Function _saveClientY

docs/app/js/sanddance-app.js:21496–21498

(event)

    var _element = null;
    // remember the clientY for future calls of _preventOverscrolling
    var _saveClientY = function(event) {
        if (event.targetTouches.length === 1) _previousClientY = event.targetTouches[0].clientY;
    };
    // prevent the body from scrolling when the user attempts
    // to scroll past the top or bottom of the element
    var _preventOverscrolling = function(event) {