DragAndDropContainer::startDragging() allows an image to be specified but, as far as I can tell, the placement of this image relative to the mouse pointer is derived from the mouse position within the control when the drag was started, and there seems to be no public way to change it.
I’m doing a thumbnail-harvester - a sort of dual-pane image browser to collect images from various resources - and for this sort of work, it seems more natural to have the dragged thumbnails centered than to have their alignment determined by the mouse coordinates at drag start. I could imagine other uses - such as dragging pins around city maps or plugs into outlets, or tail-on-donkey - where one might prefer to have the mouse pointer on a specific pixel of the image, perhaps suppressing the normal mouse arrow while dragging.
Also, I wonder if click-click-dragging is possible. Don’t know if this term is proper English, what I mean is, I’d like to be able to use a drag mode where, instead of keeping the mouse button down when dragging, one click starts the dragging and another click ends it. (With the touchpads of the cheap subnotebooks we use in our living-lab experiments, click-move-click is somewhat easier than press-move-release.)