## Superclass for events that can be passed to the
## event manager.
class event:
    pass

class event_manager:
    def __init__(self):
        from weakref import WeakKeyDictionary
        self.listeners = WeakKeyDictionary()

    def add_listener(self, listener):
        self.listeners[listener] = 1

    def remove_listener(self, listener):
        if listener in self.listeners.keys():
            del self.listeners[listener]

    def announce(self, event):
        for listener in self.listeners.keys():
            listener.notify(event)

## Events that may occurr around the View,
## Controller and Game. In other words, events
## that can occur in the engine.
class tick_event(event):
    pass
class mouse_moved_event(event):
    def __init__(self, pos):
        self.pos = pos
    def get_pos(self):
        return self.pos
class mouse_pressed_event(event):
    def __init__(self, pos):
        self.pos = pos
    def get_pos(self):
        return self.pos

## The keyboard event contains a pygame keypress.
class keyboard_event(event):
    def __init__(self, key):
        self.key = key
    def get_key(self):
        return self.key
class quit_event(event):
    pass

## The draw event contains a reference back
## to the screen which we want everything
## to be drawn onto.
class draw_event(event):
    def __init__(self, screen):
        self.screen = screen
    def get_screen(self):
        return self.screen

## Abstract listener class for adding a couple
## of common methods for "all" listeners
## (except for the ones that shouldn't know
## how to announce events).
class listener:
    def notify(self, event):
        print "Generic notify() called."
    def set_event_handler(self, event_handler):
        self.event_handler = event_handler