/* functions slideshow */

function startSlideshow(obj)
{
    var slides = Object.values(obj);
    var html = '';
    var t = 0;
    var randomId = false;
    
    if (slides.length > 0)
    {
        randomId = Math.floor(Math.random()*(slides.length));
        
        slides.each(function(slide) {
            html += '<div class="slide" id="slide_' + t + '" style="display: none;"><img src="' + slide.href + '"></div>';
            t++;
        });
    }
    
    if (randomId !== false)
    {
        $('slideshow').update(html);
        
        // nieuwe slide verschijnt
        $('slide_' + randomId).addClassName('active');
        $('slide_' + randomId).setStyle({
	        zIndex: '12'
        });
        
        Effect.Appear($('slide_' + randomId), {
		    queue: {
			    position : 'front',
			    scope : 'new',
			    limit: 1					
		    },
		    duration: 0.8
	    });
	    
        setTimeout( "loadNextSlide()", 4000);
    }    
}

function loadNextSlide()
{    
    var current = false;
    var next = '';
    var number = -1;
    
    $$('div.slide').each(function(el) {
		number++;
	});
	
    // wat is de huidige foto?
    $$('div.active').each(function(el) {
		$(el.id).removeClassName('active');
		$(el.id).setStyle({
			zIndex: '10'
		});
		current = el.id;
	});	
	
	if (current !== false)
	{
	    // huidige slide verdwijnt en de volgende verschijnt!
	    Effect.Fade($(current), {
		    queue: {
			    position: 'back',
			    scope: 'old',
			    limit: 1
		    }, 
		    duration: 1.4
	    });
	} 
	
	next = current.replace('slide_', ''); 	
	next = parseFloat(next) + 1;
	
    if (next > number)
    {
        next = 0;
    }
    
    $('slide_' + next).addClassName('active');
    $('slide_' + next).setStyle({
        zIndex: '12'
    });
    
    Effect.Appear($('slide_' + next), {
		queue: {
			position : 'front',
			scope : 'new',
			limit: 1					
		},
		duration: 1.3
	});
    
	setTimeout( "loadNextSlide()", 4000);
	
}