RandomActuator

class pygamelib.actuators.RandomActuator(moveset: List[Vector2D | int] | None = None, parent: BoardItem | None = None)

Bases: Actuator

A class that implements a random choice of movement.

The random actuator is a subclass of Actuator. It is simply implementing a random choice in a predefined move set.

Parameters:

moveset (list) – A list of movements.
parent (pygamelib.board_items.BoardItem) – The parent object to actuate.

__init__(moveset: List[Vector2D | int] | None = None, parent: BoardItem | None = None): The constructor take only one (positional) parameter: the parent object.

Important

The default state of ALL actuators is RUNNING. If you want your actuator to be in a different state (PAUSED for example), you have to do it yourself.

Methods

`__init__`([moveset, parent])	The constructor take only one (positional) parameter: the parent object.
`attach`(observer)	Attach an observer to this instance.
`detach`(observer)	Detach an observer from this instance.
`handle_notification`(subject[, attribute, value])	A virtual method that needs to be implemented by the observer.
`load`(data)	Load data and create a new RandomActuator out of it.
`next_move`()	Return a randomly selected movement
`notify`([modifier, attribute, value])	Notify all the observers that a change occurred.
`pause`()	Set the actuator state to PAUSED.
`serialize`()	Return a dictionary with all the attributes of this object.
`start`()	Set the actuator state to RUNNING.
`stop`()	Set the actuator state to STOPPED.
`store_screen_position`(row, column)	Store the screen position of the object.

Attributes

`moveset`	Return the moveset.
`screen_column`	A property to get/set the screen column.
`screen_row`	A property to get/set the screen row.

attach(observer)

Attach an observer to this instance. It means that until it is detached, it will be notified every time that a notification is issued (usually on changes).

An object cannot add itself to the list of observers (to avoid infinite recursions).

Parameters:: observer (PglBaseObject) – An observer to attach to this object.
Returns:: True or False depending on the success of the operation.
Return type:: bool

Example:

myboard = Board()
screen = Game.instance().screen
# screen will be notified of all changes in myboard
myboard.attach(screen)

detach(observer)

Detach an observer from this instance. If observer is not in the list this returns False.

Parameters:: observer (PglBaseObject) – An observer to detach from this object.
Returns:: True or False depending on the success of the operation.
Return type:: bool

Example:

# screen will no longer be notified of the changes in myboard.
myboard.detach(screen)

handle_notification(subject, attribute=None, value=None)

A virtual method that needs to be implemented by the observer. By default it does nothing but each observer needs to implement it if something needs to be done when notified.

This method always receive the notifying object as first parameter. The 2 other parameters are optional and can be None.

You can use the attribute and value as you see fit. You are free to consider attribute as an event and value as the event’s value.

Parameters:

subject (PglBaseObject) – The object that has changed.
attribute (str) – The attribute that has changed, it is usually a “FQDN style” string. This can be None.
value (Any) – The new value of the attribute. This can be None.

classmethod load(data: dict) → RandomActuator

Load data and create a new RandomActuator out of it.

Parameters:: data (dict) – Data to create a new actuator (usually generated by serialize())
Returns:: A new actuator.
Return type:: RandomActuator

Example:

npc2.actuator = actuators.RandomActuator.load( npc1.actuator.serialize() )

property moveset: List[Vector2D | int]

Return the moveset.

Returns:: The moveset.
Return type:: list

next_move() → Vector2D | int

Return a randomly selected movement

The movement is randomly selected from moveset if state is RUNNING, otherwise it returns NO_DIR from the constants module.

Returns:: The next movement Vector2D | int

Example:

random_actuator.next_move()

notify(modifier=None, attribute: str = None, value: Any = None) → None

Notify all the observers that a change occurred.

Parameters:

modifier (PglBaseObject) – An optional parameter that identify the modifier object to exclude it from the notified objects.
attribute (str) – An optional parameter that identify the attribute that has changed.
value (Any) – An optional parameter that identify the new value of the attribute.

Example:

# This example is silly, you would usually notify other objects from inside
# an object that changes a value that's important for the observers.
color = Color(255,200,125)
color.attach(some_text_object)
color.notify()

pause()

Set the actuator state to PAUSED.

Example:

mygame.pause()

property screen_column: int

A property to get/set the screen column.

Parameters:: value (int) – the screen column
Return type:: int

property screen_row: int

A property to get/set the screen row.

Parameters:: value (int) – the screen row
Return type:: int

serialize() → dict

Return a dictionary with all the attributes of this object.

Returns:: A dictionary with all the attributes of this object.
Return type:: dict

start()

Set the actuator state to RUNNING.

If the actuator state is not RUNNING, actuators’ next_move() function (and all derivatives) should not return anything.

Example:

mygame.start()

stop()

Set the actuator state to STOPPED.

Example:

mygame.stop()

store_screen_position(row: int, column: int) → bool

Store the screen position of the object.

This method is automatically called by Screen.place().

Parameters:

row (int) – The row (or y) coordinate.
column (int) – The column (or x) coordinate.

Example:

an_object.store_screen_coordinate(3,8)