Thank you so much @tatiang and @catsarisky for putting in the time to help me.
@tatiang, I liked your solution but it is going to take more time than I need.
So I have a better idea. I can temporarily move my character sprite outside the range the presents are moving and then move it back again when they are done moving.
Hope this can be a reference to other people who are facing the same issue.
I will edit this post to include a link to WDC #16, where you can see my updated app and remix it.