multitouch/src/window.py

from geometry import Surface, RectangularSurface, CircularSurface
from screen import screen_size


class Window(Surface):
    """
    Abstract class that represents a 2D object on the screen to which gesture
    trackers can be added. Implementations of this class should define a method
    that can detect wether a touch point is located within the window.

    Because any type of window on the screen has (at least) an (x, y) position,
    it extends the Positionable object.

    Note: Dimensions used in implementations of this class should be in pixels.
    """
    def __init__(self, **kwargs):
        # All trackers that are currently bound to this window
        self.trackers = []

        # List of points that originated in this window
        self.points = []

        if 'server' in kwargs:
            kwargs['server'].add_window(self)

    def add_tracker(self, tracker):
        self.trackers.append(tracker)

    def remove_tracker(self, tracker):
        self.trackers.remove(tracker)

    def on_point_down(self, point):
        self.points.append(point)
        self.update_trackers('down', point)

    def on_point_move(self, point):
        self.update_trackers('move', point)

    def on_point_up(self, point):
        self.points.remove(point)
        self.update_trackers('up', point)

    def update_trackers(self, event_type, point):
        """
        Update all gesture trackers that are bound to this window with an
        added/moved/removed touch point.
        """
        handler_name = 'on_point_' + event_type

        for tracker in self.trackers:
            if hasattr(tracker, handler_name):
                getattr(tracker, handler_name)(point)


class RectangularWindow(Window, RectangularSurface):
    """
    Rectangular window.
    """
    def __init__(self, x, y, width, height, **kwargs):
        Window.__init__(self, **kwargs)
        RectangularSurface.__init__(self, x, y, width, height)


class CircularWindow(Window, CircularSurface):
    """
    Circular window.
    """
    def __init__(self, x, y, width, height, **kwargs):
        Window.__init__(self, **kwargs)
        CircularSurface.__init__(self, x, y, radius)


class FullscreenWindow(RectangularWindow):
    """
    Window representation for the entire screen. This class provides an easy
    way to create a single rectangular window that catches all gestures.
    """
    def __init__(self, **kwargs):
        super(FullscreenWindow, self).__init__(0, 0, *screen_size, **kwargs)

    def __str__(self):
        return '<FullscreenWindow size=(%d, %d)>' % (self.width, self.height)

    def contains(self, point):
        return True