source/input/gesturedetector.h

   1 #ifndef MSP_INPUT_GESTUREDETECTOR_H_
   2 #define MSP_INPUT_GESTUREDETECTOR_H_
   3
   4 #include "device.h"
   5
   6 namespace Msp {
   7 namespace Input {
   8
   9 class Touchscreen;
  10
  11 enum Gesture
  12 {
  13         GESTURE_NONE,
  14         GESTURE_TAP,
  15         GESTURE_TAP_2,
  16         GESTURE_DRAG,
  17         GESTURE_DRAG_2,
  18         GESTURE_PINCH,
  19         GESTURE_ROTATE
  20 };
  21
  22 /**
  23 Interprets events from a Touchscreen as high-level gestures.  One button is
  24 provided for each type of gesture.  Axes 0 and 1 indicate the starting position
  25 of the gesture; axes 2 and 3 track its progress.  The progress axis may exhibit
  26 absolute values greater than one.
  27 */
  28 class GestureDetector: public Device
  29 {
  30 private:
  31         enum
  32         {
  33                 MAX_POINTS = 3
  34         };
  35
  36         struct TouchPoint
  37         {
  38                 bool down;
  39                 float down_x;
  40                 float down_y;
  41                 float x;
  42                 float y;
  43                 bool threshold_exceeded;
  44
  45                 TouchPoint();
  46         };
  47
  48         Touchscreen &touchscreen;
  49         TouchPoint points[MAX_POINTS];
  50         Gesture current_gesture;
  51         unsigned active_points;
  52         Gesture pending_tap;
  53         bool invalid_gesture;
  54         float threshold_x_sq;
  55         float threshold_y_sq;
  56
  57 public:
  58         GestureDetector(Touchscreen &);
  59
  60         virtual std::string get_button_name(unsigned) const;
  61         virtual std::string get_axis_name(unsigned) const;
  62
  63 private:
  64         void touch_down(unsigned);
  65         void touch_up(unsigned);
  66         void touch_move(unsigned, float, float);
  67         void start_gesture();
  68         void set_gesture_location(unsigned);
  69         void update_progress();
  70         void end_gesture();
  71         void window_resized(unsigned, unsigned);
  72 };
  73
  74 } // namespace Input
  75 } // namespace Msp
  76
  77 #endif