import java.awt.Dimension; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JPanel; public class ButtonPanel extends JPanel { JButton red; JButton green; ColorPanel colorpanel; public ButtonPanel(ColorPanel colorpanel) { this.colorpanel = colorpanel; this.setLayout(new GridLayout(1, 2)); ButtonListener listen = new ButtonListener(); red = new JButton("Red"); red.addActionListener(listen); add(red); green = new JButton("Green"); green.addActionListener(listen); add(green); setPreferredSize(new Dimension(200, 50)); } private class ButtonListener implements ActionListener { public void actionPerformed(ActionEvent event) { if (event.getSource() == red) { colorpanel.makeRed(); } else { colorpanel.makeGreen(); } } } }