event.py

class MouseEvent(Event):
    """ Class describing mouse events.
    
    Input arguments
    ---------------
    source : object
        The visualization object that this event is created from or applies to.
    type : str
       string indicating the event type (e.g. mouse_press, key_release)
    kwds : keyword arguments
        Any additional keyword arguments are stored as attributes on the event.
        
    """
    def __init__(self, source, subtype, x, y, button=None, modifiers=None):
        Event.__init__(self, source, 'mouse_'+subtype)
        self._x = x
        self._y = y
        self._button = int(button)
        self._modifiers = tuple( modifiers or () )
    
    @property
    def x(self):
        """ The x-position of the mouse (in screen coordinates).
        """
        return self._x
    
    @property
    def y(self):
        """ The y-position of the mouse (in screen coordinates).
        """
        return self._y
    
    @property
    def button(self):
        """ The button that this event applies to (can be None).
        Left=1, right=2, middle=3.
        """
        return self._button
    
    @property
    def modifiers(self):
        """ Tuple that specifies which modifier keys wee pressed down at the
        time of the event (shift, control, alt).
        """
        return self._modifiers