摘要：源碼地址使用說明注意參數瀑布流外容器瀑布流寬度，如果初始化時外容器未隱藏狀態則需使用該參數默認獲取外容器寬度子元素選擇器，比如樣式名元素間的間隔元素間垂直方向間隔，默認使用值元素寬度默認會根據容器寬度自動調整強制元素寬度，

源碼地址： https://github.com/capricornc...

Install zx-waterfall using npm

npm i --save zx-waterfall

ES6+

import ZxWaterfall from "zx-waterfall"

const waterfall = new ZxWaterfall({
  // HTMLElement, waterfall items"s outer container
  container: document.getElementById("zxWaterfall"),
  // children item selector, eg. ".item-container"
  itemSelector: ".item-wrapper",
  // item"s spacing, unit px
  gutter: 20,
  // item"s width
  itemWidth: 300
})
// reset
waterfall.reset()
// loaMedias
waterfall.loadMedia(["http://xx.com/aaa.jpg"]).then(_ => {
  // change
  waterfall.change()
})

browser

https://capricorncd.github.io...

container "s style must be style.position=relative|absolute|fixed

container: HTMLElement

瀑布流外容器.

containerWidth: Number

瀑布流寬度，如果初始化時外容器未隱藏狀態則需使用該參數.

默認獲取外容器寬度.

itemSelector: String

子元素選擇器，比如 樣式名".item-container".

gutter: Number

元素間的間隔.

verticalGutter: Number

元素間垂直方向間隔，默認使用gutter值.

itemWidth: Number

元素寬度, 默認 300, 會根據容器寬度自動調整.

forceItemWidth: Boolean

強制元素寬度，即使用itemWidth作為寬度值，默認 false.

align: String, Optional value left|center|right

強制寬度時，元素顯示靠邊位置，默認 center.

reset()

重置瀑布流初始值

loadMeida(array)

預加載列表數據中的image媒體元素.

array: ["http://a.com/1.jpg", "http://a.com/2.jpg"]

@return promise

change()

列表數據改變后后，通知瀑布流更新元素位置.

/**
 * preload image
 * @param url
 * @param handler
 */
function loadImage (url, handler) {
  let $el = document.createElement("img")
  $el.src = url
  $el.onload = handler
  $el.onerror = handler
  $el = null
}

/**
 * to int
 * @param m
 * @returns {number}
 */
function int (m) {
  let n = parseInt(m)
  return isNaN(n) ? 0 : n
}

/**
 * convert pseudoArray to array
 * @param pseudoArray
 * @param index
 * @returns {T[]}
 */
function slice (pseudoArray, index) {
  return Array.prototype.slice.call(pseudoArray, int(index))
}

// default options
const DEF_OPTIONS = {
  // HTMLElement, waterfall items"s outer container
  container: null,
  // container"s width, container are hidden when initialized
  // default get container offsetWidth when it"s visible
  containerWidth: 0,
  // children item selector, eg. ".item-container"
  itemSelector: "",
  // item"s spacing, unit px
  gutter: 20,
  // item"s vertical spacing, default use gutter"s value
  verticalGutter: 0,
  // item"s width
  itemWidth: 300,
  // force item width
  forceItemWidth: false,
  // Horizontal align when forceItemWidth is true
  align: "center"
}

/**
 * ZxWaterfall
 */
class ZxWaterfall {
  /**
   * constructor
   * @param opts
   */
  constructor (opts) {
    opts = Object.assign({}, DEF_OPTIONS, opts)
    // check container
    if (!opts.container || opts.container.nodeType !== 1) {
      throw new TypeError(`Instancing parameter "container" is not HTMLElement.`)
    }
    // check itemSelector
    if (!opts.itemSelector || typeof opts.itemSelector !== "string") {
      throw new TypeError(`Instancing parameter "itemSelector" is null or is"t a string.`)
    }
    // check verticalGutter
    if (!opts.verticalGutter) {
      opts.verticalGutter = opts.gutter
    }
    // item number
    this.count = 0
    this.opts = opts
    this._init()
    // clone this.reset
    this._resetClone = this.reset.bind(this)
    window.addEventListener("resize", this._resetClone)
  }

  /**
   * initialization
   * @private
   */
  _init () {
    let opts = this.opts
    // container width
    let containerWidth = int(opts.containerWidth) || opts.container.offsetWidth
    // column number
    let columnNum = Math.floor(containerWidth / (opts.itemWidth + opts.gutter))
    // opts.itemWidth when opts.forceItemWidth = true
    // else use compute new width
    this.itemWidth = opts.forceItemWidth
      ? opts.itemWidth
      : (containerWidth - (columnNum + 1) * opts.gutter) / columnNum
    // column current height array
    this.columns = Array(columnNum)
    this.columns.fill(0, 0)
    // offset left when forceItemWidth=true
    this.offsetLeft = 0
    if (opts.forceItemWidth) {
      let residualSpaceWidth = containerWidth - (this.itemWidth + opts.gutter) * columnNum - opts.gutter
      switch (opts.align) {
        case "center":
          this.offsetLeft = residualSpaceWidth / 2
          break
        case "right":
          this.offsetLeft = residualSpaceWidth
          break
      }
    }
  }

  /**
   * set items position
   * @private
   */
  _setPosition () {
    let opts = this.opts
    // get new item elements
    let $childs = slice(opts.container.querySelectorAll(opts.itemSelector), this.count)
    // console.log(this.count, $childs)
    let len = $childs.length
    // reset this.count value
    this.count += len
    // handle new $item
    let i, $item
    for (i = 0; i < len; i++) {
      $item = $childs[i]
      if (!$item) continue
      $item.style.position = "absolute"
      $item.style.width = this.itemWidth + "px"
      $item.style.display = "inline-block"
      // get columns min value
      let min = Math.min.apply(null, this.columns)
      let index = this.columns.findIndex(val => val === min)
      // set $item position
      $item.style.top = `${min + opts.verticalGutter}px`
      $item.style.left = `${this.offsetLeft + (this.itemWidth + opts.gutter) * index + opts.gutter}px`
      // reset waterfall current column height value
      let itemHeight = $item.offsetHeight
      this.columns[index] = min + itemHeight + opts.verticalGutter
      // update container new min height style
      // opts.container.style.minHeight = Math.max.apply(null, this.columns) + opts.verticalGutter + "px"
    }
  }

  /**
   * container"s items number change
   */
  change () {
    // reset postion, when new item element append to container, or remove
    this._setPosition()
  }

  /**
   * reset
   */
  reset () {
    this.count = 0
    this._init()
    this._setPosition()
  }

  /**
   * preload media items
   * @param arr media source urls array
   * @returns {Promise}
   */
  loadMedia (arr) {
    return new Promise(resolve => {
      if (Array.isArray(arr) && arr.length) {
        let len = arr.length
        let count = 0
        /* eslint-disable */
        arr.forEach(url => {
          loadImage(url, () => {
            count++
            if (len === count) resolve()
          })
        })
      } else {
        resolve()
      }
    })
  }

  /**
   * destroy
   * removeEventListener window resize
   */
  destroy () {
    window.removeEventListener("resize", this._resetClone)
  }
}

export default ZxWaterfall

demo: https://github.com/capricornc...