$(document).ready(function() {
  preloadNavImages();
  initScreenshotLinks();
});


function preloadNavImages()
{
  active_clients     = new Image(81,12); active_clients.src = "/design/images/nav/our_clients_on.gif";
  active_work       = new Image(86,12); active_work.src = "/design/images/nav/the_work_on.gif";
  active_about       = new Image(86,12); active_about.src = "/design/images/nav/about_us_on.gif";
  active_services   = new Image(84,12); active_services.src = "/design/images/nav/services_on.gif";
  active_news        = new Image(97,12); active_news.src = "/design/images/nav/good_news_on.gif";
  active_getintouch = new Image(87,12); active_getintouch.src = "/design/images/nav/get_in_touch_on.gif";                    
}

/******************************************************************

project "pages"

******************************************************************/
var total_pages  = 1;
var current_page = 1;

function showDescription(num)
{
  $('#current_page').html($('#project_page_'+num).html());

  sIFR.replace(galaxie, {
    selector: "h1",
    css: {    
      '.sIFR-root': {'color': '#1e1918', 'letter-spacing': '-2'}
    }
  })
    
  // update nav links  
  $('.project_nav a').each(function(index) {
    $(this).removeClass("current");
  });
  $('#project_nav_'+num).addClass("current");

  current_page = num;
    
  // check arrow states
  if (current_page == total_pages) {
    $('#next_arrow').attr('src', '/design/images/arrow_forward_off.gif');    
  }
  else {
    $('#next_arrow').attr('src', '/design/images/arrow_forward_on.gif');        
  }

  if (current_page == 1) {
    $('#previous_arrow').attr('src', '/design/images/arrow_back_off.gif');            
  }
  else {
    $('#previous_arrow').attr('src', '/design/images/arrow_back_on.gif');                
  }
  
  // reset screenshot links
  initScreenshotLinks();
}

function showNextPage()
{
  if (current_page+1 <= total_pages) {
    showDescription(current_page+1);
  }  
}

function showPreviousPage()
{
  if (current_page-1 > 0) {
    showDescription(current_page-1);    
  }  
}

function initScreenshotLinks()
{
  $('a.screenshots').click(function() {
    scroll(0,0);
    showDescription(2);
    return false;    
  });
}

/******************************************************************

sidebar project elements

******************************************************************/

var num_projects_per_page   = 5;
var num_sidebar_projects     = 0;
var project_height          = 96;
var current_top_project      = 0;
var animation_speed          = 300;

function viewWork(url) 
{
  if (current_top_project > 0) {
    window.location = url + "?nav=" + current_top_project;
  }
  else {
    window.location = url;
  }
}

function initScrollPosition()
{
  var distance = project_height * (current_top_project) ;
  $('#portfolio_table').css('top', "-" + distance + "px");
}      

function currentBottomProject()
{
  return current_top_project + num_projects_per_page;
}

function checkNavArrows()
{
  if (canScrollUp()) {
    $('#portfolio_nav_up').css('background-position', '0 -30px');
  }
  else {  
    $('#portfolio_nav_up').css('background-position', '0 0');    
  }

  if (canScrollDown()) {
    $('#portfolio_nav_down').css('background-position', '0 -30px');    
  }
  else {
    $('#portfolio_nav_down').css('background-position', '0 0');    
  }
}  

function canScrollDown()
{
  return (current_top_project > 0);
}      

function canScrollUp()
{
  return (currentBottomProject() < num_sidebar_projects);
}      

function scrollDown()
{
  var distance = project_height * (current_top_project + 1);

  $("#portfolio_table").animate({ 
    left: 0,
    top: -distance
  }, animation_speed );

  current_top_project += 1;          
  checkNavArrows();          
}      

function scrollUp()
{
  var distance = project_height * (current_top_project - 1);

  $("#portfolio_table").animate({ 
    left: 0,
    top: -distance
  }, animation_speed );

  current_top_project -= 1;          
  checkNavArrows();
}