Glade Custom Widgets

Note: This page contains old documentation from 2007, but may still be helpful. And it would still be okay to update, correct, and add to this page.

Glade and GTK# are a powerful combination. One that we are using for our Mono re-implementation of WorldPad. It's quite possible to build a very functional application using just the standard widgets provided by GTK, but sometimes specific functionality is needed which is not found in the regular set of widgets.

In this instance, a "custom widget" can be inserted into a Glade interface. This is easy to do, but filling in the custom widget with something useful is a bit more tricky.

How do we implement the custom widget?

In our case, we needed a custom colour picking widget. (Note that GTK does have a colour selection button, but we wanted something simpler, to more closely follow WorldPad). All that is needed is to stick a custom widget from the "GTK+ Additional" set into your window or dialog. You can then set a few generic string and integer properties that can be used when the widget is instantiated.

If you have custom controls in your glade file, an [http://www.go-mono.com/docs/index.aspx?link=T%3aGlade.XMLCustomWidgetHandler XMLCustomWidgetHandler] should be registered and will be called when you run load the Glade file. This function accepts a few parameters, most usefully the name of the widget and the properties that you may have defined in Glade.

To register the handler, create a method (we called ours on_custom_widget_found()*) and set the static property [http://www.go-mono.com/docs/index.aspx?link=T%3aGlade.XML%2f* Glade.XML.CustomWidgetHandler] to a new XMLCustomWidgetHandler constructed with the above method as a parameter

In our program, we simply took the name of the widget and used it to decide which widget to create and set up**. The widget is then returned by the function, et voila! Any widget you can construct using GTK# can appear in your Glade application.

*Gtk.Widget on_custom_widget_found(XML xml, string func_name, string name, string string1, string string2, int int1, int int2)

**Each widget was constructed, had an event attached, and was displayed using Show().