Class

GtkExpander

Description [src]

final class Gtk.Expander : Gtk.Widget {
  /* No available fields */
}

GtkExpander allows the user to reveal its child by clicking on an expander triangle.

An example GtkExpander

This is similar to the triangles used in a GtkTreeView.

Normally you use an expander as you would use a frame; you create the child widget and use gtk_expander_set_child() to add it to the expander. When the expander is toggled, it will take care of showing and hiding the child automatically.

Special Usage

There are situations in which you may prefer to show and hide the expanded widget yourself, such as when you want to actually create the widget at expansion time. In this case, create a GtkExpander but do not add a child to it. The expander widget has an [property@Gtk.Expander:expanded[ property which can be used to monitor its expansion state. You should watch this property with a signal connection as follows:

static void
expander_callback (GObject    *object,
                   GParamSpec *param_spec,
                   gpointer    user_data)
{
  GtkExpander *expander;

  expander = GTK_EXPANDER (object);

  if (gtk_expander_get_expanded (expander))
    {
      // Show or create widgets
    }
  else
    {
      // Hide or destroy widgets
    }
}

static void
create_expander (void)
{
  GtkWidget *expander = gtk_expander_new_with_mnemonic ("_More Options");
  g_signal_connect (expander, "notify::expanded",
                    G_CALLBACK (expander_callback), NULL);

  // ...
}

GtkExpander as GtkBuildable

The GtkExpander implementation of the GtkBuildable 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
╰── box
    ├── title
    │   ├── arrow
    │   ╰── <label widget>
    ╰── <child>

GtkExpander 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.

Accessibility

GtkExpander uses the GTK_ACCESSIBLE_ROLE_BUTTON role.

Hierarchy

hierarchy this GtkExpander implements_0 GtkAccessible this--implements_0 implements_1 GtkBuildable this--implements_1 implements_2 GtkConstraintTarget this--implements_2 ancestor_0 GtkWidget ancestor_0--this ancestor_1 GInitiallyUnowned ancestor_1--ancestor_0 ancestor_2 GObject ancestor_2--ancestor_1

Constructors

gtk_expander_new

Creates a new expander using label as the text of the label.

gtk_expander_new_with_mnemonic

Creates a new expander using label as the text of the label.

Instance methods

gtk_expander_get_child

Gets the child widget of expander.

gtk_expander_get_expanded

Queries a GtkExpander and returns its current state.

gtk_expander_get_label

Fetches the text from a label widget.

gtk_expander_get_label_widget

Retrieves the label widget for the frame.

gtk_expander_get_resize_toplevel

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

gtk_expander_get_use_markup

Returns whether the label’s text is interpreted as Pango markup.

gtk_expander_get_use_underline

Returns whether an underline in the text indicates a mnemonic.

gtk_expander_set_child

Sets the child widget of expander.

gtk_expander_set_expanded

Sets the state of the expander.

gtk_expander_set_label

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

gtk_expander_set_label_widget

Set the label widget for the expander.

gtk_expander_set_resize_toplevel

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

gtk_expander_set_use_markup

Sets whether the text of the label contains Pango markup.

gtk_expander_set_use_underline

If true, an underline in the text indicates a mnemonic.

Methods inherited from GtkWidget (159)
gtk_widget_action_set_enabled

Enable or disable an action installed with gtk_widget_class_install_action().

gtk_widget_activate

For widgets that can be “activated” (buttons, menu items, etc.), this function activates them.

gtk_widget_activate_action

Looks up the action in the action groups associated with widget and its ancestors, and activates it.

gtk_widget_activate_action_variant

Looks up the action in the action groups associated with widget and its ancestors, and activates it.

gtk_widget_activate_default

Activates the default.activate action from widget.

gtk_widget_add_controller

Adds controller to widget so that it will receive events.

gtk_widget_add_css_class

Adds a style class to widget.

gtk_widget_add_mnemonic_label

Adds a widget to the list of mnemonic labels for this widget.

gtk_widget_add_tick_callback

Queues an animation frame update and adds a callback to be called before each frame.

gtk_widget_allocate

This function is only used by GtkWidget subclasses, to assign a size, position and (optionally) baseline to their child widgets.

gtk_widget_child_focus

Called by widgets as the user moves around the window using keyboard shortcuts.

gtk_widget_compute_bounds

Computes the bounds for widget in the coordinate space of target.

gtk_widget_compute_expand

Computes whether a container should give this widget extra space when possible.

gtk_widget_compute_point

Translates the given point in widgets coordinates to coordinates relative to target’s coordinate system.

gtk_widget_compute_transform

Computes a matrix suitable to describe a transformation from widgets coordinate system into targets coordinate system.

gtk_widget_contains

Tests if the point at (x, y) is contained in widget.

gtk_widget_create_pango_context

Creates a new PangoContext with the appropriate font map, font options, font description, and base direction for drawing text for this widget.

gtk_widget_create_pango_layout

Creates a new PangoLayout with the appropriate font map, font description, and base direction for drawing text for this widget.

gtk_drag_check_threshold

Checks to see if a drag movement has passed the GTK drag threshold.

gtk_widget_error_bell

Notifies the user about an input-related error on this widget.

gtk_widget_get_allocated_baseline

Returns the baseline that has currently been allocated to widget.

gtk_widget_get_allocated_height

Returns the height that has currently been allocated to widget.

gtk_widget_get_allocated_width

Returns the width that has currently been allocated to widget.

Methods inherited from GObject (42)
Methods inherited from GtkAccessible (10)
gtk_accessible_get_accessible_role

Retrieves the GtkAccessibleRole for the given GtkAccessible.

gtk_accessible_reset_property

Resets the accessible property to its default value.

gtk_accessible_reset_relation

Resets the accessible relation to its default value.

gtk_accessible_reset_state

Resets the accessible state to its default value.

gtk_accessible_update_property

Updates a list of accessible properties.

gtk_accessible_update_property_value

Updates an array of accessible properties.

gtk_accessible_update_relation

Updates a list of accessible relations.

gtk_accessible_update_relation_value

Updates an array of accessible relations.

gtk_accessible_update_state

Updates a list of accessible states. See the GtkAccessibleState documentation for the value types of accessible states.

gtk_accessible_update_state_value

Updates an array of accessible states.

Methods inherited from GtkBuildable (1)
gtk_buildable_get_buildable_id

Gets the ID of the buildable object.

Properties

Gtk.Expander:child

The child widget.

Gtk.Expander:expanded

Whether the expander has been opened to reveal the child.

Gtk.Expander:label

The text of the expanders label.

Gtk.Expander:label-widget

A widget to display instead of the usual expander label.

Gtk.Expander:resize-toplevel

When this property is TRUE, the expander will resize the toplevel widget containing the expander upon expanding and collapsing.

Gtk.Expander:use-markup

Whether the text in the label is Pango markup.

Gtk.Expander:use-underline

Whether an underline in the text indicates a mnemonic.

Properties inherited from GtkWidget (34)
Gtk.Widget:can-focus

Whether the widget or any of its descendents can accept the input focus.

Gtk.Widget:can-target

Whether the widget can receive pointer events.

Gtk.Widget:css-classes

A list of css classes applied to this widget.

Gtk.Widget:css-name

The name of this widget in the CSS tree.

Gtk.Widget:cursor

The cursor used by widget.

Gtk.Widget:focus-on-click

Whether the widget should grab focus when it is clicked with the mouse.

Gtk.Widget:focusable

Whether this widget itself will accept the input focus.

Gtk.Widget:halign

How to distribute horizontal space if widget gets extra space.

Gtk.Widget:has-default

Whether the widget is the default widget.

Gtk.Widget:has-focus

Whether the widget has the input focus.

Gtk.Widget:has-tooltip

Enables or disables the emission of the ::query-tooltip signal on widget.

Gtk.Widget:height-request

Override for height request of the widget.

Gtk.Widget:hexpand

Whether to expand horizontally.

Gtk.Widget:hexpand-set

Whether to use the hexpand property.

Gtk.Widget:layout-manager

The GtkLayoutManager instance to use to compute the preferred size of the widget, and allocate its children.

Gtk.Widget:margin-bottom

Margin on bottom side of widget.

Gtk.Widget:margin-end

Margin on end of widget, horizontally.

Gtk.Widget:margin-start

Margin on start of widget, horizontally.

Gtk.Widget:margin-top

Margin on top side of widget.

Gtk.Widget:name

The name of the widget.

Gtk.Widget:opacity

The requested opacity of the widget.

Gtk.Widget:overflow

How content outside the widget’s content area is treated.

Gtk.Widget:parent

The parent widget of this widget.

Gtk.Widget:receives-default

Whether the widget will receive the default action when it is focused.

Gtk.Widget:root

The GtkRoot widget of the widget tree containing this widget.

Gtk.Widget:scale-factor

The scale factor of the widget.

Gtk.Widget:sensitive

Whether the widget responds to input.

Gtk.Widget:tooltip-markup

Sets the text of tooltip to be the given string, which is marked up with Pango markup.

Gtk.Widget:tooltip-text

Sets the text of tooltip to be the given string.

Gtk.Widget:valign

How to distribute vertical space if widget gets extra space.

Gtk.Widget:vexpand

Whether to expand vertically.

Gtk.Widget:vexpand-set

Whether to use the vexpand property.

Gtk.Widget:visible

Whether the widget is visible.

Gtk.Widget:width-request

Override for width request of the widget.

Properties inherited from GtkAccessible (1)
Gtk.Accessible:accessible-role

The accessible role of the given GtkAccessible implementation.

Signals

Gtk.Expander::activate

Activates the GtkExpander.

Signals inherited from GtkWidget (13)
Gtk.Widget::destroy

Signals that all holders of a reference to the widget should release the reference that they hold.

Gtk.Widget::direction-changed

Emitted when the text direction of a widget changes.

Gtk.Widget::hide

Emitted when widget is hidden.

Gtk.Widget::keynav-failed

Emitted if keyboard navigation fails.

Gtk.Widget::map

Emitted when widget is going to be mapped.

Gtk.Widget::mnemonic-activate

Emitted when a widget is activated via a mnemonic.

Gtk.Widget::move-focus

Emitted when the focus is moved.

Gtk.Widget::query-tooltip

Emitted when the widgets tooltip is about to be shown.

Gtk.Widget::realize

Emitted when widget is associated with a GdkSurface.

Gtk.Widget::show

Emitted when widget is shown.

Gtk.Widget::state-flags-changed

Emitted when the widget state changes.

Gtk.Widget::unmap

Emitted when widget is going to be unmapped.

Gtk.Widget::unrealize

Emitted when the GdkSurface associated with widget is destroyed.

Signals inherited from GObject (1)