/*
 Flyout Code

 Alex Fahey - 0419 47 9898
 
*/

var adjustTop = 0;                   // Set if flyout top not aligned
var adjustLeft = 0;                  // Set if flyout not aligned on right side of menu bar
var flyoutMenu = null;               // Selected menu reference
var highlighted = null;              // The top level menu item selected
var offsetX = 0;                     // Flyout left offset
var offsetY = 0;                     // Flyout top offset
var timeout = null;                  // Reference to timeout event

/*
Calculators the X and Y coordination offsets for the flyout 
from the root of the document xml tree.
*/
function calculateOffsets(obj)
{
  var tagObject = obj;
  
  offsetY = adjustTop; 
  offsetX = obj.offsetWidth;
  
  while (tagObject) // Calculate x,y offsets 
  {
    offsetY = offsetY + tagObject.offsetTop;
    offsetX = offsetX + tagObject.offsetLeft;
    tagObject = tagObject.offsetParent;
  }

  // Perform adjustments
  offsetY += adjustTop; 
  offsetX += adjustLeft;
}

/*
Cancels the current window timeout event
*/
function cancelTimeout()
{
  window.clearTimeout(timeout);
  timeout = null; // Remove reference
}

/*
Displays the flyout menu at the specified X and Y coordination
*/
function display(xPos, yPos, stayOpen)
{
//alert(xPos);
//alert(yPos);

  flyoutMenu.style.display = "block";
  flyoutMenu.style.visibility = "visible";

  //flyoutMenu.style.left = (xPos - 1000) + "px";
  flyoutMenu.style.left = "170px";
  flyoutMenu.style.top =  (yPos - 100) + "px";

  // turn highlight on  
  highLightOn();
}

/*
Hides the currently displayed flyout menu
*/
function hide()
{ 
  if((flyoutMenu != null) && (flyoutMenu != undefined))
  {
    flyoutMenu.style.display="none";
    flyoutMenu.style.visibility="hidden";

    // Reset offsets to zero
    flyoutMenu.style.left =  0 + "px";
    flyoutMenu.style.top = 0 + "px";

    // Reset references
    flyoutMeanu = null;

    // turn highlight off
    highLightOff();
  }
}
  
/*
Starts the display of flyout menu by determining the select menu
*/
function mouseOver(strGroup)
{
  if(!(typeof(strGroup) == "string")) // guard
  { 
    // The strGroup must be a string value of the id attribute of the menu group UL tag
    return; 
  }

  var stayOpen = false;
  var group = document.getElementById(strGroup) // Get the LI nav-group
  
  if((flyoutMenu != null) && (flyoutMenu.parentNode.id == group.id))
  {
    stayOpen = true;
    cancelTimeout();
  }
  else // Menu group selected
  {
    if((flyoutMenu != null) && (flyoutMenu != undefined))
    { 
      // A flyout menu currently open
      cancelTimeout();
      hide(); // Hide now
    }

    // Get the first unordered list in the nav-group DIV tag
    flyoutMenu = group.getElementsByTagName("ul")[0];

    // Calculate the x,y position from the menu_grop
    calculateOffsets(group);

    // Get the first A child tag of the DIV within the nav-group
    //highlighted = document.getElementById(strGroup);
    highlighted = group.getElementsByTagName("a")[0];
  }
  
  if((flyoutMenu != null) && (flyoutMenu != undefined))
  {
    display(offsetX, offsetY, stayOpen); // display the flyout
  }
}

/*
Closes the currently display flyout menu in a delayed time period
*/
function shut()
{
  if((flyoutMenu != null) && (flyoutMenu != undefined))
  {
    timeout = window.setTimeout("hide();", 400);
  }
}

function highLightOff()
{
  //Restore original colours
  //highlighted.style.backgroundColor = '#ff0000';
  highlighted.style.textDecorationUnderline = '';

}

function highLightOn()  
{
  // Set highlight colours
  //highlighted.style.backgroundColor = '#00ff00';
  highlighted.style.textDecorationUnderline = 'true';

}