Template:H4Z-Hangzhou/js/lib/smoothscroll.js
// SmoothScroll v0.9.9 // Licensed under the terms of the MIT license.
// People involved // - Balazs Galambosi: maintainer (CHANGELOG.txt) // - Patrick Brunner (patrickb1991@gmail.com) // - Michael Herf: ssc_pulse Algorithm
function ssc_init() {
if (!document.body) return;
var e = document.body;
var t = document.documentElement;
var n = window.innerHeight;
var r = e.scrollHeight;
ssc_root = document.compatMode.indexOf("CSS") >= 0 ? t : e;
ssc_activeElement = e;
ssc_initdone = true;
if (top != self) {
ssc_frame = true
} else if (r > n && (e.offsetHeight <= n || t.offsetHeight <= n)) {
ssc_root.style.height = "auto";
if (ssc_root.offsetHeight <= n) {
var i = document.createElement("div");
i.style.clear = "both";
e.appendChild(i)
}
}
if (!ssc_fixedback) {
e.style.backgroundAttachment = "scroll";
t.style.backgroundAttachment = "scroll"
}
if (ssc_keyboardsupport) {
ssc_addEvent("keydown", ssc_keydown)
}
}
function ssc_scrollArray(e, t, n, r) {
r || (r = 1e3);
ssc_directionCheck(t, n);
ssc_que.push({
x: t,
y: n,
lastX: t < 0 ? .99 : -.99,
lastY: n < 0 ? .99 : -.99,
start: +(new Date)
});
if (ssc_pending) {
return
}
var i = function () {
var s = +(new Date);
var o = 0;
var u = 0;
for (var a = 0; a < ssc_que.length; a++) {
var f = ssc_que[a];
var l = s - f.start;
var c = l >= ssc_animtime;
var h = c ? 1 : l / ssc_animtime;
if (ssc_pulseAlgorithm) {
h = ssc_pulse(h)
}
var p = f.x * h - f.lastX >> 0;
var d = f.y * h - f.lastY >> 0;
o += p;
u += d;
f.lastX += p;
f.lastY += d;
if (c) {
ssc_que.splice(a, 1);
a--
}
}
if (t) {
var v = e.scrollLeft;
e.scrollLeft += o;
if (o && e.scrollLeft === v) {
t = 0
}
}
if (n) {
var m = e.scrollTop;
e.scrollTop += u;
if (u && e.scrollTop === m) {
n = 0
}
}
if (!t && !n) {
ssc_que = []
}
if (ssc_que.length) {
setTimeout(i, r / ssc_framerate + 1)
} else {
ssc_pending = false
}
};
setTimeout(i, 0);
ssc_pending = true
}
function ssc_wheel(e) {
if (!ssc_initdone) {
ssc_init()
}
var t = e.target;
var n = ssc_overflowingAncestor(t);
if (!n || e.defaultPrevented || ssc_isNodeName(ssc_activeElement, "embed") || ssc_isNodeName(t, "embed") && /\.pdf/i.test(t.src)) {
return true
}
var r = e.wheelDeltaX || 0;
var i = e.wheelDeltaY || 0;
if (!r && !i) {
i = e.wheelDelta || 0
}
if (Math.abs(r) > 1.2) {
r *= ssc_stepsize / 120
}
if (Math.abs(i) > 1.2) {
i *= ssc_stepsize / 120
}
ssc_scrollArray(n, -r, -i);
e.preventDefault()
}
function ssc_keydown(e) {
var t = e.target;
var n = e.ctrlKey || e.altKey || e.metaKey;
if (/input|textarea|embed/i.test(t.nodeName) || t.isContentEditable || e.defaultPrevented || n) {
return true
}
if (ssc_isNodeName(t, "button") && e.keyCode === ssc_key.spacebar) {
return true
}
var r, i = 0,
s = 0;
var o = ssc_overflowingAncestor(ssc_activeElement);
var u = o.clientHeight;
if (o == document.body) {
u = window.innerHeight
}
switch (e.keyCode) {
case ssc_key.up:
s = -ssc_arrowscroll;
break;
case ssc_key.down:
s = ssc_arrowscroll;
break;
case ssc_key.spacebar:
r = e.shiftKey ? 1 : -1;
s = -r * u * .9;
break;
case ssc_key.pageup:
s = -u * .9;
break;
case ssc_key.pagedown:
s = u * .9;
break;
case ssc_key.home:
s = -o.scrollTop;
break;
case ssc_key.end:
var a = o.scrollHeight - o.scrollTop - u;
s = a > 0 ? a + 10 : 0;
break;
case ssc_key.left:
i = -ssc_arrowscroll;
break;
case ssc_key.right:
i = ssc_arrowscroll;
break;
default:
return true
}
ssc_scrollArray(o, i, s);
e.preventDefault()
}
function ssc_mousedown(e) {
ssc_activeElement = e.target
}
function ssc_setCache(e, t) {
for (var n = e.length; n--;) ssc_cache[ssc_uniqueID(e[n])] = t; return t
}
function ssc_overflowingAncestor(e) {
var t = [];
var n = ssc_root.scrollHeight;
do {
var r = ssc_cache[ssc_uniqueID(e)];
if (r) {
return ssc_setCache(t, r)
}
t.push(e);
if (n === e.scrollHeight) {
if (!ssc_frame || ssc_root.clientHeight + 10 < n) {
return ssc_setCache(t, document.body)
}
} else if (e.clientHeight + 10 < e.scrollHeight) {
overflow = getComputedStyle(e, "").getPropertyValue("overflow");
if (overflow === "scroll" || overflow === "auto") {
return ssc_setCache(t, e)
}
}
} while (e = e.parentNode)
}
function ssc_addEvent(e, t, n) {
window.addEventListener(e, t, n || false)
}
function ssc_removeEvent(e, t, n) {
window.removeEventListener(e, t, n || false)
}
function ssc_isNodeName(e, t) {
return e.nodeName.toLowerCase() === t.toLowerCase()
}
function ssc_directionCheck(e, t) {
e = e > 0 ? 1 : -1;
t = t > 0 ? 1 : -1;
if (ssc_direction.x !== e || ssc_direction.y !== t) {
ssc_direction.x = e;
ssc_direction.y = t;
ssc_que = []
}
}
function ssc_pulse_(e) {
var t, n, r;
e = e * ssc_pulseScale;
if (e < 1) {
t = e - (1 - Math.exp(-e))
} else {
n = Math.exp(-1);
e -= 1;
r = 1 - Math.exp(-e);
t = n + r * (1 - n)
}
return t * ssc_pulseNormalize
}
function ssc_pulse(e) {
if (e >= 1) return 1;
if (e <= 0) return 0;
if (ssc_pulseNormalize == 1) {
ssc_pulseNormalize /= ssc_pulse_(1)
}
return ssc_pulse_(e)
}
var ssc_framerate = 150; var ssc_animtime = 500; var ssc_stepsize = 150; var ssc_pulseAlgorithm = true; var ssc_pulseScale = 6; var ssc_pulseNormalize = 1; var ssc_keyboardsupport = true; var ssc_arrowscroll = 50; var ssc_frame = false; var ssc_direction = {
x: 0, y: 0
};
var ssc_initdone = false; var ssc_fixedback = true; var ssc_root = document.documentElement; var ssc_activeElement; var ssc_key = {
left: 37, up: 38, right: 39, down: 40, spacebar: 32, pageup: 33, pagedown: 34, end: 35, home: 36
};
var ssc_que = []; var ssc_pending = false; var ssc_cache = {};
setInterval(function () {
ssc_cache = {}
}, 10 * 1e3);
var ssc_uniqueID = function () {
var e = 0;
return function (t) {
return t.ssc_uniqueID || (t.ssc_uniqueID = e++)
}
}();
var ischrome = /chrome/.test(navigator.userAgent.toLowerCase());
if (ischrome) {
ssc_addEvent("mousedown", ssc_mousedown);
ssc_addEvent("mousewheel", ssc_wheel);
ssc_addEvent("load", ssc_init)
}