Browse the available stock icons in the list of stock IDs found <link linkend="gtk-Stock-Items">here</link>. You can also use the <application>gtk-demo</application> application for this purpose. An icon factory manages a collection of GtkIconSet; a GtkIconSet manages a set of variants of a particular icon (i.e. a GtkIconSet contains variants for different sizes and widget states). Icons in an icon factory are named by a stock ID, which is a simple string identifying the icon. Each GtkStyle has a list of GtkIconFactory derived from the current theme; those icon factories are consulted first when searching for an icon. If the theme doesn't set a particular icon, GTK+ looks for the icon in a list of default icon factories, maintained by gtk_icon_factory_add_default() and gtk_icon_factory_remove_default(). Applications with icons should add a default icon factory with their icons, which will allow themes to override the icons for the application. To display an icon, always use gtk_style_lookup_icon_set() on the widget that will display the icon, or the convenience function gtk_widget_render_icon(). These functions take the theme into account when looking up the icon to use for a given stock ID. <refsect2 id="GtkIconFactory-BUILDER-UI"> <title>GtkIconFactory as GtkBuildable</title> <para> GtkIconFactory supports a custom <sources> element, which can contain multiple <source> elements. The following attributes are allowed: <variablelist> <varlistentry> <term>stock-id</term> <listitem><para> The stock id of the source, a string. This attribute is mandatory </para></listitem> </varlistentry> <varlistentry> <term>filename</term> <listitem><para> The filename of the source, a string. This attribute is optional </para></listitem> </varlistentry> <varlistentry> <term>icon-name</term> <listitem><para> The icon name for the source, a string. This attribute is optional. </para></listitem> </varlistentry> <varlistentry> <term>size</term> <listitem><para> Size of the icon, a GtkIconSize enum value. This attribute is optional. </para></listitem> </varlistentry> <varlistentry> <term>direction</term> <listitem><para> Direction of the source, a GtkTextDirection enum value. This attribute is optional. </para></listitem> </varlistentry> <varlistentry> <term>state</term> <listitem><para> State of the source, a GtkStateType enum value. This attribute is optional. </para></listitem> </varlistentry> </variablelist> <example> <title>A GtkIconFactory UI definition fragment.</title> <programlisting><![CDATA[ <object class="GtkIconFactory" id="iconfactory1"> <sources> <source stock-id="apple-red" filename="apple-red.png"/> </sources> </object> <object class="GtkWindow" id="window1"> <child> <object class="GtkButton" id="apple_button"> <property name="label">apple-red</property> <property name="use-stock">True</property> </object> </child> </object> ]]> </programlisting> </example> </para> </refsect2>