function largeur_fenetre(){
 if (window.innerWidth) return window.innerWidth;
 else if (document.body && document.body.offsetWidth) return document.body.offsetWidth;
 else return 0;
}

function hauteur_fenetre(){
 if (window.innerHeight) return window.innerHeight ;
 else if (document.body && document.body.offsetHeight) return document.body.offsetHeight;
 else return 0;
}

function chgImg(){
 var grandeimg = document.getElementById('grandeimg');
 grandeimg.src = this.src.replace(new RegExp("/petits/", "g"),"/grands/");
 document.getElementById('diapo').style.visibility = "visible";
 document.getElementById('titrePiece').style.visibility = "hidden";
 document.getElementById('nav').style.visibility = "hidden";
 document.getElementById('titreExpo').style.visibility = "hidden";
 document.getElementById('cadre').style.visibility = "hidden";
}

function supImg(){
 document.getElementById('diapo').style.visibility = "hidden"
 document.getElementById('cadre').style.visibility = "visible";
 document.getElementById('titrePiece').style.visibility = "visible";
 document.getElementById('nav').style.visibility = "visible";
 document.getElementById('titreExpo').style.visibility = "visible";
 document.getElementById('cadre').style.visibility = "visible";
}

function chgFd(){
 var srcFd = this.src.replace(new RegExp("/petits/", "g"),"/grands/");
 var fondExpo = document.getElementById('fondExpo');
 fondExpo.style.backgroundPosition = "center " + backgroundOffset;
 fondExpo.style.backgroundImage="url("+srcFd+")";
 fondExpo.style.backgroundRepeat = "no-repeat";
 chgTitrePiece(this.titrePiece);
 if(ScrollTimer) clearInterval(ScrollTimer);
 ScrollTimer = window.setInterval("scrollBG(2000)", 64);
}

function supFd(){
 if(document.getElementById("cadre").style.visibility=="hidden") return;
 document.getElementById("fondExpo").style.backgroundImage="";
 supTitrePiece();
 if(ScrollTimer) clearInterval(ScrollTimer);
}

function scrollBG(maxSize) {
 if (-backgroundOffset > maxSize - hauteur_fenetre()) {
  clearInterval(ScrollTimer);
  backgroundOffset = 0;
  return;
 }
 backgroundOffset = backgroundOffset - 1;
 document.getElementById("fondExpo").style.backgroundPosition = "center " + backgroundOffset;
}

function chgTitrePiece(titrePiece){
 document.getElementById("titrePiece").innerHTML = titrePiece;
}

function supTitrePiece(){
 document.getElementById("titrePiece").innerHTML = " ";
}

function rollOver(){ this.src = this.src.replace(new RegExp("_f1.gif", "g"),"_f2.gif");}
function rollOut(){ this.src = this.src.replace(new RegExp("_f2.gif", "g"),"_f1.gif");}

function expoPrec(){
 if (eval(numExpo) == 1){
  message("Première exposition !");
  return;
 }
 chargeExpo(-1);
}

function expoSuiv(){
 if (eval(numExpo) == nbExpo){
  message("Dernière exposition !");
  return;
 }
 chargeExpo(1);
 }
 
 function chargeExpo(delta){
 var oldNumExpo = numExpo;
 numExpo = (eval(numExpo) + delta)<10? "0" + (eval(numExpo)+delta) : eval(numExpo)+delta;
 document.getElementById('numExpo').innerHTML = eval(numExpo) +"/"+ eval(nbExpo);
 
 var xhr=null;
 if (window.XMLHttpRequest){xhr=new XMLHttpRequest();}
 else if (window.ActiveXObject){xhr=new ActiveXObject("Microsoft.XMLHTTP");} 
 //on appelle le fichier details.txt
 xhr.open("GET", "images/expo"+numExpo+"/details.xml", false);
 xhr.send(null);

 var docXML= xhr.responseXML;
 document.getElementById('titreExpo').innerHTML = docXML.getElementsByTagName("titre").item(i).firstChild.data;

 var items = docXML.getElementsByTagName("img");
 var imgs = document.getElementById('cadre').getElementsByTagName('img');
 for (var i=0;i<imgs.length;i++) {
  //imgs[i].src = imgs[i].src.replace(new RegExp("/expo"+oldNumExpo+"/", "g"),"/expo"+numExpo+"/");
  imgs[i].src = "images/expo"+numExpo+"/petits/"+items.item(i).attributes.getNamedItem("src").nodeValue;
  imgs[i].titrePiece = items.item(i).attributes.getNamedItem("title").nodeValue;
 }
}

function message(msg){
 var message = document.getElementById("message");
 message.innerHTML = msg;
 message.style.visibility = "visible";
 setTimeout("supMessage()", 3000);
}

function supMessage(){
 document.getElementById("message").style.visibility = "hidden";
}

function MM_reloadPage(init) {
 //reloads the window if Nav4 resized
 if (init==true) with (navigator) {
  if ((appName=="Netscape")&&(parseInt(appVersion)==4)) {
   document.MM_pgW=innerWidth; document.MM_pgH=innerHeight; onresize=MM_reloadPage; }
 }
 else if (innerWidth!=document.MM_pgW || innerHeight!=document.MM_pgH) location.reload();
}

function initMouseOversClicks() {
 document.getElementById('grandeimg').onclick = supImg;
 document.getElementById('expoprec').onclick = expoPrec;
 document.getElementById('exposuiv').onclick = expoSuiv;
 var imgs = document.getElementById('cadre').getElementsByTagName('img');
 for (var i=0;i<imgs.length;i++) {
  imgs[i].onmouseover = chgFd;
  imgs[i].onmouseout = supFd
  imgs[i].onclick = chgImg;
  imgs[i].titrePiece = imgs[i].title;
  imgs[i].title = "Cliquez pour afficher.";
 }
 document.getElementById('grandeimg').title = "Cliquez pour refermer.";
 document.getElementById("expoprec").onmouseover = rollOver;
 document.getElementById("exposuiv").onmouseover = rollOver;
 document.getElementById("expoprec").onmouseout = rollOut;
 document.getElementById("exposuiv").onmouseout = rollOut;
}

function addLoadEvent(func){
 var oldonload = window.onload;
 if(typeof window.onload != 'function'){window.onload = func;}
 else{window.onload = function(){oldonload();func();}}
}

var ScrollTimer;
var backgroundOffset = -100;
var numExpo = "01";
var nbExpo = "01";
addLoadEvent(function () {
//MM_reloadPage(true);
initMouseOversClicks();
});