void gtk_widget_queue_resize ( GtkWidget* widget )
Flags a widget to have its size renegotiated.
This should be called when a widget for some reason has a new
size request. For example, when you change the text in a
GtkLabel, the label queues a resize to ensure there’s
enough space for the new text.
Note that you cannot call gtk_widget_queue_resize() on a widget
from inside its implementation of the
virtual method. Calls to gtk_widget_queue_resize() from inside
Gtk.WidgetClass.size_allocate will be silently ignored.
This function is only for use in widget implementations.