/**
 * ImageFlow 0.8
 *
 * This code is based on Michael L. Perrys Cover flow in Javascript.
 * For he wrote that "You can take this code and use it as your own" [1]
 * this is my attempt to improve some things. Feel free to use it! If
 * you have any questions on it leave me a message in my shoutbox [2].
 *
 * The reflection is generated server-sided by a slightly hacked  
 * version of Richard Daveys easyreflections [3] written in PHP.
 * 
 * The mouse wheel support is an implementation of Adomas Paltanavicius
 * JavaScript mouse wheel code [4].
 *
 * Thanks to Stephan Droste ImageFlow is now compatible with Safari 1.x.
 *
 *
 * [1] http://www.adventuresinsoftware.com/blog/?p=104#comment-1981
 * [2] http://shoutbox.finnrudolph.de/
 * [3] http://reflection.corephp.co.uk/v2.php
 * [4] http://adomas.org/javascript-mouse-wheel/
 */
 

/* Configuration variables */
var conf_reflection_p = 0.5;         // Sets the height of the reflection in % of the source image 
var conf_focus = 4;                  // Sets the numbers of images on each side of the focussed one
var conf_slider_width = 14;          // Sets the px width of the slider div
var conf_images_cursor = 'pointer';  // Sets the cursor type for all images default is 'default'
var conf_slider_cursor = 'default';  // Sets the slider cursor type: try "e-resize" default is 'default'
 
/* Id names used in the HTML */
var conf_imageflow = 'imageflow';    // Default is 'imageflow'
var conf_loading = 'loading';        // Default is 'loading'
var conf_images = 'images';          // Default is 'images'
var conf_captions = 'captions';      // Default is 'captions'
var conf_scrollbar = 'scrollbar';    // Default is 'scrollbar'
var conf_slider = 'slider';          // Default is 'slider'
 
/* Define global variables */
var caption_id = 0;
var new_caption_id = 0;
var current = 0;
var target = 0;
var mem_target = 0;
var timer = 0;
var array_images = new Array();
var new_slider_pos = 0;
var dragging = false;
var dragobject = null;
var dragx = 0;
var posx = 0;
var new_posx = 0;
var xstep = 150;

var logo = 0; 

function step()
{
 switch (target < current-1 || target > current+1) 
 {
  case true:
   moveTo(current + (target-current)/3);
   window.setTimeout(step, 50);
   timer = 1;
   break;
 
  default:
   timer = 0;
   break;
 }
}
 
function glideTo(x, new_caption_id)
{ 
 /* Animate gliding to new x position */
 target = x;
 mem_target = x;
 if (timer == 0)
 {
  window.setTimeout(step, 50);
  timer = 1;
 }
 
 /* Display new caption */
 caption_id = new_caption_id;
 caption = img_div.childNodes.item(array_images[caption_id]).getAttribute('alt');
 if (caption == '') caption = '&nbsp;';
 caption_div.innerHTML = caption;
 
 /* Set scrollbar slider to new position */
 if (dragging == false)
 {
  new_slider_pos = (scrollbar_width * (-(x*100/((max-1)*xstep))) / 100) - new_posx;
  slider_div.style.marginLeft = (new_slider_pos - conf_slider_width) + 'px';
 }
}
 

function moveTo(x)
{
 current = x;
 var zIndex = max;
 
 /* Main loop */
 for (var index = 0; index < max; index++)
 {
  
  var image = img_div.childNodes.item(array_images[index]);
  var current_image = index * -xstep;
 
  /* Don't display images that are not conf_focussed */
  if ((current_image+max_conf_focus) < mem_target || (current_image-max_conf_focus) > mem_target)
  {
   image.style.visibility = 'hidden';
   image.style.display = 'none';
  }
  else 
  {
   var z = Math.sqrt(10000 + x * x) + 100;
   var xs = x / z * size + size;
 
   /* Still hide images until they are processed, but set display style to block */
   image.style.display = 'block';
  
   /* Process new image height and image width */
   var new_img_h = (image.h / image.w * image.pc) / z * size;
   switch ( new_img_h > max_height )
   {
    case false:
     var new_img_w = image.pc / z * size;
     break;
 
    default:
     new_img_h = max_height;
     var new_img_w = image.w * new_img_h / image.h;
     break;
   }
   var new_img_top = (images_width * 0.34 - new_img_h) + images_top + ((new_img_h / (conf_reflection_p + 1)) * conf_reflection_p);
 
 
   /* Set new image properties */
   image.style.left = xs - (image.pc / 2) / z * size + images_left + 'px';
   image.style.height = new_img_h + 'px';
   image.style.width = new_img_w + 'px';
   image.style.top = new_img_top + 'px';
   image.style.visibility = 'visible';
 
   /* Set image layer through zIndex */
   switch ( x < 0 )
   {
    case true:
     zIndex++;
     break;
 
    default:
     zIndex = zIndex - 1;
     break;
   }
   
   /* Change zIndex and onclick function of the focussed image */
   switch ( image.i == caption_id )
   {
    case false:
     image.onclick = function() { glideTo(this.x_pos, this.i); }
     break;
 
    default:
     zIndex = zIndex + 1;
     image.onclick = function() { document.location = this.url; }
     break;
   }
   image.style.zIndex = zIndex;
  }
  x += xstep;
 }
 
}
 
/* Main function */
function refresh(onload)
{
 /* Cache document objects in global variables */
 imageflow_div = document.getElementById(conf_imageflow);
 img_div = document.getElementById(conf_images);
 scrollbar_div = document.getElementById(conf_scrollbar);
 slider_div = document.getElementById(conf_slider);
 caption_div = document.getElementById(conf_captions);
 
 /* Cache global variables, that only change on refresh */
 images_width = img_div.offsetWidth;
 images_top = imageflow_div.offsetTop;
 
 // Hack to raise the images up closer to the menu
images_top=120;
 
 images_left = imageflow_div.offsetLeft;
 max_conf_focus = conf_focus * xstep;
 size = images_width * 0.5;
 scrollbar_width = images_width * 0.6;
 conf_slider_width = conf_slider_width * 0.5;
 max_height = images_width * 0.51;
 
 /* Change imageflow div properties */
 imageflow_div.style.height = max_height + 'px';
 
 /* Change images div properties */
 img_div.style.height = images_width * 0.338 + 'px';
 
 /* Change captions div properties */
 caption_div.style.width = images_width + 'px';
 caption_div.style.marginTop = images_width * 0.03 + 'px';
 
 /* Change scrollbar div properties */
 scrollbar_div.style.marginTop = images_width * 0.02 + 'px';
 scrollbar_div.style.marginLeft = images_width * 0.2 + 'px';
 scrollbar_div.style.width = scrollbar_width + 'px';
 
 /* Set slider attributes */
 slider_div.onmousedown = function () { dragstart(this); };
 slider_div.style.cursor = conf_slider_cursor;
 
 /* Cache EVERYTHING! */
 max = img_div.childNodes.length;
 var i = 0;
 for (var index = 0; index < max; index++)
 { 
  var image = img_div.childNodes.item(index);
  if (image.nodeType == 1)
  {
   array_images[i] = index;
   
   /* Set image onclick by adding i and x_pos as attributes! */
   image.onclick = function() { glideTo(this.x_pos, this.i); }
   image.x_pos = (-i * xstep);
   image.i = i;
   
   /* Add width and height as attributes ONLY once onload */
   if(onload == true)
   {
    image.w = image.width;
    image.h = image.height;
   }
 
   /* Check source image format. Get image height minus reflection height! */
   switch ((image.w + 1) > (image.h / (conf_reflection_p + 1))) 
   {
    /* Landscape format */
    case true:
     image.pc = 118;
     break;
 
    /* Portrait and square format */
    default:
     image.pc = 100;
     break;
   }
 
   /* Set ondblclick event */
   image.url = image.getAttribute('longdesc');
   image.ondblclick = function() { document.location = this.url; }
 
   /* Set image cursor type */
   image.style.cursor = conf_images_cursor;
 
   i++;
  }
 }
 max = array_images.length;
 
 /* Display images in current order */
 moveTo(current);
 glideTo(current, caption_id);
 
}
 
/* Show/hide element functions */
function show(id)
{
 var element = document.getElementById(id);
 element.style.visibility = 'visible';
}
function hide(id)
{
 var element = document.getElementById(id);
 element.style.visibility = 'hidden';
 element.style.display = 'none';
}

/* 
// Hide loading bar, show content and initialize mouse event listening after loading 
function loadImageFlow()
{
 if(document.getElementById(conf_imageflow))
 {
  hide(conf_loading);
  // hide intro hack
  
  hide("introduction");
  
  
  refresh(true);
  show(conf_images);
  show(conf_scrollbar);
  initMouseWheel();
  initMouseDrag();
 }
}
 
// Refresh ImageFlow on window resize 
window.onresize = function()
{
 if(document.getElementById(conf_imageflow)) refresh();
}
 
 */
/* Hide loading bar, show content and initialize mouse event listening after loading */
function loadImageFlow()
{
if(document.getElementById(conf_imageflow))
{



//hide(conf_loading);
  // hide intro hack
  
  //hide("introduction");


refresh(true);
show(conf_images);

show(conf_scrollbar);
initMouseWheel();
initMouseDrag();
window.onresize = resizeWindow;  //initialize the window resize handler
}
}



/* Refresh ImageFlow on window resize */
function resizeWindow()
{
if(document.getElementById(conf_imageflow)) refresh();
}
 
 
 
 
 
 
/* Handle the wheel angle change (delta) of the mouse wheel */
function handle(delta )
{
 
 var change = false;
 switch (delta > 0)
 {
  case true:
   if(caption_id >= 1)
   {
    target = target + xstep;
    new_caption_id = caption_id - 1;
    change = true;
   }
   break;
 
  default:
   if(caption_id < (max-1))
   {
    target = target - xstep;
    new_caption_id = caption_id + 1;
    change = true;
   }
   break;
 }
 
 /* Glide to next (mouse wheel down) / previous (mouse wheel up) image */
 if (change == true)
 {
  glideTo(target, new_caption_id);
 }
}
 
/* Event handler for mouse wheel event */
function wheel(event)
{
 var delta = 0;
 if (!event) event = window.event;
 if (event.wheelDelta)
 {
  delta = event.wheelDelta / 120;
 }
 else if (event.detail)
 {
  delta = -event.detail / 3;
 }
 if (delta) handle(delta);
 if (event.preventDefault) event.preventDefault();
 event.returnValue = false;
}
 
/* Initialize mouse wheel event listener */
function initMouseWheel()
{
 if(window.addEventListener) imageflow_div.addEventListener('DOMMouseScroll', wheel, false);
 imageflow_div.onmousewheel = wheel;
}
 
/* This function is called to drag an object (= slider div) */
function dragstart(element)
{
 dragobject = element;
 dragx = posx - dragobject.offsetLeft + new_slider_pos;
}
 
/* This function is called to stop dragging an object */
function dragstop()
{
 dragobject = null;
 dragging = false;
}
 
/* This function is called on mouse movement and moves an object (= slider div) on user action */
function drag(e)
{
 posx = document.all ? window.event.clientX : e.pageX;
 if(dragobject != null)
 {
  dragging = true;
  new_posx = (posx - dragx) + conf_slider_width;
 
  /* Make sure, that the slider is moved in proper relation to previous movements by the glideTo function */
  if(new_posx < ( - new_slider_pos)) new_posx = - new_slider_pos;
  if(new_posx > (scrollbar_width - new_slider_pos)) new_posx = scrollbar_width - new_slider_pos;
  
  var slider_pos = (new_posx + new_slider_pos);
  var step_width = slider_pos / ((scrollbar_width) / (max-1));
  var image_number = Math.round(step_width);
  var new_target = (image_number) * -xstep;
  var new_caption_id = image_number;
 
  dragobject.style.left = new_posx + "px";
  glideTo(new_target, new_caption_id);
 }
}
 
/* Initialize mouse event listener */
function initMouseDrag()
{
 document.onmousemove = drag;
 document.onmouseup = dragstop;
}
 
function getKeyCode(event)
{
 event = event || window.event;
 return event.keyCode;
}
 
document.onkeydown = function(event)
{
 var charCode  = getKeyCode(event);
 switch (charCode)
 {
  /* Right arrow key */
  case 39:
   handle(-1);
   break;
  
  /* Left arrow key */
  case 37:
   handle(1);
   break;
 }
}
 

var slideshowIncrement = -1;
var slideshowTimer = 0;
var slideshowInterval = 1500;

function startSlideshow( interval ){
  slideshowInterval = interval || slideshowInterval;
  slideshowTimer = setInterval( "cycle()", slideshowInterval );
}

function stopSlideshow(){
  clearInterval( slideshowTimer );
}

function cycle(){
  if (caption_id>=array_images.length-1) slideshowIncrement = 1;
  else if (caption_id==0) slideshowIncrement = -1;
  handle(slideshowIncrement);
}