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 "expanded" property which can be used to monitor its expansion state. You should watch this property with a signal connection as follows:

expander = gtk_expander_new_with_mnemonic ("_More Options");
g_signal_connect (expander, "notify::expanded",
                  G_CALLBACK (expander_callback), NULL);

...

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 */
    }
}

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 <child> element. A normal content child can be specified without specifying a <child> type attribute.

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

struct GtkExpander

struct GtkExpander;

gtk_expander_new ()

GtkWidget *         gtk_expander_new                    (const gchar *label);

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

Since 2.4

gtk_expander_new_with_mnemonic ()

GtkWidget *         gtk_expander_new_with_mnemonic      (const gchar *label);

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.

Since 2.4

gtk_expander_set_expanded ()

void                gtk_expander_set_expanded           (GtkExpander *expander,
                                                         gboolean 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.

Since 2.4

gtk_expander_get_expanded ()

gboolean            gtk_expander_get_expanded           (GtkExpander *expander);

Queries a GtkExpander and returns its current state. Returns TRUE if the child widget is revealed.

See gtk_expander_set_expanded().

Since 2.4

gtk_expander_set_spacing ()

void                gtk_expander_set_spacing            (GtkExpander *expander,
                                                         gint spacing);

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

Since 2.4

gtk_expander_get_spacing ()

gint                gtk_expander_get_spacing            (GtkExpander *expander);

Gets the value set by gtk_expander_set_spacing().

Since 2.4

gtk_expander_set_label ()

void                gtk_expander_set_label              (GtkExpander *expander,
                                                         const gchar *label);

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

This will also clear any previously set labels.

Since 2.4

gtk_expander_get_label ()

const gchar *       gtk_expander_get_label              (GtkExpander *expander);

Fetches the text from a label widget including any embedded underlines indicating mnemonics and Pango markup, as set by gtk_expander_set_label(). If the label text has not been set the return value will be NULL. 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.

Since 2.4

gtk_expander_set_use_underline ()

void                gtk_expander_set_use_underline      (GtkExpander *expander,
                                                         gboolean 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.

Since 2.4

gtk_expander_get_use_underline ()

gboolean            gtk_expander_get_use_underline      (GtkExpander *expander);

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

Since 2.4

gtk_expander_set_use_markup ()

void                gtk_expander_set_use_markup         (GtkExpander *expander,
                                                         gboolean use_markup);

Sets whether the text of the label contains markup in Pango's text markup language. See gtk_label_set_markup().

Since 2.4

gtk_expander_get_use_markup ()

gboolean            gtk_expander_get_use_markup         (GtkExpander *expander);

Returns whether the label's text is interpreted as marked up with the Pango text markup language. See gtk_expander_set_use_markup().

Since 2.4

gtk_expander_set_label_widget ()

void                gtk_expander_set_label_widget       (GtkExpander *expander,
                                                         GtkWidget *label_widget);

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

Since 2.4

gtk_expander_get_label_widget ()

GtkWidget *         gtk_expander_get_label_widget       (GtkExpander *expander);

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

Since 2.4

gtk_expander_set_label_fill ()

void                gtk_expander_set_label_fill         (GtkExpander *expander,
                                                         gboolean label_fill);

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

Since 2.22

gtk_expander_get_label_fill ()

gboolean            gtk_expander_get_label_fill         (GtkExpander *expander);

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

Since 2.22

The "expanded" property

  "expanded"                 gboolean              : Read / Write / Construct

Whether the expander has been opened to reveal the child widget.

Default value: FALSE

The "label" property

  "label"                    gchar*                : Read / Write / Construct

Text of the expander's label.

Default value: NULL

The "label-fill" property

  "label-fill"               gboolean              : Read / Write / Construct

Whether the label widget should fill all available horizontal space.

Default value: FALSE

The "label-widget" property

  "label-widget"             GtkWidget*            : Read / Write

A widget to display in place of the usual expander label.

The "spacing" property

  "spacing"                  gint                  : Read / Write

Space to put between the label and the child.

Allowed values: >= 0

Default value: 0

The "use-markup" property

  "use-markup"               gboolean              : Read / Write / Construct

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

Default value: FALSE

The "use-underline" property

  "use-underline"            gboolean              : Read / Write / Construct

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

Default value: FALSE

The "expander-size" style property

  "expander-size"            gint                  : Read

Size of the expander arrow.

Allowed values: >= 0

Default value: 10

The "expander-spacing" style property

  "expander-spacing"         gint                  : Read

Spacing around expander arrow.

Allowed values: >= 0

Default value: 2

The "activate" signal

void                user_function                      (GtkExpander *expander,
                                                        gpointer     user_data)      : Action