Template:ZJUT-China/js3

/*

* jQuery One Page Nav Plugin
* http://github.com/davist11/jQuery-One-Page-Nav
*
* Copyright (c) 2010 Trevor Davis (http://trevordavis.net)
* Dual licensed under the MIT and GPL licenses.
* Uses the same license as jQuery, see:
* http://jquery.org/license
*
* @version 2.1
*
* Example usage:
* $('#nav').onePageNav({
*   currentClass: 'current',
*   changeHash: false,
*   scrollSpeed: 750
* });
*/

(function($, window, document, undefined){

// our plugin constructor var OnePageNav = function(elem, options){ this.elem = elem; this.$elem = $(elem); this.options = options; this.metadata = this.$elem.data('plugin-options'); this.$nav = this.$elem.find('a'); this.$win = $(window); this.sections = {}; this.didScroll = false; this.$doc = $(document); this.docHeight = this.$doc.height(); };

// the plugin prototype OnePageNav.prototype = { defaults: { currentClass: 'current', changeHash: false, easing: 'swing', filter: ':not(.external)', scrollSpeed: 750, scrollOffset: 0, scrollThreshold: 0.5, begin: false, end: false, scrollChange: false },

init: function() { var self = this;

// Introduce defaults that can be extended either // globally or using an object literal. self.config = $.extend({}, self.defaults, self.options, self.metadata);

//Filter any links out of the nav if(self.config.filter !== ) { self.$nav = self.$nav.filter(self.config.filter); }

//Handle clicks on the nav self.$nav.on('click.onePageNav', $.proxy(self.handleClick, self));

//Get the section positions self.getPositions();

//Handle scroll changes self.bindInterval();

//Update the positions on resize too self.$win.on('resize.onePageNav', $.proxy(self.getPositions, self));

return this; },

adjustNav: function(self, $parent) { self.$elem.find('.' + self.config.currentClass).removeClass(self.config.currentClass); $parent.addClass(self.config.currentClass); },

bindInterval: function() { var self = this; var docHeight;

self.$win.on('scroll.onePageNav', function() { self.didScroll = true; });

self.t = setInterval(function() { docHeight = self.$doc.height();

//If it was scrolled if(self.didScroll) { self.didScroll = false; self.scrollChange(); }

//If the document height changes if(docHeight !== self.docHeight) { self.docHeight = docHeight; self.getPositions(); } }, 250); },

getHash: function($link) { return $link.attr('href').split('#')[1]; },

getPositions: function() { var self = this; var linkHref; var topPos;

self.$nav.each(function() { linkHref = self.getHash($(this)); topPos = $('#' + linkHref).offset().top;

self.sections[linkHref] = Math.round(topPos) - self.config.scrollOffset; }); },

getSection: function(windowPos) { var returnValue = null; var windowHeight = Math.round(this.$win.height() * this.config.scrollThreshold);

for(var section in this.sections) { if((this.sections[section] - windowHeight) < windowPos) { returnValue = section; } }

return returnValue; },

handleClick: function(e) { var self = this; var $link = $(e.currentTarget); var $parent = $link.parent(); var newLoc = '#' + self.getHash($link);

if(!$parent.hasClass(self.config.currentClass)) { //Start callback if(self.config.begin) { self.config.begin(); }

//Change the highlighted nav item self.adjustNav(self, $parent);

//Removing the auto-adjust on scroll self.unbindInterval();

//Scroll to the correct position $.scrollTo(newLoc, self.config.scrollSpeed, { axis: 'y', easing: self.config.easing, offset: { top: -self.config.scrollOffset }, onAfter: function() { //Do we need to change the hash? if(self.config.changeHash) { window.location.hash = newLoc; }

//Add the auto-adjust on scroll back in self.bindInterval();

//End callback if(self.config.end) { self.config.end(); } } }); }

e.preventDefault(); },

scrollChange: function() { var windowTop = this.$win.scrollTop(); var position = this.getSection(windowTop); var $parent;

//If the position is set if(position !== null) { $parent = this.$elem.find('a[href$="#' + position + '"]').parent();

//If it's not already the current section if(!$parent.hasClass(this.config.currentClass)) { //Change the highlighted nav item this.adjustNav(this, $parent);

//If there is a scrollChange callback if(this.config.scrollChange) { this.config.scrollChange($parent); } } } },

unbindInterval: function() { clearInterval(this.t); this.$win.unbind('scroll.onePageNav'); } };

OnePageNav.defaults = OnePageNav.prototype.defaults;

$.fn.onePageNav = function(options) { return this.each(function() { new OnePageNav(this, options).init(); }); };

})( jQuery, window , document );