https://www.westinghouse.cn/Application/Xin/View/Public/js/jquery.nav.js

1/*
2 * jQuery One Page Nav Plugin
3 * http://github.com/davist11/jQuery-One-Page-Nav
4 *
5 * Copyright (c) 2010 Trevor Davis (http://trevordavis.net)
6 * Dual licensed under the MIT and GPL licenses.
7 * Uses the same license as jQuery, see:
8 * http://jquery.org/license
9 *
10 * @version 3.0.0
11 *
12 * Example usage:
13 * $('#nav').onePageNav({
14 *   currentClass: 'current',
15 *   changeHash: false,
16 *   scrollSpeed: 750
17 * });
18 */
19;(function($, window, document, undefined){
20
21	// our plugin constructor
22	var OnePageNav = function(elem, options){
23		this.elem = elem;
24		this.$elem = $(elem);
25		this.options = options;
26		this.metadata = this.$elem.data('plugin-options');
27		this.$win = $(window);
28		this.sections = {};
29		this.didScroll = false;
30		this.$doc = $(document);
31		this.docHeight = this.$doc.height();
32	};
33
34	// the plugin prototype
35	OnePageNav.prototype = {
36		defaults: {
37			navItems: 'a',
38			currentClass: 'current',
39			changeHash: false,
40			easing: 'swing',
41			filter: '',
42			scrollSpeed: 750,
43			scrollThreshold: 0.5,
44			begin: false,
45			end: false,
46			scrollChange: false
47		},
48
49		init: function() {
50			// Introduce defaults that can be extended either
51			// globally or using an object literal.
52			this.config = $.extend({}, this.defaults, this.options, this.metadata);
53
54			this.$nav = this.$elem.find(this.config.navItems);
55
56			//Filter any links out of the nav
57			if(this.config.filter !== '') {
58				this.$nav = this.$nav.filter(this.config.filter);
59			}
60
61			//Handle clicks on the nav
62			this.$nav.on('click.onePageNav', $.proxy(this.handleClick, this));
63
64			//Get the section positions
65			this.getPositions();
66
67			//Handle scroll changes
68			this.bindInterval();
69
70			//Update the positions on resize too
71			this.$win.on('resize.onePageNav', $.proxy(this.getPositions, this));
72
73			return this;
74		},
75
76		adjustNav: function(self, $parent) {
77			self.$elem.find('.' + self.config.currentClass).removeClass(self.config.currentClass);
78			$parent.addClass(self.config.currentClass);
79		},
80
81		bindInterval: function() {
82			var self = this;
83			var docHeight;
84
85			self.$win.on('scroll.onePageNav', function() {
86				self.didScroll = true;
87			});
88
89			self.t = setInterval(function() {
90				docHeight = self.$doc.height();
91
92				//If it was scrolled
93				if(self.didScroll) {
94					self.didScroll = false;
95					self.scrollChange();
96				}
97
98				//If the document height changes
99				if(docHeight !== self.docHeight) {
100					self.docHeight = docHeight;
101					self.getPositions();
102				}
103			}, 250);
104		},
105
106		getHash: function($link) {
107			return $link.attr('href').split('#')[1];
108		},
109
110		getPositions: function() {
111			var self = this;
112			var linkHref;
113			var topPos;
114			var $target;
115
116			self.$nav.each(function() {
117				linkHref = self.getHash($(this));
118				$target = $('#' + linkHref);
119
120				if($target.length) {
121					topPos = $target.offset().top;
122					self.sections[linkHref] = Math.round(topPos);
123				}
124			});
125		},
126
127		getSection: function(windowPos) {
128			var returnValue = null;
129			var windowHeight = Math.round(this.$win.height() * this.config.scrollThreshold);
130
131			for(var section in this.sections) {
132				if((this.sections[section] - windowHeight) < windowPos) {
133					returnValue = section;
134				}
135			}
136
137			return returnValue;
138		},
139
140		handleClick: function(e) {
141			var self = this;
142			var $link = $(e.currentTarget);
143			var $parent = $link.parent();
144			var newLoc = '#' + self.getHash($link);
145
146			if(!$parent.hasClass(self.config.currentClass)) {
147				//Start callback
148				if(self.config.begin) {
149					self.config.begin();
150				}
151
152				//Change the highlighted nav item
153				self.adjustNav(self, $parent);
154
155				//Removing the auto-adjust on scroll
156				self.unbindInterval();
157
158				//Scroll to the correct position
159				self.scrollTo(newLoc, function() {
160					//Do we need to change the hash?
161					if(self.config.changeHash) {
162						window.location.hash = newLoc;
163					}
164
165					//Add the auto-adjust on scroll back in
166					self.bindInterval();
167
168					//End callback
169					if(self.config.end) {
170						self.config.end();
171					}
172				});
173			}
174
175			e.preventDefault();
176		},
177
178		scrollChange: function() {
179			var windowTop = this.$win.scrollTop();

180			var position = this.getSection(windowTop);
181			var $parent;
182
183			//If the position is set
184			if(position !== null) {
185				$parent = this.$elem.find('a[href$="#' + position + '"]').parent();
186
187				//If it's not already the current section
188				if(!$parent.hasClass(this.config.currentClass)) {
189					//Change the highlighted nav item
190					this.adjustNav(this, $parent);
191
192					//If there is a scrollChange callback
193					if(this.config.scrollChange) {
194						this.config.scrollChange($parent);
195					}
196				}
197			}
198		},
199
200		scrollTo: function(target, callback) {
201			var offset = $(target).offset().top;
202
203			$('html, body').animate({
204				scrollTop: offset
205			}, this.config.scrollSpeed, this.config.easing, callback);
206		},
207
208		unbindInterval: function() {
209			clearInterval(this.t);
210			this.$win.unbind('scroll.onePageNav');
211		}
212	};
213
214	OnePageNav.defaults = OnePageNav.prototype.defaults;
215
216	$.fn.onePageNav = function(options) {
217		return this.each(function() {
218			new OnePageNav(this, options).init();
219		});
220	};
221
222})( jQuery, window , document );