gtk2/gtk/glade

The catalog in this directory defines some widgets that are private
to GTK and is needed to edit .ui files defining composite classes
in GTK.

In order to edit any composite classes in GTK, startup Glade
in the following way, example:

    cd /path/to/gtk/
    GLADE_CATALOG_SEARCH_PATH=`pwd`/gtk/glade glade gtk/ui/gtkfilechooserwidget.ui

Documentation for updating this catalog can be found here:
    https://developer.gnome.org/gladeui/stable/

Note also that when including private GTK widgets as components, it is
important to call g_type_ensure () to register the type explicitly
before calling gtk_container_init_template(), otherwise GtkBuilder will
not be able to properly load the type.