//
//---popover.js     DHTML "pop overs".  Simulate a pop-up "window" on 
//                  mouseover or other event.
//   Purpose:
//      Provide the mechanism and functions for doing DHTML style
//      "pop over" little windows on "mouse over" of a link or other
//      event, without actually opening a new window.
//
//   Usage example:
//      <a href="..." onMouseOver="popOver('divId', true);" 
//                     onMouseOut="popOver('divId', false);">link text</a>
//      ...
//      <div id="divId" style="POSITION: absolute; visibility: hidden">
//         (pop-up text here)
//      </div>
//
//      Causes div 'divId' to pop (or "float") over the link text when the
//      user mouses-over the link, and to disappear again when the user
//      moves the mouse away.
//
//      The full calling sequence for popOver is actually:
//         popOver (divid, updown, [x, [y]]);
//
//      where x and y can optionally be used to set the location of the pop-up.
//      X and Y are specified as "R" (relative) or "A" (absolute), followed 
//      by a number. 
//
//      E.g. if x is "R32", the top-left corner of the pop-up appears 32
//      pixels to the right of the mouse position.  "R-10" means 10 pixels
//      to the left. "A100" means 100 pixels from the window left border,
//      and so on.  If A or R is not specified, assumes R.
//
//      Known to work with: IE 5.2+, Netscape 6+, Mozilla 1.3+, Safari.
//
//   Copyright (C) 2004 CaucusCare.com, permission granted to anyone to
//   use for any purpose, so long as the copyright notice is retained.
//
//   Version history.  
//:CR 12/07/04 New file, based very loosely on John Faucher's wizard script.
//:CR 12/22/04 Add "A" and "R" prefixes to x and y optional args 
//:CR 01/07/05 Finish "A" and "R" features.
//--------------------------------------------------------------------------

//---Netscape/Mozilla needs explicit mouse capture.
if (! document.all) document.captureEvents(Event.MOUSEMOVE)

//---Set-up to use popOverMouse function onMouseMove
document.onmousemove = popOverMouse;

var popOverY;
var popOverX;

function popOver (what, up) {  //---with optional args xoffset, yoffset
   xnum = 0;   xabs = false;
   ynum = 0;   yabs = false;
   if (arguments.length >= 3) {
      x  = arguments[2] + "";
      x  = x.toLowerCase();
      x0 = x.substring(0,1);
      if      (x0 == "a")  { xabs = true;   xnum = x.substring(1,100) - 0; }
      else if (x0 == "r")                   xnum = x.substring(1,100) - 0;
      else                                  xnum = x - 0;
   }
   if (arguments.length >= 4) {
      y  = arguments[3] + "";
      y  = y.toLowerCase();
      y0 = y.substring(0,1);
      if      (y0 == "a")  { yabs = true;   ynum = y.substring(1,100) - 0; }
      else if (y0 == "r")                   ynum = y.substring(1,100) - 0;
      else                                  ynum = y - 0;
   }

   obj     = document.getElementById(what);
   if (obj == null) { confirm ("Error: no div named " + what);   return false; }

   if (up) {
      //---Netscape 6, Mozilla, etc.
      if (document.getElementById && !document.all) {
         xmouse = popOverX;
         ymouse = popOverY;
      }

      //---IE
      if (document.all) {
         xmouse = event.clientX + document.body.scrollLeft;
         ymouse = event.clientY + document.body.scrollTop;
      }

      obj.style.left       = Math.max (0, xnum + (xabs ? 0 : xmouse));
      obj.style.top        = Math.max (0, ynum + (yabs ? 0 : ymouse));
      obj.style.visibility = 'visible';
   }

   else obj.style.visibility='hidden';

   return false;   //---in case we're called from onClick.
}

//---Retrieve mouse x-y positions.
function popOverMouse(e) {
   //---Explicitly grab xy pos for Netscape/Mozilla.
   if (! document.all) {
      popOverX = e.pageX;
      popOverY = e.pageY;
   }
   return true;
}