/*
file:		slideshow.js
created:	christopher volz / EA
desc: 		code for basic slideshow functionality
*/

//globals
var currentSlideshowImage = 0;

// jumps to a specific image
function jumpToImage(n) {
	var getImage = n;
	var currentImage = document.getElementById("currentImage");
	
	currentImage.innerHTML = getDivContentForIndex(getImage);
	currentSlideshowImage = getImage;
	
}

function prevImage() {
	var getImage = currentSlideshowImage - 1;
	if(getImage >= 0) {
		jumpToImage(getImage);
	}
}

function nextImage() {
	var getImage = currentSlideshowImage + 1;
	if( doesClassnameExist(getImage) ) {
		jumpToImage(getImage);
	}
}

// gets the innerHTML for a div
function getDivContentForIndex(n) {
	var divs = document.getElementsByTagName("div");
	var classname = "slideshow none "+n;

	for(var i=0;i<divs.length;i++) {
		if( divs[i].className == classname ) {
			return divs[i].innerHTML;
		}
	}

}


function doesClassnameExist(n) {
	var divs = document.getElementsByTagName("div");
	var classname = "slideshow none "+n;

	for(var i=0;i<divs.length;i++) {
		if( divs[i].className == classname ) {
			return true;
		}
	}
	
	return false;
}