ui/events/gesture_detection/motion_event.h

   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_MOTION_EVENT_H_
   6 #define UI_EVENTS_GESTURE_DETECTION_MOTION_EVENT_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "base/time/time.h"
  10 #include "ui/events/gesture_detection/gesture_detection_export.h"
  11
  12 namespace ui {
  13
  14 // Abstract class for a generic motion-related event, patterned after that
  15 // subset of Android's MotionEvent API used in gesture detection.
  16 class GESTURE_DETECTION_EXPORT MotionEvent {
  17  public:
  18   enum Action {
  19     ACTION_DOWN,
  20     ACTION_UP,
  21     ACTION_MOVE,
  22     ACTION_CANCEL,
  23     ACTION_POINTER_DOWN,
  24     ACTION_POINTER_UP,
  25   };
  26
  27   enum ToolType {
  28     TOOL_TYPE_UNKNOWN,
  29     TOOL_TYPE_FINGER,
  30     TOOL_TYPE_STYLUS,
  31     TOOL_TYPE_MOUSE,
  32     TOOL_TYPE_ERASER
  33   };
  34
  35   enum ButtonType {
  36     BUTTON_PRIMARY = 1 << 0,
  37     BUTTON_SECONDARY = 1 << 1,
  38     BUTTON_TERTIARY = 1 << 2,
  39     BUTTON_BACK = 1 << 3,
  40     BUTTON_FORWARD = 1 << 4,
  41   };
  42
  43   // The implementer promises that |GetPointerId()| will never exceed
  44   // MAX_POINTER_ID.
  45   enum { MAX_POINTER_ID = 31, MAX_TOUCH_POINT_COUNT = 16 };
  46
  47   virtual ~MotionEvent() {}
  48
  49   // An unique identifier this motion event.
  50   virtual uint32 GetUniqueEventId() const = 0;
  51   virtual Action GetAction() const = 0;
  52   // Only valid if |GetAction()| returns ACTION_POINTER_UP or
  53   // ACTION_POINTER_DOWN.
  54   virtual int GetActionIndex() const = 0;
  55   virtual size_t GetPointerCount() const = 0;
  56   virtual int GetPointerId(size_t pointer_index) const = 0;
  57   virtual float GetX(size_t pointer_index) const = 0;
  58   virtual float GetY(size_t pointer_index) const = 0;
  59   virtual float GetRawX(size_t pointer_index) const = 0;
  60   virtual float GetRawY(size_t pointer_index) const = 0;
  61   virtual float GetTouchMajor(size_t pointer_index) const = 0;
  62   virtual float GetTouchMinor(size_t pointer_index) const = 0;
  63   virtual float GetOrientation(size_t pointer_index) const = 0;
  64   virtual float GetPressure(size_t pointer_index) const = 0;
  65   virtual ToolType GetToolType(size_t pointer_index) const = 0;
  66   virtual int GetButtonState() const = 0;
  67   virtual int GetFlags() const = 0;
  68   virtual base::TimeTicks GetEventTime() const = 0;
  69
  70   // Optional historical data, default implementation provides an empty history.
  71   virtual size_t GetHistorySize() const;
  72   virtual base::TimeTicks GetHistoricalEventTime(size_t historical_index) const;
  73   virtual float GetHistoricalTouchMajor(size_t pointer_index,
  74                                         size_t historical_index) const;
  75   virtual float GetHistoricalX(size_t pointer_index,
  76                                size_t historical_index) const;
  77   virtual float GetHistoricalY(size_t pointer_index,
  78                                size_t historical_index) const;
  79
  80   // Get the id of the device which created the event. Currently Aura only.
  81   virtual int GetSourceDeviceId(size_t pointer_index) const;
  82
  83   // Utility accessor methods for convenience.
  84   int GetPointerId() const { return GetPointerId(0); }
  85   float GetX() const { return GetX(0); }
  86   float GetY() const { return GetY(0); }
  87   float GetRawX() const { return GetRawX(0); }
  88   float GetRawY() const { return GetRawY(0); }
  89   float GetRawOffsetX() const { return GetRawX() - GetX(); }
  90   float GetRawOffsetY() const { return GetRawY() - GetY(); }
  91
  92   float GetTouchMajor() const { return GetTouchMajor(0); }
  93   float GetTouchMinor() const { return GetTouchMinor(0); }
  94
  95   // Returns the orientation in radians. The meaning is overloaded:
  96   // * For a touch screen or pad, it's the orientation of the major axis
  97   //   clockwise from vertical. The return value lies in [-PI/2, PI/2].
  98   // * For a stylus, it indicates the direction in which the stylus is pointing.
  99   //   The return value lies in [-PI, PI].
 100   float GetOrientation() const { return GetOrientation(0); }
 101
 102   float GetPressure() const { return GetPressure(0); }
 103   ToolType GetToolType() const { return GetToolType(0); }
 104
 105   // O(N) search of pointers (use sparingly!). Returns -1 if |id| nonexistent.
 106   int FindPointerIndexOfId(int id) const;
 107
 108   // Note that these methods perform shallow copies of the originating events.
 109   // They guarantee only that the returned type will reflect the same
 110   // data exposed by the MotionEvent interface; no guarantees are made that the
 111   // underlying implementation is identical to the source implementation.
 112   scoped_ptr<MotionEvent> Clone() const;
 113   scoped_ptr<MotionEvent> Cancel() const;
 114 };
 115
 116 }  // namespace ui
 117
 118 #endif  // UI_EVENTS_GESTURE_DETECTION_MOTION_EVENT_H_