Delay jquery hover event?

Solution 1:

Use the hoverIntent plugin for jquery: http://cherne.net/brian/resources/jquery.hoverIntent.html

It's absolutely perfect for what you describe and I've used it on nearly every project that required mouseover activation of menus etc...

There is one gotcha to this approach, some interfaces are devoid of a 'hover' state eg. mobile browsers like safari on the iphone. You may be hiding an important part of the interface or navigation with no way to open it on such a device. You could get round this with device specific CSS.

Solution 2:

You need to check a timer on hover. If it does not exist (ie this is the first hover), create it. If it exists (ie this is not the first hover), kill it and restart it. Set the timer payload to your code.

$(function() {
    var timer;

    $('#container a').hover(function() {
        if(timer) {
            clearTimeout(timer);
            timer = null
        }
        timer = setTimeout(function() {
            $('<div id="fileinfo" />').load('ReadTextFileX.aspx',
                {filename:'file.txt'},
                function() {
                    $(this).appendTo('#info');
                }
            );
        }, 500)
    },
    // mouse out
    });
});

I bet jQuery has a function that wraps this all up for you.

Edit: Ah yes, jQuery plugin to the rescue

Solution 3:

Totally agree that hoverIntent is the best solution, but if you happen to be an unfortunate sod who works on a website with a long and protracted process for approval of jQuery plugins, here's a quick and dirty solution which worked well for me:

$('li.contracted').hover(function () {
    var expanding = $(this);
    var timer = window.setTimeout(function () {
        expanding.data('timerid', null);

            ... do stuff

    }, 300);
    //store ID of newly created timer in DOM object
    expanding.data('timerid', timer);
}, function () {
    var timerid = $(this).data('timerid');
    if (timerid != null) {
        //mouse out, didn't timeout. Kill previously started timer
        window.clearTimeout(timerid);
    }
});

This one's just for expanding an <li> if the mouse has been on it for longer than 300ms.