// FILE        : font_size.js
// DESCRIPTION : Functions for increasing/decreasing story text size; 
//               uses cookie to set prefs for lifetime of browser opened
// AUTHOR      : Christian Calloway callowaylc@yahoo.com

var NAME_COOKIE="font_size";
var min=8;
var max=18;
var dflt=13;


function increaseFontSize() {
	//var contentBodyElement = document.getElementById("story_content");
	var contentElements = document.getElementsByClassName("story_content");
	var fs=null;
	var ns=null;
	var currentSize=null;
	
	// compute current size of font
	currentSize = 
		((fs=contentElements[0].style.fontSize)) ?  
			parseInt(fs) : dflt;

	// now check that increase font size will not exceed max size
	if (currentSize<max) { 
		for (var counter=0; counter < contentElements.length; counter++) { 
			var element = contentElements[counter];
			element.style.fontSize = (ns=(currentSize+1))+"px";
		}
		
				
		// now set cookie font-size preference
		_createCookie(NAME_COOKIE, ns);
	}
	
	
	
}


function decreaseFontSize() {
	//var contentBodyElement = document.getElementById("story_content");
	var contentElements = document.getElementsByClassName("story_content");
	var fs=null;
	var ns=null;
	var currentSize=null;
	
	// compute current size of font
	currentSize = 
		((fs=contentElements[0].style.fontSize)) ?  
			parseInt(fs) : dflt;

	// now check that increase font size will not exceed max size
	if (currentSize>min) { 
		for (var counter=0; counter < contentElements.length; counter++) { 
			var element = contentElements[counter];
			element.style.fontSize = (ns=(currentSize-1))+"px";

		}
			
		// now set cookie font-size preference
		_createCookie(NAME_COOKIE, ns);				
	}	
	
}

function _createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
	
	//alert (document.cookie);
}

function _readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}