stock with concept - game stage/scene

OpenGL Development
#1

Hello guys …
I have been programming my first game in lwjgl and I get stuck thinking how to make some sort of game stage/scene management in the main class (who create the Display and AL)

I make the following Interface


package interfaces;

import gametools.TimerTool;

public interface Stage {

	public void setUpObjects();
	
	public void draw();

	public void update(TimerTool timer);

	public void input();

	public void unloadObjects();

}

and an Abstract class for my game stages classes…
but Im not sure how to manage the navigation between one stage to another …

I follow some tutorials that propose making something like this in the main class


public enum GameState {
		INTRO, MAIN_MENU, GAME;
	}

private void checkInput() {
		switch (state) {
		case INTRO:
			if(Keyboard.isKeyDown(Keyboard.KEY_RETURN)){
				state=State.MAIN_MENU;
			}
			if(Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)){
				Display.destroy();
				System.exit(0);
			}
			break;
		case GAME:
			if(Keyboard.isKeyDown(Keyboard.KEY_BACK)){
				state=State.MAIN_MENU;
			}
			break;
		case MAIN_MENU:
			if(Keyboard.isKeyDown(Keyboard.KEY_RETURN)){
				state=State.GAME;
			}
			if(Keyboard.isKeyDown(Keyboard.KEY_SPACE)){
				state=State.INTRO;
			}
			break;
		}
	}

and rendering and updating different stuff depending on the current stage … but it is pretty basic …
How can i manage this transition when each stage have his own class (extending my Abstract Stage class) and make each class capable to say to the main class go to n stage, unload his content and the main class load the next stage?, and if its possible want to render and update two stages at the same time (like OPTION over MAIN_MENU, and OPTIONS over GAME).

Has been thinking in static stages or something like that but nothing accomplish what I want … :clue:

can anyone make me some suggestions …
thank you a lot…

by the way … forgive me if my english is a bit primitive … its not my native language