/**
* dropload
* 西门(http://ons.me/526.html)
* 0.9.0(160215)
*/
;(function($){
'use strict';
var win = window;
var doc = document;
var $win = $(win);
var $doc = $(doc);
$.fn.dropload = function(options){
return new MyDropLoad(this, options);
};
var MyDropLoad = function(element, options){
var me = this;
me.$element = element;
// 上方是否插入DOM
me.upInsertDOM = false;
// loading状态
me.loading = false;
// 是否锁定
me.isLockUp = false;
me.isLockDown = false;
// 是否有数据
me.isData = true;
me._scrollTop = 0;
me._threshold = 0;
me.init(options);
};
// 初始化
MyDropLoad.prototype.init = function(options){
var me = this;
me.opts = $.extend(true, {}, {
scrollArea : me.$element, // 滑动区域
domUp : { // 上方DOM
domClass : 'dropload-up',
domRefresh : '<div class="dropload-refresh">↓下拉刷新</div>',
domUpdate : '<div class="dropload-update">↑释放更新</div>',
domLoad : '<div class="dropload-load"><span class="loading"></span>加载中...</div>'
},
domDown : { // 下方DOM
domClass : 'dropload-down',
domRefresh : '<div class="dropload-refresh">↑上拉加载更多</div>',
domLoad : '<div class="dropload-load"><span class="loading"></span>加载中...</div>',
domNoData : '<div class="dropload-noData">暂无数据</div>'
},
autoLoad : true, // 自动加载
distance : 50, // 拉动距离
threshold : '', // 提前加载距离
loadUpFn : '', // 上方function
loadDownFn : '' // 下方function
}, options);
// 如果加载下方，事先在下方插入DOM
if(me.opts.loadDownFn != ''){
me.$element.append('<div class="'+me.opts.domDown.domClass+'">'+me.opts.domDown.domRefresh+'</div>');
me.$domDown = $('.'+me.opts.domDown.domClass);
}
// 计算提前加载距离
if(!!me.$domDown && me.opts.threshold === ''){
// 默认滑到加载区2/3处时加载
me._threshold = Math.floor(me.$domDown.height()*1/3);
}else{
me._threshold = me.opts.threshold;
}
// 判断滚动区域
if(me.opts.scrollArea == win){
me.$scrollArea = $win;
// 获取文档高度
me._scrollContentHeight = $doc.height();
// 获取win显示区高度 —— 这里有坑
me._scrollWindowHeight = doc.documentElement.clientHeight;
}else{
me.$scrollArea = me.opts.scrollArea;
me._scrollContentHeight = me.$element[0].scrollHeight;
me._scrollWindowHeight = me.$element.height();
}
fnAutoLoad(me);
// 窗口调整
$win.on('resize',function(){
if(me.opts.scrollArea == win){
// 重新获取win显示区高度
me._scrollWindowHeight = win.innerHeight;
}else{
me._scrollWindowHeight = me.$element.height();
}
});
// 绑定触摸
me.$element.on('touchstart',function(e){
if(!me.loading){
fnTouches(e);
fnTouchstart(e, me);
}
});
me.$element.on('touchmove',function(e){
if(!me.loading){
fnTouches(e, me);
fnTouchmove(e, me);
}
});
me.$element.on('touchend',function(){
if(!me.loading){
fnTouchend(me);
}
});
// 加载下方
me.$scrollArea.on('scroll',function(){
me._scrollTop = me.$scrollArea.scrollTop();
// 滚动页面触发加载数据
if(me.opts.loadDownFn != '' && !me.loading && !me.isLockDown && (me._scrollContentHeight - me._threshold) <= (me._scrollWindowHeight + me._scrollTop)){
loadDown(me);
}
});
};
// touches
function fnTouches(e){
if(!e.touches){
e.touches = e.originalEvent.touches;
}
}
// touchstart
function fnTouchstart(e, me){
me._startY = e.touches[0].pageY;
// 记住触摸时的scrolltop值
me.touchScrollTop = me.$scrollArea.scrollTop();
}
// touchmove
function fnTouchmove(e, me){
me._curY = e.touches[0].pageY;
me._moveY = me._curY - me._startY;
if(me._moveY > 0){
me.direction = 'down';
}else if(me._moveY < 0){
me.direction = 'up';
}
var _absMoveY = Math.abs(me._moveY);
// 加载上方
if(me.opts.loadUpFn != '' && me.touchScrollTop <= 0 && me.direction == 'down' && !me.isLockUp){
e.preventDefault();
me.$domUp = $('.'+me.opts.domUp.domClass);
// 如果加载区没有DOM
if(!me.upInsertDOM){
me.$element.prepend('<div class="'+me.opts.domUp.domClass+'"></div>');
me.upInsertDOM = true;
}
fnTransition(me.$domUp,0);
// 下拉
if(_absMoveY <= me.opts.distance){
me._offsetY = _absMoveY;
// todo：move时会不断清空、增加dom，有可能影响性能，下同
me.$domUp.html(me.opts.domUp.domRefresh);
// 指定距离 < 下拉距离 < 指定距离*2
}else if(_absMoveY > me.opts.distance && _absMoveY <= me.opts.distance*2){
me._offsetY = me.opts.distance+(_absMoveY-me.opts.distance)*0.5;
me.$domUp.html(me.opts.domUp.domUpdate);
// 下拉距离 > 指定距离*2
}else{
me._offsetY = me.opts.distance+me.opts.distance*0.5+(_absMoveY-me.opts.distance*2)*0.2;
}
me.$domUp.css({'height': me._offsetY});
}
}
// touchend
function fnTouchend(me){
var _absMoveY = Math.abs(me._moveY);
if(me.opts.loadUpFn != '' && me.touchScrollTop <= 0 && me.direction == 'down' && !me.isLockUp){
fnTransition(me.$domUp,300);
if(_absMoveY > me.opts.distance){
me.$domUp.css({'height':me.$domUp.children().height()});
me.$domUp.html(me.opts.domUp.domLoad);
me.loading = true;
me.opts.loadUpFn(me);
}else{
me.$domUp.css({'height':'0'}).on('webkitTransitionEnd mozTransitionEnd transitionend',function(){
me.upInsertDOM = false;
$(this).remove();
});
}
me._moveY = 0;
}
}
// 如果文档高度不大于窗口高度，数据较少，自动加载下方数据
function fnAutoLoad(me){
if(me.opts.autoLoad){
if((me._scrollContentHeight - me._threshold) <= me._scrollWindowHeight){
loadDown(me);
}
}
}
// 重新获取文档高度
function fnRecoverContentHeight(me){
if(me.opts.scrollArea == win){
me._scrollContentHeight = $doc.height();
}else{
me._scrollContentHeight = me.$element[0].scrollHeight;
}
}
// 加载下方
function loadDown(me){
me.direction = 'up';
me.$domDown.html(me.opts.domDown.domLoad);
me.loading = true;
me.opts.loadDownFn(me);
}
// 锁定
MyDropLoad.prototype.lock = function(direction){
var me = this;
// 如果不指定方向
if(direction === undefined){
// 如果操作方向向上
if(me.direction == 'up'){
me.isLockDown = true;
// 如果操作方向向下
}else if(me.direction == 'down'){
me.isLockUp = true;
}else{
me.isLockUp = true;
me.isLockDown = true;
}
// 如果指定锁上方
}else if(direction == 'up'){
me.isLockUp = true;
// 如果指定锁下方
}else if(direction == 'down'){
me.isLockDown = true;
// 为了解决DEMO5中tab效果bug，因为滑动到下面，再滑上去点tab，direction=down，所以有bug
me.direction = 'up';
}
};
// 解锁
MyDropLoad.prototype.unlock = function(){
var me = this;
// 简单粗暴解锁
me.isLockUp = false;
me.isLockDown = false;
// 为了解决DEMO5中tab效果bug，因为滑动到下面，再滑上去点tab，direction=down，所以有bug
me.direction = 'up';
};
// 无数据
MyDropLoad.prototype.noData = function(flag){
var me = this;
if(flag === undefined || flag == true){
me.isData = false;
}else if(flag == false){
me.isData = true;
}
};
// 重置
MyDropLoad.prototype.resetload = function(){
var me = this;
if(me.direction == 'down' && me.upInsertDOM){
me.$domUp.css({'height':'0'}).on('webkitTransitionEnd mozTransitionEnd transitionend',function(){
me.loading = false;
me.upInsertDOM = false;
$(this).remove();
fnRecoverContentHeight(me);
});
}else if(me.direction == 'up'){
me.loading = false;
// 如果有数据
if(me.isData){
// 加载区修改样式
me.$domDown.html(me.opts.domDown.domRefresh);
fnRecoverContentHeight(me);
fnAutoLoad(me);
}else{
// 如果没数据
me.$domDown.html(me.opts.domDown.domNoData);
}
}
};
// css过渡
function fnTransition(dom,num){
dom.css({
'-webkit-transition':'all '+num+'ms',
'transition':'all '+num+'ms'
});
}
})(window.Zepto || window.jQuery);
