14. 8. 2. JToggleButton is a button that has two states. Pressed and not pressed.

import java.awt.Color; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JDialog; import javax.swing.JPanel; import javax.swing.JToggleButton; public class ToggleButton extends JDialog implements ActionListener { private JToggleButton red = new JToggleButton("red"); private JToggleButton green = new JToggleButton("green"); private JToggleButton blue = new JToggleButton("blue"); private JPanel display = new JPanel(); public ToggleButton() { JPanel bottom = new JPanel(); JPanel leftPanel = new JPanel(); red.addActionListener(this); green.addActionListener(this); blue.addActionListener(this); leftPanel.add(red); leftPanel.add(green); leftPanel.add(blue); bottom.add(leftPanel); display.setBackground(Color.black); bottom.add(display); add(bottom); pack(); setResizable(false); setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE); setVisible(true); } public static void main(String[] args) { new ToggleButton(); } public void actionPerformed(ActionEvent e) { Color color = display.getBackground(); int red = color.getRed(); int green = color.getGreen(); int blue = color.getBlue(); if (e.getActionCommand() == "red") { if (red == 0) { red = 255; } else { red = 0; } } if (e.getActionCommand() == "green") { if (green == 0) { green = 255; } else { green = 0; } } if (e.getActionCommand() == "blue") { if (blue == 0) { blue = 255; } else { blue = 0; } } Color setCol = new Color(red, green, blue); display.setBackground(setCol); } }