GUI Properties

class arcade.gui.DictProperty

Bases: Property

Property that represents a dict. Only dict are allowed. Any other classes are forbidden.

set(instance, value: dict)

default_factory

name: str

obs: WeakKeyDictionary[Any, _Obs]

class arcade.gui.ListProperty

Bases: Property

Property that represents a list. Only list are allowed. Any other classes are forbidden.

set(instance, value: dict)

default_factory

name: str

obs: WeakKeyDictionary[Any, _Obs]

class arcade.gui.Property(default: P | None = None, default_factory: Callable[[Any, Any], P] | None = None)

Bases: Generic[P]

An observable property which triggers observers when changed.

    def log_change(instance, value):
        print("Something changed")

    class MyObject:
        name = Property()

    my_obj = MyObject()
    bind(my_obj, "name", log_change)
    unbind(my_obj, "name", log_change)

    my_obj.name = "Hans"
    # > Something changed

:param default: Default value which is returned, if no value set before
:param default_factory: A callable which returns the default value.
                        Will be called with the property and the instance

bind(instance, callback)

dispatch(instance, value)

get(instance) → P

set(instance, value)

unbind(instance, callback)

default_factory

name: str

obs: WeakKeyDictionary[Any, _Obs]

arcade.gui.bind(instance, property: str, callback)

Binds a function to the change event of the property. A reference to the function will be kept, so that it will be still invoked, even if it would normally have been garbage collected.

def log_change(instance, value):

print(f”Value of {instance} changed to {value}”)

class MyObject:

name = Property()

my_obj = MyObject() bind(my_obj, “name”, log_change)

my_obj.name = “Hans” # > Value of <__main__.MyObject …> changed to Hans

Parameters:

• instance – Instance owning the property

• property – Name of the property

• callback – Function to call

Returns:

None

arcade.gui.unbind(instance, property: str, callback)

Unbinds a function from the change event of the property.

def log_change(instance, value):

print(“Something changed”)

class MyObject:

name = Property()

my_obj = MyObject() bind(my_obj, “name”, log_change) unbind(my_obj, “name”, log_change)

my_obj.name = “Hans” # > Something changed

Parameters:

• instance – Instance owning the property

• property – Name of the property

• callback – Function to unbind

Returns:

None