I'd like to suggest to add a small new feature to FLTK 1.4, the possibility

to use an Fl_RGB_Image as visual feedback for the drag-n-drop operation.
The intention is to produce an image that evokes what is being dragged.

API:

Fl::dnd(Fl_RGB_Image *rgb = NULL)

which extends the previous API Fl::dnd(void)

As a demo, I have modified test/editor.cxx to call this new API

after drawing in an image the start of the text being dragged.

That's all in attached "dnd.patch".

This would solve the request expressed in "Making a draggable item" of fltk.general.