keyboard_agent.py

# keyboard_agent.py
# -----------------
# Licensing Information: Please do not distribute or publish solutions to this
# project. You are free to use and extend these projects for educational
# purposes. The Pacman AI projects were developed at UC Berkeley, primarily by
# John DeNero (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
# For more info, see http://inst.eecs.berkeley.edu/~cs188/sp09/pacman.html

from game import Agent, Action


class KeyboardAgent(Agent):
    """
    An agent controlled by the keyboard.
    """
    LEFT_KEY = 'a'
    RIGHT_KEY = 'd'
    UP_KEY = 'w'
    DOWN_KEY = 's'

    def __init__(self, tk_window):
        super().__init__()
        self.keys = []
        tk_window.subscribe_to_keyboard_pressed(self.listener)
        self.tk_window = tk_window
        self._should_stop = False

    def get_action(self, state):
        self._should_stop = False
        move = self._get_move(state)
        while move is None and not self._should_stop:
            self.tk_window.mainloop_iteration()
            move = self._get_move(state)
        if self._should_stop:
            return Action.STOP
        return move

    def stop_running(self):
        self._should_stop = True

    def _get_move(self, state):
        move = None
        legal_actions = state.get_agent_legal_actions()
        if Action.LEFT in legal_actions and (self.LEFT_KEY in self.keys or 'Left' in self.keys):  move = Action.LEFT
        if Action.RIGHT in legal_actions and (self.RIGHT_KEY in self.keys or 'Right' in self.keys):  move = Action.RIGHT
        if Action.UP in legal_actions and (self.UP_KEY in self.keys or 'Up' in self.keys):  move = Action.UP
        if Action.DOWN in legal_actions and (self.DOWN_KEY in self.keys or 'Down' in self.keys):  move = Action.DOWN
        self.keys = []
        return move

    def listener(self, tk_event=None, *args, **kw):
        self.keys.append(tk_event.keysym)