CS1 Standard Demo Page

/*
 *This is interpreter is intended to paint different colored dots in a window.
 *
 * The commands that the interpreter can recognize and respond to are;
 * -BLUE: paint a blue dot
 * -RED: paint a red dot
 * -HELP: show a list of the commands in a dialog message box
 * -EXIT: terminate the program
 */
package interpreters;

import java.awt.Color;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;
import painter.SPainter;
import shapes.SCircle;

public class Interpreter2 {
    private void interpreter() {
        //CREATE OBJECTS TO THINK WITH
        SPainter miro = new SPainter("Dot Thing", 400, 400);
        miro.setScreenLocation(0,0);
        SCircle dot = new SCircle(180);
        //REPEATEDLY TAKE A COMMAN FROM AN INPUT DIALOG BOX AND INTERPRET IT
        while (true) {
            String command = JOptionPane.showInputDialog(null, "Command?");
            if ( command == null ) { command = "exit";} //user clicked on cancel
            if ( command.equalsIgnoreCase("blue")) {
                miro.setColor(Color.BLUE);
                miro.paint(dot);
            } else if ( command.equalsIgnoreCase("red")) {
                miro.setColor(Color.RED);
                miro.paint(dot);
            }else if ( command.equalsIgnoreCase("green")) {
                    miro.setColor(Color.GREEN);
                    miro.paint(dot);
            }else if ( command.equalsIgnoreCase("yellow")) {
                miro.setColor(Color.YELLOW);
                miro.paint(dot);
            } else if (command.equalsIgnoreCase("help")) {
                JOptionPane.showMessageDialog(null, "Valid commands are:" + "RED | BLUE | GREEN | YELLOW| HELP | EXIT");
            } else if ( command.equalsIgnoreCase("exit")) {
                miro.end();
                System.out.println("Thank you for viewing the dots ...");
                break;
            } else {
                JOptionPane.showMessageDialog( null, "Unrecognizable command:" + command.toUpperCase());
            }
        }
    }
    //INFRASTRUCTURE FOR SOME SIMPLE PAINTING
    public Interpreter2() {
        interpreter();
    }
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new Interpreter2();
            }
        });
    }
}