GtkWidget::queue_draw

This method is the one to use if you need to force a widget to redraw itself. Put it into a callback function and determine an appropriate signal to trigger the redraws. queue_draw() creates an expose event, in most situations.

In the event that this method does not have the desired effect, try calling queue_resize() instead. If that also fails, you will need to resort to calling hide() followed immediately by show() in the callback.