// ========================================================
//              ===== images slider ====
// script: Gerard Ferrandez - Ge-1-doot - February 2008
// http://www.dhteumeuleu.com
// CC-BY-NC
// ========================================================

/* ==== slider nameSpace ==== */
var slider = function() {
   /* ==== private methods ==== */
   function getElementsByClass(object, tag, className) {
      var o = object.getElementsByTagName(tag);
      for ( var i = 0, n = o.length, ret = []; i < n; i++) {
         if (o[i].className == className) ret.push(o[i]);
      }
      if (ret.length == 1) ret = ret[0];
      return ret;
   }
   var slides = [];
   var S, S0, iW, iH, oP, oc, frm, NF, view, Z;
   var wh, ht, wr, r, mx, mn;
   /* ==== animation loop ==== */
   var run = function () {
      Z += (mn - Z) * .5;
      view.calc();
      var i = NF;
      while (i--) slides[i].move();
   }
   /* ==== resize  ==== */
   var resize = function () {
      wh = oc.clientWidth;
      ht = oc.clientHeight;
      wr = wh * iW;
      r  = ht / wr;
      mx = wh / NF;
      mn = (wh * (1 - iW)) / (NF - 1);
   }

   /* ==== Slide Constructor ==== */
   Slide = function (N) {
      this.N      = N;
      this.x0     = this.x1 = N * mx;
      this.v      = 0;
      this.loaded = false;
      this.cpt    = 0;
      this.start  = new Date();
      this.obj    = frm[N];
      this.txt    = getElementsByClass(this.obj, 'div', 'text');
      this.img    = getElementsByClass(this.obj, 'img', 'diapo');
      this.bkg    = document.createElement('div');
      this.bkg.className = 'backgroundText';
      this.obj.insertBefore(this.bkg, this.txt);
      if (N == 0) this.obj.style.borderLeft = 'none';
      this.obj.style.left = Math.floor(this.x0) + 'px';
      /* ==== mouse events ==== */
      this.obj.parent = this;
      this.obj.onmouseover = function() {
         this.parent.over();
         return false;
      }
   }
   /* ==== target positions ==== */
   Slide.prototype.calc = function () {
      for (var i = 0; i <= this.N; i++)
         slides[i].x1 = i * Z;
      for (var i = this.N + 1; i < NF; i++)
         slides[i].x1 = wh - (NF - i) * Z;
   }
   /* ==== HTML animation : move slides ==== */
   Slide.prototype.move = function() {
      var s = (this.x1 - this.x0) / S;
      /* ==== lateral slide ==== */
      if (this.N && Math.abs(s) > .5)
         this.obj.style.left = Math.floor(this.x0 += s) + 'px';
      /* ==== vertical text ==== */
      var v = (this.N < NF - 1) ? slides[this.N + 1].x0 - this.x0 : wh - this.x0;
      if (Math.abs(v - this.v) > .5) {
         this.bkg.style.top = this.txt.style.top = Math.floor(2 + ht - (v - Z) * iH * r) + 'px';
         this.v = v;
         this.cpt++;
      } else {
         if (!this.pro) {
            /* ==== adjust speed ==== */
            this.pro = true;
            var tps = new Date() - this.start;
            if(this.cpt > 1) {
               S = Math.max(2, (28 / (tps / this.cpt)) * S0);
            }
         }
      }
      if (!this.loaded) {
         if (this.img.complete) {
            this.img.style.visibility = 'visible';
            this.loaded = true;
         }
      }
   }
   /* ==== over ==== */
   Slide.prototype.over = function () {
      resize();
      view = this;
      this.start = new Date();
      this.cpt = 0;
      this.pro = false;
      this.calc();
   }
   /* ==== start script ==== */
   var init = function (oCont, speed, iw, ih, op) {
      S   = S0 = speed;
      iW  = iw;
      iH  = ih;
      oP  = op;
      oc  = document.getElementById(oCont);
      frm = getElementsByClass(oc, 'div', 'slide');
      NF  = frm.length;
      resize();
      for (var i = 0; i < NF; i++)
         slides[i] = new Slide(i);
      view = slides[0];
      Z = mx;
      setInterval(run, 32);
   }
   /* ==== public methods ==== */
   return {
      init : init
   }
}();