How can I attach an additional action to the "reset" button in the drag and drop interaction?

Question

Hello,
I would like to know how to attach an additional behavior to the "reset" button in my drag and drop exercise.
Here is the background:
In my drag and drop exercise, when the user drops the source on a target of his choice, certain elements appear and certain elements disappear
This means that depending on where he dropped the sources, certain elements will be visible and certain elements invisible when he is finished the activity
Because the sources are not re-draggable once he drops them, he will have the option to reset the exercise and start again from the beginning using the reset button
My challenge:
I would like exercise to return to its original state when the user selects the rest button .  this means:
the dragged objects return to their orginal starting location (this is what naturally occurs when you hit the reset button)
any objects that had disappeared during the course of the activity reappear
objects that were not visible in the beginning , but had appeared during the course of the activity, again become invisible
So how can I add this action to the reset button?

Answer 1

Allowing the user to redrag the souce after it has been dropped would work for my particular problem  if I could bind an action to the event redragging, namely making the elements reappear that had disappeared and the elements disappear that had appeared when the user dropped it the first time.