GtkExpander

GtkExpander — A container which can hide its child

Synopsis


#include <gtk/gtk.h>


                    GtkExpander;
GtkWidget*          gtk_expander_new                    (const gchar *label);
GtkWidget*          gtk_expander_new_with_mnemonic      (const gchar *label);
void                gtk_expander_set_expanded           (GtkExpander *expander,
                                                         gboolean expanded);
gboolean            gtk_expander_get_expanded           (GtkExpander *expander);
void                gtk_expander_set_spacing            (GtkExpander *expander,
                                                         gint spacing);
gint                gtk_expander_get_spacing            (GtkExpander *expander);
void                gtk_expander_set_label              (GtkExpander *expander,
                                                         const gchar *label);
const gchar*        gtk_expander_get_label              (GtkExpander *expander);
void                gtk_expander_set_use_underline      (GtkExpander *expander,
                                                         gboolean use_underline);
gboolean            gtk_expander_get_use_underline      (GtkExpander *expander);
void                gtk_expander_set_use_markup         (GtkExpander *expander,
                                                         gboolean use_markup);
gboolean            gtk_expander_get_use_markup         (GtkExpander *expander);
void                gtk_expander_set_label_widget       (GtkExpander *expander,
                                                         GtkWidget *label_widget);
GtkWidget*          gtk_expander_get_label_widget       (GtkExpander *expander);

Object Hierarchy


  GObject
   +----GInitiallyUnowned
         +----GtkObject
               +----GtkWidget
                     +----GtkContainer
                           +----GtkBin
                                 +----GtkExpander

Implemented Interfaces

GtkExpander implements GtkBuildable and AtkImplementorIface.

Properties


  "expanded"                 gboolean              : Read / Write / Construct
  "label"                    gchararray            : Read / Write / Construct
  "label-widget"             GtkWidget             : Read / Write
  "spacing"                  gint                  : Read / Write
  "use-markup"               gboolean              : Read / Write / Construct
  "use-underline"            gboolean              : Read / Write / Construct

Style Properties


  "expander-size"            gint                  : Read
  "expander-spacing"         gint                  : Read

Signals


  "activate"                                       : Run Last / Action

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 37. 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>

Details

GtkExpander

typedef struct _GtkExpander GtkExpander;

gtk_expander_new ()

GtkWidget*          gtk_expander_new                    (const gchar *label);

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

label : the text of the label
Returns : a new GtkExpander widget.

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.

label : the text of the label with an underscore in front of the mnemonic character
Returns : a new GtkExpander widget.

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.

expander : a GtkExpander
expanded : whether the child widget is revealed

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().

expander : a GtkExpander
Returns : the current state of the expander.

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.

expander : a GtkExpander
spacing : distance between the expander and child in pixels.

Since 2.4

gtk_expander_get_spacing ()

gint                gtk_expander_get_spacing            (GtkExpander *expander);

Gets the value set by gtk_expander_set_spacing().

expander : a GtkExpander
Returns : spacing between the expander and child.

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.

expander : a GtkExpander
label : a string

Since 2.4

gtk_expander_get_label ()

const gchar*        gtk_expander_get_label              (GtkExpander *expander);

Fetches the text from the label of the expander, 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.

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

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.

expander : a GtkExpander
use_underline : TRUE if underlines in the text indicate mnemonics

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().

expander : a GtkExpander
Returns : TRUE if an embedded underline in the expander label indicates the mnemonic accelerator keys.

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().

expander : a GtkExpander
use_markup : TRUE if the label's text should be parsed for 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().

expander : a GtkExpander
Returns : TRUE if the label's text will be parsed for 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.

expander : a GtkExpander
label_widget : the new label widget

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().

expander : a GtkExpander
Returns : the label widget, or NULL if there is none.

Since 2.4

Property Details

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"                    gchararray            : Read / Write / Construct

Text of the expander's label.

Default value: NULL

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

Style Property Details

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

Signal Details

The "activate" signal

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

expander : the object which received the signal.
user_data : user data set when the signal handler was connected.