New comment by sgn on void-packages repository

https://github.com/void-linux/void-packages/pull/17766#issuecomment-576518424

Comment:
> As far as I can see those modules are not for the interface designer,
> but rather they contain widget implementations that can be used
> at runtime by applications _as well as the designer_, same with the xfce plugin.

I don't think so,
Let's take libxfce4uiglade2.so as an example, it's compiled from a single C source file,
and contains only 3 functions:
```
void       glade_xfce_titled_dialog_post_create        (GladeWidgetAdaptor *adaptor,
                                                        GObject            *object,
                                                        GladeCreateReason   reason);
GtkWidget *glade_xfce_titled_dialog_get_internal_child (GladeWidgetAdaptor *adaptor,
                                                        GtkDialog          *dialog,
                                                        const gchar        *name);
GList     *glade_xfce_titled_dialog_get_children       (GladeWidgetAdaptor *adaptor,
                                                        GtkDialog          *dialog);
```
Which is used by glade
```
<?xml version="1.0" encoding="UTF-8"?>
<glade-catalog version="4.12.0" supports="gtkbuilder" name="libxfce4ui-2" library="xfce4uiglade2" domain="glade3" depends="gtk+" book="xfce4">
  <glade-widget-classes>
    <glade-widget-class name="XfceTitledDialog" generic-name="xfce-titled-dialog" title="Titled Dialog">
      <post-create-function>glade_xfce_titled_dialog_post_create</post-create-function>
      <get-internal-child-function>glade_xfce_titled_dialog_get_internal_child</get-internal-child-function>
      <get-children-function>glade_xfce_titled_dialog_get_children</get-children-function>
      <properties>
        <property translatable="True" ignore="False" id="subtitle" name="Subtitle"></property>
        <property translatable="True" ignore="False" id="title"/>
        <property ignore="True" id="icon"/>
        <property themed-icon="True" ignore="False" id="icon-name"/>
      </properties>
    </glade-widget-class>
  </glade-widget-classes>
  <glade-widget-group name="xfce4-widgets" title="Xfce 4 Widgets">
    <glade-widget-class-ref name="XfceTitledDialog"/>
  </glade-widget-group>
</glade-catalog>
```
as described by: https://developer.gnome.org/gladeui/stable/catalogintro.html

As far as I can tell, those functions are used to tell glade3
 the supported properties of XfceTitledDialog.


> I.e. the modules are loaded and used by `libgladeui`, which exposes them both to the interface designer itself as well as applications with interfaces designed using GLADE.

I strongly believe that the application itself uses the Gtk+ derived Widget,
those modules were there to tell glade their supported properties.