python设计模式-命令模式

python-design-patter-command.py

#! -*- coding: utf-8 -*-

"""
命令模式
"""


class Command(object):

    def execute(self):
        raise NotImplementedError()

    def undo(self):
        raise NotImplementedError()


class NoCommand(Command):

    def execute(self):
        print('Command Not Found')

    def undo(self):
        print('Command Not Found')


class Light(object):

    def __init__(self, name):
        self.name = name

    def on(self):
        print('%s Light is On' % self.name)

    def off(self):
        print('%s Light is Off' % self.name)


class LightOnCommand(Command):

    def __init__(self, light):
        self.light = light

    def execute(self):
        self.light.on()

    def undo(self):
        self.light.off()


class LightOffCommand(Command):

    def __init__(self, light):
        self.light = light

    def execute(self):
        self.light.off()

    def undo(self):
        self.light.on()


class GarageDoor(object):

    def open(self):
        print('Garage Door is Open')

    def close(self):
        print('Garage Door is Close')


class GarageDoorOpenCommand(Command):

    def __init__(self, door):
        self.door = door

    def execute(self):
        self.door.open()

    def undo(self):
        self.door.close()


class GarageDoorCloseCommand(Command):

    def __init__(self, door):
        self.door = door

    def execute(self):
        self.door.close()

    def undo(self):
        self.door.open()


class MacroCommand(Command):

    def __init__(self, commands):
        self.commands = commands

    def execute(self):
        for command in self.commands:
            command.execute()

    def undo(self):
        for command in self.commands:
            command.undo()


class RemoteControl(object):

    def __init__(self):
        self.on_commands = [NoCommand() for i in range(7)]
        self.off_commands = [NoCommand() for i in range(7)]
        self.undo_command = None

    def set_command(self, slot, on_command, off_command):
        # 预先给每个插槽设置一个空命令的命令
        self.on_commands[slot] = on_command
        self.off_commands[slot] = off_command

    def on_button_was_pressed(self, slot):
        command = self.on_commands[slot]
        command.execute()
        self.undo_command = command

    def off_button_was_pressed(self, slot):
        command = self.off_commands[slot]
        command.execute()
        self.undo_command = command

    def undo_button_was_pressed(self):
        self.undo_command.undo()

    def __str__(self):
        for i in range(7):
            print('[slot %d] %s %s' % (i,
                                       self.on_commands[i].__class__.__name__,
                                       self.off_commands[i].__class__.__name__))
        return ''


def remote_control_test():
    remote = RemoteControl()

    living_room_light = Light('Living Room')
    kitchen_light = Light('Kitchen')
    garage_door = GarageDoor()

    living_room_light_on = LightOnCommand(living_room_light)
    living_room_light_off = LightOffCommand(living_room_light)
    kitchen_light_on = LightOnCommand(kitchen_light)
    kitchen_light_off = LightOffCommand(kitchen_light)

    garage_door_open = GarageDoorOpenCommand(garage_door)
    garage_door_close = GarageDoorCloseCommand(garage_door)

    remote.set_command(0, living_room_light_on, living_room_light_off)
    remote.set_command(1, kitchen_light_on, kitchen_light_off)
    remote.set_command(2, garage_door_open, garage_door_close)

    print(remote)

    remote.on_button_was_pressed(0)
    remote.off_button_was_pressed(0)
    remote.undo_button_was_pressed()
    remote.on_button_was_pressed(1)
    remote.off_button_was_pressed(1)
    remote.undo_button_was_pressed()
    remote.on_button_was_pressed(2)
    remote.off_button_was_pressed(2)
    remote.undo_button_was_pressed()

    # 测试开关集合
    party_on_macro = MacroCommand([living_room_light_on, kitchen_light_on])
    party_off_macro = MacroCommand([living_room_light_off, kitchen_light_off])
    remote.set_command(3, party_on_macro, party_off_macro)
    print('--pushing macro on--')
    remote.on_button_was_pressed(3)
    print('--pushing macro off--')
    remote.off_button_was_pressed(3)
    print('--push macro undo--')
    remote.undo_button_was_pressed()


if __name__ == '__main__':
    remote_control_test()