Class: Gio::PropertyAction

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Overview

A GProperty::Action 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 GParam::Spec).

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 GEnum::Value 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). GProperty::Action 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 Gtk::Stack 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 Gtk::Stack.

An anti-example would be binding the “active-id” property on a Gtk::ComboBox. This is because the state of the combobox 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 Gtk::Stack 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().

Instance Method Summary collapse

Instance Method Details

#enabled=(enabled) ⇒ TrueClass

If action is currently enabled.

If the action is disabled then calls to g_action_activate() and g_action_change_state() have no effect.

Parameters:

  • enabled (TrueClass)

Returns:

  • (TrueClass) —

    enabled

  • (TrueClass) —

    enabled

#enabled? ⇒ TrueClass

If action is currently enabled.

If the action is disabled then calls to g_action_activate() and g_action_change_state() have no effect.

Returns:

  • (TrueClass) —

    enabled

#invert_boolean=(invert_boolean) ⇒ TrueClass

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

Parameters:

  • invert_boolean (TrueClass)

Returns:

  • (TrueClass) —

    invert-boolean

  • (TrueClass) —

    invert-boolean

#invert_boolean? ⇒ TrueClass

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

Returns:

  • (TrueClass) —

    invert-boolean

#name ⇒ String

The name of the action. This is mostly meaningful for identifying the action once it has been added to a GAction::Map.

Returns:

  • (String) —

    name

#name=(name) ⇒ String

The name of the action. This is mostly meaningful for identifying the action once it has been added to a GAction::Map.

Parameters:

  • name (String)

Returns:

  • (String) —

    name

  • (String) —

    name

#new(name, object, property_name) ⇒ Gio::PropertyAction

Creates a #GAction 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.

Parameters:

  • name (String) —

    the name of the action to create

  • object (GObject::Object) —

    the object that has the property to wrap

  • property_name (String) —

    the name of the property

Returns:

#object=(object) ⇒ GObject::Object

The object to wrap a property on.

The object must be a non-nil #GObject with properties.

Parameters:

  • object (GObject::Object)

Returns:

  • (GObject::Object) —

    object

#parameter_type ⇒ GLib::VariantType

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

Returns:

  • (GLib::VariantType) —

    parameter-type

#parameter_type=(parameter_type) ⇒ GLib::VariantType

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

Parameters:

  • parameter_type (GLib::VariantType)

Returns:

  • (GLib::VariantType) —

    parameter-type

  • (GLib::VariantType) —

    parameter-type

#property_name=(property_name) ⇒ String

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).

Parameters:

  • property_name (String)

Returns:

  • (String) —

    property-name

#state ⇒ GLib::Variant

The state of the action, or nil if the action is stateless.

Returns:

  • (GLib::Variant) —

    state

#state=(state) ⇒ GLib::Variant

The state of the action, or nil if the action is stateless.

Parameters:

  • state (GLib::Variant)

Returns:

  • (GLib::Variant) —

    state

  • (GLib::Variant) —

    state

#state_type ⇒ GLib::VariantType

The GVariant::Type of the state that the action has, or nil if the action is stateless.

Returns:

  • (GLib::VariantType) —

    state-type

#state_type=(state_type) ⇒ GLib::VariantType

The GVariant::Type of the state that the action has, or nil if the action is stateless.

Parameters:

  • state_type (GLib::VariantType)

Returns:

  • (GLib::VariantType) —

    state-type

  • (GLib::VariantType) —

    state-type