/* Origianlly designed and used on www.iht.com */

var classFix;
if (document.all){
	classFix = "className";
} else {
	classFix = "class";
}

// these values come from the cookie
var columnMode = 3;

// set some defaults values
var originalHeight;
var lineHeight = 16;
var currentPos = 0;
// set vars for top and bottom offset for auto resizing
var iUDOffetSetTop	= 0;
var iUDOffetSetBottom	= 0;

// use these values to manipulate the width of the text columns
// col3Width is used in the 3 column layout and col1Width is 
// used in the 1 column layout.
var col3Width = 210;

// use this number to manipulate the height of the article text box
// it is counter intuitive: smaller is taller, bigger is shorter
var heightOfColumns = 250;


// returns the height of the current window
function getHeight(obj){
	if (obj == "window"){
		if (window.innerHeight){
			return window.innerHeight;
		} else {
			return document.getElementById("bodyNode").offsetHeight;
		}
	} else {
		obj = document.getElementById(obj);
		if (obj.offsetHeight){
			return obj.offsetHeight;
		}
	}
}
	
// makes the columns and copies the text node into the newly
// created columns ac is the div holding the cloned node - at
function articleSetup(){
	var fontSize = 12;
    
    var cv1 = 12;
	var parentDiv = document.getElementById("divContentParent");
	var currentPos = 0;
	for (var i = 0; i < 3; i++){
		var col = document.createElement("div");
		col.setAttribute("id", "ac" + i);
		//col.setAttribute("class", "artCol");
		col.setAttribute(classFix, "artCol");
		parentDiv.appendChild(col);
		var obj = document.getElementById("divContentBody");
		var artText = obj.cloneNode(true);
		artText.setAttribute("id", "at" + i);
		artText.style.display = "block";
		artText.style.top = "0px";
		artText.style.fontSize = fontSize + "px";
		artText.style.lineHeight = lineHeight + "px";
		col.appendChild(artText);		
	}
}

// moves the columns into position, but adjust the top
function layoutArticles(){	
	var parentHeight = getHeight("divContentParent");
	for (var i = 0; i < columnMode; i++){
		var obj = document.getElementById("at" + i);
		//make sure at least 2 rows of article text are available 
		if (parentHeight > (2 * lineHeight)){
			obj.style.top = -1 * (parentHeight * (i + currentPos));
		}
	}
	articlePages();
}

// resets the article to the first "page"
function resetArticle(){
	currentPos = 0;
	layoutArticles();
}

// returns the snap to align article; this adjusts the height of the 
// article window with a number divisible by line height. the minium 
// number of rows is 10
function setSnap(mod){
	if (mod == null){
		mod = 0;
	}
	var snap = lineHeight * Math.round((getHeight("window") - mod) / lineHeight);
	if (snap < (lineHeight * 10)){
		snap = lineHeight * 10;
		if (window.scrollTo){
			window.scrollTo(0, 75);
		}
	} else if (window.scrollTo){
		window.scrollTo(0, 0);
	}
	return snap;
}

// clips the parent layer to the defined visible area
// if space allows include bottom, otherwise clip out most of bottom
function setArticleHeight(){
	if (columnMode > 1){
		if (document.getElementById("divContentBody") != null){
			var iOffsetTop = findPosTop( document.getElementById("divContentParent") );
			document.getElementById("divContentParent").style.height = setSnap(heightOfColumns)-iUDOffetSetTop - iOffsetTop - iUDOffetSetBottom;
			var tHeight = getHeight("at1");
			parentHeight = getHeight("divContentParent");
			//check to make sure page is still visible
			while ((parentHeight * (currentPos + (columnMode - 1))) > tHeight && currentPos > 0){
				currentPos = currentPos - 1;
			}
		}
	}
}

// find the position of the object
function findPosLeft(obj) {
	var curleft = curtop = 0;
	if (obj.offsetParent) {
		curleft = obj.offsetLeft
		curtop = obj.offsetTop
		while (obj = obj.offsetParent) {
			curleft += obj.offsetLeft
			curtop += obj.offsetTop
		}
	}
	return [curleft];
}

// find the position of the object
function findPosTop(obj) {
	var curleft = curtop = 0;
	if (obj.offsetParent) {
		curleft = obj.offsetLeft
		curtop = obj.offsetTop
		while (obj = obj.offsetParent) {
			curleft += obj.offsetLeft
			curtop += obj.offsetTop
		}
	}
	return [curtop];
}


// returns the number of screens an article spans, ie the number of pages
function articlePages(){
	var parentHeight = getHeight("divContentParent");
	var tHeight = getHeight("at1");
	var totalColumns = tHeight / parentHeight;
	var totalPages = Math.ceil(totalColumns);
	var tPos = (currentPos + columnMode) / columnMode;
	var pagesTotal = Math.ceil(totalPages / columnMode);
	var pagesCurrent = Math.round(tPos);
	var obj = document.getElementById("divPageNavMid");
	obj.innerHTML = "" + pagesCurrent + " of " + pagesTotal;
    
    // button activation/deactivation
    var prevButtonBG = document.getElementById("divPageNavPrev");
    var prevButtonText = document.getElementById("divPageNavPrevTXT");
    var nextButtonBG = document.getElementById("divPageNavNext");
    var nextButtonText = document.getElementById("divPageNavNextTXT");
    if (pagesTotal > 1) {
        if (pagesCurrent == 1) {
            // activate next button
            nextButtonText.style.color = "#000";
            nextButtonBG.onclick = function () { nextPage(); }
            // deactivate prev button
            prevButtonText.style.color = "#ccc";
        } 
        
        if (pagesCurrent > 1 && (pagesCurrent <= pagesTotal)) {
            // activate prev button
            prevButtonText.style.color = "#000";
            prevButtonBG.onclick = function () { prevPage(); }
            if (pagesCurrent == pagesTotal) {
                // deactivate next button
                nextButtonText.style.color = "#ccc";
            } else {
                // activate next button
                nextButtonText.style.color = "#000";
                nextButtonBG.onclick = function () { nextPage(); }
            }
        }
    }
}



// adjusts the article to display the next page
function nextPage(){
	tHeight = getHeight("at1")
	var parentHeight = getHeight("divContentParent");
	// check to make sure page is still visible 
	if ((parentHeight * (currentPos + columnMode)) < tHeight){
		currentPos = currentPos + columnMode;
	}
	layoutArticles();
}

// adjusts the article to display the previous page
function prevPage(){
	currentPos = currentPos - columnMode;
	if (currentPos < 0){
		currentPos = 0;
	}
	layoutArticles();
}

// switches to three Column mode
function threeColumn(){
	var fontSize = 12;
    var cv1 = 12;
	currentPos = 0;
	columnMode = 3;
	colWidth = col3Width;

	if (fontSize > 18){
		fontSize = 18;
	}
	var obj1 = document.getElementById("at0");
	obj1.style.zIndex = 5;
	obj1.style.display = "block";
	obj1.style.width = colWidth;
	obj1.style.left = 0;
	
	var obj2 = document.getElementById("at1");

	obj2.style.zIndex = 5;
	obj2.style.display = "block";
	obj2.style.width = colWidth;
	obj2.style.left = colWidth + 20;

	var obj3 = document.getElementById("at2");

	obj3.style.zIndex = 5;
	obj3.style.display = "block";
	obj3.style.width = colWidth;
	obj3.style.left = 2 * (colWidth + 20);

}

function initArticle(){
	if (document.getElementById("divContentBody") != null){
		articleSetup();
		setArticleHeight();
		threeColumn();
		layoutArticles();
	}
}



// adjust article layout when the window is resized
function windowResize(){
	setArticleHeight();
	layoutArticles();
}

window.onresize = windowResize;