How to prevent parent scrolling during touch tap drag and drop event on html canvas?

[Kelly St. John]

I am currently using easel.js (create.js) on my polymer 1.0+ site to handle rendering of shapes on the html canvas, and I'm handling mouse events using "pressmove", "mousedown" and "pressup" on those shapes within the canvas.  Everything is working well with the mouse.  However, drag and dropping of those shapes on mobile devices doesn't work.  A tap and drag with the finger on a touch enable device instead scrolls the page itself (which does need to be scrollable).  Is there a way to prevent polymer scrolling of the page when the user taps on the canvas or one of the shapes within the canvas itself? 

Here is the SO question if you prefer to answer it there:  http://stackoverflow.com/questions/35786299/how-to-prevent-polymer-scrolling-page-on-touch-screen-during-touch-drag-and-drop