click_delay| is true and double-tap support is disabled,
38    // there will be no delay before tap events. When double-tap support is
39    // enabled, there will always be a delay before a tap event is fired, in
40    // order to allow the double tap gesture to occur without firing any tap
41    // events.
42    bool disable_click_delay;
43
44    // If |gesture_begin_end_types_enabled| is true, fire an ET_GESTURE_BEGIN
45    // event for every added touch point, and an ET_GESTURE_END event for every
46    // removed touch point. Defaults to false.
47    bool gesture_begin_end_types_enabled;
48  };
49
50  GestureProvider(const Config& config, GestureProviderClient* client);
51  ~GestureProvider();
52
53  // Handle the incoming MotionEvent, returning false if the event could not
54  // be handled.
55  bool OnTouchEvent(const MotionEvent& event);
56
57  // Update whether multi-touch pinch zoom is supported by the platform.
58  void SetMultiTouchZoomSupportEnabled(bool enabled);
59
60  // Update whether double-tap gestures are supported by the platform.
61  void SetDoubleTapSupportForPlatformEnabled(bool enabled);
62
63  // Update whether double-tap gesture detection should be suppressed, e.g.,
64  // if the page scale is fixed or the page has a mobile viewport. This disables
65  // the tap delay, allowing rapid and responsive single-tap gestures.
66  void SetDoubleTapSupportForPageEnabled(bool enabled);
67
68  // Whether a scroll gesture is in-progress.
69  bool IsScrollInProgress() const;
70
71  // Whether a pinch gesture is in-progress (i.e. a pinch update has been
72  // forwarded and detection is still active).
73  bool IsPinchInProgress() const;
74
75  // Whether a double-tap gesture is in-progress (either double-tap or
76  // double-tap drag zoom).
77  bool IsDoubleTapInProgress() const;
78
79  // May be NULL if there is no currently active touch sequence.
80  const ui::MotionEvent* current_down_event() const {
81    return current_down_event_.get();
82  }
83
84 private:
85  void InitGestureDetectors(const Config& config);
86
87  bool CanHandle(const MotionEvent& event) const;
88
89  void Fling(const MotionEvent& e, float velocity_x, float velocity_y);
90  void Send(const GestureEventData& gesture);
91  bool SendLongTapIfNecessary(const MotionEvent& event);
92  void EndTouchScrollIfNecessary(const MotionEvent& event,
93                                 bool send_scroll_end_event);
94  void OnTouchEventHandlingBegin(const MotionEvent& event);
95  void OnTouchEventHandlingEnd(const MotionEvent& event);
96  void UpdateDoubleTapDetectionSupport();
97
98  GestureProviderClient* const client_;
99
100  class GestureListenerImpl;
101  friend class GestureListenerImpl;
102  scoped_ptr<GestureListenerImpl> gesture_listener_;
103
104  class ScaleGestureListenerImpl;
105  friend class ScaleGestureListenerImpl;
106  scoped_ptr<ScaleGestureListenerImpl> scale_gesture_listener_;
107
108  scoped_ptr<MotionEvent> current_down_event_;
109
110  // Whether the respective {SCROLL,PINCH}_BEGIN gestures have been terminated
111  // with a {SCROLL,PINCH}_END.
112  bool touch_scroll_in_progress_;
113  bool pinch_in_progress_;
114
115  // Whether double-tap gesture detection is currently supported.
116  bool double_tap_support_for_page_;
117  bool double_tap_support_for_platform_;
118
119  // Keeps track of the current GESTURE_LONG_PRESS event. If a context menu is
120  // opened after a GESTURE_LONG_PRESS, this is used to insert a
121  // GESTURE_TAP_CANCEL for removing any ::active styling.
122  base::TimeTicks current_longpress_time_;
123
124  bool gesture_begin_end_types_enabled_;
125};
126
127}  //  namespace ui
128
129#endif  // UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_
130