/**
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* 选择列表插件
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* varstion 2.0.0
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* by Houfeng
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* Houfeng@DCloud.io
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*/
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(function($, window, document, undefined) {
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var MAX_EXCEED = 30;
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var VISIBLE_RANGE = 90;
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var DEFAULT_ITEM_HEIGHT = 40;
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var BLUR_WIDTH = 10;
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var rad2deg = $.rad2deg = function(rad) {
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return rad / (Math.PI / 180);
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};
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var deg2rad = $.deg2rad = function(deg) {
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return deg * (Math.PI / 180);
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};
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var platform = navigator.platform.toLowerCase();
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var userAgent = navigator.userAgent.toLowerCase();
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var isIos = (userAgent.indexOf('iphone') > -1 ||
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userAgent.indexOf('ipad') > -1 ||
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userAgent.indexOf('ipod') > -1) &&
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(platform.indexOf('iphone') > -1 ||
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platform.indexOf('ipad') > -1 ||
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platform.indexOf('ipod') > -1);
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//alert(isIos);
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var Picker = $.Picker = function(holder, options) {
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var self = this;
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self.holder = holder;
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self.options = options || {};
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self.init();
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self.initInertiaParams();
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self.calcElementItemPostion(true);
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self.bindEvent();
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};
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Picker.prototype.findElementItems = function() {
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var self = this;
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self.elementItems = [].slice.call(self.holder.querySelectorAll('li'));
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return self.elementItems;
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};
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Picker.prototype.init = function() {
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var self = this;
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self.list = self.holder.querySelector('ul');
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self.findElementItems();
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self.height = self.holder.offsetHeight;
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self.r = self.height / 2 - BLUR_WIDTH;
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self.d = self.r * 2;
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self.itemHeight = self.elementItems.length > 0 ? self.elementItems[0].offsetHeight : DEFAULT_ITEM_HEIGHT;
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self.itemAngle = parseInt(self.calcAngle(self.itemHeight * 0.8));
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self.hightlightRange = self.itemAngle / 2;
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self.visibleRange = VISIBLE_RANGE;
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self.beginAngle = 0;
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self.beginExceed = self.beginAngle - MAX_EXCEED;
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self.list.angle = self.beginAngle;
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if (isIos) {
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self.list.style.webkitTransformOrigin = "center center " + self.r + "px";
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}
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};
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Picker.prototype.calcElementItemPostion = function(andGenerateItms) {
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var self = this;
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if (andGenerateItms) {
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self.items = [];
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}
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self.elementItems.forEach(function(item) {
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var index = self.elementItems.indexOf(item);
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self.endAngle = self.itemAngle * index;
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item.angle = self.endAngle;
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item.style.webkitTransformOrigin = "center center -" + self.r + "px";
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item.style.webkitTransform = "translateZ(" + self.r + "px) rotateX(" + (-self.endAngle) + "deg)";
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if (andGenerateItms) {
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var dataItem = {};
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dataItem.text = item.innerHTML || '';
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dataItem.value = item.getAttribute('data-value') || dataItem.text;
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self.items.push(dataItem);
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}
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});
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self.endExceed = self.endAngle + MAX_EXCEED;
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self.calcElementItemVisibility(self.beginAngle);
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};
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Picker.prototype.calcAngle = function(c) {
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var self = this;
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var a = b = parseFloat(self.r);
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//直径的整倍数部分直接乘以 180
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c = Math.abs(c); //只算角度不关心正否值
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var intDeg = parseInt(c / self.d) * 180;
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c = c % self.d;
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//余弦
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var cosC = (a * a + b * b - c * c) / (2 * a * b);
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var angleC = intDeg + rad2deg(Math.acos(cosC));
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return angleC;
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};
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Picker.prototype.calcElementItemVisibility = function(angle) {
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var self = this;
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self.elementItems.forEach(function(item) {
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var difference = Math.abs(item.angle - angle);
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if (difference < self.hightlightRange) {
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item.classList.add('highlight');
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} else if (difference < self.visibleRange) {
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item.classList.add('visible');
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item.classList.remove('highlight');
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} else {
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item.classList.remove('highlight');
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item.classList.remove('visible');
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}
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});
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};
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Picker.prototype.setAngle = function(angle) {
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var self = this;
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self.list.angle = angle;
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self.list.style.webkitTransform = "perspective(1000px) rotateY(0deg) rotateX(" + angle + "deg)";
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self.calcElementItemVisibility(angle);
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};
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Picker.prototype.bindEvent = function() {
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var self = this;
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var lastAngle = 0;
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var startY = null;
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var isPicking = false;
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self.holder.addEventListener($.EVENT_START, function(event) {
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isPicking = true;
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event.preventDefault();
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self.list.style.webkitTransition = '';
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startY = (event.changedTouches ? event.changedTouches[0] : event).pageY;
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lastAngle = self.list.angle;
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self.updateInertiaParams(event, true);
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}, false);
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self.holder.addEventListener($.EVENT_END, function(event) {
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isPicking = false;
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event.preventDefault();
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self.startInertiaScroll(event);
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}, false);
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self.holder.addEventListener($.EVENT_CANCEL, function(event) {
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isPicking = false;
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event.preventDefault();
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self.startInertiaScroll(event);
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}, false);
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self.holder.addEventListener($.EVENT_MOVE, function(event) {
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if (!isPicking) {
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return;
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}
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event.preventDefault();
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var endY = (event.changedTouches ? event.changedTouches[0] : event).pageY;
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var dragRange = endY - startY;
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var dragAngle = self.calcAngle(dragRange);
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var newAngle = dragRange > 0 ? lastAngle - dragAngle : lastAngle + dragAngle;
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if (newAngle > self.endExceed) {
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newAngle = self.endExceed
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}
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if (newAngle < self.beginExceed) {
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newAngle = self.beginExceed
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}
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self.setAngle(newAngle);
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self.updateInertiaParams(event);
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}, false);
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//--
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self.list.addEventListener('tap', function(event) {
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elementItem = event.target;
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if (elementItem.tagName == 'LI') {
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self.setSelectedIndex(self.elementItems.indexOf(elementItem), 200);
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}
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}, false);
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};
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Picker.prototype.initInertiaParams = function() {
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var self = this;
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self.lastMoveTime = 0;
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self.lastMoveStart = 0;
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self.stopInertiaMove = false;
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};
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Picker.prototype.updateInertiaParams = function(event, isStart) {
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var self = this;
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var point = event.changedTouches ? event.changedTouches[0] : event;
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if (isStart) {
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self.lastMoveStart = point.pageY;
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self.lastMoveTime = event.timeStamp || Date.now();
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self.startAngle = self.list.angle;
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} else {
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var nowTime = event.timeStamp || Date.now();
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if (nowTime - self.lastMoveTime > 300) {
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self.lastMoveTime = nowTime;
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self.lastMoveStart = point.pageY;
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}
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}
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self.stopInertiaMove = true;
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};
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Picker.prototype.startInertiaScroll = function(event) {
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var self = this;
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var point = event.changedTouches ? event.changedTouches[0] : event;
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/**
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* 缓动代码
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*/
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var nowTime = event.timeStamp || Date.now();
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var v = (point.pageY - self.lastMoveStart) / (nowTime - self.lastMoveTime); //最后一段时间手指划动速度
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var dir = v > 0 ? -1 : 1; //加速度方向
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var deceleration = dir * 0.0006 * -1;
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var duration = Math.abs(v / deceleration); // 速度消减至0所需时间
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var dist = v * duration / 2; //最终移动多少
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var startAngle = self.list.angle;
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var distAngle = self.calcAngle(dist) * dir;
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//----
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var srcDistAngle = distAngle;
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if (startAngle + distAngle < self.beginExceed) {
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distAngle = self.beginExceed - startAngle;
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duration = duration * (distAngle / srcDistAngle) * 0.6;
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}
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if (startAngle + distAngle > self.endExceed) {
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distAngle = self.endExceed - startAngle;
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duration = duration * (distAngle / srcDistAngle) * 0.6;
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}
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//----
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if (distAngle == 0) {
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self.endScroll();
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return;
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}
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self.scrollDistAngle(nowTime, startAngle, distAngle, duration);
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};
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Picker.prototype.scrollDistAngle = function(nowTime, startAngle, distAngle, duration) {
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var self = this;
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self.stopInertiaMove = false;
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(function(nowTime, startAngle, distAngle, duration) {
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var frameInterval = 13;
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var stepCount = duration / frameInterval;
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var stepIndex = 0;
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(function inertiaMove() {
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if (self.stopInertiaMove) return;
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var newAngle = self.quartEaseOut(stepIndex, startAngle, distAngle, stepCount);
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self.setAngle(newAngle);
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stepIndex++;
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if (stepIndex > stepCount - 1 || newAngle < self.beginExceed || newAngle > self.endExceed) {
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self.endScroll();
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return;
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}
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setTimeout(inertiaMove, frameInterval);
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})();
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})(nowTime, startAngle, distAngle, duration);
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};
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Picker.prototype.quartEaseOut = function(t, b, c, d) {
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return -c * ((t = t / d - 1) * t * t * t - 1) + b;
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};
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Picker.prototype.endScroll = function() {
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var self = this;
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if (self.list.angle < self.beginAngle) {
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self.list.style.webkitTransition = "150ms ease-out";
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self.setAngle(self.beginAngle);
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} else if (self.list.angle > self.endAngle) {
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self.list.style.webkitTransition = "150ms ease-out";
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self.setAngle(self.endAngle);
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} else {
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var index = parseInt((self.list.angle / self.itemAngle).toFixed(0));
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self.list.style.webkitTransition = "100ms ease-out";
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self.setAngle(self.itemAngle * index);
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}
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self.triggerChange();
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};
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Picker.prototype.triggerChange = function(force) {
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var self = this;
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setTimeout(function() {
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var index = self.getSelectedIndex();
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var item = self.items[index];
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if ($.trigger && (index != self.lastIndex || force === true)) {
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$.trigger(self.holder, 'change', {
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"index": index,
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"item": item
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});
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//console.log('change:' + index);
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}
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self.lastIndex = index;
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typeof force === 'function' && force();
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}, 0);
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};
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Picker.prototype.correctAngle = function(angle) {
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var self = this;
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if (angle < self.beginAngle) {
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return self.beginAngle;
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} else if (angle > self.endAngle) {
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return self.endAngle;
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} else {
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return angle;
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}
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};
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Picker.prototype.setItems = function(items) {
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var self = this;
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self.items = items || [];
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var buffer = [];
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self.items.forEach(function(item) {
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if (item !== null && item !== undefined) {
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buffer.push('<li>' + (item.text || item) + '</li>');
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}
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});
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self.list.innerHTML = buffer.join('');
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self.findElementItems();
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self.calcElementItemPostion();
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self.setAngle(self.correctAngle(self.list.angle));
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self.triggerChange(true);
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};
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Picker.prototype.getItems = function() {
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var self = this;
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return self.items;
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};
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Picker.prototype.getSelectedIndex = function() {
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var self = this;
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return parseInt((self.list.angle / self.itemAngle).toFixed(0));
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};
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Picker.prototype.setSelectedIndex = function(index, duration, callback) {
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var self = this;
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self.list.style.webkitTransition = '';
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var angle = self.correctAngle(self.itemAngle * index);
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if (duration && duration > 0) {
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var distAngle = angle - self.list.angle;
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self.scrollDistAngle(Date.now(), self.list.angle, distAngle, duration);
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} else {
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self.setAngle(angle);
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}
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self.triggerChange(callback);
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};
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Picker.prototype.getSelectedItem = function() {
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var self = this;
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return self.items[self.getSelectedIndex()];
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};
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Picker.prototype.getSelectedValue = function() {
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var self = this;
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return (self.items[self.getSelectedIndex()] || {}).value;
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};
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Picker.prototype.getSelectedText = function() {
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var self = this;
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return (self.items[self.getSelectedIndex()] || {}).text;
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};
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Picker.prototype.setSelectedValue = function(value, duration, callback) {
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var self = this;
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for (var index in self.items) {
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var item = self.items[index];
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if (item.value == value) {
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self.setSelectedIndex(index, duration, callback);
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return;
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}
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}
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};
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if ($.fn) {
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$.fn.picker = function(options) {
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//遍历选择的元素
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this.each(function(i, element) {
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if (element.picker) return;
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if (options) {
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element.picker = new Picker(element, options);
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} else {
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var optionsText = element.getAttribute('data-picker-options');
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var _options = optionsText ? JSON.parse(optionsText) : {};
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element.picker = new Picker(element, _options);
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}
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});
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return this[0] ? this[0].picker : null;
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};
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//自动初始化
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$.ready(function() {
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$('.mui-picker').picker();
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});
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}
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})(window.mui || window, window, document, undefined);
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//end
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