https://www.wecannetwork.org/app/themes/wecannetwork/resources/scripts/dist/modules/back.to.top.min.mjs

1/**
2 * ----------------------------------------
3 * Back to Top Button
4 */
5export default function backToTop() {
6  const backButton = document.querySelector(".btn-back-to-top");
7  // if (!backButton) return; // Ensure the button exists before proceeding
8
9  // const scrollContainer = document.documentElement || document.body;
10
11  // const handleScroll = () => {
12  //   // console.log("Current Scroll Position:", scrollContainer.scrollTop);
13  //   if (scrollContainer.scrollTop >= 100) {
14  //     backButton.classList.add("show");
15  //     backButton.classList.remove("hide");
16  //   } else {
17  //     backButton.classList.remove("show");
18  //     backButton.classList.add("hide");
19  //   }
20  // };
21
22  // const handleClick = () => {
23  //   // console.log("Clicked the button, starting scroll animation...");
24  //   let startTimestamp = null;
25  //   const duration = 1000; // Duration in milliseconds
26  //   const totalScroll = scrollContainer.scrollHeight - window.innerHeight;
27
28  //   const animateScroll = (timestamp) => {
29  //     if (!startTimestamp) startTimestamp = timestamp;
30  //     const progress = Math.min((timestamp - startTimestamp) * duration, 1);
31  //     const easeInOutQuad = (t) => (t < 0.5 ? 2 * t * t : -1 + (4 - 2 * t) * t);
32  //     window.scrollTo({
33  //       top: 0,
34  //       behavior: "smooth",
35  //     });
36  //     // console.log("Scroll Progress:", progress);
37  //     if (progress < 1) requestAnimationFrame(animateScroll);
38  //   };
39
40  //   const easeInOut = (t) => (t < 0.5 ? 2 * t * t : -1 + (4 - 2 * t) * t);
41  //   const reverseEaseInOut = (t) => 1 - easeInOutQuad(1 - t);
42  //   requestAnimationFrame(animateScroll);
43  // };
44
45  // document.addEventListener("scroll", handleScroll);
46  // backButton.addEventListener("click", handleClick);
47
48  function Util() {}
49  /*
50	class manipulation functions
51*/
52  Util.hasClass = (el, className) => {
53    if (el.classList) return el.classList.contains(className);
54    else
55      return !!el.className.match(
56        new RegExp("(\\s|^)" + className + "(\\s|$)"),
57      );
58  };
59
60  Util.scrollTo = (final, duration, cb) => {
61    var start = window.scrollY || document.documentElement.scrollTop,
62      currentTime = null;
63
64    var animateScroll = (timestamp) => {
65      if (!currentTime) currentTime = timestamp;
66      var progress = timestamp - currentTime;
67      if (progress > duration) progress = duration;
68      var val = Math.easeInOutQuad(progress, start, final - start, duration);
69      window.scrollTo(0, val);
70      if (progress < duration) {
71        window.requestAnimationFrame(animateScroll);
72      } else {
73        cb && cb();
74      }
75    };
76
77    window.requestAnimationFrame(animateScroll);
78  };
79
80  Util.addClass = (el, className) => {
81    var classList = className.split(" ");
82    if (el.classList) el.classList.add(classList[0]);
83    else if (!Util.hasClass(el, classList[0]))
84      el.className += " " + classList[0];
85    if (classList.length > 1) Util.addClass(el, classList.slice(1).join(" "));
86  };
87
88  Util.removeClass = (el, className) => {
89    var classList = className.split(" ");
90    if (el.classList) el.classList.remove(classList[0]);
91    else if (Util.hasClass(el, classList[0])) {
92      var reg = new RegExp("(\\s|^)" + classList[0] + "(\\s|$)");
93      el.className = el.className.replace(reg, " ");
94    }
95    if (classList.length > 1)
96      Util.removeClass(el, classList.slice(1).join(" "));
97  };
98
99  Util.toggleClass = (el, className, bool) => {
100    if (bool) Util.addClass(el, className);
101    else Util.removeClass(el, className);
102  };
103
104  Util.setAttributes = (el, attrs) => {
105    for (var key in attrs) {
106      el.setAttribute(key, attrs[key]);
107    }
108  };
109
110  Math.easeInOutQuad = (t, b, c, d) => {
111    t /= d / 2;
112    if (t < 1) return (c / 2) * t * t + b;
113    t--;
114    return (-c / 2) * (t * (t - 2) - 1) + b;
115  };
116
117  // Back to Top - by CodyHouse.co
118  // var backTop = document.getElementsByClassName(".btn-back-to-top")[0],
119  let backTop = document.querySelector(".btn-back-to-top"),
120    offset = 100, // browser window scroll (in pixels) after which the "back to top" link is shown
121    offsetOpacity = 99999, //browser window scroll (in pixels) after which the "back to top" link opacity is reduced
122    scrollDuration = 700,
123    scrolling = false;

124
125  if (backTop) {
126    //update back to top visibility on scrolling
127    window.addEventListener("scroll", (event) => {
128      if (!scrolling) {
129        scrolling = true;
130        !window.requestAnimationFrame
131          ? setTimeout(handleScroll, 250)
132          : window.requestAnimationFrame(handleScroll);
133      }
134    });
135
136    //smooth scroll to top
137    backTop.addEventListener("click", (event) => {
138      event.preventDefault();
139      !window.requestAnimationFrame
140        ? window.scrollTo(0, 0)
141        : Util.scrollTo(0, scrollDuration);
142    });
143  }
144
145  function checkBackToTop() {
146    var windowTop = window.scrollY || document.documentElement.scrollTop;
147    windowTop > offset
148      ? Util.addClass(backTop, "show")
149      : Util.removeClass(backTop, "show cd-top--fade-out");
150    windowTop > offsetOpacity && Util.addClass(backTop, "cd-top--fade-out");
151    scrolling = false;
152  }
153
154  const handleScroll = () => {
155    var windowTop = window.scrollY || document.documentElement.scrollTop;
156    windowTop >= offset
157      ? Util.addClass(backTop, "show")
158      : Util.removeClass(backTop, "show hide");
159    windowTop > offsetOpacity && Util.addClass(backTop, "hide");
160    scrolling = false;
161
162    // const handleScroll = () => {
163    //   //   // console.log("Current Scroll Position:", scrollContainer.scrollTop);
164    //   if (scrollContainer.scrollTop >= offset) {
165    //     backButton.classList.add("show");
166    //     backButton.classList.remove("hide");
167    //   } else {
168    //     backButton.classList.remove("show");
169    //     backButton.classList.add("hide");
170    //   }
171    // };
172  };
173}