I have seen this documentation
about how to turn the drop zone visible. I wanted the user to know where he could drop his files so I changed the style to a div with a visible gray dashed border.
However, I would like this border to turn black whenever a file is being dragged. It will give a better feedback to the user to where he has to drop the file.
I know this is possible because in the default configuration, the drop zone is invisible and turns visible whenever a file is being dragged in the window.
So long story short, what function is triggered when dragging occurs?
Thanks for your help!