Interfacing Raku to Gnome GTK+

Gnome::Gtk3::Expander

A container which can hide its child

Description

A Gnome::Gtk3::Expander allows the user to hide or show its child by clicking on an expander triangle similar to the triangles used in a Gnome::Gtk3::TreeView.

Normally you use an expander as you would use any other descendant of Gnome::Gtk3::Bin; you create the child widget and use add() to add it to the expander. When the expander is toggled, it will take care of showing and hiding the child automatically.

Gnome::Gtk3::Expander as Gnome::Gtk3::Buildable

The Gnome::Gtk3::Expander implementation of the Gnome::Gtk3::Buildable interface supports placing a child in the label position by specifying “label” as the “type” attribute of a element. A normal content child can be specified without specifying a type attribute.

An example of a UI definition fragment with GtkExpander:

<object class="GtkExpander">
  <child type="label">
    <object class="GtkLabel" id="expander-label"/>
  </child>
  <child>
    <object class="GtkEntry" id="expander-content"/>
  </child>
</object>

Css Nodes

expander
├── title
│  ├── arrow
│  ╰── <label widget>
╰── <child>

Gnome::Gtk3::Expander has three CSS nodes, the main node with the name expander, a subnode with name title and node below it with name arrow. The arrow of an expander that is showing its child gets the :checked pseudoclass added to it.

Synopsis

Declaration

unit class Gnome::Gtk3::Expander;
also is Gnome::Gtk3::Bin;

Inheriting this class

Inheriting is done in a special way in that it needs a call from new() to get the native object created by the class you are inheriting from.

use Gnome::Gtk3::Expander;

unit class MyGuiClass;
also is Gnome::Gtk3::Expander;

submethod new ( |c ) {
  # let the Gnome::Gtk3::Expander class process the options
  self.bless( :GtkExpander, |c);
}

submethod BUILD ( ... ) {
  ...
}

Types

Methods

new

:label

Create a new Expander object using label as the text of the label.

multi method new ( Str :$label! )

:mnemonic

Creates a new expander using label as the text of the label. If characters in label are preceded by an underscore, they are underlined. If you need a literal underscore character in a label, use “__” (two underscores). The first underlined character represents a keyboard accelerator called a mnemonic. Pressing Alt and that key activates the button.

multi method new ( Str :$mnemonic! )

:native-object

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

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

:build-id

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

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

get-expanded

Queries a Gnome::Gtk3::Expander and returns its current state. Returns True if the child widget is revealed.

See set_expanded().

Returns: the current state of the expander

method get-expanded ( --> Bool )

get-label

Fetches the text from a label widget including any embedded underlines indicating mnemonics and Pango markup, as set by set_label(). If the label text has not been set the return value will be undefined. This will be the case if you create an empty button with gtk_button_new() to use as a container.

Note that this function behaved differently in versions prior to 2.14 and used to return the label text stripped of embedded underlines indicating mnemonics and Pango markup. This problem can be avoided by fetching the label text directly from the label widget.

Returns: The text of the label widget. This string is owned by the widget and must not be modified or freed.

method get-label ( --> Str )

get-label-fill

Returns whether the label widget will fill all available horizontal space allocated to this expander.

Returns: True if the label widget will fill all available horizontal space

method get-label-fill ( --> Bool )

get-label-widget

Retrieves the label widget for the frame. See set_label_widget().

Returns: the label widget, or undefined if there is none

method get-label-widget ( --> N-GObject )

get-resize-toplevel

Returns whether the expander will resize the toplevel widget containing the expander upon resizing and collpasing.

Returns: the “resize toplevel” setting.

method get-resize-toplevel ( --> Bool )

get-spacing

Gets the value set by set_spacing().

Returns: spacing between the expander and child

Deprecated: 3.20: Use margins on the child instead.

method get-spacing ( --> Int )

get-use-markup

Returns whether the label’s text is interpreted as marked up with the [Pango text markup language][PangoMarkupFormat]. See set_use_markup().

Returns: True if the label’s text will be parsed for markup

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

get-use-underline

Returns whether an embedded underline in the expander label indicates a mnemonic. See set_use_underline().

Returns: True if an embedded underline in the expander label indicates the mnemonic accelerator keys

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

set-expanded

Sets the state of the expander. Set to True, if you want the child widget to be revealed, and False if you want the child widget to be hidden.

method set-expanded ( Bool $expanded )
  • $expanded; whether the child widget is revealed

set-label

Sets the text of the label of the expander to label.

This will also clear any previously set labels.

method set-label ( Str $label )
  • $label; a string

set-label-fill

Sets whether the label widget should fill all available horizontal space allocated to expander.

Note that this function has no effect since 3.20.

method set-label-fill ( Bool $label_fill )
  • $label_fill; True if the label should should fill all available horizontal space

set-label-widget

Set the label widget for the expander. This is the widget that will appear embedded alongside the expander arrow.

method set-label-widget ( N-GObject() $label_widget )
  • $label_widget; the new label widget

set-resize-toplevel

Sets whether the expander will resize the toplevel widget containing the expander upon resizing and collpasing.

method set-resize-toplevel ( Bool $resize_toplevel )
  • $resize_toplevel; whether to resize the toplevel

set-spacing

Sets the spacing field of expander, which is the number of pixels to place between expander and the child.

Deprecated: 3.20: Use margins on the child instead.

method set-spacing ( Int() $spacing )
  • $spacing; distance between the expander and child in pixels

set-use-markup

Sets whether the text of the label contains markup in [Pango’s text markup language][PangoMarkupFormat]. See gtk_label_set_markup().

method set-use-markup ( Bool $use_markup )
  • $use_markup; True if the label’s text should be parsed for markup

set-use-underline

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

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

Signals

activate

method handler (
  Gnome::Gtk3::Expander :_widget($expander),
  Int :$_handler-id,
  N-GObject :$_native-object,
  *%user-options
)

  • $expander; 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

expanded

Whether the expander has been opened to reveal the child widget

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

  • Parameter is readable and writable.

  • Parameter is set on construction of object.

  • Default value is FALSE.

label

Text of the expander’s label

  • 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.

label-fill

Whether the label widget should fill all available horizontal space

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

  • Parameter is readable and writable.

  • Parameter is set on construction of object.

  • Default value is FALSE.

label-widget

A widget to display in place of the usual expander label

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

  • The type of this G_TYPE_OBJECT object is GTK_TYPE_WIDGET

  • Parameter is readable and writable.

resize-toplevel

Whether the expander will resize the toplevel window upon expanding and collapsing

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

  • Parameter is readable and writable.

  • Default value is FALSE.

use-markup

The text of the label includes XML markup. See pango_parse_markup()

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

  • Parameter is readable and writable.

  • Parameter is set on construction of object.

  • Default value is FALSE.

use-underline

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

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

  • Parameter is readable and writable.

  • Parameter is set on construction of object.

  • Default value is FALSE.