/** Swinburne University of Technology Website: js functions javascript
 *  javascript file including functions destined to the 
 *  implementation of visual effects in the website
 *
 *  MODIFIED:
 *  version 1.0, 12 July 2004.
 * @version 1.1, 28 July 2004.
 * @version 1.2, 27 October 2004. added text size and cookie functions
 * @version 1.3, 6 January 2005. added domain parameter for the text size and cookie functions
 * @version 2.0, 8 January 2007. updated resize text.
 * @author Caroline Rojas crojas@swin.edu.au
 */

/**
 *  Preloads rollover images so they are ready to the rollover effect
 */
 
function function_preloadImages() { 
  var d=document; if(d.images){ if(!d.function_p) d.function_p=new Array();
    var i,j=d.function_p.length,a=function_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.function_p[j]=new Image; d.function_p[j++].src=a[i];}}
}

/**
 *  Restores original images after the rollover effect
 */

function function_swapImgRestore() { 
  var i,x,a=document.function_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function function_findObj(n, d) { 
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=function_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

/**
 *  Swaps the image when the mouse is over the image doing a rollover effect
 */

function function_swapImage() { 
  var i,j=0,x,a=function_swapImage.arguments; document.function_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=function_findObj(a[i]))!=null){document.function_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}


//Specify spectrum of different font sizes:
//var swin_szs = new Array( 'xx-small','x-small','small','medium','large','x-large','xx-large' );
var swin_szs = new Array( '0.98em','0.99em','1.04em','1.06em' );
var swin_tgs = new Array( 'tr','p','td','div','h1','span','h2','a', 'font');

//Gets textSize cookie value
function getSwinCookie(name) {
    var swin_dc = document.cookie;
    var swin_prefix = name + "=";
    var swin_begin = swin_dc.indexOf("; " + swin_prefix);
    if (swin_begin == -1) {
        swin_begin = swin_dc.indexOf(swin_prefix);
        if (swin_begin != 0) return null;
    } else {
        swin_begin += 2;
    }
    var swin_end = document.cookie.indexOf(";", swin_begin);
    if (swin_end == -1) {
        swin_end = swin_dc.length;
    }
    return unescape(swin_dc.substring(swin_begin + swin_prefix.length, swin_end));
}

//Updates the font size according to cookie value
function setSwinFontSize(){
	var swin_textSize = getSwinCookie("swinTextSize");
	if(swin_textSize==null || swin_textSize=="" || isNaN(swin_textSize))
	{

	}
	else {
		for (i=0; i<swin_tgs.length; i++) {
			var swintgs = swin_tgs[i];
			var swinFontSize=document.getElementsByTagName(swintgs);
			for(var j=0;j<swinFontSize.length;j++)
			{
				swinFontSize[j].style.fontSize = swin_szs[swin_textSize];
			}
		}
	}		
}

//create cookies
function swinCreateCookie(swincookie_name,swincookie_value,swincookie_days,swincookie_domain) {
  if (swincookie_days) {
    var swincookie_date = new Date();
    swincookie_date.setTime(swincookie_date.getTime()+(swincookie_days*24*60*60*1000));
    var swincookie_expires = "; expires="+swincookie_date.toGMTString();	
  }
  else swincookie_expires = "";
  if (swincookie_domain) {
	var theDomain = "; domain="+swincookie_domain;
  }
  else swincookie_domain = "";  
  document.cookie = swincookie_name+"="+swincookie_value+swincookie_expires+"; path=/";
}

//Smaller Font
function swinResizeSmall()
{
	var swin_textSize = getSwinCookie("swinTextSize");
	if(swin_textSize==null || swin_textSize=="" || isNaN(swin_textSize))
	{
		if(navigator.appName == 'Netscape'){
			textsize = 1; 
		} else {
			textsize = 0; 
		}
		swin_textSize = textsize;		
		//swin_textSize -= 1;
			
		swinCreateCookie("swinTextSize",swin_textSize,0);

		for (i=0; i<swin_tgs.length; i++) {
			var swintgs = swin_tgs[i];
			var swinFontSize=document.getElementsByTagName(swintgs);

			for(var j=0;j<swinFontSize.length;j++)
			{
				swinFontSize[j].style.fontSize = swin_szs[swin_textSize];
			}
		}

	}
	else {
			
		if (swin_textSize > 0) {
		
			swin_textSize -= 1; 
				
			swinCreateCookie("swinTextSize",swin_textSize,0);
							
			for (i=0; i<swin_tgs.length; i++) {
				var swintgs = swin_tgs[i];
				var swinFontSize=document.getElementsByTagName(swintgs);
				for(var j=0;j<swinFontSize.length;j++)
				{
					swinFontSize[j].style.fontSize = swin_szs[swin_textSize];
				}
			}
		}
	}
}

//Larger Font
function swinResizeLarge()
{
	var swin_textSize = getSwinCookie("swinTextSize");
		if(swin_textSize==null || swin_textSize=="" || isNaN(swin_textSize))
		{
			if(navigator.appName == 'Netscape'){
				textsize = 2; 
			} else {
				textsize = 1; 
			}
			swin_textSize = textsize;
			swin_textSize = swin_textSize+1 
			swinCreateCookie("swinTextSize",swin_textSize,0);
		

			for (i=0; i<swin_tgs.length; i++) {
				var swintgs = swin_tgs[i];
				var swinFontSize=document.getElementsByTagName(swintgs);
				for(var j=0;j<swinFontSize.length;j++)

				{
					swinFontSize[j].style.fontSize = swin_szs[swin_textSize];
				}
			}
		}
		else {
			swin_textSize *= 1;	

			if (swin_textSize >= 0 && swin_textSize < 6) {	
				swin_textSize += 1 		
				swinCreateCookie("swinTextSize",swin_textSize,0);		

				for (i=0; i<swin_tgs.length; i++) {
					var swintgs = swin_tgs[i];		
					var swinFontSize=document.getElementsByTagName(swintgs);
			
					for(var j=0;j<swinFontSize.length;j++)
					{
						swinFontSize[j].style.fontSize = swin_szs[swin_textSize];
					}
				}
			}
		}
}

//Create Resize Cookie
function createSwinFontSize(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
	setSwinFontSize();
}

//Remove Resize Cookie
function removeSwinFontSize(name) {
	createSwinFontSize(name,"",-1);
	self.location = window.location.href;
}

window.onload = function(e) {
setSwinFontSize();
}