disable touch scrolling bubbling up DOM

disable_bubbling_up_scrolling.js

//http://stackoverflow.com/questions/16889447/prevent-full-page-scrolling-ios

elem.addEventListener('touchstart', function(event){
    this.allowUp = (this.scrollTop > 0);
    this.allowDown = (this.scrollTop < this.scrollHeight - this.clientHeight);
    this.prevTop = null; this.prevBot = null;
    this.lastY = event.pageY;
});

elem.addEventListener('touchmove', function(event){
    var up = (event.pageY > this.lastY), down = !up;
    this.lastY = event.pageY;

    if ((up && this.allowUp) || (down && this.allowDown)) event.stopPropagation();
    else event.preventDefault();
});