Singleton и с чем его едят.

Код AS3:

package  
{
	import flash.events.*;
	import flash.utils.*;
	/**
	 * ...
	 * @author drnet_ua
	 */
	public class SimpleClass extends EventDispatcher
	{
 
		private var currentNumber:Number;
		private var _lastPrime:Number;
		private var progressTimer:Timer;
 
		public function get lastPrime():Number {
			return _lastPrime;
		}
 
		public static function isPrime(a:Number):Boolean {
			var multiplier:Number = 2;
			var numberIsPrime:Boolean = true;
 
			while (numberIsPrime && ( multiplier <= (a / multiplier))) {
 
				if ((a % multiplier) == 0) {
					numberIsPrime = false
				} else {
					multiplier++;
				}
 
			}
			return numberIsPrime;
		}
 
		private function onTimerHandler(e:TimerEvent):void {
 
			currentNumber++;
 
			while (!isPrime(currentNumber)) {
				currentNumber++;	
			}
 
				_lastPrime = currentNumber;
				this.dispatchEvent(new Event('NEW_PRIME'));						
 
 
		}
 
		public function StartCalculations(startNumber:Number = 1):void {
			currentNumber = startNumber;			
			progressTimer = new Timer(1000, 0);
			progressTimer.addEventListener(TimerEvent.TIMER, onTimerHandler);
			progressTimer.start();
		}
 
		public function SimpleClass() 
		{
 
		}		
	}
}

Код AS3:

private function traceActivity(e:Event):void {
			trace(e.target.lastPrime);
		}
 
...
 
var a:SimpleClass = new SimpleClass();
a.addEventListener('NEW_PRIME', traceActivity);
a.StartCalculations(1);

Код AS3:

private static var _instance:SimpleSinglton;

Код AS3:

private static var allowConstructor:Boolean;

Код AS3:

	public function SimpleSinglton() 
		{
			if (!allowConstructor) {			
				throw(new Error('Class cannot be instansiated'));
			}
 
		}

Код AS3:

	private static get instance():SimpleSinglton {
			if (_instance == null) {
				allowConstructor = true;
				_instance = new SimpleSinglton();
				allowConstructor = false;
			}
 
			return _instance;
		}

Код AS3:

public static function StartCalculations(startNumber:Number):void {
			instance._StartCalculations(startNumber);
		}

Код AS3:

                public static function addPrimeListener(targetFunction:Function):void {
			instance.addEventListener('NEW_PRIME', targetFunction);
		}
 
		public static function removePrimeListener(targetFunction:Function):void {
			instance.removeEventListener('NEW_PRIME', targetFunction);
		}

Код AS3:

SimpleSinglton.addPrimeListener(traceActivity);
SimpleSinglton.StartCalculations(10);

Код AS3:

package  
{
	import flash.events.*;
	import flash.utils.*;
	/**
	 * ...
	 * @author drnet_ua
	 */
	public class SimpleSinglton extends EventDispatcher
	{
 
		private static var _instance:SimpleSinglton;
		private static var allowConstructor:Boolean;
 
		private var currentNumber:Number;
		private var _lastPrime:Number;
		private var progressTimer:Timer;
 
		private static function get instance():SimpleSinglton {
			if (_instance == null) {
				allowConstructor = true;
				_instance = new SimpleSinglton();
			}
 
			return _instance;
		}
 
		public function get lastPrime():Number {
			return _lastPrime;
		}
 
		public static function isPrime(a:Number):Boolean {
			var multiplier:Number = 2;
			var numberIsPrime:Boolean = true;
 
			while (numberIsPrime && ( multiplier <= (a / multiplier))) {
 
				if ((a % multiplier) == 0) {
					numberIsPrime = false
				} else {
					multiplier++;
				}
 
			}
			return numberIsPrime;
		}
 
		private function onTimerHandler(e:TimerEvent):void {
 
			currentNumber++;
 
			while (!isPrime(currentNumber)) {
				currentNumber++;	
			}
 
				_lastPrime = currentNumber;
				this.dispatchEvent(new Event('NEW_PRIME'));					
 
 
		}
 
		public function _StartCalculations(startNumber:Number):void {
			currentNumber = startNumber;			
			progressTimer = new Timer(1000, 0);
			progressTimer.addEventListener(TimerEvent.TIMER, onTimerHandler);
			progressTimer.start();
		}
 
		public static function StartCalculations(startNumber:Number):void {
			instance._StartCalculations(startNumber);
		}
 
		public static function addPrimeListener(targetFunction:Function):void {
			instance.addEventListener('NEW_PRIME', targetFunction);
		}
 
		public static function removePrimeListener(targetFunction:Function):void {
			instance.removeEventListener('NEW_PRIME', targetFunction);
		}
 
		public function SimpleSinglton() 
		{
			if (!allowConstructor) {			
				throw(new Error('Class cannot be instansiated'));
			}
 
		}		
	}
}