GtkExpander

## GtkExpander GtkExpander — A container which can hide its child |

## Includes

    #include <gtk/gtk.h>

## Description

A GtkExpander allows the user to hide or show its child by clicking on an expander triangle similar to the triangles used in a GtkTreeView.

Normally you use an expander as you would use any other descendant of GtkBin; you create the child widget and use `gtk_container_add()` 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 `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.

Example 33. A UI definition fragment with GtkExpander

    1
    2
    3
    4
    5
    6
    7
    8
    <object class="GtkExpander">
      <child type="label">
        <object class="GtkLabel" id="expander-label"/>
      </child>
      <child>
        <object class="GtkEntry" id="expander-content"/>
      </child>
    </object>

## Functions

## Types and Values