var pauzaMeziProlinanim = 3000;
var iProlinani = 15;
var opacityKrok = 0.05;
var pObr = 4;
var aLay = 1;
var aOpacity = 0;
var aObr = 1;
var timer = 0;
var i; 

function zmenOpacity ( hodnota ) {
  document.getElementById("obraz2").style.opacity = hodnota;
  document.getElementById("obraz2").style.filter = 'alpha(opacity=' + (hodnota * 100)  +')'; /* For IE8 and earlier */
}

function cyklujObrazky () {
  if ( aObr >= pObr)
    aObr = 1;
  else
    aObr++;

  var p = "url(/img/design/ram/obraz" + aObr + ".jpeg)";

  // vidime spodni vrstvu .. potaji menime horni zneviditelnenou localhost/superzahrady.cz/web/images/design/obraz" + aObr + ".jpeg)";
  if ( aLay == 1 )
    document.getElementById('obraz2').style.backgroundImage = p;
  else 
    document.getElementById('obraz1').style.backgroundImage = p;
}

function prolni () {
  timer = 0;

  // dosavad byla videt prvni, spodni vrstva -> horni vtrstvu zvitelnujeme -> aOpacity zvysujem  
  if ( aLay == 1 ) {
    for ( i = 0; i < 1; i += opacityKrok ) {
      setTimeout("zmenOpacity(" + i + ")", iProlinani * timer);
      timer++;
    }
    setTimeout("zmenOpacity(1)", iProlinani * timer);
    aLay = 2;
  } 
  // dosavad byla videt druha, vrchni vvrstva -> horni vrstvu zneviditelnujeme -> aOpacity snizujeme 
  else if ( aLay == 2 ) {
    for ( i = 1; i > 0; i -= opacityKrok ){
      setTimeout("zmenOpacity(" + i + ")", iProlinani * timer);
      timer++;
    }
    setTimeout("zmenOpacity(0)", iProlinani * timer);
    aLay = 1;
  }

  setTimeout("cyklujObrazky()", iProlinani * timer);
  setTimeout("prolni()", iProlinani * timer + pauzaMeziProlinanim);
}

function initProlinani () {
  document.getElementById('header').innerHTML = '<div><div id="obraz1"></div><div id="obraz2"></div><div id="ram"></div></div>';
  setTimeout("prolni()", pauzaMeziProlinanim);
}

function getBrowserWidth()
{
    if (window.innerWidth)
    {
        return window.innerWidth;
    }
    else if (document.documentElement && document.documentElement.clientWidth != 0)
    {
        return document.documentElement.clientWidth;
    }
    else if (document.body)
    {
        return document.body.clientWidth;
    }

    return 0;
};

function positionFollowers(e)
{
  if(getBrowserWidth()<=800) /* hodnota 800 koresponduje s CSS pri zmensovani okna, navigace se umisti pevne nahoru */
  {
    $('#nav').removeClass('fixed');
    $('#nav').css('margin-top', '0px');
    return;
  }

  MaxMarginTopNav = $('#maintext').height() - $('#nav').height() - 146 + 55;
  if(MaxMarginTopNav<0)
    MaxMarginTopNav = 0;
  insetTop = $('#header').offset().top - parseInt($('#header').css("marginTop"), 10);
  scrollerVisualTop = insetTop + $('#header').outerHeight(true) - 55;
  mainVisualTop = $('#maintext').offset().top;
  scrollerCssTop = scrollerVisualTop - mainVisualTop;
  scrollerVisualBottom = $('#maintext').offset().top + $('#maintext').height() - $('#nav').height() - 146;
  $('#maintext').css('max-height', $('#maintext').css('height'));
  // document.title = $(window).scrollTop() + ' ' + scrollerVisualTop + ' ' + scrollerVisualBottom + ' ' + MaxMarginTopNav;

  /* Fix to Bottom */
  if ($(window).scrollTop() > scrollerVisualBottom)
  {
    $('#nav').removeClass('fixed');
    $('#nav').css('margin-top', MaxMarginTopNav+'px');
    $('#nav').css('margin-bottom', 0+'px');
  }

  /* Scroll with Page */
  else if ($(window).scrollTop() > scrollerVisualTop)
  {
    $('#nav').addClass('fixed');
    $('#nav').css('margin-top', '0px');
  }

  /* Fix to Top */
  else
  {
    $('#nav').removeClass('fixed');
    $('#nav').css('margin-top', '0px');
  }
}

$(window).resize(positionFollowers);
$(window).scroll(positionFollowers);
$(window).load(positionFollowers);