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