Implementation.as

var menu:NativeMenu = new NativeMenu();
var runner:IRecycleOperationRunner = new RecycleOperationRunner();
var operation:IRecycleOperation = new RecycleOperation();

function updateMenu(menu:NativeMenu, data:Vector.<String>):void
{
	operation.menu = menu;
	operation.labelList = labelList;

	runner.run(operation);
}

updateMenu(menu, Vector.<(['One', 'Two'])>); // creates 2 items
updateMenu(menu, Vector.<(['Red', 'Orange', 'Yellow', 'Green', 'Blue', 'Indigo', 'Violet'])>); // reuses 2, creates 5
updateMenu(menu, Vector.<(['Banana', 'Apple', 'Peach', 'Grape'])>); // reuses 4, disposes 3 to the pool

IRecycleOperation.as

package
{
	public interface IRecycleOperation extends IDisposable
	{
		function get numObjects():int;
		function get numDataItems():int;

		function createObject():void;
		function reuseObject(i:int):void;
		function setupObject(i:int):void;
		function removeObject():void;
	}
}

IRecycleOperationRunner.as

package
{
	public interface IRecycleOperationRunner
	{
		function run(operation:IRecycleOperation):void;
	}
}

MenuItemRecycleOperation.as

package
{
	public class MenuItemRecycleOperation
	{
		public var itemLabelList:Vector.<String>;

		public var menu:NativeMenu;

		protected var pool:ObjectPool = new ObjectPool(NativeMenuItem);

		protected var currentMenuItem:NativeMenuItem;

		public function MenuItemRecycleOperation()
		{
		}

		public function get numObjects():int
		{
			return menu.numItems;
		}

		public function get numDataItems():int
		{
			return itemLabelList.length;
		}

		public function createObject():void
		{
			currentMenuItem = pool.getObject();
		}

		public function reuseObject(i:int):void
		{
			currentMenuItem = menu.getItemAt(i);
		}

		public function setupObject(i:int):void
		{
			currentMenuItem.label = itemLabelList[i];
		}

		public function removeObject():void
		{
			currentItem = removeItemAt(menu.numItems - 1);

			pool.disposeObject(currentItem);
		}

		public function dispose():void
		{
			currentItem = null;
		}
	}
}

RecycleOperationRunner.as

package
{
	public class RecycleOperationRunner implements IRecycleOperationRunner
	{
		public function RecycleOperationRunner()
		{

		}

		public function run(operation:IRecycleOperation):void
		{
			const m:int = Math.max(numObjects, numDataItems);

			for (var i:int = 0; i < m; i++)
			{
				if (i < numDataItems)
				{
					if (i < numObjects)
					{
						operation.reuseItem(i);
					}
					else
					{
						operation.createItem(i);
					}

					operation.setupItem(i);
				}
				else
				{
					operation.removeItem(i);
				}
			}

			operation.dispose();
		}
	}
}