Fire javascript after images have loaded

Question

I have a div that can be dynaimcally changed with an ajax script:

{
     var xmlHttp = GetXmlHttpObject();
     var url="/dashboard/ajax/images_pop_ajax.asp";
     if (!xmlHttp){
          alert ("Browser does not support HTTP Request")
          return
     }
     xmlHttp.onreadystatechange=function()
     {
          if (xmlHttp.readyState == 1)
          {
               document.getElementById("images_inner").innerHTML = LoadingAlert;
          }
          if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
          {
               var result = xmlHttp.responseText;
               document.getElementById('images_inner').innerHTML = result;
               window.onload = function(){AdjustColumns();}
          }
     };
     xmlHttp.open("GET", url , true)
     xmlHttp.send(null)
}

function GetXmlHttpObject()
{
     var objXMLHttp=null;
     if (window.XMLHttpRequest)
     {
          objXMLHttp=new XMLHttpRequest();
     }
     else if (window.ActiveXObject)
     {
          objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP");
     }
     return objXMLHttp;
}

When the images_pop_ajax.asp file runs it returns 8 images, which are then placed into the div tab id images_inner. Once this is complete, i want to adjust the columns of my page so everything is aligned. so I run this script:

function AdjustColumns()
{
     var ImgCol = document.getElementById('images_inner').offsetHeight;
     var ClassCol = 820;
     if (ImgCol > 574)
     {
          var ToAdd = eval(ImgCol - 574);
          document.getElementById('class_inner').style.height = eval(ClassCol + ToAdd) + 'px';
     }
}

The problem I have is that the AdjustColumns() script runs before all the images are loaded so consequently the columns dont line up. How can I get it to run, after the images have loaded?

Many thanks in advance,

neojakey

Answer 1

for each image you should add this event and wait for them when they are all loaded (use a counter)

   var counter = 0;
   var image = new Image();
    //attachEvent("onload") for ie
    image.addEventListener("load", function() {
                                   counter++;
    if(counter == 8) adjustColumns();
    }, false);
    image.src = "image.jpg";

beware though there are some times it doesn't work well, for example when the image is in the cache already.