// pages/swiper.js
var startY, endY

Page({

    /**
     * 页面的初始数据
     */
    data: {
        isLoop          : false,
        swiperNumber    : 0,
        swiperArr       : [],
        dataArr         : [
            { id: 0, type: "text", data: "0" },
            { id: 1, type: "text", data: "1" },
            { id: 2, type: "text", data: "2" },
            { id: 3, type: "text", data: "3" },
            { id: 4, type: "text", data: "4" },
            { id: 5, type: "text", data: "5" }
        ]
    },

    /**
     * 生命周期函数--监听页面加载
     */
    onLoad(options) {
        let initData = this.data.dataArr.slice(0, 3)
        this.setData({
            swiperArr: initData
        })
    },
    // 触摸开始
    onStart(e){
        let { clientY } = e.changedTouches[0]
        startY = clientY
    },
    // 触摸结束
    onEnd(e){
        let { clientY } = e.changedTouches[0]
        endY = clientY
        if(startY-endY >50 || endY-startY>50){
            this.onIsDirection()
        }
    },
    // 计算前后滚动
    onIsDirection(){
        let { swiperArr, dataArr, swiperNumber } = this.data
        if(startY > endY){
            this.setData({
                swiperNumber: swiperNumber += 1,
                isLoop      : true
            })
            let newNumber  = swiperNumber%3 >= 2 ? 0 : swiperNumber%3 + 1
            let nextNumber = swiperNumber + 1

            if(nextNumber >= dataArr.length){
                this.setData({
                    isLoop: false
                })
                wx.showToast({
                    title: '没有更多内容了~',
                    icon : 'none'
                })
                return
            }
            swiperArr[newNumber] = dataArr[nextNumber]
        }else{
            this.setData({
                swiperNumber: swiperNumber > 0 ? swiperNumber -= 1: 0,
                isLoop      : true
            })
            let newNumber  = swiperNumber%3 <= 0 ? 2 : swiperNumber%3 - 1
            let preNumber = swiperNumber >= 0 ? swiperNumber - 1 : 0

            if(preNumber < 0){
                this.setData({
                    isLoop: false
                })
                wx.showToast({
                    title: '没有更多内容了~',
                    icon : 'none'
                })
                return
            }
            swiperArr[newNumber] = dataArr[preNumber]
        }
        this.setData({
            swiperArr
        })
    }
})