[design mode AS3 version] two. Observer mode

Published by

Package 
{Public
	interface Subject {
		
		function Addobserver (observer:observer): void;
		function Removeobserver (observer:observer): void;
		function notifyobservers (): void;
		
	}
}

Observers

Package 
{Public
	interface Observer {
		
		function Update (data:object=null): void;
	}
}

Publisher-Specific Implementation class

Package 
{Public	
	class Timedata implements Subject {
		
		private var _now:date;
		
		private Var observers:vector.<observer>;
		
		Public Function Timedata () {
			observers = new vector.<observer> ();	
		}
		
		Public Function Addobserver (observer:observer): void {
			OBSERVERS.PUSH (Observer);	
		}
		
		Public Function Removeobserver (observer:observer): void {
			var index:int = OBSERVERS.INDEXOF (Observer);
			if (index >= 0) {
				observers.splice (index, 1);	
			}
		} 
		
		Public Function notifyobservers (): void {for each
			(Var observer:observer in observers) {
				Observer.update (_now );
			}
		}

		Public function Get Now ():D ate {
			return _now;
		}

		Public function set Now (value:date): void {
			_now = value;
			Notifyobservers ();}}}

Viewer-Specific implementation class

Package
{
	import flash.display.Shape;
	
	public class Graphicdisplay extends Shape implements Observer {
		
		private var _subject:subject;
		
		Public Function Graphicdisplay () {
			
		} public
		
		function set subject (Value:subject): void {
			if (_subject) {
				_subject.removeobserver (this);	
			}
			_subject = value;
			if (_subject) {
				_subject.addobserver (this);	
			}
		}
		
		Public Function Update (data:object=null): void {
			var now:date = data as Date;
			if (now) {
				var width:number = now.seconds * 5;
				Graphics.clear ();
				Graphics.beginfill (0x000088);
				Graphics.drawrect (0, 0, Width, 5);
				Graphics.endfill ();}}}

Viewer-Specific implementation class

Package
{
	import flash.display.Sprite;
	Import Flash.text.TextField;
	
	public class Textdisplay extends Sprite implements Observer {
		
		private var _subject:subject;
		private Var Text:textfield;
		
		Public Function Textdisplay () {
			text = new TextField ();
			Text.text = "Current time: 00:00:00";
			AddChild (text);
		}
		
		Public function set Subject (Value:subject): void {
			if (_subject) {
				_subject.removeobserver (this);	
			}
			_subject = value;
			if (_subject) {
				_subject.addobserver (this);	
			}
		}
		
		Public Function Update (data:object=null): void {
			var now:date = data as Date;
			if (now) {
				var str:string = "Current time:";
				str + = (now.hours >=   now.hours   : "0" + now.hours);
				str + = ":";
				str + = (now.minutes >= now.minutes: "0" + now.minutes);
				str + = ":";
				str + = (now.seconds >= now.seconds: "0" + now.seconds);
				Text.text = str;}}}

Test class

Package 
{
	import flash.display.Sprite;
	Import flash.events.TimerEvent;
	Import Flash.utils.Timer;
	
	[SWF (width= ", height=")]
	public class Observertest extends Sprite {
		
		private var timedata:timedata;
		private Var Graphicdisplay:graphicdisplay;
		private Var Textdisplay:textdisplay;
		
		Public Function Observertest () {
			timedata = new Timedata ();
			Textdisplay = new Textdisplay ();
			Textdisplay.subject = Timedata;
			AddChild (textdisplay);
			TEXTDISPLAY.Y = ten;
			Graphicdisplay = new Graphicdisplay ();
			Graphicdisplay.subject = Timedata;
			AddChild (graphicdisplay);
			GRAPHICDISPLAY.Y = +;
			
			var timer:timer = new timer (+);
			Timer.addeventlistener (Timerevent.timer, onTimer);
			Timer.start ();
		}
		
		Private Function OnTimer (event:timerevent): void {
			timedata.now = new Date ();}}
}