DHTML Lab - DHTML Diner - Element Page Coordinates, Part 4 | 2

Determining Element Page Coordinates, Part 4
IE Win - Final Comments

The Functions To-Now

At the end of Part 3, we had modified the functions created in Part 1 and Part 2 to read:

function DL_GetElementLeft(eElement)
{
   if (!eElement && this)                    // if argument is invalid
   {                                         // (not specified, is null or is 0)
      eElement = this;                       // and function is a method
   }                                         // identify the element as the method owner
   var DL_bIE = document.all ? true : false; // initialize var to identify IE
   var nLeftPos = eElement.offsetLeft;       // initialize var to store calculations
   var eParElement = eElement.offsetParent;  // identify first offset parent element
   while (eParElement != null)
   {                                         // move up through element hierarchy
      if(DL_bIE)                             // if browser is IE, then...
      {
         if(eParElement.tagName == "TD")     // if parent a table cell, then...
         {
            nLeftPos += eParElement.clientLeft; // append cell border width to calcs
         }
      }
      else                                   // if browser is Gecko, then...
      {
         if(eParElement.tagName == "TABLE")  // if parent is a table, then...
         {                                   // get its border as a number
            var nParBorder = parseInt(eParElement.border);
            if(isNaN(nParBorder))            // if no valid border attribute, then...
            {                                // check the table's frame attribute
               var nParFrame = eParElement.getAttribute('frame');
               if(nParFrame != null)         // if frame has ANY value, then...
               {
                  nLeftPos += 1;             // append one pixel to counter
               }
            }
            else if(nParBorder > 0)          // if a border width is specified, then...
            {
               nLeftPos += nParBorder;       // append the border width to counter
            }
         }
      }

      nLeftPos += eParElement.offsetLeft;    // append left offset of parent
      eParElement = eParElement.offsetParent; // and move up the element hierarchy
   }                                         // until no more offset parents exist
   return nLeftPos;                          // return the number calculated
}
function DL_GetElementTop(eElement)
{
   if (!eElement && this)                    // if argument is invalid
   {                                         // (not specified, is null or is 0)
      eElement = this;                       // and function is a method
   }                                         // identify the element as the method owner
   var DL_bIE = document.all ? true : false; // initialize var to identify IE
   var nTopPos = eElement.offsetTop;         // initialize var to store calculations
   var eParElement = eElement.offsetParent;  // identify first offset parent element
   while (eParElement != null)
   {                                         // move up through element hierarchy
      if(DL_bIE)                             // if browser is IE, then...
      {
         if(eParElement.tagName == "TD")     // if parent a table cell, then...
         {
            nTopPos += eParElement.clientTop; // append cell border width to calcs
         }
      }
      else                                   // if browser is Gecko, then...
      {
         if(eParElement.tagName == "TABLE")  // if parent is a table, then...
         {                                   // get its border as a number
            var nParBorder = parseInt(eParElement.border);
            if(isNaN(nParBorder))            // if no valid border attribute, then...
            {                                // check the table's frame attribute
               var nParFrame = eParElement.getAttribute('frame');
               if(nParFrame != null)         // if frame has ANY value, then...
               {
                  nTopPos += 1;              // append one pixel to counter
               }
            }
            else if(nParBorder > 0)          // if a border width is specified, then...
            {
               nTopPos += nParBorder;        // append the border width to counter
            }
         }
      }

      nTopPos += eParElement.offsetTop;      // append top offset of parent
      eParElement = eParElement.offsetParent; // and move up the element hierarchy
   }                                         // until no more offset parents exist
   return nTopPos;                           // return the number calculated
}

These functions can be called in either of two ways:

elementReference.getTrueXPosition = DL_GetElementLeft;
elementReference.getTrueYPosition = DL_GetElementTop;
var nMyElementsTrueXPosition = elementReference.getTrueXPosition();
var nMyElementsTrueYPosition = elementReference.getTrueYPosition();

or:

var nMyElementsTrueXPosition = DL_GetElementLeft(elementReference);
var nMyElementsTrueYPosition = DL_GetElementTop(elementReference);

The functions are currently intended for use in IE for Windows and NS6+.

Now, let's finalize the functions for IE for Windows.