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avalon.iscroll.js
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avalon.iscroll.js
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define(["avalon"], function() {
var rAF = window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
var noScroll = avalon.oneObject("TEXTAREA,INPUT,SELECT")
var utils = {
ease: {
quadratic: {
style: 'cubic-bezier(0.25, 0.46, 0.45, 0.94)',
fn: function(k) {
return k * (2 - k);
}
},
circular: {
style: 'cubic-bezier(0.1, 0.57, 0.1, 1)', // Not properly "circular" but this looks better, it should be (0.075, 0.82, 0.165, 1)
fn: function(k) {
return Math.sqrt(1 - (--k * k));
}
},
back: {
style: 'cubic-bezier(0.175, 0.885, 0.32, 1.275)',
fn: function(k) {
var b = 4;
return (k = k - 1) * k * ((b + 1) * k + b) + 1;
}
},
bounce: {
style: '',
fn: function(k) {
if ((k /= 1) < (1 / 2.75)) {
return 7.5625 * k * k;
} else if (k < (2 / 2.75)) {
return 7.5625 * (k -= (1.5 / 2.75)) * k + 0.75;
} else if (k < (2.5 / 2.75)) {
return 7.5625 * (k -= (2.25 / 2.75)) * k + 0.9375;
} else {
return 7.5625 * (k -= (2.625 / 2.75)) * k + 0.984375;
}
}
},
elastic: {
style: '',
fn: function(k) {
var f = 0.22,
e = 0.4;
if (k === 0) {
return 0;
}
if (k === 1) {
return 1;
}
return (e * Math.pow(2, -10 * k) * Math.sin((k - f / 4) * (2 * Math.PI) / f) + 1);
}
}
},
offset: function(el) {
var left = -el.offsetLeft,
top = -el.offsetTop;
// jshint -W084
while (el = el.offsetParent) {
left -= el.offsetLeft;
top -= el.offsetTop;
}
// jshint +W084
return {
left: left,
top: top
};
},
momentum: function(current, start, time, lowerMargin, wrapperSize, deceleration) {
var distance = current - start,
speed = Math.abs(distance) / time,
destination,
duration;
deceleration = deceleration === void 0 ? 0.0006 : deceleration;
destination = current + (speed * speed) / (2 * deceleration) * (distance < 0 ? -1 : 1)
duration = speed / deceleration
if (destination < lowerMargin) {
destination = wrapperSize ? lowerMargin - (wrapperSize / 2.5 * (speed / 8)) : lowerMargin
distance = Math.abs(destination - current)
duration = distance / speed
} else if (destination > 0) {
destination = wrapperSize ? wrapperSize / 2.5 * (speed / 8) : 0
distance = Math.abs(current) + destination
duration = distance / speed
}
return {
destination: Math.round(destination),
duration: duration
};
},
isBadAndroid: /Android /.test(window.navigator.appVersion) && !(/Chrome\/\d/.test(window.navigator.appVersion)),
style: {
transform: avalon.cssName("transform"),
transitionTimingFunction: avalon.cssName("transitionTimingFunction"),
transitionDuration: avalon.cssName("transitionDuration"),
transitionDelay: avalon.cssName("transitionDelay"),
transformOrigin: avalon.cssName("transformOrigin")
},
addEvent: function(el, type, fn, capture) {
el.addEventListener(type, fn, !!capture);
},
removeEvent: function(el, type, fn, capture) {
el.removeEventListener(type, fn, !!capture);
}
}
if (!window.addEventListener) {
utils.addEvent = function(el, type, fn, capture) {
el.attachEvent("on" + type, fn)
}
utils.removeEvent = function(el, type, fn, capture) {
el.detachEvent("on" + type, fn)
}
}
avalon.mix(utils, {
hasTransform: !!avalon.cssName("transform"),
hasPerspective: !!avalon.cssName("perspective"),
hasTransition: !!avalon.cssName("transition")
})
var touchNames = ["mousedown", "mousemove", "mouseup", ""]
var IE11touch = navigator.pointerEnabled
var IE9_10touch = navigator.msPointerEnabled
if (IE11touch) { //IE11 与 W3C
touchNames = ["pointerdown", "pointermove", "pointerup", "pointercancel"]
} else if (IE9_10touch) { //IE9-10
touchNames = ["MSPointerDown", "MSPointerMove", "MSPointerUp", "MSPointerCancel"]
} else if ("ontouchstart" in window) {
touchNames = ["touchstart", "touchmove", "touchend", "touchcancel"]
}
var Passthrough = {
vertical: "vertical",
horizontal: "horizontal",
true: "vertical"
}
//https://www.gitbook.io/book/iiunknown/iscroll-5-api-cn/reviews
function IScroll(el, options) {
this.wrapper = typeof el === 'string' ? document.querySelector(el) : el;
this.scroller = this.wrapper.children[0];
this.scrollerStyle = this.scroller.style;
//默认参数
this.options = {
mouseWheelSpeed: 20,
snapThreshold: 0.334,
startX: 0,
startY: 0,
scrollY: true,
directionLockThreshold: 5,
momentum: true, //动量效果，拖动惯性;关闭此功能将大幅度提升性能。
bounce: true, //当滚动器到达容器边界时他将执行一个小反弹动画。在老的或者性能低的设备上禁用反弹对实现平滑的滚动有帮助。
bounceTime: 600,
bounceEasing: '',
preventDefault: true,
HWCompositing: true, //开启CSS3硬件加速(通过translateZ(0)实现)
useTransition: true,
useTransform: true,
scrollbars: false, //是否出现滚动条
fadeScrollbars: false, //不想使用滚动条淡入淡出方式时，需要设置此属性为false以便节省资源。
interactiveScrollbars: false, //此属性可以让滚动条能拖动，用户可以与之交互。
//滚动条尺寸改变基于容器和滚动区域的宽/高之间的比例。此属性设置为false让滚动条固定大小。
//这可能有助于自定义滚动条样式（参考下面）。
resizeScrollbars: true
};
avalon.mix(this.options, options)
// 调整参数
this.translateZ = this.options.HWCompositing && utils.hasPerspective ? ' translateZ(0)' : '';
//使用CSS transition来实现动画效果（动量和弹力）。如果设置为false，那么将使用requestAnimationFrame代替。
//在现在浏览器中这两者之间的差异并不明显。在老的设备上transitions执行得更好。
this.options.useTransition = utils.hasTransition && this.options.useTransition
//默认情况下引擎会使用CSStransform属性。如果现在还是2007年，那么可以设置这个属性为false，这就是说：引擎将使
//用top/left属性来进行滚动。
//这个属性在滚动器感知到Flash，iframe或者视频插件内容时会有用，但是需要注意：性能会有极大的损耗。
this.options.useTransform = utils.hasTransform && this.options.useTransform;
// 决定哪一个滚动条使用原生滚动条
// 当其值为horizontal时，横向为人工的，纵向为原生的；
// 当其值为vertical时，横向为原生的，纵向为人工的；
// 它只有horizontal,vertical,undefined三种值
var ep = this.options.eventPassthrough
ep = this.options.eventPassthrough = Passthrough[ep]
// 默认情况下scrollY为true, scrollX为false，因此只出现纵向滚动条，想出现横向滚动条，需要设置scrollX = true
this.options.scrollY = ep === "vertical" ? false : !!this.options.scrollY
this.options.scrollX = ep === "horizontal" ? false : !!this.options.scrollX
this.options.preventDefault = !this.options.eventPassthrough && !!this.options.preventDefault;
// 此属性针对于两个两个纬度的滚动条（当你需要横向和纵向滚动条）。通常情况下你开始滚动一个方向上的滚动条，另外一
// 个方向上会被锁定不动。有些时候，你需要无约束的移动（横向和纵向可以同时响应），在这样的情况下此属性需要设置
// 为true。默认值：false
this.options.freeScroll = !!(this.options.freeScroll && !this.options.eventPassthrough);
this.options.directionLockThreshold = this.options.eventPassthrough ? 0 : this.options.directionLockThreshold;
this.options.bounceEasing = typeof this.options.bounceEasing === 'string' ? utils.ease[this.options.bounceEasing] || utils.ease.circular : this.options.bounceEasing;
this.options.resizePolling = this.options.resizePolling === void 0 ? 60 : this.options.resizePolling;
if (this.options.tap === true) {
this.options.tap = 'tap';
}
if (this.options.shrinkScrollbars == 'scale') {
this.options.useTransition = false;
}
this.options.invertWheelDirection = this.options.invertWheelDirection ? -1 : 1;
// INSERT POINT: NORMALIZATION
// Some defaults
this.x = 0;
this.y = 0;
this.directionX = 0;
this.directionY = 0;
this._events = {};
// INSERT POINT: DEFAULTS
this._init();
this.refresh();
this.scrollTo(this.options.startX, this.options.startY);
this.enable();
}
avalon.IScroll = IScroll
function getTransitionEndEventName() {
var obj = {
TransitionEvent: "transitionend",
WebKitTransitionEvent: "webkittransitionEnd",
OTransitionEvent: "OTransitionEnd",
otransitionEvent: "otransitionEnd",
MSTransitionEvent: "MSTransitionEnd"
}
// var ev = document.createEvent("TransitionEvent"); // FIXME: un-specified
// ev.initTransitionEvent("transitionend", true, true, "some-unknown-prop", -4.75);
// document.body.dispatchEvent(ev);
var ret = false, ev
for (var name in obj) {
try {
ev = document.createEvent(name)//只有firefox不支持
ret = obj[name]
break
} catch (e) {
}
}
if (ret === false) {
//https://bugzilla.mozilla.org/show_bug.cgi?id=868751
//https://hg.mozilla.org/integration/mozilla-inbound/rev/a20ea0d494a0
try {
ev = new TransitionEvent("transitionend",
{
bubbles: true,
cancelable: true,
propertyName: "some-unknown-prop",
elapsedTime: 0.5,
pseudoElement: "pseudo"
});
ret = "transitionend"
} catch (e) {
}
}
getTransitionEndEventName = function() {
return ret
}
return ret
}
function fixEvent(event) {
var ret = {}
for (var i in event) {
ret[i] = event[i]
}
var target = ret.target = event.srcElement
if (event.type.indexOf("key") === 0) {
ret.which = event.charCode != null ? event.charCode : event.keyCode
} else if (/mouse|click/.test(event.type)) {
var doc = target.ownerDocument || DOC
var box = doc.compatMode === "BackCompat" ? doc.body : doc.documentElement
ret.pageX = event.clientX + (box.scrollLeft >> 0) - (box.clientLeft >> 0)
ret.pageY = event.clientY + (box.scrollTop >> 0) - (box.clientTop >> 0)
}
ret.timeStamp = new Date - 0
ret.originalEvent = event
ret.preventDefault = function() { //阻止默认行为
event.returnValue = false
}
ret.stopPropagation = function() { //阻止事件在DOM树中的传播
event.cancelBubble = true
}
return ret
}
IScroll.prototype = {
version: '5.1.2',
_init: function() {
this._initEvents()
console.log(this.options.scrollbars || this.options.indicators)
if (this.options.scrollbars || this.options.indicators) {
// this._initIndicators();
}
if (this.options.mouseWheel) {
this._initWheel();
}
if (this.options.snap) {
// this._initSnap();
}
if (this.options.keyBindings) {
// this._initKeys();
}
},
destroy: function() {
this._initEvents(true);
this._execEvent('destroy');
},
_transitionEnd: function(e) {
if (e.target !== this.scroller || !this.isInTransition) {
return;
}
this._transitionTime();
if (!this.resetPosition(this.options.bounceTime)) {
this.isInTransition = false;
this._execEvent('scrollEnd');
}
},
refresh: function() {
var rf = this.wrapper.offsetHeight; // Force reflow
this.wrapperWidth = this.wrapper.clientWidth;
this.wrapperHeight = this.wrapper.clientHeight;
/* REPLACE START: refresh */
this.scrollerWidth = this.scroller.offsetWidth;
this.scrollerHeight = this.scroller.offsetHeight;
this.maxScrollX = this.wrapperWidth - this.scrollerWidth;
this.maxScrollY = this.wrapperHeight - this.scrollerHeight;
/* REPLACE END: refresh */
this.hasHorizontalScroll = this.options.scrollX && this.maxScrollX < 0;
this.hasVerticalScroll = this.options.scrollY && this.maxScrollY < 0;
if (!this.hasHorizontalScroll) {
this.maxScrollX = 0;
this.scrollerWidth = this.wrapperWidth;
}
if (!this.hasVerticalScroll) {
this.maxScrollY = 0;
this.scrollerHeight = this.wrapperHeight;
}
this.endTime = 0;
this.directionX = 0;
this.directionY = 0;
this.wrapperOffset = utils.offset(this.wrapper);
this._execEvent('refresh');
this.resetPosition();
// INSERT POINT: _refresh
},
_initEvents: function(remove) {
//绑定或卸载事件
var eventType = remove ? utils.removeEvent : utils.addEvent
var target = this.options.bindToWrapper ? this.wrapper : window
var that = this
function hander(e) {
if (!("target" in e)) {
e = fixEvent(e)
}
that.handleEvent(e)
}
eventType(window, 'onorientationchange' in window ? "orientationchange" : "resize", hander)
if (this.options.click) {
eventType(this.wrapper, "click", hander, true)
}
for (var i = 0, type; type = touchNames[i]; i++) {
var el = i === 0 ? this.wrapper : target
eventType(el, type, hander)
}
eventType(this.scroller, getTransitionEndEventName(), hander)
},
handleEvent: function(e) {
switch (e.type) {
case touchNames[0]:
this._start(e)
break
case touchNames[1]:
this._move(e)
break
case touchNames[2]:
case touchNames[3]:
this._end(e)
break
case "orientationchange":
case "resize":
this._resize()
break
case getTransitionEndEventName():
this._transitionEnd(e)
break
case "keydown":
this._key(e)
break
case "click":
if (!e._constructed) {
e.preventDefault()
e.stopPropagation()
}
break
}
},
on: function(type, fn) {//添加用户回调
if (!this._events[type]) {
this._events[type] = []
}
this._events[type].push(fn)
},
off: function(type, fn) {//卸载用户回调
var fns = this._events[type] || []
var index = fns.indexOf(fn)
if (index > -1) {
this._events[type].splice(index, 1)
}
},
_execEvent: function(type) {//触发用户回调
var fns = this._events[type] || []
var args = [].slice.call(arguments, 1)
for (var i = 0, fn; fn = fns[i++]; ) {
fn.apply(this, args)
}
},
_start: function(e) {
if (!this.enabled || this.initiated || e.button !== 0) {
return//只处理左键
}
if (this.options.preventDefault && !utils.isBadAndroid && !noScroll[e.target.tagName]) {
if (!this.options.mouseWheel) {
e.preventDefault();
}
}
var point = e.touches ? e.touches[0] : e
this.initiated = true
this.moved = false;
this.distX = 0;
this.distY = 0;
this.directionX = 0;
this.directionY = 0;
this.directionLocked = 0;
this._transitionTime()
this.startTime = new Date - 0
if (this.options.useTransition && this.isInTransition) {
this.isInTransition = false;
var pos = this.getComputedPosition();
this._translate(Math.round(pos.x), Math.round(pos.y));
this._execEvent('scrollEnd');
} else if (!this.options.useTransition && this.isAnimating) {
this.isAnimating = false;
this._execEvent('scrollEnd');
}
this.startX = this.x;
this.startY = this.y;
this.absStartX = this.x;
this.absStartY = this.y;
this.pointStartX = point.pageX;
this.pointStartY = point.pageY;
this.pointX = point.pageX;
this.pointY = point.pageY;
this._execEvent('beforeScrollStart') //
},
_move: function(e) {
if (!this.initiated) {
return;
}
if (this.options.preventDefault) { // increases performance on Android? TODO: check!
e.preventDefault();
}
var point = e.touches ? e.touches[0] : e,
deltaX = point.pageX - this.pointStartX,
deltaY = point.pageY - this.pointStartY,
timestamp = new Date - 0,
newX, newY,
absDistX, absDistY;
this.pointX = point.pageX;//当前相对于页面的坐标
this.pointY = point.pageY;
this.distX = deltaX;
this.distY = deltaY;
absDistX = Math.abs(this.distX);
absDistY = Math.abs(this.distY);
// We need to move at least 10 pixels for the scrolling to initiate
if (timestamp - this.endTime > 300 && (absDistX < 10 && absDistY < 10)) {
return;
}
// If you are scrolling in one direction lock the other
if (!this.directionLocked && !this.options.freeScroll) {
if (absDistX > absDistY + this.options.directionLockThreshold) {
this.directionLocked = 'h'; // lock horizontally
} else if (absDistY >= absDistX + this.options.directionLockThreshold) {
this.directionLocked = 'v'; // lock vertically
} else {
this.directionLocked = 'n'; // no lock
}
}
if (this.directionLocked === 'h') {
if (this.options.eventPassthrough === 'vertical') {
e.preventDefault();
} else if (this.options.eventPassthrough === 'horizontal') {
this.initiated = false;
return;
}
deltaY = 0;
} else if (this.directionLocked === 'v') {
if (this.options.eventPassthrough === 'horizontal') {
e.preventDefault();
} else if (this.options.eventPassthrough === 'vertical') {
this.initiated = false;
return;
}
deltaX = 0;
}
deltaX = this.hasHorizontalScroll ? deltaX : 0;
deltaY = this.hasVerticalScroll ? deltaY : 0;
newX = this.x + deltaX;
newY = this.y + deltaY;
// Slow down if outside of the boundaries
if (newX > 0 || newX < this.maxScrollX) {
newX = this.options.bounce ? this.x + deltaX / 3 : newX > 0 ? 0 : this.maxScrollX;
}
if (newY > 0 || newY < this.maxScrollY) {
newY = this.options.bounce ? this.y + deltaY / 3 : newY > 0 ? 0 : this.maxScrollY;
}
this.directionX = deltaX > 0 ? -1 : deltaX < 0 ? 1 : 0;
this.directionY = deltaY > 0 ? -1 : deltaY < 0 ? 1 : 0;
if (!this.moved) {
this._execEvent('scrollStart');
}
this.moved = true;
this._translate(newX, newY);
/* REPLACE START: _move */
if (timestamp - this.startTime > 300) {
this.startTime = timestamp;
this.startX = this.x;
this.startY = this.y;
}
/* REPLACE END: _move */
},
_end: function(e) {
if (!this.enabled) {
return;
}
if (this.options.preventDefault && !noScroll[e.target.tagName]) {
e.preventDefault();
}
var point = e.changedTouches ? e.changedTouches[0] : e,
momentumX,
momentumY,
duration = new Date - this.startTime,
newX = Math.round(this.x),
newY = Math.round(this.y),
distanceX = Math.abs(newX - this.startX),
distanceY = Math.abs(newY - this.startY),
time = 0,
easing = '';
this.isInTransition = 0;
this.initiated = false;
this.endTime = new Date - 0;
// reset if we are outside of the boundaries
if (this.resetPosition(this.options.bounceTime)) {
return;
}
this.scrollTo(newX, newY); // ensures that the last position is rounded
// we scrolled less than 10 pixels
if (!this.moved) {
this._execEvent('scrollCancel');
return;
}
// start momentum animation if needed
if (this.options.momentum && duration < 300) {
momentumX = this.hasHorizontalScroll ? utils.momentum(this.x, this.startX, duration, this.maxScrollX, this.options.bounce ? this.wrapperWidth : 0, this.options.deceleration) : {destination: newX, duration: 0};
momentumY = this.hasVerticalScroll ? utils.momentum(this.y, this.startY, duration, this.maxScrollY, this.options.bounce ? this.wrapperHeight : 0, this.options.deceleration) : {destination: newY, duration: 0};
newX = momentumX.destination;
newY = momentumY.destination;
time = Math.max(momentumX.duration, momentumY.duration);
this.isInTransition = 1;
}
// INSERT POINT: _end
if (newX !== this.x || newY !== this.y) {
// change easing function when scroller goes out of the boundaries
if (newX > 0 || newX < this.maxScrollX || newY > 0 || newY < this.maxScrollY) {
easing = utils.ease.quadratic;
}
this.scrollTo(newX, newY, time, easing);
return;
}
this._execEvent('scrollEnd');
},
_translate: function(x, y) {
if (this.options.useTransform) {//使用transform
this.scrollerStyle[utils.style.transform] = 'translate(' + x + 'px,' + y + 'px)' + this.translateZ;
} else {
x = Math.round(x);//使用translate
y = Math.round(y);
this.scrollerStyle.left = x + 'px';
this.scrollerStyle.top = y + 'px';
}
this.x = x;
this.y = y;
},
_animate: function(destX, destY, duration, easingFn) {
var that = this,
startX = this.x,
startY = this.y,
startTime = utils.getTime(),
destTime = startTime + duration;
function step() {
var now = utils.getTime(),
newX, newY,
easing;
if (now >= destTime) {
that.isAnimating = false;
that._translate(destX, destY);
if (!that.resetPosition(that.options.bounceTime)) {
that._execEvent('scrollEnd');
}
return;
}
now = (now - startTime) / duration;
easing = easingFn(now);
newX = (destX - startX) * easing + startX;
newY = (destY - startY) * easing + startY;
that._translate(newX, newY);
if (that.isAnimating) {
rAF(step);
}
}
this.isAnimating = true;
step();
},
_transitionTime: function(time) {
//调整时长
time = time || 0
this.scrollerStyle[utils.style.transitionDuration] = time + 'ms';
if (!time && utils.isBadAndroid) {
this.scrollerStyle[utils.style.transitionDuration] = '0.001s';
}
},
_transitionTimingFunction: function(easing) {
//设置缓动公式
this.scrollerStyle[utils.style.transitionTimingFunction] = easing;
},
getComputedPosition: function() {
var matrix = window.getComputedStyle(this.scroller, null),
x, y;
if (this.options.useTransform) {
matrix = matrix[utils.style.transform].split(')')[0].split(', ');
x = +(matrix[12] || matrix[4]);
y = +(matrix[13] || matrix[5]);
} else {
x = +matrix.left.replace(/[^-\d.]/g, '');
y = +matrix.top.replace(/[^-\d.]/g, '');
}
return {x: x, y: y};
},
_resize: function() {
var that = this;
clearTimeout(this.resizeTimeout);
this.resizeTimeout = setTimeout(function() {
that.refresh();
}, this.options.resizePolling);
},
resetPosition: function(time) {
var x = this.x,
y = this.y;
time = time || 0;
if (!this.hasHorizontalScroll || this.x > 0) {
x = 0;
} else if (this.x < this.maxScrollX) {
x = this.maxScrollX;
}
if (!this.hasVerticalScroll || this.y > 0) {
y = 0;
} else if (this.y < this.maxScrollY) {
y = this.maxScrollY;
}
if (x === this.x && y === this.y) {
return false;
}
this.scrollTo(x, y, time, this.options.bounceEasing);
return true;
},
//调用这个方法会立即停止动画滚动，并且把滚动位置还原成0，取消绑定touchmove, touchend、touchcancel事件。
disable: function() {
this.enabled = false;
},
//调用这个方法，使得iscroll恢复默认正常状态
enable: function() {
this.enabled = true;
},
/*********************************************************************
* 滚动到目标位置 *
**********************************************************************/
scrollBy: function(x, y, time, easing) {
x = this.x + x;
y = this.y + y;
time = time || 0;
this.scrollTo(x, y, time, easing);
},
//这个方法接受4个参数 x, y, time, easing x 为移动的x轴坐标，y为移动的y轴坐标, time为移动时间，easing表示使用何种缓动公式。
scrollTo: function(x, y, time, easing) {
easing = easing || utils.ease.circular;
this.isInTransition = this.options.useTransition && time > 0;// 正在使用CSS3transition
if (!time || (this.options.useTransition && easing.style)) {
this._transitionTimingFunction(easing.style);
this._transitionTime(time);
this._translate(x, y);
} else {//如果不支持，使用JS动画
this._animate(x, y, time, easing.fn);
}
},
// scrollToElement --> scrollTo --> _translate or _animate
// scrollBy --> scrollTo --> _translate or _animate
scrollToElement: function(el, time, offsetX, offsetY, easing) {
el = el.nodeType ? el : this.scroller.querySelector(el);
if (!el) {
return;
}
var pos = utils.offset(el);
pos.left -= this.wrapperOffset.left;
pos.top -= this.wrapperOffset.top;
// if offsetX/Y are true we center the element to the screen
if (offsetX === true) {
offsetX = Math.round(el.offsetWidth / 2 - this.wrapper.offsetWidth / 2);
}
if (offsetY === true) {
offsetY = Math.round(el.offsetHeight / 2 - this.wrapper.offsetHeight / 2);
}
pos.left -= offsetX || 0;
pos.top -= offsetY || 0;
pos.left = pos.left > 0 ? 0 : pos.left < this.maxScrollX ? this.maxScrollX : pos.left;
pos.top = pos.top > 0 ? 0 : pos.top < this.maxScrollY ? this.maxScrollY : pos.top;
time = time == null || time === 'auto' ? Math.max(Math.abs(this.x - pos.left), Math.abs(this.y - pos.top)) : time;
this.scrollTo(pos.left, pos.top, time, easing);
},
/*********************************************************************
* 对齐处理 *
**********************************************************************/
_initWheel: function() {
var that = this
var removeFn = avalon.bind(this.wrapper, "mousewheel", function(e) {
if (!that.enabled) {
return;
}
e.preventDefault();
e.stopPropagation()
if (that.wheelTimeout === undefined) {
that._execEvent('scrollStart');
}
// Execute the scrollEnd event after 400ms the wheel stopped scrolling
clearTimeout(that.wheelTimeout);
that.wheelTimeout = setTimeout(function() {
that._execEvent('scrollEnd');
that.wheelTimeout = undefined;
}, 400);
if (e.wheelDeltaX === void 0) {
e.wheelDeltaY = e.wheelDelta
e.wheelDeltaX = 0
}
var wheelDeltaX = e.wheelDeltaX / 120 * that.options.mouseWheelSpeed
var wheelDeltaY = e.wheelDeltaY / 120 * that.options.mouseWheelSpeed
wheelDeltaX *= that.options.invertWheelDirection
wheelDeltaY *= that.options.invertWheelDirection
if (!that.hasVerticalScroll) {
wheelDeltaX = wheelDeltaY;
wheelDeltaY = 0;
}
if (that.options.snap) {
var newX = that.currentPage.pageX;
var newY = that.currentPage.pageY;
if (wheelDeltaX > 0) {
newX--;
} else if (wheelDeltaX < 0) {
newX++;
}
if (wheelDeltaY > 0) {
newY--;
} else if (wheelDeltaY < 0) {
newY++;
}
that.goToPage(newX, newY);
return;
}
newX = that.x + Math.round(that.hasHorizontalScroll ? wheelDeltaX : 0);
newY = that.y + Math.round(that.hasVerticalScroll ? wheelDeltaY : 0);
if (newX > 0) {
newX = 0;
} else if (newX < that.maxScrollX) {
newX = that.maxScrollX;
}
if (newY > 0) {
newY = 0;
} else if (newY < that.maxScrollY) {
newY = that.maxScrollY;
}
that.scrollTo(newX, newY, 0);
})
this.on('destroy', function() {
avalon.bind(this.wrapper, "mousewheel", removeFn)
});
},
/*********************************************************************
* Snap *
**********************************************************************/
_initSnap: function() {
this.currentPage = {};
if (typeof this.options.snap === 'string') {
this.options.snap = this.scroller.querySelectorAll(this.options.snap);
}
this.on('refresh', function() {
var i = 0, l,
m = 0, n,
cx, cy,
x = 0, y,
stepX = this.options.snapStepX || this.wrapperWidth,
stepY = this.options.snapStepY || this.wrapperHeight,
el;
this.pages = [];
if (!this.wrapperWidth || !this.wrapperHeight || !this.scrollerWidth || !this.scrollerHeight) {
return;
}
if (this.options.snap === true) {
cx = Math.round(stepX / 2);
cy = Math.round(stepY / 2);
while (x > -this.scrollerWidth) {
this.pages[i] = [];
l = 0;
y = 0;
while (y > -this.scrollerHeight) {
this.pages[i][l] = {
x: Math.max(x, this.maxScrollX),
y: Math.max(y, this.maxScrollY),
width: stepX,
height: stepY,
cx: x - cx,
cy: y - cy
};
y -= stepY;
l++;
}
x -= stepX;
i++;
}
} else {
el = this.options.snap;
l = el.length;
n = -1;
for (; i < l; i++) {
if (i === 0 || el[i].offsetLeft <= el[i - 1].offsetLeft) {
m = 0;
n++;
}
if (!this.pages[m]) {
this.pages[m] = [];
}
x = Math.max(-el[i].offsetLeft, this.maxScrollX);
y = Math.max(-el[i].offsetTop, this.maxScrollY);
cx = x - Math.round(el[i].offsetWidth / 2);