一款由jquery实现的整屏切换特效(2)

'use strict';
$(document).ready(function () {
var $wrap = $(".wrapper"),
pages = $(".page").length,
scrolling = false,
currentPage = 1,
$navPanel = $(".nav-panel"),
$scrollBtn = $(".scroll-btn"),
$navBtn = $(".nav-btn");

/*****************************
***** NAVIGATE FUNCTIONS *****
*****************************/
function manageClasses() {
$wrap.removeClass(function (index, css) {
return (css.match(/(^|\s)active-page\S+/g) || []).join(' ');
});
$wrap.addClass("active-page" + currentPage);
$navBtn.removeClass("active");
$(".nav-btn.nav-page" + currentPage).addClass("active");
$navPanel.addClass("invisible");
scrolling = true;
setTimeout(function () {
$navPanel.removeClass("invisible");
scrolling = false;
}, 1000);
}
function navigateUp() {
if (currentPage > 1) {
currentPage--;
if (Modernizr.csstransforms) {
manageClasses();
} else {
$wrap.animate({ "top": "-" + ((currentPage - 1) * 100) + "%" }, 1000);
}
}
}

function navigateDown() {
if (currentPage < pages) {
currentPage++;
if (Modernizr.csstransforms) {
manageClasses();
} else {
$wrap.animate({ "top": "-" + ((currentPage - 1) * 100) + "%" }, 1000);
}
}
}

/*********************
***** MOUSEWHEEL *****
*********************/
$(document).on("mousewheel DOMMouseScroll", function (e) {
if (!scrolling) {
if (e.originalEvent.wheelDelta > 0 || e.originalEvent.detail < 0) {
navigateUp();
} else {
navigateDown();
}
}
});

/**************************
***** RIGHT NAVIGATION ****
**************************/

/* NAV UP/DOWN BTN PAGE NAVIGATION */
$(document).on("click", ".scroll-btn", function () {
if ($(this).hasClass("up")) {
navigateUp();
} else {
navigateDown();
}
});

/* NAV CIRCLE DIRECT PAGE BTN */
$(document).on("click", ".nav-btn", function () {
if (!scrolling) {
var target = $(this).attr("data-target");
if (Modernizr.csstransforms) {
$wrap.removeClass(function (index, css) {
return (css.match(/(^|\s)active-page\S+/g) || []).join(' ');
});
$wrap.addClass("active-page" + target);
$navBtn.removeClass("active");
$(this).addClass("active");
$navPanel.addClass("invisible");
currentPage = target;
scrolling = true;
setTimeout(function () {
$navPanel.removeClass("invisible");
scrolling = false;
}, 1000);
} else {
$wrap.animate({ "top": "-" + ((target - 1) * 100) + "%" }, 1000);
}
}
});

}); //@ sourceURL=pen.js