toggle-states

function getCookies() {
    var c = document.cookie, v = 0, cookies = {};
    if (document.cookie.match(/^\s*\$Version=(?:"1"|1);\s*(.*)/)) {
        c = RegExp.$1;
        v = 1;
    }
    if (v === 0) {
        c.split(/[,;]/).map(function(cookie) {
            var parts = cookie.split(/=/, 2),
                name = decodeURIComponent(parts[0].trimLeft()),
                value = parts.length > 1 ? decodeURIComponent(parts[1].trimRight()) : null;
            cookies[name] = value;
        });
    } else {
        c.match(/(?:^|\s+)([!#$%&'*+\-.0-9A-Z^`a-z|~]+)=([!#$%&'*+\-.0-9A-Z^`a-z|~]*|"(?:[\x20-\x7E\x80\xFF]|\\[\x00-\x7F])*")(?=\s*[,;]|$)/g).map(function($0, $1) {
            var name = $0,
                value = $1.charAt(0) === '"'
                          ? $1.substr(1, -1).replace(/\\(.)/g, "$1")
                          : $1;
            cookies[name] = value;
        });
    }
    return cookies;
}
function getCookie(name) {
    return getCookies()[name];
}

function setCookie(c_name, value, exdays) {
	var exdate = new Date();
	exdate.setDate(exdate.getDate() + exdays);
	var c_value = escape(value) + ((exdays == null) ? "" : "; expires=" + exdate.toUTCString());
	document.cookie = c_name + "=" + c_value;
}

function layerToggleStates(states, options) {
	if(states.length <= 0)
		throw "No states defined." 
	
	var that = this;
	
	this.states = states;
	
	this.stateCurrent = null; // idx
	
	this.buttonZoomIn = options.buttonZoomIn || null;
	this.buttonZoomOut = options.buttonZoomOut || null;
	this.stateRememberCookie = options.stateRememberCookie || null;
	this.defaultState = options.defaultState || null;
	
	this.buttonStack = [
		this.buttonZoomIn,
		this.buttonZoomOut
	]
	
	/**
	 * Try to discover index
	 */
	if(this.stateCurrent === null && this.stateRememberCookie) {
		this.stateCurrent = getCookie(this.stateRememberCookie)
		
		if(typeof this.stateCurrent == 'undefined' || this.stateCurrent < 0 || this.stateCurrent > (this.states.length-1))
			this.stateCurrent = null;
	}
	if(this.stateCurrent === null && this.defaultState) {
		this.stateCurrent = this.defaultState;
		
		if(this.stateCurrent < 0 || this.stateCurrent > (this.states.length-1))
			this.stateCurrent = null;
	}
	if(this.stateCurrent === null) {
		this.stateCurrent = 0
	}
	
	if(this.buttonZoomIn) {
		this.buttonZoomIn.on('click', function() {
			var btn = $(this);
			
			if(btn.hasClass('disabled'))
				return false;
			
			++that.stateCurrent;
			
			$.each(that.buttonStack, function() {
				this.removeClass('disabled');
			})
			
			if(that.stateCurrent >= (that.states.length-1))
				btn.addClass('disabled');
			
			that.runToggle();
			return false;
		})
	}
	
	if(this.buttonZoomOut) {
		this.buttonZoomOut.on('click', function() {
			var btn = $(this);
			
			if(btn.hasClass('disabled'))
				return false;
			
			--that.stateCurrent;
			
			$.each(that.buttonStack, function() {
				this.removeClass('disabled');
			})
			
			if(that.stateCurrent <= 0)
				btn.addClass('disabled');
			
			that.runToggle();
			return false;
		})
	}
	
	this.runToggle = function() {
		console.log('Enable state #' + that.stateCurrent);
		that.states[that.stateCurrent]();
		
		if(that.stateRememberCookie) {
			setCookie(that.stateRememberCookie, that.stateCurrent, 365);
		}
	}
	
	this.runToggle();
}