var gSlideShowInterval;
if (gSlideShowInterval == undefined)
	gSlideShowInterval = 6000; // msecs between images.

var gAutoStartSlideShow;
if (gAutoStartSlideShow == undefined)
	gAutoStartSlideShow = true;

var gBehaviorsArray = [];
var gSlideShowOn = false;
var gSlideShowTimer = null;
var gImageLoader = null;

// Register a callback on the dsPhotos data set so we can turn
// off the slide show before it attempts to load new data.

ds1.addObserver(function(nType, notifier, data) {
	if (nType == "onPreLoad")
		StopSlideShow();
});

// Register a callback on the thumbnails region so we can show the first
// image in the data set after all the thumbnails have loaded.

Spry.Data.Region.addObserver("thumbnails", function(nType, notifier, data) {
	if (nType == "onPostUpdate")
	{
;
		
		ShowCurrentImage();
        if (gAutoStartSlideShow)
			StartSlideShow(true);
			
	}
});

// Trigger the transition animation from the current image
// being displayed to the image at imgPath.

function SetMainImage(imgPath, width, height, tnID, title)
{
	var img = document.getElementById("mainImage");
   	var maintitle = document.getElementById("mainTitle");

	if (!img)
		return;
    
	CancelBehavior("mainImage");

	//Spry.Utils.SelectionManager.clearSelection("thumbnailSelection");

	if (tnID)
		//Spry.Utils.SelectionManager.select("thumbnailSelection", document.getElementById(tnID), "selectedThumbnail");

	if (gImageLoader)
	{
		gImageLoader.onload = function() {};
		gImageLoader = null;
	}

			

	gBehaviorsArray["mainImage"] = new Spry.Effect.Opacity(img, Spry.Effect.getOpacity(img), 0, { duration: 400,
		finish: function()
		{    
			gBehaviorsArray["mainImage"] = new Spry.Effect.Size(img.parentNode, Spry.Effect.getDimensions(img.parentNode), { width: 454, height: 345, units:"px"}, {duration: 400,
				finish: function()
				{
					// Use an image loader to make sure we only fade in the new image after
					// it is completely loaded.
					gImageLoader = new Image();
					maintitle.innerHTML = title;
					gImageLoader.onload = function()
					{
						img.src = gImageLoader.src;
						gImageLoader = null;
						
						gBehaviorsArray["mainImage"] = new Spry.Effect.Opacity(img, 0, 1, { duration: 400,
							finish: function()
							{
								gBehaviorsArray["mainImage"] = null;
								
								// Our new image is fully visible now. Remove any opacity related
								// style properties on the img to workaround the IE bug that creates
								// white dots/holes in the images. Removing the properties forces
								// IE to re-render the image correctly.

								img.style.opacity = "";
								img.style.filter = "";

								// If the slide show is on, fire off the timer for the next image.

								if (gSlideShowOn)
									SetSlideShowTimer();
							}});
						gBehaviorsArray["mainImage"].start();
						
					};
					gImageLoader.src = imgPath;
				}
		  });
		
		  gBehaviorsArray["mainImage"].start();
		}
	});
	gBehaviorsArray["mainImage"].start();
}

// Cancel the animation behavior of the object with the given id.

function CancelBehavior(id)
{
	if (gBehaviorsArray[id])
	{
		gBehaviorsArray[id].cancel();
		gBehaviorsArray[id] = null;
	}
}



// Trigger the animation of the thumbnail growing.



// Trigger the animation of the thumbnail shrinking.

function ShrinkThumbnail(img)
{
	Spry.Utils.addClassName(img, "inFocus");
	img.style.zIndex = 1;
	
	var id = img.getAttribute("id");

}

// Show the image of the current selected row inside the dsPhotos data set.

function ShowCurrentImage()
{
	var curRow = ds1.getCurrentRow();
	SetMainImage(curRow["@url"],"","", "tn" + curRow["ds_RowID"],curRow["@title"]);
}

// Utility function to advance (forwards or backwards) the current selected row
// in dsPhotos. This has the side effect of "selecting" the thumbnail and image
// of the new current row.

function AdvanceToNextImage(moveBackwards)
{
	var rows = ds1.getData();
	var curRow = ds1.getCurrentRow();
	
	if (rows.length < 1)
		return;
	
	for (var i = 0; i < rows.length; i++)
	{
		if (rows[i] == curRow)
		{
			if (moveBackwards)
				--i;
			else
				++i;
			break;
		}
	}
	
	if (!moveBackwards && i >= rows.length)
		i = 0;
	else if (moveBackwards && i < 0)
		i = rows.length - 1;
	
	curRow = rows[i];
	ds1.setCurrentRow(curRow["ds_RowID"]);
	ShowCurrentImage();
}

function SetSlideShowTimer()
{
	KillSlideShowTimer();
	gSlideShowTimer = setTimeout(function(){ gSlideShowTimer = null; AdvanceToNextImage(false); }, gSlideShowInterval);
}

function KillSlideShowTimer()
{
	if (gSlideShowTimer)
		clearTimeout(gSlideShowTimer);
	gSlideShowTimer = null;
}

// Start the slide show that runs forwards through all
// the rows in dsPhotos.

function StartSlideShow(skipTimer)
{
	gSlideShowOn = true;
	if (!skipTimer)
		SetSlideShowTimer();
	var playLabel = document.getElementById("playLabel");
	if (playLabel)
		playLabel.firstChild.data = "Pause";
}

// Kill any slide show that is currently running.

function StopSlideShow()
{
	gSlideShowOn = false;
	KillSlideShowTimer();
	var playLabel = document.getElementById("playLabel");
	if (playLabel)
		playLabel.firstChild.data = "Play";
}

function HandleThumbnailClick(id)
{
	StopSlideShow();
	ds1.setCurrentRow(id);
	ShowCurrentImage();
}