Enable scrolling via mousewheel

// Defined in seperate JS file
function scrollEnd(flickelem) {
    // FLICKITY DragEnd

    if ( flickelem.options.freeScroll ) {
        flickelem.isFreeScrolling = true;
    }
    // set selectedIndex based on where flick will end up
    var index = flickelem.dragEndRestingSelect();

    if ( flickelem.options.freeScroll && !flickelem.options.wrapAround ) {
    // if free-scroll & not wrap around
    // do not free-scroll if going outside of bounding cells
    // so bounding cells can attract slider, and keep it in bounds
    var restingX = flickelem.getRestingPosition();
    flickelem.isFreeScrolling = -restingX > flickelem.cells[0].target &&
    -restingX < flickelem.getLastCell().target;
    } else if ( !flickelem.options.freeScroll && index == flickelem.selectedIndex ) {
    // boost selection if selected index has not changed
    index += flickelem.dragEndBoostSelect();
    }
    // apply selection
    // TODO refactor this, selecting here feels weird
    flickelem.select( index );
}

// Inside a <script> tag inside the document
$(function(){
    $(document).ready(function(e) {
        var cellCount = $('.gallery-cell').length;
        var canWrapAround = false;
        if(cellCount > 1) canWrapAround = true;
        $('.text-slider').flickity({
            accessibility: true,
            autoPlay: false,
            cellAlign: 'center',
            cellSelector: undefined,
            contain: true,
            draggable: true,
            freeScroll: true,
            friction: 0.2,
            imagesLoaded: true,
            initialIndex: 0,
            percentPosition: true,
            prevNextButtons: false,
            pageDots: false,
            resize: true,
            rightToLeft: false,
            watchCSS: false,
            wrapAround: canWrapAround
        }).mousewheel(function(e) {
            e.preventDefault();
            var flickelem = Flickity.data(this);

            if (e.deltaX) {
                flickelem.x += e.deltaX * e.deltaFactor;
            }
            else if (e.deltaY) {
                flickelem.x += e.deltaY * e.deltaFactor;
            }
            scrollEnd(flickelem);
        });
        $(window).load(function(e) {
            $('.text-slider').flickity('resize');
        });
    });
});