Gio.PropertyAction
Description: Reference for Gio.PropertyAction

### Class

# GioPropertyAction

since: 2.38

#### Description [src]

    final class Gio.PropertyAction : GObject.Object
      implements Gio.Action {
      /* No available fields */
    }

A `GPropertyAction` is a way to get a `GAction` with a state value reflecting and controlling the value of a `GObject` 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 `GParamSpec`).

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 `GEnumValue` 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 `GVariant` 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 `GAction` corresponding to the `visible-child-name` property of a `GtkStack` 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`. 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` if this value is actually stored in `GSettings`. In that case, the real source of the value is* `GSettings`. If you want a `GAction` to control a setting stored in `GSettings`, see `g_settings_create_action()` instead, and possibly combine its use with `g_settings_bind()`.

Available since: 2.38

#### Hierarchy

#### Ancestors

- GObject

#### Implements

- GAction

#### Constructors

###### g_property_action_new

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

since: 2.38

#### Instance methods

##### Methods inherited from GObject (43)

Please see GObject for a full list of methods.

##### Methods inherited from GAction (8)

###### g_action_activate

Activates the action.

since: 2.28

###### g_action_change_state

Request for the state of `action` to be changed to `value`.

since: 2.30

###### g_action_get_enabled

Checks if `action` is currently enabled.

since: 2.28

###### g_action_get_name

Queries the name of `action`.

since: 2.28

###### g_action_get_parameter_type

Queries the type of the parameter that must be given when activating `action`.

since: 2.28

###### g_action_get_state

Queries the current state of `action`.

since: 2.28

###### g_action_get_state_hint

Requests a hint about the valid range of values for the state of `action`.

since: 2.28

###### g_action_get_state_type

Queries the type of the state of `action`.

since: 2.28

#### Properties

###### Gio.PropertyAction:enabled

If `action` is currently enabled.

since: 2.38

###### Gio.PropertyAction:invert-boolean

If `TRUE`, the state of the action will be the negation of the property value, provided the property is boolean.

since: 2.46

###### Gio.PropertyAction:name

The name of the action. This is mostly meaningful for identifying the action once it has been added to a `GActionMap`.

since: 2.38

###### Gio.PropertyAction:object

The object to wrap a property on.

since: 2.38

###### Gio.PropertyAction:parameter-type

The type of the parameter that must be given when activating the action.

since: 2.38

###### Gio.PropertyAction:property-name

The name of the property to wrap on the object.

since: 2.38

###### Gio.PropertyAction:state

The state of the action, or `NULL` if the action is stateless.

since: 2.38

###### Gio.PropertyAction:state-type

The `GVariantType` of the state that the action has, or `NULL` if the action is stateless.

since: 2.38

##### Properties inherited from GAction (5)

###### GAction:enabled

If `action` is currently enabled.

since: 2.28

###### GAction:name

The name of the action. This is mostly meaningful for identifying the action once it has been added to a `GActionGroup`. It is immutable.

since: 2.28

###### GAction:parameter-type

The type of the parameter that must be given when activating the action. This is immutable, and may be `NULL` if no parameter is needed when activating the action.

since: 2.28

###### GAction:state

The state of the action, or `NULL` if the action is stateless.

since: 2.28

###### GAction:state-type

The `GVariantType` of the state that the action has, or `NULL` if the action is stateless. This is immutable.

since: 2.28

#### Signals

##### Signals inherited from GObject (1)

###### GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.