네비게이션 위치 활성화

by hlee0126

HTML

<ul id="top-menu">
    <li class="active"> <a href="#">Top</a>

    </li>
    <li> <a href="#foo">Foo</a>

    </li>
    <li> <a href="#bar">Bar</a>

    </li>
    <li> <a href="#baz">Baz</a>

    </li>
</ul>
<a id="foo">Foo</a>

<a id="bar">Bar</a>

<a id="baz">Baz</a>

CSS

body {
    height: 2000px;
    font-family: Helvetica, Arial;
}
#top-menu {
    position: fixed;
    z-index: 1;
    background: white;
    left: 0;
    right: 0;
    top: 0;
}
#top-menu li {
    float: left;
}
#top-menu a {
    display: block;
    padding: 5px 25px 7px 25px;
    width: 4em;
    text-align: center;
    -webkit-transition: .5s all ease-out;
    -moz-transition: .5s all ease-out;
    transition: .5s all ease-out;
    border-top: 3px solid white;
    color: #aaa;
    text-decoration: none;
}
#top-menu a:hover {
    color: #000;
}
#top-menu li.active a {
    border-top: 3px solid #333;
    color: #333;
}
#foo {
    position: absolute;
    top: 400px;
}
#bar {
    position: absolute;
    top: 800px;
}
#baz {
    position: absolute;
    top: 1200px;
}

JavaScript

// Cache selectors
var lastId,
topMenu = $("#top-menu"),
    topMenuHeight = topMenu.outerHeight() + 15,
    // All list items
    menuItems = topMenu.find("a"),
    // Anchors corresponding to menu items
    scrollItems = menuItems.map(function () {
        var item = $($(this).attr("href"));
        if (item.length) {
            return item;
        }
    });

// Bind click handler to menu items
// so we can get a fancy scroll animation
menuItems.click(function (e) {
    var href = $(this).attr("href"),
        offsetTop = href === "#" ? 0 : $(href).offset().top - topMenuHeight + 1;
    $('html, body').stop().animate({
        scrollTop: offsetTop
    }, 300);
    e.preventDefault();
});

// Bind to scroll
$(window).scroll(function () {
    // Get container scroll position
    var fromTop = $(this).scrollTop() + topMenuHeight;

    // Get id of current scroll item
    var cur = scrollItems.map(function () {
        if ($(this).offset().top < fromTop) return this;
    });
    // Get the id of the current element
    cur = cur[cur.length - 1];
    var id = cur && cur.length ? cur[0].id : "";

    if (lastId !== id) {
        lastId = id;
        // Set/remove active class
        menuItems.parent().removeClass("active")
            .end().filter("[href=#" + id + "]").parent().addClass("active");
    }
});