Merge pull request FromEndWorld#11 from sulibo/back-to-top-button

add back-to-top button

Author: FromEndWorld

_layouts/default.html

@@ -30,5 +30,8 @@
       {% include footer.html %}
     </footer>
 
+  <!--back-top-button-->
+  <script src="{{ site.url }}/{{ site.baseurl }}/assets/js/vanilla-back-to-top.min.js"></script>
+  <script>addBackToTop()</script>
 
 </html>

assets/js/vanilla-back-to-top.min.js

@@ -0,0 +1,75 @@
+"use strict";
+
+function addBackToTop() {
+    var o, t, e, n, i = arguments.length > 0 && void 0 !== arguments[0] ? arguments[0] : {},
+        r = i.backgroundColor,
+        d = void 0 === r ? "#000" : r,
+        a = i.cornerOffset,
+        c = void 0 === a ? 20 : a,
+        s = i.diameter,
+        l = void 0 === s ? 45 : s,
+        u = i.ease,
+        p = void 0 === u ? function(o) {
+            return .5 * (1 - Math.cos(Math.PI * o))
+        } : u,
+        m = i.id,
+        h = void 0 === m ? "back-to-top" : m,
+        b = i.innerHTML,
+        v = void 0 === b ? '<svg viewBox="0 0 24 24"><path d="M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z"></path></svg>' : b,
+        f = i.onClickScrollTo,
+        x = void 0 === f ? 0 : f,
+        w = i.scrollContainer,
+        g = void 0 === w ? document.body : w,
+        k = i.scrollDuration,
+        y = void 0 === k ? 100 : k,
+        T = i.showWhenScrollTopIs,
+        M = void 0 === T ? 1 : T,
+        z = i.size,
+        E = void 0 === z ? l : z,
+        C = i.textColor,
+        L = void 0 === C ? "#fff" : C,
+        N = i.zIndex,
+        I = void 0 === N ? 1 : N,
+        A = g === document.body,
+        B = A && document.documentElement;
+    o = Math.round(.43 * E), t = Math.round(.29 * E), e = "#" + h + "{background:" + d + ";-webkit-border-radius:50%;-moz-border-radius:50%;border-radius:50%;bottom:" + c + "px;-webkit-box-shadow:0 2px 5px 0 rgba(0,0,0,.26);-moz-box-shadow:0 2px 5px 0 rgba(0,0,0,.26);box-shadow:0 2px 5px 0 rgba(0,0,0,.26);color:" + L + ";cursor:pointer;display:block;height:" + E + "px;opacity:1;outline:0;position:fixed;right:" + c + "px;-webkit-tap-highlight-color:transparent;-webkit-touch-callout:none;-webkit-transition:bottom .2s,opacity .2s;-o-transition:bottom .2s,opacity .2s;-moz-transition:bottom .2s,opacity .2s;transition:bottom .2s,opacity .2s;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none;width:" + E + "px;z-index:" + I + "}#" + h + " svg{display:block;fill:currentColor;height:" + o + "px;margin:" + t + "px auto 0;width:" + o + "px}#" + h + ".hidden{bottom:-" + E + "px;opacity:0}", (n = document.createElement("style")).appendChild(document.createTextNode(e)), document.head.insertAdjacentElement("afterbegin", n);
+    var D = function() {
+            var o = document.createElement("div");
+            return o.id = h, o.className = "hidden", o.innerHTML = v, o.addEventListener("click", function(o) {
+                o.preventDefault(),
+                    function() {
+                        var o = "function" == typeof x ? x() : x,
+                            t = window,
+                            e = t.performance,
+                            n = t.requestAnimationFrame;
+                        if (y <= 0 || void 0 === e || void 0 === n) return q(o);
+                        var i = e.now(),
+                            r = j(),
+                            d = r - o;
+                        n(function o(t) {
+                            var e = Math.min((t - i) / y, 1);
+                            q(r - Math.round(p(e) * d)), e < 1 && n(o)
+                        })
+                    }()
+            }), document.body.appendChild(o), o
+        }(),
+        H = !0;
+
+    function S() {
+        j() >= M ? function() {
+            if (!H) return;
+            D.className = "", H = !1
+        }() : function() {
+            if (H) return;
+            D.className = "hidden", H = !0
+        }()
+    }
+
+    function j() {
+        return g.scrollTop || B && document.documentElement.scrollTop || 0
+    }
+
+    function q(o) {
+        g.scrollTop = o, B && (document.documentElement.scrollTop = o)
+    }(A ? window : g).addEventListener("scroll", S), S()
+}