JSFiddle - React, Tailwind, and code Playground

by Kabir Hossain

HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    
    <title>Solution for Long Dropdowns</title>
    
    <link rel="stylesheet" href="css/style.css" type="text/css" media="screen, projection"/>
            
    <script type='text/javascript' src='http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js?ver=1.3.2'></script>
    <script type="text/javascript" language="javascript" src="js/jquery.dropdown.js"></script>
</head>

<body>

    <?php include("../header.php"); ?>

    <div id="page-wrap">
    
        <h1>Long Dropdowns</h1>
        
        <p>If your dropdowns are this long, you might wanna take a re-look at your navigational strategy. But, if it makes sense, a 
        technique like this may be beneficial.</p>
        
        <p>PROBLEM: Dropdown menu goes down below the fold when opened, making lower items inaccesible.</p>
        <p>SOLUTION? Make menu scroll up and down as you mouse through it.</p>
              
        <ul class="dropdown">
            <li><a href="#">Really Tall Menu</a>
                <ul class="sub_menu">
                     <li><a href="#">Artificial Turf</a></li>
                     <li><a href="#">Benches &amp; Bleachers</a></li>
                     <li><a href="#">Communication Devices</a></li>
                     <li><a href="#">Dugouts</a></li>
                     <li><a href="#">Fencing &amp; Windscreen</a></li>
                     <li><a href="#">Floor Protectors</a></li>
                     <li><a href="#">Foul Poles</a></li>
                     <li><a href="#">Netting</a></li>
                     <li><a href="#">Outdoor Furniture &amp; Storage</a></li>
                     <li><a href="#">Outdoor Signs</a></li>
                     <li><a href="#">Padding</a></li>
                     <li><a...

CSS

*                                     { margin: 0; padding: 0; }
body                                { font: 15px Helvetica, Sans-Serif; } 
html                                { overflow-y: scroll; }
#page-wrap                            { width: 960px; margin: 25px auto; } 
p                                   { margin: 0 0 8px 0; }
a                                    { text-decoration: none; }
img                                 { vertical-align: middle; }
a img                               { border: 0; 180}
ul                                    { list-style: none; }
h1                                  { margin: 0 0 10px 0; }

/* 
    LEVEL ONE
*/
ul.dropdown                         { position: relative; width: 100%; }
ul.dropdown li                      { font-weight: bold; float: left; width: 225px; background: #ccc; position: relative; }
ul.dropdown a:hover                    { color: #000; }
ul.dropdown li a                    { display: block; padding: 20px 8px; color: #222; position: relative; z-index: 2000; }
ul.dropdown li a:hover,
ul.dropdown li a.hover              { background: #F3D673; position: relative; }


/* 
    LEVEL TWO
*/
ul.dropdown ul                         { display: none; position: absolute; top: 0; left: 0; width: 180px; z-index: 1000; }
ul.dropdown ul li                     { font-weight: normal; background: #f6f6f6; color: #000; border-bottom: 1px solid #ccc; }
ul.dropdown ul li a                    { display: block; background: #eee !important; } 
ul.dropdown ul li a:hover            { display: block; background: #F3D673 !important; }

JavaScript

var maxHeight = 400;

$(function(){

    $(".dropdown > li").hover(function() {
    
         var $container = $(this),
             $list = $container.find("ul"),
             $anchor = $container.find("a"),
             height = $list.height() * 1.1,       // make sure there is enough room at the bottom
             multiplier = height / maxHeight;     // needs to move faster if list is taller
        
        // need to save height here so it can revert on mouseout            
        $container.data("origHeight", $container.height());
        
        // so it can retain it's rollover color all the while the dropdown is open
        $anchor.addClass("hover");
        
        // make sure dropdown appears directly below parent list item    
        $list
            .show()
            .css({
                paddingTop: $container.data("origHeight")
            });
        
        // don't do any animation if list shorter than max
        if (multiplier > 1) {
            $container
                .css({
                    height: maxHeight,
                    overflow: "hidden"
                })
                .mousemove(function(e) {
                    var offset = $container.offset();
                    var relativeY = ((e.pageY - offset.top) * multiplier) - ($container.data("origHeight") * multiplier);
                    if (relativeY > $container.data("origHeight")) {
                        $list.css("top", -relativeY + $container.data("origHeight"));
                    };
                });
        }
        
    }, function() {
    
        var $el = $(this);
        
        // put things back to normal
        $el
            .height($(this).data("origHeight"))
            .find("ul")
            .css({ top: 0 })
            .hide()
            .end()
            .find("a")
            .removeClass("hover");
    
    });
    
    // Add down arrow only to menu items with submenus
    $(".dropdown > li:has('ul')").each(function() {
       ...