/*! iScroll v5.1.2 ~ (c) 2008-2014 Matteo Spinelli ~ http://cubiq.org/license */
(function (window, document, Math) {
//请求动画帧
var rAF = window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function (callback) { window.setTimeout(callback, 1000 / 60); };
//显示器16.7ms刷新间隔之前发生了其他绘制请求(setTimeout)，导致所有帧丢失，setTimeout的定时器值推荐最小使用16.7ms的原因（16.7 = 1000 / 60, 即每秒60帧）
//requestAnimationFrame与setTimeout的不同在于，前者跟着浏览器重绘时间走，不存在后者丢帧的问题
var utils = (function () {
var me = {};
var _elementStyle = document.createElement('div').style;
//获取浏览器特性前缀
var _vendor = (function () {
var vendors = ['t', 'webkitT', 'MozT', 'msT', 'OT'],
transform,
i = 0,
l = vendors.length;
for ( ; i < l; i++ ) {
transform = vendors[i] + 'ransform';
if ( transform in _elementStyle ) return vendors[i].substr(0, vendors[i].length-1);
}
return false;
})();
//拼装样式属性名
function _prefixStyle (style) {
if ( _vendor === false ) return false;
if ( _vendor === '' ) return style;
return _vendor + style.charAt(0).toUpperCase() + style.substr(1);
}
//获取当前时间
me.getTime = Date.now || function getTime () { return new Date().getTime(); };
//对象复制
me.extend = function (target, obj) {
for ( var i in obj ) {
target[i] = obj[i];
}
};
//事件
me.addEvent = function (el, type, fn, capture) {
el.addEventListener(type, fn, !!capture);
};
me.removeEvent = function (el, type, fn, capture) {
el.removeEventListener(type, fn, !!capture);
};
//MSPointerEvent 指针事件是一些事件和相关接口，用于处理来自鼠标、手写笔或触摸屏等设备的硬件不可知的指针输入，IE10引入，IE11去掉前缀，其他浏览器都不支持指针事件。
me.prefixPointerEvent = function (pointerEvent) {
return window.MSPointerEvent ?
'MSPointer' + pointerEvent.charAt(9).toUpperCase() + pointerEvent.substr(10):
pointerEvent;
};
//deceleration减速
/**
* 根据我们的拖动返回运动的长度与耗时，用于惯性拖动判断
* @param current 当前鼠标位置
* @param start touchStart时候记录的Y（可能是X）的开始位置，但是在touchmove时候可能被重写
* @param time touchstart到手指离开时候经历的时间，同样可能被touchmove重写
* @param lowerMargin y可移动的最大距离，这个一般为计算得出 this.wrapperHeight - this.scrollerHeight
* @param wrapperSize 如果有边界距离的话就是可拖动，不然碰到0的时候便停止
* @param deceleration 匀减速
* @returns {{destination: number, duration: number}}
*/
me.momentum = function (current, start, time, lowerMargin, wrapperSize, deceleration) {
var distance = current - start,
speed = Math.abs(distance) / time,
destination,
duration;
//减速变量
deceleration = deceleration === undefined ? 0.0006 : deceleration;
//减速路程
destination = current + ( speed * speed ) / ( 2 * deceleration ) * ( distance < 0 ? -1 : 1 );
//持续时间
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
};
};
var _transform = _prefixStyle('transform');
me.extend(me, {
hasTransform: _transform !== false,
hasPerspective: _prefixStyle('perspective') in _elementStyle, //透视
hasTouch: 'ontouchstart' in window,
hasPointer: window.PointerEvent || window.MSPointerEvent, // IE10 is prefixed
hasTransition: _prefixStyle('transition') in _elementStyle
});
// This should find all Android browsers lower than build 535.19 (both stock browser and webview) 低版本安卓机
me.isBadAndroid = /Android /.test(window.navigator.appVersion) && !(/Chrome\/\d/.test(window.navigator.appVersion));
me.extend(me.style = {}, {
transform: _transform,
transitionTimingFunction: _prefixStyle('transitionTimingFunction'),
transitionDuration: _prefixStyle('transitionDuration'),
transitionDelay: _prefixStyle('transitionDelay'),
transformOrigin: _prefixStyle('transformOrigin')
});
me.hasClass = function (e, c) {
var re = new RegExp("(^|\\s)" + c + "(\\s|$)");
return re.test(e.className);
};
me.addClass = function (e, c) {
if ( me.hasClass(e, c) ) {
return;
}
var newclass = e.className.split(' ');
newclass.push(c);
e.className = newclass.join(' ');
};
me.removeClass = function (e, c) {
if ( !me.hasClass(e, c) ) {
return;
}
var re = new RegExp("(^|\\s)" + c + "(\\s|$)", 'g');
e.className = e.className.replace(re, ' ');
};
me.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
};
};
// 配合config里面的preventDefaultException属性，不对匹配到的element使用e.preventDefault()。
me.preventDefaultException = function (el, exceptions) {
for ( var i in exceptions ) {
if ( exceptions[i].test(el[i]) ) {
return true;
}
}
return false;
};
// 事件类型
me.extend(me.eventType = {}, {
touchstart: 1,
touchmove: 1,
touchend: 1,
mousedown: 2,
mousemove: 2,
mouseup: 2,
pointerdown: 3,
pointermove: 3,
pointerup: 3,
MSPointerDown: 3,
MSPointerMove: 3,
MSPointerUp: 3
});
// 缓动函数
me.extend(me.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 );
}
}
});
me.tap = function (e, eventName) {
var ev = document.createEvent('Event');
/**
只有在新创建的 Event 对象被 Document 对象或 Element 对象的 dispatchEvent() 方法分派之前，才能调用 Event.initEvent() 方法
初始化新事件对象的属性
*/
ev.initEvent(eventName, true, true);
ev.pageX = e.pageX;
ev.pageY = e.pageY;
//事件触发器就是用来触发某个元素下的某个事件
e.target.dispatchEvent(ev);
};
me.click = function (e) {
var target = e.target,
ev;
//不是select/input/textarea就创建事件
if ( !(/(SELECT|INPUT|TEXTAREA)/i).test(target.tagName) ) {
ev = document.createEvent('MouseEvents');
ev.initMouseEvent('click', true, true, e.view, 1,
target.screenX, target.screenY, target.clientX, target.clientY,
e.ctrlKey, e.altKey, e.shiftKey, e.metaKey,
0, null);
ev._constructed = true;
target.dispatchEvent(ev);
}
};
return me;
})();
function IScroll (el, options) {
//传入的元素 必须要有子元素
this.wrapper = typeof el == 'string' ? document.querySelector(el) : el;
//子元素 实际滑动元素
this.scroller = this.wrapper.children[0];
this.scrollerStyle = this.scroller.style; // cache style for better performance
this.options = {
// INSERT POINT: OPTIONS
startX: 0,
startY: 0,
//默认是Y轴上下滚动
scrollY: true,
//方向锁定阈值，比如用户点击屏幕后，x与y之间差距大于5px，判断用户的拖动意图，是x方向拖动还是y方向
directionLockThreshold: 5,
//是否有惯性缓冲动画
momentum: true,
//超出边界时候是否还能拖动
bounce: true,
//超出边界还原时间点
bounceTime: 600,
//超出边界返回的动画
bounceEasing: '',
//是否阻止默认滚动事件
preventDefault: true,
//当遇到表单元素则不阻止冒泡，而是弹出系统自带相应的输入控件
preventDefaultException: { tagName: /^(INPUT|TEXTAREA|BUTTON|SELECT)$/ },
//硬件合成 通过GPU做图形渲染
HWCompositing: true,
//使用transition
useTransition: true,
//使用transform
useTransform: true
};
for ( var i in options ) {
this.options[i] = options[i];
}
// Normalize options
this.translateZ = this.options.HWCompositing && utils.hasPerspective ? ' translateZ(0)' : '';
this.options.useTransition = utils.hasTransition && this.options.useTransition;
this.options.useTransform = utils.hasTransform && this.options.useTransform;
// 默认false，当你想保留原生垂直滚动但能够添加水平iscroll时候，设置为true，iscroll区域水平滑动时候的touch垂直移动，不会触发原生的垂直滑动
// 通常设置为：{eventPassthrough:true,scrollX:true,scrollY:false}
//
this.options.eventPassthrough = this.options.eventPassthrough === true ? 'vertical' : this.options.eventPassthrough;
//当设置了eventPassthrough时候，不阻止默认的滚动事件
this.options.preventDefault = !this.options.eventPassthrough && this.options.preventDefault;
// If you want eventPassthrough I have to lock one of the axes
// eventPassthrough可以传入具体名字(vertical/horizontal)，这里更好说明了eventPassthrough的作用，对于传入的值来阻止相应轴的滑动事件
// eventPassthrough -> true -> vertical -> scrollY : false 垂直滚动忽略
this.options.scrollY = this.options.eventPassthrough == 'vertical' ? false : this.options.scrollY;
this.options.scrollX = this.options.eventPassthrough == 'horizontal' ? false : this.options.scrollX;
// With eventPassthrough we also need lockDirection mechanism
// freeScroll只能与scrollX一起使用 {scrollX:true,freeScroll:true}
this.options.freeScroll = this.options.freeScroll && !this.options.eventPassthrough;
this.options.directionLockThreshold = this.options.eventPassthrough ? 0 : this.options.directionLockThreshold;
// 缓动函数
this.options.bounceEasing = typeof this.options.bounceEasing == 'string' ? utils.ease[this.options.bounceEasing] || utils.ease.circular : this.options.bounceEasing;
//window resize时重新获取位置
this.options.resizePolling = this.options.resizePolling === undefined ? 60 : this.options.resizePolling;
if ( this.options.tap === true ) {
this.options.tap = 'tap';
}
// INSERT POINT: NORMALIZATION
// Some defaults
this.x = 0;
this.y = 0;
this.directionX = 0;
this.directionY = 0;
this._events = {};
// INSERT POINT: DEFAULTS
// IScroll初始化
this._init();
//
this.refresh();
// 定位到最顶最左
this.scrollTo(this.options.startX, this.options.startY);
// 代表“启用”的一个标志
this.enable();
}
IScroll.prototype = {
version: '5.1.2',
_init: function () {
this._initEvents();
// INSERT POINT: _init
},
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');
}
},
_start: function (e) {
// React to left mouse button only
// 不是已经注册的事件，而且按下的不是左键，就返回不处理。
if ( utils.eventType[e.type] != 1 ) {
if ( e.button !== 0 ) {
return;
}
}
// 没有启用，返回不处理。
if ( !this.enabled || (this.initiated && utils.eventType[e.type] !== this.initiated) ) {
return;
}
// 如果 preventDefault === true 且 不是落后的安卓版本 且 不是需要过滤的target 就 阻止默认的行为
if ( this.options.preventDefault && !utils.isBadAndroid && !utils.preventDefaultException(e.target, this.options.preventDefaultException) ) {
e.preventDefault();
}
//e.touches表示的在屏幕上所有的触摸点，但事实上，绝大数手机浏览器并不支持多点触摸，所有用e.touchees[0]捕获一个触点就知足吧，
//不要再奢望获取e.touches[>0]了，这个触点的位置可以有e.touches[0].pageX获取页面x坐标（像素）；
var point = e.touches ? e.touches[0] : e,
pos;
// 事件类型
this.initiated = utils.eventType[e.type];
this.moved = false; //是否移动的标志
this.distX = 0; //
this.distY = 0; //
this.directionX = 0; //x方向移动数
this.directionY = 0; //y方向移动数
this.directionLocked = 0; //方向锁
// 设置运动时间
this._transitionTime();
// 开始时间
this.startTime = utils.getTime();
// 如果还在运动中
if ( this.options.useTransition && this.isInTransition ) {
this.isInTransition = false;
// 获取当前位置
pos = this.getComputedPosition();
// 滑动到当前位置 相当于停止于此处
this._translate(Math.round(pos.x), Math.round(pos.y));
// 触发滑动结束回调函数
this._execEvent('scrollEnd');
} else if ( !this.options.useTransition && this.isAnimating ) {
this.isAnimating = false;
this._execEvent('scrollEnd');
}
this.startX = this.x; // scroller开始位置x
this.startY = this.y; // scroller开始位置y
this.absStartX = this.x; //
this.absStartY = this.y; //
this.pointX = point.pageX; // 触点x
this.pointY = point.pageY; // 触点y
// 触发滑动前回调函数
this._execEvent('beforeScrollStart');
},
_move: function (e) {
// 禁止 or 不存在此eventType 则返回
if ( !this.enabled || utils.eventType[e.type] !== this.initiated ) {
return;
}
if ( this.options.preventDefault ) { // increases performance on Android? TODO: check!
e.preventDefault();
}
// point 触点
var point = e.touches ? e.touches[0] : e,
deltaX = point.pageX - this.pointX, // 当前触点的pagex - 开始时的pagex = 触点档次增量x
deltaY = point.pageY - this.pointY, // 触点增量y
timestamp = utils.getTime(),
newX, newY,
absDistX, absDistY;
// 最近上一次的触点位置
this.pointX = point.pageX;
this.pointY = point.pageY;
// 触点移动的距离
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
// 触点至少移动10px才会触发scroll的move 并且 移动大于300ms
if ( timestamp - this.endTime > 300 && (absDistX < 10 && absDistY < 10) ) {
return;
}
// If you are scrolling in one direction lock the other
// 除非设置了freeScroll，否则将只允许同一时间一个方向滑动
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;
// this.x this.y 是最近上一次的scroller位置
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; // -1 手势向左 1 手势向右
this.directionY = deltaY > 0 ? -1 : deltaY < 0 ? 1 : 0; // -1 手势向上 1 手势向下
if ( !this.moved ) {
this._execEvent('scrollStart');
}
this.moved = true;
this._translate(newX, newY);
/* REPLACE START: _move */
if ( timestamp - this.startTime > 300 ) {
//300ms更新一次
this.startTime = timestamp;
this.startX = this.x;
this.startY = this.y;
}
/* REPLACE END: _move */
},
// touchEnd时候处理缓动
_end: function (e) {
if ( !this.enabled || utils.eventType[e.type] !== this.initiated ) {
return;
}
if ( this.options.preventDefault && !utils.preventDefaultException(e.target, this.options.preventDefaultException) ) {
e.preventDefault();
}
var point = e.changedTouches ? e.changedTouches[0] : e,
momentumX,
momentumY,
duration = utils.getTime() - this.startTime,
newX = Math.round(this.x),
newY = Math.round(this.y),
distanceX = Math.abs(newX - this.startX), //单次移动过程的x轴移动距离
distanceY = Math.abs(newY - this.startY),
time = 0,
easing = '';
this.isInTransition = 0;
this.initiated = 0;
this.endTime = utils.getTime();
// reset if we are outside of the boundaries
// 超过了边界就重新回到边界位
if ( this.resetPosition(this.options.bounceTime) ) {
return;
}
// 坚持滑动到
this.scrollTo(newX, newY); // ensures that the last position is rounded
// we scrolled less than 10 pixels
if ( !this.moved ) {
if ( this.options.tap ) {
utils.tap(e, this.options.tap);
}
if ( this.options.click ) {
utils.click(e);
}
this._execEvent('scrollCancel');
return;
}
if ( this._events.flick && duration < 200 && distanceX < 100 && distanceY < 100 ) {
this._execEvent('flick');
return;
}
// start momentum animation if needed
// 获取缓动的距离 和 时间 { destination ， duration }
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');
},
_resize: function () {
var that = this;
clearTimeout(this.resizeTimeout);
this.resizeTimeout = setTimeout(function () {
that.refresh();
}, this.options.resizePolling);
},
/**
* 重新定位
*/
resetPosition: function (time) {
var x = this.x,
y = this.y;
time = time || 0;
/**
* 如果禁止水平滑动或者x大于0，x=0。如果可以滑动的情况，x应该是小于0的。
* 否则（可水平滑动），x为maxScrollX即最左
*/
if ( !this.hasHorizontalScroll || this.x > 0 ) {
x = 0;
} else if ( this.x < this.maxScrollX ) {
x = this.maxScrollX;
}
/**
* 如果禁止垂直滑动或者y大于0，y=0。如果可以滑动的情况，y应该是小于0的。
* 否则（可垂直滑动），y为maxScrollY即最上
*/
if ( !this.hasVerticalScroll || this.y > 0 ) {
y = 0;
} else if ( this.y < this.maxScrollY ) {
y = this.maxScrollY;
}
// 初始化时候x y 都是0 返回。
if ( x == this.x && y == this.y ) {
return false;
}
this.scrollTo(x, y, time, this.options.bounceEasing);
return true;
},
/**
* scroll关闭的标志
*/
disable: function () {
this.enabled = false;
},
/**
* scroll启用的标志
*/
enable: function () {
this.enabled = true;
},
/**
* 重新获取位置等参数信息
*/
refresh: function () {
var rf = this.wrapper.offsetHeight; // Force reflow
// 获取包含块的宽度/高度
this.wrapperWidth = this.wrapper.clientWidth;
this.wrapperHeight = this.wrapper.clientHeight;
/* REPLACE START: refresh */
// 滑动区的高度/宽度
this.scrollerWidth = this.scroller.offsetWidth;
this.scrollerHeight = this.scroller.offsetHeight;
// 最多允许滑动的x/y
this.maxScrollX = this.wrapperWidth - this.scrollerWidth;
this.maxScrollY = this.wrapperHeight - this.scrollerHeight;
/* REPLACE END: refresh */
// 是否可以垂直/水平滑动
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;
// 获取包含块的offsetLeft offsetTop
this.wrapperOffset = utils.offset(this.wrapper);
this._execEvent('refresh');
this.resetPosition();
// INSERT POINT: _refresh
},
/**
* 自定义事件三件套，不解释。
*/
on: function (type, fn) {
if ( !this._events[type] ) {
this._events[type] = [];
}
this._events[type].push(fn);
},
off: function (type, fn) {
if ( !this._events[type] ) {
return;
}
var index = this._events[type].indexOf(fn);
if ( index > -1 ) {
this._events[type].splice(index, 1);
}
},
_execEvent: function (type) {
if ( !this._events[type] ) {
return;
}
var i = 0,
l = this._events[type].length;
if ( !l ) {
return;
}
for ( ; i < l; i++ ) {
this._events[type][i].apply(this, [].slice.call(arguments, 1));
}
},
scrollBy: function (x, y, time, easing) {
x = this.x + x;
y = this.y + y;
time = time || 0;
this.scrollTo(x, y, time, easing);
},
/**
*
* @param x 为移动的x轴坐标
* @param y 为移动的y轴坐标
* @param time 为移动时间
* @param easing 为移动的动画效果
*/
scrollTo: function (x, y, time, easing) {
easing = easing || utils.ease.circular;
this.isInTransition = this.options.useTransition && time > 0;
if ( !time || (this.options.useTransition && easing.style) ) {
this._transitionTimingFunction(easing.style);
this._transitionTime(time);
this._translate(x, y);
} else {
this._animate(x, y, time, easing.fn);
}
},
/**
* 这个方法实际上是对scrollTo的进一步封装,滚动到相应的元素区域。
* @param el 为需要滚动到的元素引用
* @param time 为滚动时间
* @param offsetX 为X轴偏移量
* @param offsetY 为Y轴偏移量
* @param easing 动画效果
*/
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 === undefined || 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);
},
// 动画运动时间
_transitionTime: function (time) {
time = time || 0;
this.scrollerStyle[utils.style.transitionDuration] = time + 'ms';
// 落后的安卓机运动時間需要把0转0.001s
if ( !time && utils.isBadAndroid ) {
this.scrollerStyle[utils.style.transitionDuration] = '0.001s';
}
// INSERT POINT: _transitionTime
},
_transitionTimingFunction: function (easing) {
this.scrollerStyle[utils.style.transitionTimingFunction] = easing;
// INSERT POINT: _transitionTimingFunction
},
/**
* @param x 为移动的x轴坐标
* @param y 为移动的y轴坐标
*/
_translate: function (x, y) {
if ( this.options.useTransform ) {
/* REPLACE START: _translate */
this.scrollerStyle[utils.style.transform] = 'translate(' + x + 'px,' + y + 'px)' + this.translateZ;
/* REPLACE END: _translate */
} else {
x = Math.round(x);
y = Math.round(y);
this.scrollerStyle.left = x + 'px';
this.scrollerStyle.top = y + 'px';
}
this.x = x;
this.y = y;
// INSERT POINT: _translate
},
/**
* @param remove 是否解绑事件
*/
_initEvents: function (remove) {
var eventType = remove ? utils.removeEvent : utils.addEvent,
// 是否绑定到wrapper元素上
target = this.options.bindToWrapper ? this.wrapper : window;
//旋转屏幕事件
eventType(window, 'orientationchange', this);
eventType(window, 'resize', this);
if ( this.options.click ) {
eventType(this.wrapper, 'click', this, true);
}
// 如果没禁用鼠标，绑定鼠标事件，针对PC。
if ( !this.options.disableMouse ) {
eventType(this.wrapper, 'mousedown', this);
eventType(target, 'mousemove', this);
eventType(target, 'mousecancel', this);
eventType(target, 'mouseup', this);
}
// 针对win phone的touch事件
if ( utils.hasPointer && !this.options.disablePointer ) {
eventType(this.wrapper, utils.prefixPointerEvent('pointerdown'), this);
eventType(target, utils.prefixPointerEvent('pointermove'), this);
eventType(target, utils.prefixPointerEvent('pointercancel'), this);
eventType(target, utils.prefixPointerEvent('pointerup'), this);
}
//针对ios & Android的touch事件
if ( utils.hasTouch && !this.options.disableTouch ) {
eventType(this.wrapper, 'touchstart', this);
eventType(target, 'touchmove', this);
eventType(target, 'touchcancel', this);
eventType(target, 'touchend', this);
}
// css3动画结束后的回调事件
eventType(this.scroller, 'transitionend', this);
eventType(this.scroller, 'webkitTransitionEnd', this);
eventType(this.scroller, 'oTransitionEnd', this);
eventType(this.scroller, 'MSTransitionEnd', this);
},
getComputedPosition: function () {
//获取scroller的样式
var matrix = window.getComputedStyle(this.scroller, null),
x, y;
//两种方式 transform 和 top/left ( transform在ios下,文本输入的光标fixed )
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, '');
}
//返回 (x ,y) or (top ,left)
return { x: x, y: y };
},
/**
* @param destx 为移动目的地的x轴坐标
* @param desty 为移动目的地的y轴坐标
* @param duration 为移动的时间
* @param easingFn 为移动缓动函数
*/
_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();
},
handleEvent: function (e) {
switch ( e.type ) {
case 'touchstart':
case 'pointerdown':
case 'MSPointerDown':
case 'mousedown':
this._start(e);
break;
case 'touchmove':
case 'pointermove':
case 'MSPointerMove':
case 'mousemove':
this._move(e);
break;
case 'touchend':
case 'pointerup':
case 'MSPointerUp':
case 'mouseup':
case 'touchcancel':
case 'pointercancel':
case 'MSPointerCancel':
case 'mousecancel':
this._end(e);
break;
case 'orientationchange':
case 'resize':
this._resize();
break;
case 'transitionend':
case 'webkitTransitionEnd':
case 'oTransitionEnd':
case 'MSTransitionEnd':
this._transitionEnd(e);
break;
case 'wheel':
case 'DOMMouseScroll':
case 'mousewheel':
this._wheel(e);
break;
case 'keydown':
this._key(e);
break;
case 'click':
if ( !e._constructed ) {
e.preventDefault();
e.stopPropagation();
}
break;
}
}
};
IScroll.utils = utils;
if ( typeof module != 'undefined' && module.exports ) {
module.exports = IScroll;
} else {
window.IScroll = IScroll;
}
})(window, document, Math);
