package com.game.Scenes;



import com.game.MessageHandler;

import com.game.MsgType;

import com.game.MessageHandler.MsgReceiver;



import android.app.Activity;

import android.os.Handler;



/**

 * Base class for any scene in the game. Scenes are owned and controlled by the 

 * scene manager.

 * 

 * @author Ying

 *

 */

public abstract class Scene 

{

	/**

	 * Handler for messages to the scene

	 */

	protected Handler handler = null;

	

	/**

	 * Used to ensure thread safety on scene shutdown

	 */

	protected boolean 	runScene;

	

	/**

	 * Used to ensure thread safety on scene shutdown

	 */

	private boolean 	stopScene;

	

	/**

	 * Reference to the activity to load resources.

	 */

	protected Activity refActivity = null;

	

	/**

	 * Initializes variables

	 */

	public Scene()

	{

		runScene = true;

		stopScene = false;

	}

	

	/**

	 * Override in the base class. Called on scene start.

	 */

	public abstract void Start();

	

	/**

	 * Override in the base class. Called each update cycle of the game logic.

	 */

	public abstract void Update();

	

	/**

	 * Override in the base class. Called on scene end.

	 */

	public abstract void End();

	

	/**

	 * Gets the message handler

	 * @return message handler.

	 */

	public Handler getHandler(){return handler;}

	

	

	/**

	 * Updates the scene only if the activity has not asked us to stop.

	 * If we have been asked to stop, notify the activity (only once, remember

	 * that until the scene is swapped this code is called each frame) when

	 * we are ready.

	 */

	public void safeUpdate()

	{

		if(runScene)

		{

			this.Update();

		}

		else

		{

			if(!stopScene)

			{

				stopScene = true;

				MessageHandler.Get().Send(MsgReceiver.ACTIVITY, MsgType.SCENE_STOPED_READY_FOR_CHANGE);				

			}

		}

	}



	/**

	 * Sets the reference to the activity

	 * @param refActivity

	 */

	public void setRefActivity(Activity refActivity) 

	{

		this.refActivity = refActivity;

	}

	

}