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