HeadFirstDesignPatterns_python/chapter06_command/remote_undo.py at main · dancergraham/HeadFirstDesignPatterns_python · GitHub

Name: HeadFirstDesignPatterns_python/chapter06_command/remote_undo.py at main · dancergraham/HeadFirstDesignPatterns_python · GitHub
Rating: 4.6 (3038 reviews)
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importabc


classCommand(abc.ABC):
defexecute(self):
raiseNotImplementedError

defundo(self):
raiseNotImplementedError


classNoCommand(Command):
defexecute(self):
pass

defundo(self):
pass


classLightOnCommand(Command):
def__init__(self, light):
self.light=light

defexecute(self):
self.level=self.light.get_level()
self.light.on()

defundo(self):
self.light.dim(self.level)


classLightOffCommand(Command):
def__init__(self, light):
self.light=light

defexecute(self):
self.level=self.light.get_level()
self.light.off()

defundo(self):
self.light.dim(self.level)


classLight:
def__init__(self, location: str):
self.location=location
self.level=0

defon(self):
self.level=100
print("Light is on")

defoff(self):
self.level=0
print("Light is off")

defdim(self, level):
self.level=level
ifself.level==0:
self.off()
else:
print(f"Light is dimmed to {self.level}%")

defget_level(self):
returnself.level


classRemoteControlWithUndo:
"""The Invoker"""

def__init__(self) ->None:
self.on_commands= [NoCommand() for_inrange(7)]
self.off_commands= [NoCommand() for_inrange(7)]
self.undo_command=NoCommand()

defset_command(self, i, on_command, off_command):
self.on_commands[i] =on_command
self.off_commands[i] =off_command

defon_button_was_pushed(self, i):
self.on_commands[i].execute()
self.undo_command=self.on_commands[i]

defoff_button_was_pushed(self, i):
self.off_commands[i].execute()
self.undo_command=self.off_commands[i]

defundo_button_was_pushed(self):
self.undo_command.undo()

def__str__(self) ->str:
buffer= []
buffer.append("\n------ Remote Control -------\n")
fori, (on_command, off_command) inenumerate(
zip(self.on_commands, self.off_commands)
 ):
buffer.append(
f"[slot {i}] {on_command.__class__.__name__}"
+f" {off_command.__class__.__name__}\n"
 )

buffer.append(f"[undo] {self.undo_command.__class__.__name__}\n")
return"".join(buffer)


defremote_loader():
remoteControl=RemoteControlWithUndo()
living_room_light=Light("Living Room")
living_room_light_on=LightOnCommand(living_room_light)
living_room_light_off=LightOffCommand(living_room_light)

remoteControl.set_command(0, living_room_light_on, living_room_light_off)

remoteControl.on_button_was_pushed(0)
remoteControl.off_button_was_pushed(0)
print(remoteControl)
remoteControl.undo_button_was_pushed()
remoteControl.off_button_was_pushed(0)
remoteControl.on_button_was_pushed(0)
print(remoteControl)
remoteControl.undo_button_was_pushed()


if__name__=="__main__":
remote_loader()