//////////////////////////////
// OVERLAY

// overlay_getpagesize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function overlay_getpagesize(){
    
    var xScroll, yScroll;
    
    if (window.innerHeight && window.scrollMaxY) {    
        xScroll = document.body.scrollWidth;
        yScroll = window.innerHeight + window.scrollMaxY;
    } else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
        xScroll = document.body.scrollWidth;
        yScroll = document.body.scrollHeight;
    } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
        xScroll = document.body.offsetWidth;
        yScroll = document.body.offsetHeight;
    }
    
    var windowWidth, windowHeight;
    if (self.innerHeight) {    // all except Explorer
        windowWidth = self.innerWidth;
        windowHeight = self.innerHeight;
    } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
        windowWidth = document.documentElement.clientWidth;
        windowHeight = document.documentElement.clientHeight;
    } else if (document.body) { // other Explorers
        windowWidth = document.body.clientWidth;
        windowHeight = document.body.clientHeight;
    }    
    
    // for small pages with total height less then height of the viewport
    if(yScroll < windowHeight){
        pageHeight = windowHeight;
    } else { 
        pageHeight = yScroll;
    }

    // for small pages with total width less then width of the viewport
    if(xScroll < windowWidth){    
        pageWidth = windowWidth;
    } else {
        pageWidth = xScroll;
    }

    arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
    return arrayPageSize;
}

function overlay_init()
{
   var objBody = document.getElementsByTagName("body").item(0);
   
   var objOverlay = document.createElement("div");
   objOverlay.setAttribute('id','overlay');
   objOverlay.onclick = overlay_off;
   objBody.appendChild(objOverlay);
   
   overlayEffect = new fx.Opacity(objOverlay, { duration: 300 });    
   overlayEffect.hide();        
}

function overlay_on()
{
   // stretch overlay to fill page and fade in
   var arrayPageSize = overlay_getpagesize();
   
   var objOverlay = $('overlay');
   objOverlay.style.height = arrayPageSize[1] + "px";
   overlayEffect.custom(0,0.8);
   
   
   // calculate top offset for the lightbox and display 
   //var arrayPageSize = overlay_getpagesize();
   //var arrayPageScroll = getPageScroll();
   //var lightboxTop = arrayPageScroll[1] + (arrayPageSize[3] / 15);
   
   //Element.setTop('lightbox', lightboxTop);
   //Element.show('lightbox');
   //this.changeImage(imageNum);
}

function overlay_off()
{
   overlayEffect.custom(0.8,0);
}

// -----------------------------------------------------------------------------------
//
//    Additional methods for Element added by SU, Couloir
//    - further additions by Lokesh Dhakar (huddletogether.com)
//
Object.extend(Element, {
    hide: function() {
        for (var i = 0; i < arguments.length; i++) {
            var element = $(arguments[i]);
            element.style.display = 'none';
        }
    },
    show: function() {
        for (var i = 0; i < arguments.length; i++) {
            var element = $(arguments[i]);
            element.style.display = '';
        }
    },
    getWidth: function(element) {
           element = $(element);
           return element.offsetWidth; 
    },
    setWidth: function(element,w) {
           element = $(element);
        element.style.width = w +"px";
    },
    getHeight: function(element) {
        element = $(element);
        return element.offsetHeight;
    },
    setHeight: function(element,h) {
           element = $(element);
        element.style.height = h +"px";
    },
    setTop: function(element,t) {
           element = $(element);
        element.style.top = t +"px";
    },
    setSrc: function(element,src) {
        element = $(element);
        element.src = src; 
    },
    setInnerHTML: function(element,content) {
        element = $(element);
        element.innerHTML = content;
    }
});