multitouch/src/event.py

from geometry import Positionable
from touch_objects import OBJECT_NAMES


class Event(Positionable):
    """
    Abstract base class for events triggered by an event driver. These events
    are delegated to gesture trackers, to be translated to gestures. To be able
    to check whether an event is located within a area, a position is
    required. Therefore, the touch object that triggers the event is is linked
    to the event object.
    """
    _type = NotImplemented

    def __init__(self, touch_object):
        super(Event, self).__init__(*touch_object)
        self.touch_object = touch_object
        self.stopped = self.stopped_immidiate = False
        self.offset = Positionable(0, 0)

    def __getattr__(self, name):
        if name in OBJECT_NAMES \
                and type(self.touch_object) == OBJECT_NAMES[name]:
            return self.touch_object

        raise AttributeError("'%s' object has no attribute '%s'"
                             % (self.__class__.__name__, name))

    def get_offset(self):
        return self - self.offset

    def set_offset(self, offset):
        self.offset.set_position(*offset)

    def set_root_area(self, area):
        x, y = area
        self.x -= x
        self.y -= y

    def get_type(self):
        return self._type

    def get_touch_object(self):
        return self.touch_object

    def stop_propagation(self):
        self.stopped = True

    def is_propagation_stopped(self):
        return self.stopped

    def stop_immidiate_propagation(self):
        self.stop_propagation()
        self.stopped_immidiate = True

    def is_immediate_propagation_stopped(self):
        return self.stopped_immidiate