PropertyAction

Added in version 2.38.

class PropertyAction(**properties: Any)

Superclasses: Object

Implemented Interfaces: Action

A GPropertyAction is a way to get a Action with a state value reflecting and controlling the value of a Object property.

The state of the action will correspond to the value of the property. Changing it will change the property (assuming the requested value matches the requirements as specified in the ParamSpec).

Only the most common types are presently supported. Booleans are mapped to booleans, strings to strings, signed/unsigned integers to int32/uint32 and floats and doubles to doubles.

If the property is an enum then the state will be string-typed and conversion will automatically be performed between the enum value and ‘nick’ string as per the EnumValue table.

Flags types are not currently supported.

Properties of object types, boxed types and pointer types are not supported and probably never will be.

Properties of Variant types are not currently supported.

If the property is boolean-valued then the action will have a NULL parameter type, and activating the action (with no parameter) will toggle the value of the property.

In all other cases, the parameter type will correspond to the type of the property.

The general idea here is to reduce the number of locations where a particular piece of state is kept (and therefore has to be synchronised between). GPropertyAction does not have a separate state that is kept in sync with the property value — its state is the property value.

For example, it might be useful to create a Action corresponding to the visible-child-name property of a `GtkStack <https://docs.gtk.org/gtk4/class.Stack.html>`_ so that the current page can be switched from a menu. The active radio indication in the menu is then directly determined from the active page of the GtkStack.

An anti-example would be binding the active-id property on a `GtkComboBox <https://docs.gtk.org/gtk4/class.ComboBox.html>`_. This is because the state of the combo box itself is probably uninteresting and is actually being used to control something else.

Another anti-example would be to bind to the visible-child-name property of a `GtkStack <https://docs.gtk.org/gtk4/class.Stack.html>`_ if this value is actually stored in Settings. In that case, the real source of the value is* Settings. If you want a Action to control a setting stored in Settings, see create_action instead, and possibly combine its use with bind.

Constructors

class PropertyAction

classmethod new(name: str, object: Object, property_name: str) → PropertyAction

Creates a Action corresponding to the value of property property_name on object.

The property must be existent and readable and writable (and not construct-only).

This function takes a reference on object and doesn’t release it until the action is destroyed.

Added in version 2.38.

Parameters:

name – the name of the action to create
object – the object that has the property to wrap
property_name – the name of the property

Properties

class PropertyAction

props.enabled: bool

If action is currently enabled.

If the action is disabled then calls to activate() and change_state() have no effect.

Added in version 2.38.

props.invert_boolean: bool: If True, the state of the action will be the negation of the property value, provided the property is boolean.

Added in version 2.46.

props.name: str: The name of the action. This is mostly meaningful for identifying the action once it has been added to a ActionMap.

Added in version 2.38.

props.object: Object

The object to wrap a property on.

The object must be a non-None Object with properties.

Added in version 2.38.

props.parameter_type: VariantType: The type of the parameter that must be given when activating the action.

Added in version 2.38.

props.property_name: str

The name of the property to wrap on the object.

The property must exist on the passed-in object and it must be readable and writable (and not construct-only).

Added in version 2.38.

props.state: Variant: The state of the action, or None if the action is stateless.

Added in version 2.38.

props.state_type: VariantType: The VariantType of the state that the action has, or None if the action is stateless.

Added in version 2.38.