https://www.elsilenciero.com/js/fixspmenu.js

1window.addEventListener('load',function(){
2
3	const fixSpmenu = document.getElementById('fix-spmenu');
4	const SpmenuMenuAll = fixSpmenu.querySelectorAll('[data-fixSpmenu="menu"]');
5	const html = document.getElementsByTagName('html')[0];
6	const wrap = document.getElementById('wrap');
7	const header = document.getElementById('header');
8	let headerStyle;
9	let headerHeight;
10	let wrapStylePaddingTop;
11	
12	// 表示
13	(new IntersectionObserver(function (entries) {
14		if (entries[0].isIntersecting) {
15			html.dataset.fixSpmenu = false;
16			fixSpmenu.classList.remove('show');
17			(new IntersectionObserver(function (entries) {
18				if (entries[0].isIntersecting) {
19					html.dataset.fixSpmenu = true;
20					fixSpmenu.classList.add('show');
21				}
22			},{
23				rootMargin: '0% 0% 0% 0%'
24			})).observe(document.getElementById('footer'));
25		} else {
26			html.dataset.fixSpmenu = true;
27			fixSpmenu.classList.add('show');
28		}
29	},{
30		rootMargin: '0% 0% 100% 0%'
31	})).observe(document.getElementById('main-header'));
32	
33	// メニュー表示用ID追加
34	(new IntersectionObserver(function (entries) {
35		if (entries[0].isIntersecting) {
36			if(html.dataset.spmenu != 'true') header.classList.remove('fixed-header');
37		} else {
38			if(!header.classList.contains('fix')) header.classList.add('fixed-header');
39		}
40	},{
41		rootMargin: '0% 0% 0% 0%'
42	})).observe(document.getElementById('header'));
43
44
45	// メニュー表示
46	if(SpmenuMenuAll != null) {
47		for (let i = 0; i < SpmenuMenuAll.length; i++){
48			SpmenuMenuAll[i].addEventListener('click', (e) => {
49				e.preventDefault();
50				if (header.classList.contains('fix') && !header.classList.contains('show-header')) {
51					header.classList.remove('hide-header');
52					header.classList.add('show-header');
53				}
54				clickFunction();
55			}, false);
56		}
57	}
58	
59	// 検索フォーム表示
60	const spmenuSearchAll = fixSpmenu.querySelectorAll('[data-fixSpmenu="search"]');
61	const spmenuSearch = document.getElementById('fix-spmenu-search');
62	if(spmenuSearchAll != null && spmenuSearch != null) {
63		for (let i = 0; i < spmenuSearchAll.length; i++){
64			spmenuSearchAll[i].addEventListener('click', (e) => {
65				e.preventDefault();
66				spmenuSearch.classList.toggle('show');
67			}, false);
68		}
69	}
70
71});