Which display is this window on?

Haven’t tried removing those (yet). Really not sure why I didn’t use a Container for the dropdown part. I’m using one for the selector part. They’re not implicit instances, though.

It just seems odd to use a DesktopWindow as a control or am I getting that wrong?

As part of one. It works nicely but I may revisit it as a control.

It’s part of the control; you have a window with my popupmenu in it, but the use case here is where the window isn’t that large and the popupmenu may have some hundreds of items in it. It’s a window so that it can have a height greater than that of the window where the control is. When you click on my popupmenu, it instantiates a tall thin window with a listbox in it, containing the choices. I position its top just below the popupmenu control, unless that would put the bottom of the popup window off the bottom of the display, in which case it’s moved up.