Say I have two lists with List A positioned directly above List B (Requirement). Both lists allow Drag-N'-Drop re-ordering, initiated by "long-touching" an item. Auto-scroll functionality also triggers for re-ordering long lists. Finally, items in List B can be dropped into List A.
Here's the problem: The auto-scrolling and List B to List A interactions are too ambiguous (i.e., when to trigger scroll, do I bring-to-front the dragged item, what if the item is half here and half there, etc.).
I thought of mitigating this with a "tap-first-then-hold-down" gesture, but such a gesture would be too close to "tap" & "double-tap" (which are also being used), no? And an "Edit" button would just increase clutter on the screen (minimizing clutter is a Requirement).
Does anyone have any suggestions on how to solve this?