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