Create function (3)

• cdata->widget should be set to the new widget
• If funny extra info is required, such as an extra widget in List (the ScrolledWidget plus the List), define a new structure with first field a ComponentData, and the rest the extra info, and do the above anyway. The cdata->widget should be set to the topmost widget.
• Create the widget and assign it to cdata->widget
• Set MappedWhenManaged to false
• Manage the widget
• Add callback functions for callbacks of interest