Support minimum gesture bounds in GestureProvider

ui/events/gesture_detection/gesture_provider.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_
 #define UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/events/gesture_detection/gesture_detection_export.h"
 #include "ui/events/gesture_detection/gesture_detector.h"
+#include "ui/events/gesture_detection/gesture_event_data.h"
 #include "ui/events/gesture_detection/scale_gesture_detector.h"
 #include "ui/events/gesture_detection/snap_scroll_controller.h"
 #include "ui/gfx/display.h"
 
 namespace ui {
 
-struct GestureEventData;
-
 class GESTURE_DETECTION_EXPORT GestureProviderClient {
  public:
   virtual ~GestureProviderClient() {}
   virtual void OnGestureEvent(const GestureEventData& gesture) = 0;
 };
 
 // Given a stream of |MotionEvent|'s, provides gesture detection and gesture
 // event dispatch.
 class GESTURE_DETECTION_EXPORT GestureProvider {
  public:
   struct GESTURE_DETECTION_EXPORT Config {
     Config();
     ~Config();
     gfx::Display display;
     GestureDetector::Config gesture_detector_config;
     ScaleGestureDetector::Config scale_gesture_detector_config;
 
     // If |disable_click_delay| is true and double-tap support is disabled,
     // there will be no delay before tap events. When double-tap support is
     // enabled, there will always be a delay before a tap event is fired, in
     // order to allow the double tap gesture to occur without firing any tap
     // events.
     bool disable_click_delay;
 
     // If |gesture_begin_end_types_enabled| is true, fire an ET_GESTURE_BEGIN
     // event for every added touch point, and an ET_GESTURE_END event for every
     // removed touch point. Defaults to false.
     bool gesture_begin_end_types_enabled;
+
+    // The minimum size (both length and width, in dips) of the generated
+    // bounding box for all gesture types. This is useful for touch streams
+    // that may report zero or unreasonably small touch sizes.
+    // Defaults to 0.
+    float min_gesture_bounds_length;
   };
 
   GestureProvider(const Config& config, GestureProviderClient* client);
   ~GestureProvider();
 
   // Handle the incoming MotionEvent, returning false if the event could not
   // be handled.
   bool OnTouchEvent(const MotionEvent& event);
 
   // Update whether multi-touch pinch zoom is supported by the platform.
@@ skipping 22 matching lines @@
   const ui::MotionEvent* current_down_event() const {
     return current_down_event_.get();
   }
 
  private:
   void InitGestureDetectors(const Config& config);
 
   bool CanHandle(const MotionEvent& event) const;
 
   void Fling(const MotionEvent& e, float velocity_x, float velocity_y);
-  void Send(const GestureEventData& gesture);
+  void Send(GestureEventData gesture);
   bool SendLongTapIfNecessary(const MotionEvent& event);
   void EndTouchScrollIfNecessary(const MotionEvent& event,
                                  bool send_scroll_end_event);
   void OnTouchEventHandlingBegin(const MotionEvent& event);
   void OnTouchEventHandlingEnd(const MotionEvent& event);
   void UpdateDoubleTapDetectionSupport();
 
   GestureProviderClient* const client_;
 
   class GestureListenerImpl;
@@ skipping 13 matching lines @@
 
   // Whether double-tap gesture detection is currently supported.
   bool double_tap_support_for_page_;
   bool double_tap_support_for_platform_;
 
   // Keeps track of the current GESTURE_LONG_PRESS event. If a context menu is
   // opened after a GESTURE_LONG_PRESS, this is used to insert a
   // GESTURE_TAP_CANCEL for removing any ::active styling.
   base::TimeTicks current_longpress_time_;
 
-  bool gesture_begin_end_types_enabled_;
+  const bool gesture_begin_end_types_enabled_;
+
+  const float min_gesture_bounds_length_;
 };
 
 }  //  namespace ui
 
 #endif  // UI_EVENTS_GESTURE_DETECTION_GESTURE_PROVIDER_H_