Opacity.js

//---------------------------------------------------------------
// Opacity Displayer, Version 1.0
// Copyright Michael Lovitt, 6/2002.
// Distribute freely, but please leave this notice intact.
//---------------------------------------------------------------

//---------------------------------------------------------------
// OPACITY OBJECT
//
// Instantiates the object, defines the properties and methods.

function OpacityObject(div, strPath) {
 this.layerObject = div;
 this.path = strPath;
/* if (ns){
  if (browserVersion>=5) {
   this.layerObject = document.getElementById(divId).style;
  } else {
   this.layerObject = eval("document."+divId);
  }
 } else {
  this.layerObject = eval(divId + ".style");
 }/**/
 this.setBackground = od_object_setBackground;
}
// Uses AlphaImageLoader filter, or the css background property,
// as appropriate, to apply a PNG or GIF as the background of the layerObject.
function od_object_setBackground() {
 if (pngAlpha) {
  this.layerObject.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+this.path+".png', sizingMethod='scale')";
 } else if (pngNormal) {
  if (browser.isMac && browser.isIE5up ) this.layerObject.backgroundColor = '#999999';
  else this.layerObject.backgroundImage = 'url('+this.path+'.png)';
 } else {
  this.layerObject.backgroundImage = 'url('+this.path+'.gif)';
 }
}
//---------------------------------------------------------------

//---------------------------------------------------------------
// OPACITY DISPLAY FUNCTION
// Outputs the image as a div with the AlphaImageLoader, or with
// a standard image tag.
function od_displayImage(strId, strPath, intWidth, intHeight, strClass, strAlt) {
 if (pngAlpha) {
  document.write('<div style="height:'+intHeight+'px;width:'+intWidth+'px;filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src=/''+strPath+'.png/', sizingMethod=/'scale/')" id="'+strId+'" class="'+strClass+'"></div>');
 } else if (pngNormal) {
  document.write('<img src="students/%27%2BstrPath%2B%27.png" width="'+intWidth+'" height="'+intHeight+'" name="'+strId+'" border="0" class="'+strClass+'" alt="'+strAlt+'" />');
 } else {
  document.write('<img src="students/%27%2BstrPath%2B%27.gif" width="'+intWidth+'" height="'+intHeight+'" name="'+strId+'" border="0" class="'+strClass+'" alt="'+strAlt+'" />');
 }
}
//---------------------------------------------------------------

//---------------------------------------------------------------
// OPACITY ROLL-OVER FUNCTIONS
function od_rollOver(strId, strColor) {
 if (pngAlpha) {
  document.getElementById(strId).style.backgroundColor = strColor;
 } else {
     if (document.images && (flag == true)) {
         document[strId].src = eval(strId + "on.src");
     }
 }
}
function od_rollOut(strId, strColor) {
 if (pngAlpha) {
  document.getElementById(strId).style.backgroundColor = strColor;
 } else {
     if (document.images) {
         document[strId].src = eval(strId + "off.src");
     }
 }
}
//---------------------------------------------------------------

//---------------------------------------------------------------
// global variables

// if IE5.5+ on win32, then display PNGs with AlphaImageLoader
if ((browser.isIE55 || browser.isIE6up) && browser.isWin32) {
 var pngAlpha = true;
 var strExt = ".png";
// else, if the browser can display PNGs normally, then do that. that list includes:
 //     -Gecko Engine: Netscape 6 or Mozilla, Mac or PC
 //     -IE5+ Mac (OpacityObject applies the background image at 100% opacity)
 //     -Opera 6+ PC
 //     -Opera 5+ Mac (Doesn't support dynamically-set background images)
 //     -Opera 6+ Linux
 //     -Omniweb 3.1+
 //     -Icab 1.9+
 //     -WebTV
 //     -Sega Dreamcast
} else if ((browser.isGecko) || (browser.isIE5up && browser.isMac) || (browser.isOpera && browser.isWin && browser.versionMajor >= 6) || (browser.isOpera && browser.isUnix && browser.versionMajor >= 6) || (browser.isOpera && browser.isMac && browser.versionMajor >= 5) || (browser.isOmniweb && browser.versionMinor >= 3.1) || (browser.isIcab && browser.versionMinor >= 1.9) || (browser.isWebtv) || (browser.isDreamcast)) {
 var pngNormal = true;
 var strExt = ".png";
 // otherwise, we use plain old GIFs
} else {
 var strExt = ".gif";
}

var ns = (document.all)?false:true;
var browserVersion = parseFloat(navigator.appVersion );
//---------------------------------------------------------------