How do I limit the touch to just one finger at a time?

Imagine having many cards on a screen. Cards can be dragged around with touch plugin. I don't want to have any cards (except one) being dragged by other fingers at the same time. How do I limit the touch to just one finger / input?

I can think of 2 approaches I could take. When you touch the screen, take the touchID and don't allow any other touch until that touchID has been released (on touch end check the ID), or more simply you could say don't allow any swiping if 'is in touch' meaning you already touched the screen once.

Thanks. I'll try to sort it out with touch id.