source: trunk/SRC/Documentation/idldoc_html_output/tree.js

var temp, temp2, cookieArray, cookieArray2, cookieCount;

function initiate() {
  cookieCount=0;

  if (document.cookie) {
    cookieArray = document.cookie.split(";");
    cookieArray2 = new Array();

    for (i in cookieArray) {
      cookieArray2[cookieArray[i].split("=")[0].replace(/ /g, "")] 
        = cookieArray[i].split("=")[1].replace(/ /g, "");
    }
  }

  cookieArray = (document.cookie.indexOf("state=") >= 0) 
    ? cookieArray2["state"].split(",") 
    : new Array();

  temp = document.getElementById("tree");

  for (var o=0; o<temp.getElementsByTagName("li").length; o++) {
    if (temp.getElementsByTagName("li")[o].getElementsByTagName("ul").length > 0) {
      temp2 = document.createElement("span");
      temp2.className = "symbols";
      temp2.style.backgroundImage = (cookieArray.length > 0)
        ? ((cookieArray[cookieCount]=="true")
           ? "url(minus.png)"
           : "url(plus.png)")
        : "url(plus.png)";
      temp2.onclick=function(){
        showhide(this.parentNode);
        writeCookie();
      }

      temp.getElementsByTagName("li")[o].insertBefore(temp2,temp.getElementsByTagName("li")[o].firstChild)
      temp.getElementsByTagName("li")[o].getElementsByTagName("ul")[0].style.display = "none";

      if (cookieArray[cookieCount]=="true") {
        showhide(temp.getElementsByTagName("li")[o]);
      }
      cookieCount++;
    } else {

      temp2 = document.createElement("span");
      temp2.className = "symbols";
      temp2.style.backgroundImage = "url(page.png)";

      temp.getElementsByTagName("li")[o].insertBefore(temp2,temp.getElementsByTagName("li")[o].firstChild);
    }
  }
}



function showhide(el) {
  el.getElementsByTagName("ul")[0].style.display = (el.getElementsByTagName("ul")[0].style.display == "block")
    ? "none"
    : "block";
  el.getElementsByTagName("span")[0].style.backgroundImage = (el.getElementsByTagName("ul")[0].style.display == "block")
    ? "url(minus.png)" 
    : "url(plus.png)";
}



// Runs through the menu and puts the "states" of each nested list into an 
// array, the array is then joined together and assigned to a cookie.
function writeCookie() {     
  cookieArray = new Array()

  for (var q=0; q < temp.getElementsByTagName("li").length; q++) {
    if (temp.getElementsByTagName("li")[q].childNodes.length > 0) {
      if (temp.getElementsByTagName("li")[q].childNodes[0].nodeName == "SPAN" 
          && temp.getElementsByTagName("li")[q].getElementsByTagName("ul").length > 0) {
        cookieArray[cookieArray.length] 
          = (temp.getElementsByTagName("li")[q].getElementsByTagName("ul")[0].style.display == "block");
      }
    }
  }

  document.cookie = "state=" + cookieArray.join(",") + ";expires=" 
    + new Date(new Date().getTime() + 365*24*60*60*1000).toGMTString();

}