https://www.sfatulmedicului.ro/external/js/new/jquery.sticky.js

1
2 $.fn.stickyfloat = function(options, lockBottom, mintop) {
3 var obj                 = this;
4 var parentPaddingTop     = parseInt(obj.parent().css('padding-top'));
5 var startOffset         = obj.parent().offset().top;
6 var opts                 = $.extend({ startOffset: startOffset, offsetY: parentPaddingTop, duration: 200, lockBottom:true }, options);
7 
8 obj.css({ position: 'absolute' });
9 
10 if(opts.lockBottom){
11 var bottomPos = obj.parent().height() - obj.height() + parentPaddingTop; //get the maximum scrollTop value
12 if( bottomPos < 0 )
13 bottomPos = 0;
14 }
15 
16 $(window).scroll(function () {
17 obj.stop(); // stop all calculations on scroll event
18 
19 var pastStartOffset            = $(document).scrollTop() > opts.startOffset;    // check if the window was scrolled down more than the start offset declared.
20 var objFartherThanTopPos    = obj.offset().top > startOffset;    // check if the object is at it's top position (starting point)
21 var objBiggerThanWindow     = obj.outerHeight() < $(window).height();    // if the window size is smaller than the Obj size, then do not animate.
22 
23 // if window scrolled down more than startOffset OR obj position is greater than
24 // the top position possible (+ offsetY) AND window size must be bigger than Obj size
25 if( (pastStartOffset || objFartherThanTopPos) && objBiggerThanWindow ){
26 var newpos = ($(document).scrollTop() -startOffset + opts.offsetY );
27 if ( newpos > bottomPos )
28 newpos = bottomPos;
29 if ( $(document).scrollTop() < opts.startOffset ) // if window scrolled < starting offset, then reset Obj position (opts.offsetY);
30 newpos = parentPaddingTop;
31 if(newpos < mintop)
32	newpos = mintop;
33 obj.animate({ top: newpos }, opts.duration );
34 }
35 });
36 };