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/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" 17 18 namespace ui { 19 20 class GESTURE_DETECTION_EXPORT GestureProviderClient { 21 public: ~GestureProviderClient()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. 28 class 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. 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; 49 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; 58 }; 59 60 GestureProvider(const Config& config, GestureProviderClient* client); 61 ~GestureProvider(); 62 63 // Handle the incoming MotionEvent, returning false if the event could not 64 // be handled. 65 bool OnTouchEvent(const MotionEvent& event); 66 67 // Update whether multi-touch pinch zoom is supported by the platform. 68 void SetMultiTouchZoomSupportEnabled(bool enabled); 69 70 // Update whether double-tap gestures are supported by the platform. 71 void SetDoubleTapSupportForPlatformEnabled(bool enabled); 72 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); 77 78 // Whether a scroll gesture is in-progress. 79 bool IsScrollInProgress() const; 80 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; 84 85 // Whether a double-tap gesture is in-progress (either double-tap or 86 // double-tap drag zoom). 87 bool IsDoubleTapInProgress() const; 88 89 // May be NULL if there is no currently active touch sequence. current_down_event()90 const ui::MotionEvent* current_down_event() const { 91 return current_down_event_.get(); 92 } 93 94 private: 95 bool CanHandle(const MotionEvent& event) const; 96 void OnTouchEventHandlingBegin(const MotionEvent& event); 97 void OnTouchEventHandlingEnd(const MotionEvent& event); 98 void UpdateDoubleTapDetectionSupport(); 99 100 class GestureListenerImpl; 101 scoped_ptr<GestureListenerImpl> gesture_listener_; 102 103 scoped_ptr<MotionEvent> current_down_event_; 104 105 // Logs information on touch and gesture events. 106 GestureTouchUMAHistogram uma_histogram_; 107 108 // Whether double-tap gesture detection is currently supported. 109 bool double_tap_support_for_page_; 110 bool double_tap_support_for_platform_; 111 112 const bool gesture_begin_end_types_enabled_; 113 }; 114 115 } // namespace ui 116 117 #endif // UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_ 118