Interfacing Raku to Gnome GTK+

Gnome::Gtk3::MenuItem

The widget used for item in menus

Description

The Gnome::Gtk3::MenuItem widget and the derived widgets are the only valid children for menus. Their function is to correctly handle highlighting, alignment, events and submenus.

As a Gnome::Gtk3::MenuItem derives from Gnome::Gtk3::Bin it can hold any valid child widget, although only a few are really useful.

By default, a Gnome::Gtk3::MenuItem sets a Gnome::Gtk3::AccelLabel as its child. Gnome::Gtk3::MenuItem has direct functions to set the label and its mnemonic. For more advanced label settings, you can fetch the child widget from the Gnome::Gtk3::Bin.

Gnome::Gtk3::MenuItem as Gnome::Gtk3::Buildable

The Gnome::Gtk3::MenuItem implementation of the Gnome::Gtk3::Buildable interface supports adding a submenu by specifying “submenu” as the “type” attribute of a element.

An example of UI definition fragment with submenus:

<object class="B<Gnome::Gtk3::MenuItem>">
  <child type="submenu">
    <object class="B<Gnome::Gtk3::Menu>"/>
  </child>
</object>

Css Nodes

menuitem
├── <child>
╰── [arrow.right]

Gnome::Gtk3::MenuItem has a single CSS node with name menuitem. If the menuitem has a submenu, it gets another CSS node with name arrow, which has the .left or .right style class.

See Also

Gnome::Gtk3::Bin, Gnome::Gtk3::MenuShell

Synopsis

Declaration

unit class Gnome::Gtk3::MenuItem;
also is Gnome::Gtk3::Bin;
also does Gnome::Gtk3::Actionable;

Uml Diagram

Methods

new

default, no options

Create a new plain object.

multi method new ( )

:label

Create a new object with a label.

multi method new ( Str :$label! )

:mnemonic

Create a new object with a mnemonic.

multi method new ( Str :$mnemonic! )

:native-object

Create a MenuItem object using a native object from elsewhere. See also Gnome::N::TopLevelClassSupport.

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

:build-id

Create a MenuItem object using a native object returned from a builder. See also Gnome::GObject::Object.

multi method new ( Str :$build-id! )

activate

Emits the activate signal on the given item.

method activate ( )

deselect

Emits the deselect signal on the given item.

method deselect ( )

get-accel-path

Retrieve the accelerator path that was previously set on menu-item.

See set-accel-path() for details.

Returns: the accelerator path corresponding to this menu item’s functionality, or undefined if not set

method get-accel-path ( --> Str )

get-label

Sets text on the menu-item label

Returns: The text in the menu-item label. This is the internal string used by the label, and must not be modified.

method get-label ( --> Str )

get-reserve-indicator

Returns whether the menu-item reserves space for the submenu indicator, regardless if it has a submenu or not.

Returns: True if menu-item always reserves space for the submenu indicator

method get-reserve-indicator ( --> Bool )

get-submenu

Gets the submenu underneath this menu item, if any. See set-submenu().

Returns: submenu for this menu item, or undefined if none

method get-submenu ( --> N-GObject )

get-use-underline

Checks if an underline in the text indicates the next character should be used for the mnemonic accelerator key.

Returns: True if an embedded underline in the label indicates the mnemonic accelerator key.

method get-use-underline ( --> Bool )

select

Emits the select signal on the given item.

method select ( )

set-accel-path

Set the accelerator path on the menu-item, through which runtime changes of the menu item’s accelerator caused by the user can be identified and saved to persistent storage (see Gnome::Gtk3::AccelMap.save() on this). To set up a default accelerator for this menu item, call Gnome::Gtk3::AccelMap.add-entry() with the same accel-path. See also Gnome::Gtk3::AccelMap.add-entry() on the specifics of accelerator paths, and Gnome::Gtk3::Menu.set-accel-path() for a more convenient variant of this function.

This function is basically a convenience wrapper that handles calling Gnome::Gtk3::Widget.set-accel-path() with the appropriate accelerator group for the menu item.

Note that you do need to set an accelerator on the parent menu with Gnome::Gtk3::Menu.set-accel-group() for this to work.

method set-accel-path ( Str $accel_path )
  • Str $accel_path; accelerator path, corresponding to this menu item’s functionality, or undefined to unset the current path.

set-label

Sets $label on the menu-item label

method set-label ( Str $label )
  • Str $label; the text you want to set

set-reserve-indicator

Sets whether the menu-item should reserve space for the submenu indicator, regardless if it actually has a submenu or not.

There should be little need for applications to call this functions.

method set-reserve-indicator ( Bool $reserve )
  • Bool $reserve; the new value

set-submenu

Sets or replaces the menu item’s submenu, or removes it when a undefined submenu is passed.

method set-submenu ( N-GObject $submenu )
  • N-GObject $submenu; (type Gnome::Gtk3::Menu): the submenu, or undefined

set-use-underline

If true, an underline in the text indicates the next character should be used for the mnemonic accelerator key.

method set-use-underline ( Bool $setting )
  • Bool $setting; True if underlines in the text indicate mnemonics

toggle-size-allocate

Emits the toggle-size-allocate signal on the given item.

method toggle-size-allocate ( Int() $allocation )
  • Int() $allocation; the allocation to use as signal data.

toggle-size-request

Emits the toggle-size-request signal on the given item.

method toggle-size-request ( --> Int )

The method returns an integer $requisition;

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 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 connect-object() are using the signatures of the handler routines to setup the native call interface.

Supported signals

activate

Emitted when the item is activated.

method handler (
  Int :$_handle_id,
  Gnome::GObject::Object :_widget($menuitem),
  *%user-options
);
  • $menuitem; the object which received the signal.

  • $_handle_id; the registered event handler id

activate-item

Emitted when the item is activated, but also if the menu item has a submenu. For normal applications, the relevant signal is activate.

method handler (
  Int :$_handle_id,
  Gnome::GObject::Object :_widget($menuitem),
  *%user-options
);
  • $menuitem; the object which received the signal.

  • $_handle_id; the registered event handler id

deselect

method handler (
  Int :$_handle_id,
  Gnome::GObject::Object :_widget($menuitem),
  *%user-options
);
  • $menuitem;

  • $_handle_id; the registered event handler id

select

method handler (
  Int :$_handle_id,
  Gnome::GObject::Object :_widget($menuitem),
  *%user-options
);
  • $menuitem;

  • $_handle_id; the registered event handler id

toggle-size-allocate

method handler (
  Int $int,
  Int :$_handle_id,
  Gnome::GObject::Object :_widget($menuitem),
  *%user-options
);
  • $menuitem;

  • $int;

  • $_handle_id; the registered event handler id

toggle-size-request

method handler (
  Unknown type G_TYPE_POINTER $unknown type g_type_pointer,
  Int :$_handle_id,
  Gnome::GObject::Object :_widget($menuitem),
  *%user-options
);
  • $menuitem;

  • $unknown type g_type_pointer;

  • $_handle_id; the registered event handler id

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 .set-text(‘my text label’).

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

Supported properties

Accel Path: accel-path

Sets the accelerator path of the menu item, through which runtime changes of the menu item’s accelerator caused by the user can be identified and saved to persistant storage.

The Gnome::GObject::Value type of property accel-path is G_TYPE_STRING.

Label: label

The text for the child label.

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

Right Justified: right-justified

Sets whether the menu item appears justified at the right side of a menu bar.

The Gnome::GObject::Value type of property right-justified is G_TYPE_BOOLEAN.

The submenu attached to the menu item, or undefined if it has none.

Widget type: GTK_TYPE_MENU

The Gnome::GObject::Value type of property submenu is G_TYPE_OBJECT.

Use underline: use-underline

True if underlines in the text indicate mnemonics.

The Gnome::GObject::Value type of property use-underline is G_TYPE_BOOLEAN.