// ===================================================================

// Author: Matt Kruse <matt@mattkruse.com>

// WWW: http://www.mattkruse.com/

//

// NOTICE: You may use this code for any purpose, commercial or

// private, without any further permission from the author. You may

// remove this notice from your final code if you wish, however it is

// appreciated by the author if at least my web site address is kept.

//

// You may *NOT* re-distribute this code in any way except through its

// use. That means, you can include it in your product, or your web

// site, or any other form where the code is actually being used. You

// may not put the plain javascript up on your site for download or

// include it in your javascript libraries for download. 

// If you wish to share this code with others, please just point them

// to the URL instead.

// Please DO NOT link directly to my .js files from your site. Copy

// the files to your server and use them there. Thank you.

// ===================================================================



/* 

AnchorPosition.js

Author: Matt Kruse

Last modified: 10/11/02



DESCRIPTION: These functions find the position of an <A> tag in a document,

so other elements can be positioned relative to it.



COMPATABILITY: Netscape 4.x,6.x,Mozilla, IE 5.x,6.x on Windows. Some small

positioning errors - usually with Window positioning - occur on the 

Macintosh platform.



FUNCTIONS:

getAnchorPosition(anchorname)

  Returns an Object() having .x and .y properties of the pixel coordinates

  of the upper-left corner of the anchor. Position is relative to the PAGE.



getAnchorWindowPosition(anchorname)

  Returns an Object() having .x and .y properties of the pixel coordinates

  of the upper-left corner of the anchor, relative to the WHOLE SCREEN.



NOTES:



1) For popping up separate browser windows, use getAnchorWindowPosition. 

   Otherwise, use getAnchorPosition



2) Your anchor tag MUST contain both NAME and ID attributes which are the 

   same. For example:

   <A NAME="test" ID="test"> </A>



3) There must be at least a space between <A> </A> for IE5.5 to see the 

   anchor tag correctly. Do not do <A></A> with no space.

*/ 



// getAnchorPosition(anchorname)

//   This function returns an object having .x and .y properties which are the coordinates

//   of the named anchor, relative to the page.

function getAnchorPosition(anchorname) {

	// This function will return an Object with x and y properties

	var useWindow=false;

	var coordinates=new Object();

	var x=0,y=0;

	// Browser capability sniffing

	var use_gebi=false, use_css=false, use_layers=false;

	if (document.getElementById) { use_gebi=true; }

	else if (document.all) { use_css=true; }

	else if (document.layers) { use_layers=true; }

	// Logic to find position

 	if (use_gebi && document.all) {

		x=AnchorPosition_getPageOffsetLeft(document.all[anchorname]);

		y=AnchorPosition_getPageOffsetTop(document.all[anchorname]);

		}

	else if (use_gebi) {

		var o=document.getElementById(anchorname);

		x=AnchorPosition_getPageOffsetLeft(o);

		y=AnchorPosition_getPageOffsetTop(o);

		}

 	else if (use_css) {

		x=AnchorPosition_getPageOffsetLeft(document.all[anchorname]);

		y=AnchorPosition_getPageOffsetTop(document.all[anchorname]);

		}

	else if (use_layers) {

		var found=0;

		for (var i=0; i<document.anchors.length; i++) {

			if (document.anchors[i].name==anchorname) { found=1; break; }

			}

		if (found==0) {

			coordinates.x=0; coordinates.y=0; return coordinates;

			}

		x=document.anchors[i].x;

		y=document.anchors[i].y;

		}

	else {

		coordinates.x=0; coordinates.y=0; return coordinates;

		}

	coordinates.x=x;

	coordinates.y=y;

	return coordinates;

	}



// getAnchorWindowPosition(anchorname)

//   This function returns an object having .x and .y properties which are the coordinates

//   of the named anchor, relative to the window

function getAnchorWindowPosition(anchorname) {

	var coordinates=getAnchorPosition(anchorname);

	var x=0;

	var y=0;

	if (document.getElementById) {

		if (isNaN(window.screenX)) {

			x=coordinates.x-document.body.scrollLeft+window.screenLeft;

			y=coordinates.y-document.body.scrollTop+window.screenTop;

			}

		else {

			x=coordinates.x+window.screenX+(window.outerWidth-window.innerWidth)-window.pageXOffset;

			y=coordinates.y+window.screenY+(window.outerHeight-24-window.innerHeight)-window.pageYOffset;

			}

		}

	else if (document.all) {

		x=coordinates.x-document.body.scrollLeft+window.screenLeft;

		y=coordinates.y-document.body.scrollTop+window.screenTop;

		}

	else if (document.layers) {

		x=coordinates.x+window.screenX+(window.outerWidth-window.innerWidth)-window.pageXOffset;

		y=coordinates.y+window.screenY+(window.outerHeight-24-window.innerHeight)-window.pageYOffset;

		}

	coordinates.x=x;

	coordinates.y=y;

	return coordinates;

	}



// Functions for IE to get position of an object

function AnchorPosition_getPageOffsetLeft (el) {

	var ol=el.offsetLeft;

	while ((el=el.offsetParent) != null) { ol += el.offsetLeft; }

	return ol;

	}

function AnchorPosition_getWindowOffsetLeft (el) {

	return AnchorPosition_getPageOffsetLeft(el)-document.body.scrollLeft;

	}	

function AnchorPosition_getPageOffsetTop (el) {

	var ot=el.offsetTop;

	while((el=el.offsetParent) != null) { ot += el.offsetTop; }

	return ot;

	}

function AnchorPosition_getWindowOffsetTop (el) {

	return AnchorPosition_getPageOffsetTop(el)-document.body.scrollTop;

	}