A simple Gnome::Gio::Action implementation

Description

A Gnome::Gio::SimpleAction is the obvious simple implementation of the Gnome::Gio::Action interface. This is the easiest way to create an action for purposes of adding it to a Gnome::Gio::SimpleActionGroup.

See also Gnome::Gio::Action.

Synopsis

Declaration

unit class Gnome::Gio::SimpleAction;
also is Gnome::GObject::Object;
also does Gnome::Gio::Action;

Uml Diagram

Methods

new

:name, :parameter-type

Create a new stateless SimpleAction object.

multi method new ( Str :$name!, N-GObject() :$parameter-type? )

• $name; the name of the action

• $parameter_type; the type of parameter that will be passed to handlers for the activate signal. The $parameter_type is a native Gnome::Glib::Variant object.

:name, :state, :parameter-type

Create a new stateful SimpleAction object. All future state values must have the same type as the initial $state variant object.

multi method new (
  Str :$name!, N-GObject() :$state!, N-GObject() :$parameter_type?
)

• $name; the name of the action

• $parameter_type; the type of the parameter that will be passed to handlers for the activate signal. The $parameter_type is a native Gnome::Glib::VariantType object.

• $state; the initial state value of the action. The state is a native Gnome::Glib::Variant object.

:native-object

Create a SimpleAction object using a native object from elsewhere. See also Gnome::GObject::Object.

multi method new ( N-GObject() :$native-object! )

set-enabled

Sets the action as enabled or not.

An action must be enabled in order to be activated or in order to have its state changed from outside callers.

This should only be called by the implementor of the action. Users of the action should not attempt to modify its enabled flag.

method set-enabled ( Bool $enabled )

• $enabled; whether the action is enabled

set-state

Sets the state of the action.

This directly updates the 'state' property to the given value.

This should only be called by the implementor of the action. Users of the action should not attempt to directly modify the 'state' property. Instead, they should call Gnome::Gio::Action.change-state() to request the change.

method set-state ( N-GObject() $value )

• $value; the new value for the state. The state is a native Gnome::Glib::Variant object.

set-state-hint

Sets the state hint for the action.

See Gnome::Gio::Action.get_state_hint() for more information about action state hints.

method set-state-hint ( N-GObject() $state_hint )

• $state_hint; a native Gnome::Gio::Variant representing the state hint, may be an undefined value.

_g_simple_action_new

Creates a new action. The created action is stateless. See g_simple_action_new_stateful() to create an action that has state.

Returns: a new GSimpleAction

method _g_simple_action_new (  Str  $name, N-GObject $parameter_type --> N-GObject )

• Str $name; the name of the action

• N-GObject $parameter_type; (nullable): the type of parameter that will be passed to handlers for the activate signal, or undefined for no parameter

_g_simple_action_new_stateful

Creates a new stateful action. All future state values must have the same N-GObject as the initial state. If the state N-GObject is floating, it is consumed.

Returns: a new GSimpleAction

method _g_simple_action_new_stateful (  Str  $name, N-GObject $parameter_type, N-GObject $state --> N-GObject )

• Str $name; the name of the action

• N-GObject $parameter_type; (nullable): the type of the parameter that will be passed to handlers for the activate signal, or undefined for no parameter

• N-GObject $state; the initial state of the action

Signals

activate

Indicates that the action was just activated.

$parameter will always be of the expected type, i.e. the parameter type specified when the action was created. If an incorrect type is given when activating the action, this signal is not emitted.

If no handler is connected to this signal then the default behaviour for boolean-stated actions with an undefined parameter type is to toggle them via the change-state signal.

For stateful actions where the state type is equal to the parameter type, the default is to forward them directly to change-state. This should allow almost all users of Gnome::Gio::SimpleAction to connect only one handler or the other.

method handler (
  N-GObject $parameter,
  Gnome::Gio::SimpleAction :_widget($simple),
  Int :$_handler-id,
  N-GObject :$_native-object,
  *%user-options
)

• $parameter; a native Gnome::Gio::Variant, the parameter to the activation, or undefined if it has no parameter

• $simple; The instance which registered the signal

• $_handler-id; The handler id which is returned from the registration

• $_native-object; The native object provided by the caller wrapped in the Raku object.

• %user-options; A list of named arguments provided at the register-signal() method

change-state

Indicates that the action just received a request to change its state.

value will always be of the correct state type, i.e. the type of the initial state passed to a new(:state, …). If an incorrect type is given when requesting to change the state, this signal is not emitted.

If no handler is connected to this signal then the default behaviour is to call set-state() to set the state to the requested value. If you connect a signal handler then no default action is taken. If the state should change then you must call set-state() from the handler.

method handler (
  N-GObject $parameter,
  Gnome::Gio::SimpleAction :_widget($simple),
  Int :$_handler-id,
  N-GObject :$_native-object,
  *%user-options
)

• $value; a native Gnome::Gio::Variant, the requested value for the state, or undefined if it has no parameter

• $simple; The instance which registered the signal

• $_handler-id; The handler id which is returned from the registration

• $_native-object; The native object provided by the caller wrapped in the Raku object.

• %user-options; A list of named arguments provided at the register-signal() method

Properties

enabled

If the action can be activated

• Gnome::GObject::Value type of this property is G_TYPE_BOOLEAN

• Parameter is readable and writable.

• Default value is TRUE.

name

The name used to invoke the action

• Gnome::GObject::Value type of this property is G_TYPE_STRING

• Parameter is readable and writable.

• Parameter is set on construction of object.

• Default value is undefined.

parameter-type

The type of GVariant passed to activate()

• Gnome::GObject::Value type of this property is G_TYPE_BOXED

• The type of this G_TYPE_BOXED object is G_TYPE_VARIANT_TYPE

• Parameter is readable and writable.

• Parameter is set on construction of object.

state

The state the action is in

• Gnome::GObject::Value type of this property is G_TYPE_VARIANT

• Parameter is readable and writable.

• Parameter is set on construction of object.

• Default value is undefined.

state-type

The type of the state kept by the action

• Gnome::GObject::Value type of this property is G_TYPE_BOXED

• The type of this G_TYPE_BOXED object is G_TYPE_VARIANT_TYPE

• Parameter is readable.

Signals

There are two ways to connect to a signal. The first option you have is to use register-signal() from Gnome::GObject::Object. The second option is to use g_signal_connect_object() directly from Gnome::GObject::Signal.

First method

The positional arguments of the signal handler are all obligatory as well as their types. The named attributes :$widget and user data are optional.

# handler method
method mouse-event ( GdkEvent $event, :$widget ) { ... }

# connect a signal on window object
my Gnome::Gtk3::Window $w .= new( ... );
$w.register-signal( self, 'mouse-event', 'button-press-event');

Second method

my Gnome::Gtk3::Window $w .= new( ... );
my Callable $handler = sub (
  N-GObject $native, GdkEvent $event, OpaquePointer $data
) {
  ...
}

$w.connect-object( 'button-press-event', $handler);

Also here, the types of positional arguments in the signal handler are important. This is because both methods register-signal() and g_signal_connect_object() are using the signatures of the handler routines to setup the native call interface.

Supported signals

activate

Indicates that the action was just activated.

parameter will always be of the expected type, i.e. the parameter type specified when the action was created. If an incorrect type is given when activating the action, this signal is not emitted.

If no handler is connected to this signal then the default behaviour for boolean-stated actions with a undefined parameter type is to toggle them via the change-state signal. For stateful actions where the state type is equal to the parameter type, the default is to forward them directly to change-state. This should allow almost all users of N-GSimpleAction to connect only one handler or the other.

method handler (
  N-GObject $parameter,
  Int :$_handle_id,
  Gnome::Gio::SimpleAction :_widget($simple),
  *%user-options
);

• $simple; the Gnome::Gio::SimpleAction

• $parameter; the parameter to the activation, or undefined if it has no parameter

change-state

Indicates that the action just received a request to change its state.

value will always be of the correct state type, i.e. the type of the initial state passed to g_simple_action_new_stateful(). If an incorrect type is given when requesting to change the state, this signal is not emitted.

If no handler is connected to this signal then the default behaviour is to call set-state() to set the state to the requested value. If you connect a signal handler then no default action is taken. If the state should change then you must call set-state() from the handler.

method handler (
  N-GObject $value,
  Int :$_handle_id,
  Gnome::Gio::SimpleAction :_widget($simple),
  *%user-options
);

• $simple; the GSimpleAction

• $value; the requested value for the state

Properties

An example of using a string type property of a Gnome::Gtk3::Label object. This is just showing how to set/read a property, not that it is the best way to do it. This is because a) The class initialization often provides some options to set some of the properties and b) the classes provide many methods to modify just those properties. In the case below one can use new(:label('my text label')) or gtk_label_set_text('my text label').

my Gnome::Gtk3::Label $label .= new;
my Gnome::GObject::Value $gv .= new(:init(G_TYPE_STRING));
$label.g-object-get-property( 'label', $gv);
$gv.g-value-set-string('my text label');

Supported properties

Enabled

If action is currently enabled.

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

Action Name

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

The Gnome::GObject::Value type of property name is G_TYPE_STRING.

Parameter Type

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

The Gnome::GObject::Value type of property parameter-type is G_TYPE_BOXED.

The Gnome::GObject::Value type of property enabled is G_TYPE_BOOLEAN.

State

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

The Gnome::GObject::Value type of property state is G_TYPE_VARIANT.

State Type

The N-GObject of the state that the action has, or undefined if the action is stateless.

The Gnome::GObject::Value type of property state-type is G_TYPE_BOXED.