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.
5 #ifndef UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_
6 #define UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_
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/gesture_event_data.h"
13 #include "ui/events/gesture_detection/gesture_touch_uma_histogram.h"
14 #include "ui/events/gesture_detection/scale_gesture_detector.h"
15 #include "ui/events/gesture_detection/snap_scroll_controller.h"
16 #include "ui/gfx/display.h"
20 class GESTURE_DETECTION_EXPORT GestureProviderClient {
22 virtual ~GestureProviderClient() {}
23 virtual void OnGestureEvent(const GestureEventData& gesture) = 0;
26 // Given a stream of |MotionEvent|'s, provides gesture detection and gesture
28 class GESTURE_DETECTION_EXPORT GestureProvider {
30 struct GESTURE_DETECTION_EXPORT Config {
34 GestureDetector::Config gesture_detector_config;
35 ScaleGestureDetector::Config scale_gesture_detector_config;
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
42 bool disable_click_delay;
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. This requires one ACTION_CANCEL event to be sent per
47 // touch point, which only occurs on Aura. Defaults to false.
48 bool gesture_begin_end_types_enabled;
50 // The min and max size (both length and width, in dips) of the generated
51 // bounding box for all gesture types. This is useful for touch streams
52 // that may report zero or unreasonably small or large touch sizes.
53 // Note that these bounds are only applied for touch or unknown tool types;
54 // mouse and stylus-derived gestures will not be affected.
55 // Both values default to 0 (disabled).
56 float min_gesture_bounds_length;
57 float max_gesture_bounds_length;
60 GestureProvider(const Config& config, GestureProviderClient* client);
63 // Handle the incoming MotionEvent, returning false if the event could not
65 bool OnTouchEvent(const MotionEvent& event);
67 // Update whether multi-touch pinch zoom is supported by the platform.
68 void SetMultiTouchZoomSupportEnabled(bool enabled);
70 // Update whether double-tap gestures are supported by the platform.
71 void SetDoubleTapSupportForPlatformEnabled(bool enabled);
73 // Update whether double-tap gesture detection should be suppressed, e.g.,
74 // if the page scale is fixed or the page has a mobile viewport. This disables
75 // the tap delay, allowing rapid and responsive single-tap gestures.
76 void SetDoubleTapSupportForPageEnabled(bool enabled);
78 // Whether a scroll gesture is in-progress.
79 bool IsScrollInProgress() const;
81 // Whether a pinch gesture is in-progress (i.e. a pinch update has been
82 // forwarded and detection is still active).
83 bool IsPinchInProgress() const;
85 // Whether a double-tap gesture is in-progress (either double-tap or
86 // double-tap drag zoom).
87 bool IsDoubleTapInProgress() const;
89 // May be NULL if there is no currently active touch sequence.
90 const ui::MotionEvent* current_down_event() const {
91 return current_down_event_.get();
95 bool CanHandle(const MotionEvent& event) const;
96 void OnTouchEventHandlingBegin(const MotionEvent& event);
97 void OnTouchEventHandlingEnd(const MotionEvent& event);
98 void UpdateDoubleTapDetectionSupport();
100 class GestureListenerImpl;
101 scoped_ptr<GestureListenerImpl> gesture_listener_;
103 scoped_ptr<MotionEvent> current_down_event_;
105 // Logs information on touch and gesture events.
106 GestureTouchUMAHistogram uma_histogram_;
108 // Whether double-tap gesture detection is currently supported.
109 bool double_tap_support_for_page_;
110 bool double_tap_support_for_platform_;
112 const bool gesture_begin_end_types_enabled_;
117 #endif // UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_