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

project "pages"

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

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

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

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

	if (current_page == 1) {
		$j('#previous_arrow').attr('src', '/images/arrow_back_off.gif');						
	}
	else {
		$j('#previous_arrow').attr('src', '/images/arrow_back_on.gif');								
	}

}

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

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

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

sidebar project elements

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

var num_projects_per_page 	= 5;
var num_sidebar_projects 		= 0;
var project_height					= 110;
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) ;
	$j('#portfolio_table').css('top', "-" + distance + "px");
}			

function currentBottomProject()
{
	return current_top_project + num_projects_per_page;
}

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

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

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

	current_top_project += 1;					
	checkNavArrows();					
}			

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

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

	current_top_project -= 1;					
	checkNavArrows();
}