whats wrong with my singleton class

rerobnett

You are incorrect that you need to do that. If you satisfy your instance's dependencies from outside, that outside thing (for instance, a Controller Class or even your Main Document Class) can only create one instance as needed and pass it in. That way, if you need two instances down the road, you haven't *'ed yourself royally. More importantly, you don't have all these hands touching your Stone and no way to control who is changing what. I've worked on an enterprise-level project where someone thought it was a good idea to stick a bunch of Singletons in, and it was a royal pain in the asterisk to track down any bug because hundreds of places in the code could have changed a value to something wrong.

For example, you could do something like this:

public class Main extends Sprite {      protected var stone:Stone = new Stone();//just created one instance, no other place in the code do we do this      public function Main() {           super();           addEventListener(Event.ADDED_TO_STAGE, checkStoner, true);      }      protected function checkStoner(e:Event):void {           //any MC's that want a reference to the stone will           //express that interest by implementing IStoner           var stoner:IStoner = e.target as IStoner;           if (stoner) {                stoner.stone = stone;           }      } } The Interface would look like this: public interface IStoner {      function get stone():Stone;      function set stone(value:Stone):void; } An implementation might look like this: public class StoneMover extends Sprite implements IStoner {      protected var _stone:Stone;      public function StoneMover() {           super();           //listen for your custom event type and move the stone based on receiving that           //note I am not providing you the code for that, I assume you know how to write an Event Class           stage.addEventListener(CustomEvent.CUSTOM_EVENT_TYPE, moveStone);      }      public function get stone():Stone {           return _stone;      }      public function set stone(value:Stone):void {           if (value != _stone) {                //may want to future-proof with cleanup code here                _stone = value;                //if you need to listen to the stone, do that here           }      }      protected function moveStone(e:CustomEvent):void {           if (e.customProperty = 'foo') {                stone.x++;           } else {                stone.y++;           }      } }

An alternate approach you could take is communicating via events, either on the Display List or via one or more EventDispatchers that can be handed out to the right instances.