set draggingItem (Some itemSource)}
adam@1784: onmouseup={fn _ => set draggingItem None}
adam@1784: onmouseover={fn _ => di <- get draggingItem;
adam@1784: case di of
adam@1784: None => return ()
adam@1784: | Some di => original <- get di;
adam@1784: movedOver <- get itemSource;
adam@1784: set di movedOver;
adam@1784: set itemSource original;
adam@1784: set draggingItem (Some itemSource)}>
adamc@918:
adamc@916: