Detailed explanation of JavaScript waterfall flow layout implementation method_javascript skills

The example in this article describes the implementation method of JavaScript waterfall flow layout. Share it with everyone for your reference, the details are as follows:

html structure:

<div id="waterfall">
  <div class="mod-box">
    <div class="mod-img">...</div>
  </div>
  <div class="mod-box">
    <div class="mod-img">...</div>
  </div>
  <div class="mod-box">
    <div class="mod-img">...</div>
  </div>
</div>

css style sheet:

*{margin:0;padding: 0}
#waterfall{position: relative;}
.mod-box{
  padding: 15px 0 0 15px;
  float: left;
}
.mod-img{
  padding: 9px;
  border: 1px solid #ccc;
  border-radius: 5px;
  box-shadow: 0 0 5px #ccc;
  position: relative;
}
.mod-img img{
  width: 310px;
  height: auto;
}

javascript code:

window.onload = function(){
   waterFall("waterfall","mod-box");
}
window.onscroll = scroll;
window.onresize = function() {
  if(re)clearTimeout(re);
  var re = setTimeout(function() {
  waterFall("waterfall","mod-box");
   }, 200);
}
var dataInit = {
  "data": [
    {
      "src": "5.jpg"
    },
    {
      "src": "6.jpg"
    }
   ]
  };
/**
 * 滚动添加数据函数
 */
function scroll(){
 var flag = checkScroll("waterfall","mod-box");
 if(flag ){
   var oparent = document.getElementById("waterfall");
   var htmlStr = "";
   var len = dataInit.data.length;
   for(var i=0;i<len;i++){
     htmlStr+=""; //需要插入的结构
   }
   oparent.innerHTML+=htmlStr;
   waterFall("waterfall","mod-box"); //重新调用一次
 }
}
/**
 * 瀑布流函数
 * @param parentID 容器id
 * @param clsName 数据块className
 */
function waterFall(parentID,clsName){
  var oParent = document.getElementById(parentID); // 父级对象
  //将content下所有class为mod-box的元素取出来
  var oBoxs = getObjsByClassName(oParent,clsName);// 获取存储块框clsName的数组oBoxs
  var oBoxWidth = oBoxs[0].offsetWidth;  //obox的宽 ==>310+9*2+2+15 = 345(包含边框和内边距) 一个块框的宽
  var pageWidth = document.documentElement.clientWidth; //页面可视宽度
  //var pageWidth = document.documentElement.offsetWidth; //页面可视宽度
  var cols = Math.floor(pageWidth/oBoxWidth); //计算整个页面显示的列数（页面宽/obox的宽）每行中能容纳的mod-box个数
  var hAarr = []; //用于存储 每列中的所有块框相加的高度。
  var minH;   
  var minHIndex;    //最小高度对应的索引值
  for(var i = 0;i<oBoxs.length;i++){//遍历数组aPin的每个块框元素
    oBoxs[i].style.position="absolute";
    if(i<cols){ //把第一行排放好，并将每一列的高度记入数据hAarr
      hAarr.push(oBoxs[i].offsetHeight);
      oBoxs[i].style.top=0+"px";
      oBoxs[i].style.left=oBoxWidth*i+"px";
    }else{
      minH = Math.min.apply(null,hAarr); //数组hAarr中的最小值minH
      minHIndex = getMinhIndex(hAarr,minH);
      oBoxs[i].style.top=minH+"px";
      // oBoxs[i].style.left=oBoxWidth*minHIndex+"px";
      oBoxs[i].style.left= oBoxs[minHIndex].offsetLeft+"px";
      //数组 最小高元素的高 + 添加上的aPin[i]块框高
      hAarr[minHIndex]+=oBoxs[i].offsetHeight; //更新添加了块框后的列高
    }
  }
  var maxH = Math.max.apply(null,hAarr);
  oParent.style.cssText = "width:"+oBoxWidth*cols+"px;margin:0 auto;height:"+maxH+"px;"; //设置父级居中样式：定宽+自动水平外边距
}
/**
 * 检查是否符合加载数据（滚动到最后一个oBox）
 * @param parentID 容器id
 * @param clsName 数据块className
 * @returns {boolean}
 */
function checkScroll(parentID,clsName){
  var parentObj = typeof parentID=="object" &#63;parentID:document.getElementById(parentID);
  var oBoxs = getObjsByClassName(parentObj,clsName);
  var lastBoxH = oBoxs[oBoxs.length-1].offsetTop+Math.floor(oBoxs[oBoxs.length-1].offsetHeight/2);
  //创建【触发添加块框函数waterfall()】的高度：最后一个块框的距离网页顶部+自身高的一半(实现未滚到底就开始加载)
  var scrolltop = document.body.scrollTop ||document.documentElement.scrollTop;
  //标准模式与混杂模式
  var height = document.documentElement.clientHeight; //页面高度
  return (lastBoxH<scrolltop+height)&#63;true:false;
}
/**
 * 根据class获得元素
 * @param id
 * @param clsName
 * @returns {Array}
 */
function getObjsByClassName(parentID,clsName){
  var parentObj = typeof parentID=="object" &#63;parentID:document.getElementById(parentID);
  if(!parentObj){
    return;
  }
  var childObjs = parentObj.getElementsByTagName("*"); //获取 父级的所有子集
  var calssObjs = []; //创建一个数组 用于收集子元素
  for(var i in childObjs){//遍历子元素、判断类别、压入数组
    if(childObjs[i].className==clsName){ 
      calssObjs.push(childObjs[i]);
    }
  }
  return calssObjs;
}
/**
 * 获取最小值的索引minIndex
 * @param arr
 * @param minH
 * @returns {string}
 */
function getMinhIndex(arr,minH){
  for(var i in arr){
    if(arr[i]===minH){
      return i;
    }
  }
}

Readers who are interested in more JavaScript-related content can check out the special topics on this site: "Summary of JavaScript switching special effects and techniques", "Summary of JavaScript animation special effects and techniques", " Summary of JavaScript errors and debugging skills", "Summary of JavaScript extension skills" and "Summary of JavaScript motion effects and skills"

I hope this article will be helpful to everyone in JavaScript programming.