They have to respond to the drag event by initiating the drag
sequence.
If no morph in the assembly responds to the mouse event, it gets
passed to the World, whose default is to grab the whole root morph.
m _ Morph new bounds: (100@100 extent: 300@300); openInWorld.
m enableDrop: true.
s _ Morph new color: Color red; position: 200@200.
m addMorph: s.
s on: #startDrag send: #startDrag:with: to: s.

Hello everyone!
I'm working on adding drag-n-drop (DnD) capabilities to an app I'm
writing. (Dynapad's calendar/scheduler)
Adding some simple DnD functionality was pretty easy, but I've run
into a problem: I can drag-n-drop morphs *into* the reciever of these
morphs, but I can't take them back out.  That is, I'd like to be able
to drag the morphs back out of the container, dropping them into
another container, the trash, etc.  But, after a morph has been
embedded, it doesn't seem that I can take it back out unless I bring
up a halo around just that morph, and use the black Pick Up handle-
not much of an option on a PDA.