Managing the Form Flow in J2ME

package tips.formstack;
import java.util.Stack;

public class FormFlow {

	private static Stack stack = new Stack();
	
	public static void addInstance(Object instance) {
		stack.push(instance);
	}

	public static Object getInstance() {
		return stack.pop();
	}
	
	public static void showPrevious() {
		((Showable)FormFlow.stack.pop()).show();
	}
}

/*
 * Design an interface to extract common functionality
 */

package tips.formstack;

public interface Showable {
	void show();
}

/*
 * Design a class that implements Showable
*/
package tips.formstack;

public class MyShowableObject implements Showable {

	int index;
	
	public MyShowableObject(int index){
		this.index = index;
	}
		
	public void show() {
		System.out.println("Showing "+index);		
	}
}