from logger import Logger


class EventServer(Logger):
    """
    Abstract class for event servers. An event server translates driver
    events to point 'down', 'move' and 'up' events. An event server
    implementation should define the methods 'start' and 'stop', which
    starts/stops some event loop that triggers on_point_up, on_point_move and
    on_point_down methods on the 'handler_obj' object.
    """
    def __init__(self, handler_obj):
        self.handler_obj = handler_obj

    def start(self):
        raise NotImplementedError

    def stop(self):
        raise NotImplementedError


class EventServerHandler(Logger):
    """
    Interface for gesture server. Defines empty on_point_up, on_point_move and
    on_point_down handlers.
    """
    def on_point_down(self, sid, x, y):
        return NotImplemented

    def on_point_move(self, sid, x, y):
        return NotImplemented

    def on_point_up(self, sid):
        return NotImplemented