var vitesse_move = 0.2;
var vitesse_opacity = 0.2;
var opacity_value = 0.5;


function init_carousel()
{
  Event.observe(window, "load", function(){ updateButtons(); Effect.Appear('list_img', { duration: 3.0 }); } ); 

  $('bt_previous').observe("mouseover", function() {
              $('bt_previous').addClassName('previous_button_over');
  });
  $('bt_previous').observe("mouseout", function() {
              $('bt_previous').removeClassName('previous_button_over');
  });
  $('bt_next').observe("mouseover", function() {
              $('bt_next').addClassName('next_button_over');
  });
  $('bt_next').observe("mouseout", function() {
              $('bt_next').removeClassName('next_button_over');
  });   
}

function updateButtons()
{  
  if ( $('list_img').positionedOffset()[0] == 0 )
  {
    $('bt_previous').addClassName('previous_button_disabled');   
  }
  else
  {
      
    if ( $('bt_previous').hasClassName('previous_button_disabled') )
    {
      $('bt_previous').removeClassName('previous_button_disabled');   
    }
  }

  width = $('list_img').positionedOffset()[0]-($('list_img').positionedOffset()[0]*2)+900;
  //$('debug').update(width + ' == ' + max_width);\\
  if ( width == max_width )
  {
    $('bt_next').addClassName('next_button_disabled');   
  }
  else
  {
    if ( $('bt_next').hasClassName('next_button_disabled') )
    {
      $('bt_next').removeClassName('next_button_disabled');   
    }
  }

  Event.observe("bt_previous","click", update_list_negatif );
  Event.observe("bt_next","click",  update_list_positif );
}

function disableButtons()
{
  
  Event.stopObserving("bt_previous","click", update_list_negatif );
  Event.stopObserving("bt_next","click", update_list_positif );
}


function update_list_negatif()
{
  if ( !$('bt_previous').hasClassName('previous_button_disabled') )
  {
    disableButtons();
    $('list_img').morph("opacity:" + opacity_value, {duration: vitesse_opacity });
    
    new Effect.Move($('list_img'), { x: 900, y: 0, mode: 'relative', afterFinish: function(){ $('list_img').morph("opacity:1", {duration: vitesse_move }); updateButtons(); } })
    
  }
}

function update_list_positif()
{
  if ( !$('bt_next').hasClassName('next_button_disabled')  )
  {
      
      disableButtons();
      new Ajax.Updater('', 'get_theme.php',
        { method: 'post', 
          frequency: 5,     
          //parameters: { force:'1',  webdemo_front_id: <?php echo $_SESSION['webdemo_front_id']?> },
          
          
          onSuccess:function(request, json)
          {
              $('list_img').morph("opacity:" + opacity_value, {duration: vitesse_opacity });

              new Insertion.Bottom('list_img', request.responseText, 
                    { afterFinish:
                          new Effect.Move($('list_img'), { x: -900, y: 0, mode: 'relative', afterFinish: function(){ $('list_img').morph("opacity:1", {duration: vitesse_move }); updateButtons();  } })
                    })
            
            
            
          }          
        });
  }
}