multitouch/src/gesture_server.py

from event_server import EventServerHandler
from tuio_server import TuioServer2D
from window import FullscreenWindow
from point import TouchPoint


class GestureServer(EventServerHandler):
    """
    Multi-touch gesture server. This uses a TUIO server to receive basic touch
    events, which are translated to gestures using gesture trackers. Trackers
    are assigned to a Window object, and gesture handlers are bound to a
    tracker.
    """
    def __init__(self):
        # List of all connected windows
        self.windows = []

        # Map of point sid to TouchPoint object
        self.points = {}

        # Create TUIO server, to be started later
        self.tuio_server = TuioServer2D(self)

    def add_window(self, window):
        self.windows.append(window)

    def remove_window(self, window):
        self.windows.remove(window)
        # TODO: Remove window from touch points

    def on_point_down(self, sid, x, y):
        if sid in self.points:
            raise ValueError('Point with sid %d already exists.' % sid)

        # Create a new touch point
        self.points[sid] = point = TouchPoint(x, y, sid)

        # Save the windows containing the point in a dictionary, and update
        # their trackers
        for window in self.windows:
            if window.contains(point):
                point.add_window(window)
                window.update_trackers('down', point)

    def on_point_move(self, sid, x, y):
        if sid not in self.points:
            raise KeyError('No point with sid %d exists.' % sid)

        # Update point position and corresponding window trackers
        point = self.points[sid]
        point.set_position(x, y)
        point.update_window_trackers('move')

    def on_point_up(self, sid):
        if sid not in self.points:
            raise KeyError('No point with sid %d exists.' % sid)

        # Clear the list of windows containing the point, and update their
        # trackers
        self.points[sid].update_window_trackers('up')
        del self.points[sid]

    def start(self):
        # Assert that at least one window exists, by adding a fullscreen window
        # if none have been added yet
        if not self.windows:
            self.add_window(FullscreenWindow())

        self.tuio_server.start()

    def stop(self):
        self.tuio_server.stop()

    def run(self):
        self.tuio_server.run()