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