The callbacks that are necessary for the menu system are much simpler than for the layouts; the example interface only contains two menu commands, and they only require one callback each.
"Graph"
menu item, display its Attributes dialog and change the CALLBACK attribute to 'display-graph-selection
. Click OK . "List Panel"
menu item, display its Attributes dialog and change the CALLBACK attribute to 'display-list-selection
. Click OK .