jQuery hover dependent on two elements

Question

I have main navigation and sub navigation that for reasons of design are in separate DIVs. I would like to show the appropriate sub-nav when a main nav item is hovered, which I can do, but I also want to keep the sub-nav open if the user moves their mouse outside of the main nav item and into the sub-nav area. The last part is the place where I'm getting stuck.

I'm thinking on the hover out I need to do something with setTimeout() and an IF statement, but I have not been able to make any progress in that area. Is that even an approach worth trying?

HTML:

<div id="mnav">
 <ul id="buttons">
  <li class="one"><a href="#">Main 1</a></li>
  <li class="two"><a href="#">Main 2</a></li>
  <li class="three"><a href="#">Main 3</a></li>
  <li class="four nav-dark"><a href="#">Main 4</a></li>
 </ul>
</div> <!-- /mnav -->

<div id="snav">
 <ul class="snav-one">
    <li><a href="#">Sub 1.1</a></li>
    <li><a href="#">Sub 1.2</a></li>
    <li><a href="#">Sub 1.3</a></li>
    <li><a href="#">Sub 1.4</a></li>
    <li><a href="#">Sub 1.5</a></li>
    <li><a href="#">Sub 1.6</a></li>
 </ul>
 <ul class="snav-two">
    <li><a href="#">Sub 2.1</a></li>
    <li><a href="#">Sub 2.2</a></li>
 </ul>
</div> <!-- /snav -->

JS:

$(document).ready(function() {
 $("#buttons li.one, #buttons li.two").hover(function(){
  var subnav = 'ul.snav-' + $(this).attr('class');

  $("#snav").slideDown('fast').addClass("open").find(subnav).show();

 }, function(e){
  var subnav = 'ul.snav-' + $(this).attr('class');

  $("#snav").slideUp('fast').removeClass("open").find(subnav).hide();
 });
});

Answer 1

For Mouse-menu ergonomics you want a small delay while mousing from main to sub menus, so the the sub menu does not close before the mouse gets there. (As the question says.)

But, you also need a delay before menus open -- both to avoid annoying "flyover" activation, and to reduce the common occurrence of accidentally switching from sub1 to sub2 while moving off the main menu.

So, the question code needs:

1. hover over the sub-menu ul elements.
2. stop to halt running animations if mouse selection changes.
3. A resettable timer controlling both open and close.

See the demo at jsFiddle.

Putting it all together:

$("#buttons li.one, #buttons li.two").hover ( function () { MenuOpenCloseErgoTimer (
        100,
        function (node) {
            var subnav = 'ul.snav-' + $(node).attr ('class');
            $("#snav ul").hide ();
            $("#snav").stop (true, true).slideDown ('fast').addClass ("open").find (subnav).show ();
        },
        this
    ); },
    function () { MenuOpenCloseErgoTimer (
        200,
        function () {
            $("#snav").stop (true, true).slideUp ('fast').removeClass ("open").find ('ul').hide ();
        }
    ); }
);

$("div#snav ul").hover ( function () { MenuOpenCloseErgoTimer (
        0,
        function () {
            $("#snav").stop (true, true).slideDown ('fast').addClass ("open");
            $(this).show ();
        }
    ); },
    function () { MenuOpenCloseErgoTimer (
        200,
        function () {
            $("#snav").stop (true, true).slideUp ('fast').removeClass ("open");
            $("#snav ul").hide ();
        }
    ); }
);

function MenuOpenCloseErgoTimer (dDelay, fActionFunction, node) {
    if (typeof this.delayTimer == "number") {
        clearTimeout (this.delayTimer);
        this.delayTimer = '';
    }
    if (node)
        this.delayTimer     = setTimeout (function() { fActionFunction (node); }, dDelay);
    else
        this.delayTimer     = setTimeout (function() { fActionFunction (); }, dDelay);
}

Note the extra operations required on #snav ul, to cleanup after interrupted swaps between sub-menus.