You would need to set up event listeners for nativeDragEnter,
nativeDragDrop and nativeDragOver events on the list object.
When a drag over or enter event occurs, you call the
acceptDrop method of the NativeDragManager class (I think that's
the right method name). This tells the system that the list object
can take the drop.
Then if/when the drop event occurs, you get the file list
from the event object. You can then loop through the list of drop
files and add each file to the list.