https://egzamin-informatyk.pl/assets/js/scroll-egzamin.js

1window.onload = (event) => {
2
3odliczanie();
4	
5var rekl_start = document.querySelector("#sidead");	
6var viewportOffset = rekl_start.getBoundingClientRect();
7var rekl_startTop1 = viewportOffset.top;
8var lastKnownScrollPosition = window.scrollY;
9var rekl_startTop = 0;
10if (rekl_startTop1<0) rekl_startTop = lastKnownScrollPosition - Math.abs(rekl_startTop1);
11else rekl_startTop = lastKnownScrollPosition + rekl_startTop1;
12var rekl_height = viewportOffset.height;
13if (rekl_height < 10) rekl_height = 620;
14var koniec = document.querySelector("#siteend");	
15var viewportOffsetkoniec = koniec.getBoundingClientRect();
16var koniecTop1 = viewportOffsetkoniec.top;
17var koniecTop = 1000;
18if (koniecTop1<0) koniecTop = lastKnownScrollPosition - Math.abs(koniecTop1);
19else koniecTop = lastKnownScrollPosition + koniecTop1;
20var topPadding = 50;
21var sideb = document.querySelector("#side");
22var sideOffset = sideb.getBoundingClientRect();
23var poczatekside1 = sideOffset.top;
24if (poczatekside1<0) poczatekside = lastKnownScrollPosition - Math.abs(poczatekside1);
25else poczatekside = lastKnownScrollPosition + poczatekside1;
26
27document.addEventListener("scroll", (event) => {
28	
29	viewportOffsetkoniec = koniec.getBoundingClientRect();
30	koniecTop1 = viewportOffsetkoniec.top;
31	koniecTop = lastKnownScrollPosition + koniecTop1;
32
33	lastKnownScrollPosition = window.scrollY;
34	var rekl = document.querySelector("#sidead");	
35	
36	if (lastKnownScrollPosition < rekl_startTop - topPadding) {
37		rekl.style.top = "0px";
38	} 
39	else if (lastKnownScrollPosition > rekl_startTop - topPadding && lastKnownScrollPosition < koniecTop - rekl_height - 400) {
40		newpos = lastKnownScrollPosition - rekl_startTop + topPadding;
41		rekl.style.top = Math.floor(newpos) + "px";
42	}
43
44});
45};