How to open a class from another class

**jsobel** · 04-06-2012, 11:55 PM

I have two classes and i want to open one from another how do i do this.

StartScreen.java

Java Code:

import javax.swing.*;
import java.awt.event.*;

public class StartScreen extends JFrame implements ActionListener
{
	public static void main(String [] args)
	{
	new StartScreen();	
	}
	
	private JButton button1;
	
	public StartScreen()
	{
		this.setSize(300, 150);
		this.setTitle("Start");
		JPanel panel1 = new JPanel();
		button1 = new JButton ("CLICK TO START");
		button1.addActionListener(this);
		panel1.add(button1);
		this.add(panel1);
		this.setVisible(true);
	}
	
	public void actionPerformed(ActionEvent e)
	{
		if (e.getSource() == button1){this is where i want to get the other class from}
	}
	}

Pong.java

Java Code:

import java.awt.*;

import javax.swing.*;

import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.*;
import java.util.Scanner;
import java.util.concurrent.*;

public class Pong extends JFrame
{
	private static final long serialVersionUID = 1L;
	public static final int WIDTH = 900;
	public static final int HEIGHT = 725;
	int x;
	int y=0;
	private PaintSurface canvas;
public Pong()
	{
		this.setSize(WIDTH, HEIGHT);
		canvas = new PaintSurface();
		this.add(canvas, BorderLayout.CENTER);
		this.setVisible(true);
		ScheduledThreadPoolExecutor executor = new ScheduledThreadPoolExecutor(3);
		executor.scheduleAtFixedRate(new AnimationThread(this),
		0L, 20L, TimeUnit.MILLISECONDS);
	}
}

class AnimationThread implements Runnable
{
	Pong c;

	public AnimationThread(Pong pong)
	{
		this.c = pong;	

	}

	public void run()
	{
		c.repaint();
	}
}

class PaintSurface extends JComponent // this is the class i want to open
{
	private static final long serialVersionUID = 1L;
	int x_pos = 0;
	int y_pos = 0;
	double x_speed = 1;
	double y_speed = 1;
	int d = 20;
	int width = Pong.WIDTH;
	int height = Pong.HEIGHT;
	int x;
	int o = 0;
	public PaintSurface()
	{
		addMouseMotionListener(new MouseMotionAdapter() 
		{
			public void mouseMoved(MouseEvent e) {
				x = e.getX();
			}
			
		});		
	}
	
	public void paint(Graphics g) {
		Graphics2D g2 = (Graphics2D) g;
		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
				RenderingHints.VALUE_ANTIALIAS_ON);
		if (x_pos < 0) {
			x_speed = -x_speed;
		}
		if (x_pos > width - d) {
			x_speed = -x_speed;
		}

		if (y_pos < 0) {
			y_speed = -y_speed;
			;
		}

		if (y_pos + 20 > 675 && x_pos > x && x_pos < x + 50) {
			y_speed = -(y_speed + .5);
			x_speed = x_speed + .5;
			o = (o + 1);
		}

		if (y_pos > 695)
		{System.exit(8);}
		String p = Integer.toString(o);
		x_pos += x_speed;
		y_pos += y_speed;
		Shape ball = new Ellipse2D.Float(x_pos, y_pos, d, d);
		g2.setColor(Color.BLACK);
		g2.fill(ball);
		Shape paddle = new Rectangle.Float(x, 675, 50, 8);
		g2.setColor(Color.BLACK);
		g2.fill(paddle);		
		g2.drawString("score " + (p), 7, 10);}
	
	public static void main(String[] args) {
		new Pong();
	}
}