https://public.katholikentag.de/shop/lib/jquery.sticky.js

1// Sticky Plugin v1.0.0 for jQuery
2// =============
3// Author: Anthony Garand
4// Improvements by German M. Bravo (Kronuz) and Ruud Kamphuis (ruudk)
5// Improvements by Leonardo C. Daronco (daronco)
6// Created: 2/14/2011
7// Date: 2/12/2012
8// Website: http://labs.anthonygarand.com/sticky
9// Description: Makes an element on the page stick on the screen as you scroll
10//       It will only set the 'top' and 'position' of your element, you
11//       might need to adjust the width in some cases.
12
13(function($) {
14  var defaults = {
15      topSpacing: 0,
16      bottomSpacing: 0,
17      className: 'is-sticky',
18      wrapperClassName: 'sticky-wrapper',
19      center: false,
20      getWidthFrom: '',
21      responsiveWidth: false
22    },
23    $window = $(window),
24    $document = $(document),
25    sticked = [],
26    windowHeight = $window.height(),
27    scroller = function() {
28      var scrollTop = $window.scrollTop(),
29        documentHeight = $document.height(),
30        dwh = documentHeight - windowHeight,
31        extra = (scrollTop > dwh) ? dwh - scrollTop : 0;
32
33      for (var i = 0; i < sticked.length; i++) {
34        var s = sticked[i],
35          elementTop = s.stickyWrapper.offset().top,
36          etse = elementTop - s.topSpacing - extra;
37
38        if (scrollTop <= etse) {
39          if (s.currentTop !== null) {
40            s.stickyElement
41              .css('position', '')
42              .css('top', '');
43            s.stickyElement.trigger('sticky-end', [s]).parent().removeClass(s.className);
44            s.currentTop = null;
45          }
46        }
47        else {
48          var newTop = documentHeight - s.stickyElement.outerHeight()
49            - s.topSpacing - s.bottomSpacing - scrollTop - extra;
50          if (newTop < 0) {
51            newTop = newTop + s.topSpacing;
52          } else {
53            newTop = s.topSpacing;
54          }
55          if (s.currentTop != newTop) {
56            s.stickyElement
57              .css('position', 'fixed')
58              .css('top', newTop);
59
60            if (typeof s.getWidthFrom !== 'undefined') {
61              s.stickyElement.css('width', $(s.getWidthFrom).width());
62            }
63
64            s.stickyElement.trigger('sticky-start', [s]).parent().addClass(s.className);
65            s.currentTop = newTop;
66          }
67        }
68      }
69    },
70    resizer = function() {
71      windowHeight = $window.height();
72
73      for (var i = 0; i < sticked.length; i++) {
74        var s = sticked[i];
75        if (typeof s.getWidthFrom !== 'undefined' && s.responsiveWidth === true) {
76          s.stickyElement.css('width', $(s.getWidthFrom).width());
77        }
78      }
79    },
80    methods = {
81      init: function(options) {
82        var o = $.extend({}, defaults, options);
83        return this.each(function() {
84          var stickyElement = $(this);
85
86          var stickyId = stickyElement.attr('id');
87          var wrapperId = stickyId ? stickyId + '-' + defaults.wrapperClassName : defaults.wrapperClassName 
88          var wrapper = $('<div></div>')
89            .attr('id', stickyId + '-sticky-wrapper')
90            .addClass(o.wrapperClassName);
91          stickyElement.wrapAll(wrapper);
92
93          if (o.center) {
94            stickyElement.parent().css({width:stickyElement.outerWidth(),marginLeft:"auto",marginRight:"auto"});
95          }
96
97          if (stickyElement.css("float") == "right") {
98            stickyElement.css({"float":"none"}).parent().css({"float":"right"});
99          }
100
101          var stickyWrapper = stickyElement.parent();
102          stickyWrapper.css('height', stickyElement.outerHeight());
103          sticked.push({
104            topSpacing: o.topSpacing,
105            bottomSpacing: o.bottomSpacing,
106            stickyElement: stickyElement,
107            currentTop: null,
108            stickyWrapper: stickyWrapper,
109            className: o.className,
110            getWidthFrom: o.getWidthFrom,
111            responsiveWidth: o.responsiveWidth
112          });
113        });
114      },
115      update: scroller,
116      unstick: function(options) {
117        return this.each(function() {
118          var unstickyElement = $(this);
119
120          var removeIdx = -1;
121          for (var i = 0; i < sticked.length; i++)
122          {
123            if (sticked[i].stickyElement.get(0) == unstickyElement.get(0))
124            {
125                removeIdx = i;
126            }
127          }
128          if(removeIdx != -1)
129          {
130            sticked.splice(removeIdx,1);
131            unstickyElement.unwrap();
132            unstickyElement.removeAttr('style');
133          }
134        });
135      }
136    };
137
138  // should be more efficient than using $window.scroll(scroller) and $window.resize(resizer):
139  if (window.addEventListener) {
140    window.addEventListener('scroll', scroller, false);
141    window.addEventListener('resize', resizer, false);
142  } else if (window.attachEvent) {
143    window.attachEvent('onscroll', scroller);
144    window.attachEvent('onresize', resizer);
145  }
146
147  $.fn.sticky = function(method) {
148    if (methods[method]) {
149      return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
150    } else if (typeof method === 'object' || !method ) {
151      return methods.init.apply( this, arguments );
152    } else {
153      $.error('Method ' + method + ' does not exist on jQuery.sticky');
154    }
155  };
156
157  $.fn.unstick = function(method) {
158    if (methods[method]) {
159      return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
160    } else if (typeof method === 'object' || !method ) {
161      return methods.unstick.apply( this, arguments );
162    } else {
163      $.error('Method ' + method + ' does not exist on jQuery.sticky');
164    }
165
166  };
167  $(function() {
168    setTimeout(scroller, 0);
169  });
170})(jQuery);