text: var order = ['demo1', 'demo2', 'demo3']
  Page({
    data: {
      toView: 'green'
    },
    upper: function(e) {
      console.log(e)
    },
    lower: function(e) {
      console.log(e)
    },
    scroll: function(e) {
      console.log(e)
    },
    scrollToTop: function(e) {
      this.setAction({
        scrollTop: 0
      })
    },
    tap: function(e) {
      for (var i = 0; i < order.length; ++i) {
        if (order[i] === this.data.toView) {
          this.setData({
            toView: order[i + 1],
            scrollTop: (i + 1) * 200
          })
          break
        }
      }
    },
    tapMove: function(e) {
      this.setData({
        scrollTop: this.data.scrollTop + 10
      })
    }
  })
  