Question

I have the following jQuery banner rotator script and I’d like to change it a bit so that the banners rotate every X seconds even if the user doensn’t click on the prev/next buttons. The current code is here:

<script type="text/javascript">

    var active_banner_index = 0;

    function banner_next(direction) {
        var banners = $(".banner-content");
        if( banners.length ) {
            var curr = $(banners[active_banner_index]);
            active_banner_index+=direction;
            if( active_banner_index>=banners.length )
                active_banner_index = 0;
            if( active_banner_index<0 )
                active_banner_index = banners.length-1;
            next = $(banners[active_banner_index]);
            curr.fadeOut(1000, 
                function() {
                    next.fadeIn(500);
                }
                );
        }       
    }

    $(document).ready(function() {
        var tbl = $("#mega-hot-deal-666");
        var tag_left = $("#hot-deal-arrow-left");
        var tag_right = $("#hot-deal-arrow-right");

        var banners = $(".banner-content");
        if( banners.length ) {
            $(banners[0]).show();
        }

        pos = tbl.position();
        tag_left.css('z-index',100);
        tag_left.css({ 
                            position: "absolute",
                top: pos.top+67, left: pos.left-37,
                cursor: "pointer"
            });
        tag_right.css('z-index',6);
        tag_right.css({ 
                            position: "absolute",
                top: pos.top+67, left: pos.left+tbl.width()-26,
                cursor: "pointer" 
            });
    active_banner_index = 0;
        tag_left.click( function(){ banner_next(-1); } );
        tag_right.click( function(){ banner_next(1); } );
    });

</script>

What code would I have to add in order to make the banners rotate by themselves, without waiting for the user to click on the buttons?

Answer 1

You need to use setInterval to periodically call the progress function. You also may want to pause it when the user hovers over the banner. Here’s the code you would need:

$(function(){
    var delay = 4000,
        int;

    // Set interval to progress
    int = setInterval(function(){
        banner_next(1);
    }, delay);

    // OPTIONAL: Pause when hovering over the banner
    $(".banner-content").hover(function(){
        clearInterval(int);
    }, function(){
        int = setInterval(function(){
            banner_next(1);
        }, delay);
    });
});

Reference for learning: window.setInterval and window.clearInterval