'Button release event handler and validator'

def release(self, event):

    if ((not self.ignore(event)) and self.eventpress):
        event = self._clean_event(event)
        self.eventrelease = event
        self._release(event)
        self.eventpress = None
        self.eventrelease = None
        self.state.discard(u'move')
        return True
    return False
