Sync ui/events to chromium @ https://codereview.chromium.org/1210203002

ui/events/gesture_detection/motion_event.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_MOTION_EVENT_H_
 #define UI_EVENTS_GESTURE_DETECTION_MOTION_EVENT_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "ui/events/gesture_detection/gesture_detection_export.h"
@@ skipping 28 matching lines @@
     BUTTON_BACK = 1 << 3,
     BUTTON_FORWARD = 1 << 4,
   };
 
   // The implementer promises that |GetPointerId()| will never exceed
   // MAX_POINTER_ID.
   enum { MAX_POINTER_ID = 31, MAX_TOUCH_POINT_COUNT = 16 };
 
   virtual ~MotionEvent() {}
 
-  virtual int GetId() const = 0;
+  // An unique identifier this motion event.
+  virtual uint32 GetUniqueEventId() const = 0;
   virtual Action GetAction() const = 0;
   // Only valid if |GetAction()| returns ACTION_POINTER_UP or
   // ACTION_POINTER_DOWN.
   virtual int GetActionIndex() const = 0;
   virtual size_t GetPointerCount() const = 0;
   virtual int GetPointerId(size_t pointer_index) const = 0;
   virtual float GetX(size_t pointer_index) const = 0;
   virtual float GetY(size_t pointer_index) const = 0;
   virtual float GetRawX(size_t pointer_index) const = 0;
   virtual float GetRawY(size_t pointer_index) const = 0;
   virtual float GetTouchMajor(size_t pointer_index) const = 0;
   virtual float GetTouchMinor(size_t pointer_index) const = 0;
   virtual float GetOrientation(size_t pointer_index) const = 0;
   virtual float GetPressure(size_t pointer_index) const = 0;
   virtual ToolType GetToolType(size_t pointer_index) const = 0;
   virtual int GetButtonState() const = 0;
   virtual int GetFlags() const = 0;
   virtual base::TimeTicks GetEventTime() const = 0;
 
   // Optional historical data, default implementation provides an empty history.
   virtual size_t GetHistorySize() const;
   virtual base::TimeTicks GetHistoricalEventTime(size_t historical_index) const;
   virtual float GetHistoricalTouchMajor(size_t pointer_index,
                                         size_t historical_index) const;
   virtual float GetHistoricalX(size_t pointer_index,
                                size_t historical_index) const;
   virtual float GetHistoricalY(size_t pointer_index,
                                size_t historical_index) const;
 
-  virtual scoped_ptr<MotionEvent> Clone() const = 0;
-  virtual scoped_ptr<MotionEvent> Cancel() const = 0;
+  // Get the id of the device which created the event. Currently Aura only.
+  virtual int GetSourceDeviceId(size_t pointer_index) const;
 
+  // Utility accessor methods for convenience.
+  int GetPointerId() const { return GetPointerId(0); }
   float GetX() const { return GetX(0); }
   float GetY() const { return GetY(0); }
   float GetRawX() const { return GetRawX(0); }
   float GetRawY() const { return GetRawY(0); }
   float GetRawOffsetX() const { return GetRawX() - GetX(); }
   float GetRawOffsetY() const { return GetRawY() - GetY(); }
 
   float GetTouchMajor() const { return GetTouchMajor(0); }
   float GetTouchMinor() const { return GetTouchMinor(0); }
 
-  // Returns the orientation of the major axis clockwise from vertical, in
-  // radians. The return value lies in [-PI/2, PI/2].
+  // Returns the orientation in radians. The meaning is overloaded:
+  // * For a touch screen or pad, it's the orientation of the major axis
+  //   clockwise from vertical. The return value lies in [-PI/2, PI/2].
+  // * For a stylus, it indicates the direction in which the stylus is pointing.
+  //   The return value lies in [-PI, PI].
   float GetOrientation() const { return GetOrientation(0); }
 
   float GetPressure() const { return GetPressure(0); }
   ToolType GetToolType() const { return GetToolType(0); }
 
   // O(N) search of pointers (use sparingly!). Returns -1 if |id| nonexistent.
   int FindPointerIndexOfId(int id) const;
+
+  // Note that these methods perform shallow copies of the originating events.
+  // They guarantee only that the returned type will reflect the same
+  // data exposed by the MotionEvent interface; no guarantees are made that the
+  // underlying implementation is identical to the source implementation.
+  scoped_ptr<MotionEvent> Clone() const;
+  scoped_ptr<MotionEvent> Cancel() const;
 };
 
-GESTURE_DETECTION_EXPORT bool operator==(const MotionEvent& lhs,
-                                         const MotionEvent& rhs);
-GESTURE_DETECTION_EXPORT bool operator!=(const MotionEvent& lhs,
-                                         const MotionEvent& rhs);
-
 }  // namespace ui
 
 #endif  // UI_EVENTS_GESTURE_DETECTION_MOTION_EVENT_H_