function Screen(dom) {
	var root = document.getElementById('screen');
	var menus = [];

	return {
		appendText: appendText,
		clear: clear,
		currentMenu: currentMenu,
		frame: frame,
		input: input,
		markAsRead: markAsRead,
		menu: menu,
		select: select,
		show: show,
		text: text
	};

	function appendText(message) {
		getTextZone().children[0].textContent += message;
	}

	function clear(elem) {
		if(elem == 'text') {
			var textElem = findTextZone();
			if(textElem != undefined) {
				root.removeChild(textElem);
			}
		} else if(elem != undefined) {
			if(currentMenu() == elem) {
				menus.pop();
			}
			root.removeChild(elem);
		} else {
			dom.clear(root);
		}
	}

	function currentMenu() {
		return menus[menus.length - 1];
	}

	function frame(n) {
		root.className = "frame" + n;
	}

	function findTextZone() {
		return root.getElementsByClassName('text')[0];
	}

	function getTextZone() {
		var textZone = findTextZone();
		if(textZone == undefined) {
			textZone = dom.make('div', {class: ['text', 'framed']}, [
				dom.make('p')
			]);
			root.appendChild(textZone);
		}
		return textZone
	}

	function input(size) {
		var elem = dom.make('input', {
			type: 'text',
			class: ['framed', 'center'],
			maxlength: size,
			size: size
		});
		show(elem);
		return elem;
	}

	function markAsRead(yes) {
		if(yes == undefined) {
			yes = true;
		}
		getTextZone().classList[yes ? 'add' : 'remove']('read');
	}

	function menu(config) {
		var domEntries = [];
		var selected = config.selected || 0;
		for(var i = 0; i < config.entries.length; i++) {
      var classes = i == selected ? 'selected' : [];
      if(config.entries[i].label != undefined) {
        domEntry = dom.make('li', {
          class: classes,
          textContent: config.entries[i].label
        }, []);
      } else if(config.entries[i].picto != undefined) {
        domEntry = dom.make('li', {
          class: classes,
        }, [dom.make('img', config.entries[i].picto, [])]);
      }
			domEntries.push(domEntry);
		}
		var ul = dom.make(
			'ul',
			{class: ['menu', 'framed', config.direction], id: config.name + 'Menu'},
			domEntries
		);
		root.appendChild(ul);
		menus.push(ul);
		return ul;
	}

	function select(cursor) {
		var ul = currentMenu();
		ul.getElementsByClassName('selected')[0].className = '';
		ul.children[cursor].className = 'selected';
	}

	function show(elem) {
		root.appendChild(elem);
	}

	function text(message) {
		getTextZone().children[0].textContent = message;
		markAsRead(message.length > 0);
	}
}