|Libglade - Graphical Interface Description Loader API|
In some cases, libglade may not provide support for the widgets you want to use, or you may want to insert a bit of hand coded interface into the larger libglade generated interface. Libglade provides support for doing this.
If you are only need a few custom widgets (eg. a word processor may have a custom widget for the document editing area), the simplest choice is probably Glade's custom widget. It allows you to specify a custom function that will be used to create the widget. The signature of the function is as follows:
GtkWidget *custom_func(gchar *widget_name, gchar *string1, gchar *string2, gint int1, gint int2);
When calling this function, widget_name is the name of the
widget given in the XML file, and
arbitrary constants whose values also come from the XML file.
Libglade supports the custom widget using gmodule. For most
cases, this is sufficient.
If you wish to get libglade to recognise a new widget type
directly, your best option is to ensure that it implements
properties for all settings required to construct the widget,
and packing properties if the widget happens to be a container.
If the widget satisifies this requirement, libglade will support
the widget with no extra code (provided the widget's
get_type() function has been called to
register it with GLib).
If a widget has more complex requirements, a libglade
module must be written (or if the library containing the widget
already depends on libglade, it may build the module in). In
the module, a widget construction routine and a build children
routine must be registered. If the widget can be manipulated
via properties for construction or adding children,
can be used here.
If the widget mostly supports properties, custom handlers
for particular properties can be registered with
If the widget implements no properties (and you have no way to convince the author to do so), you will most likely need to implement custom handlers for construction and adding children.
For a more extensive example of registering new widget
types and build functions, see
glade/glade-gtk.c in the libglade package.
For more information on the exact API's used to register new
widget types with libglade, see the Libglade Build section
of this manual.