Slider listening example for SO

SoundLevels.java

package org.dchan.orm;

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

/**
 * This class displays a window with a slider component. The user can slide the
 * left or right slider. As the sliders are adjusted it displays the maximum
 * sound level coming from either slider as well as the total.
 */

public class SoundLevels extends JFrame {
	private JLabel label1, label2, label3, label4; // Message labels
	private JTextField maxSound; // Max Sound Level
	private JTextField totalSound; // Total Sound Level
	private JPanel mpanel; // Max sound level panel
	private JPanel tpanel; // Total sound level panel
	private JPanel sliderPanel1; // Slider panel 1
	private JPanel sliderPanel2; // Slider panel 2
	private JPanel resetpanel; // Reset button panel
	private JSlider slider1; // Left sound adjuster
	private JSlider slider2; // Right sound adjuster
	private JButton resetButton; // Reset button

	/**
	 * Constructor
	 */

	public SoundLevels() {
		// Set the title.
		setTitle("Sound Levels");

		// Specify an action for the close button.
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		// Creates reset button
		resetButton = new JButton("Reset");

		// Create the message labels.
		label1 = new JLabel("Left:  ");
		label2 = new JLabel("Right: ");
		label3 = new JLabel("Max:   ");
		label4 = new JLabel("Total: ");

		// Create the read-only text fields.
		maxSound = new JTextField("0", 10);
		maxSound.setEditable(false);
		totalSound = new JTextField("0", 10);
		totalSound.setEditable(false);

		// Create the slider.
		slider1 = new JSlider(JSlider.HORIZONTAL, 0, 100, 0);
		slider2 = new JSlider(JSlider.HORIZONTAL, 0, 100, 0);
		slider1.addChangeListener(new SliderListener());
		slider2.addChangeListener(new SliderListener());
		// Create panels and place the components in them.
		mpanel = new JPanel();
		resetpanel = new JPanel();
		tpanel = new JPanel();
		sliderPanel1 = new JPanel();
		sliderPanel2 = new JPanel();

		// Add components to panels
		mpanel.add(label1);
		mpanel.add(maxSound);

		tpanel.add(label2);
		tpanel.add(totalSound);

		sliderPanel1.add(label1);
		sliderPanel1.add(slider1);

		sliderPanel2.add(label2);
		sliderPanel2.add(slider2);

		resetpanel.add(resetButton);

		// Initialize event listener
		// resetButton.addActionListener(new ResetButtonListener());

		// Sets window to a border layout format.
		setLayout(new GridLayout(1, 5));

		// Add the panels to the content pane.
		add(sliderPanel1);
		add(sliderPanel2);
		add(resetpanel);
		add(mpanel);
		add(tpanel);

		// Pack and display the frame.
		pack();
		setVisible(true);
	}

	/**
	 * Private inner class that handles the event when the user clicks the Reset
	 * button.
	 */

	/*
	 * COMMENTED THIS OUT SO IT AT LEAST RUNS
	 */private class ResetButtonListener implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			// Set the panel's background to red.
			// max = 0; // should reset sliders to 0
			// total = 0; // should reset sliders to 0
			slider1.setValue(0);
			slider2.setValue(0);
		}
	}

	/*
*/

	/**
	 * Private inner class to handle the change events that are generated when
	 * the slider is moved.
	 */

	private class SliderListener implements ChangeListener {
		public void stateChanged(ChangeEvent e) {
			int max = 0;
			int total = 0;
			// Get the slider value.
			int slider1Val = slider1.getValue();
			int slider2Val = slider2.getValue();
			if (slider1Val > slider2Val) {
				max = slider1Val;
			} else {
				max = slider2Val;
			}
			total = slider2Val + slider1Val;
			// Store the total sound level in its display field.
			totalSound.setText(Integer.toString(total));

			// Store the max sound level in its display field.
			maxSound.setText(Integer.toString(max));
		}
	}

	/*
	 * The main method creates an instance of the class, which displays a window
	 * with a slider.
	 */

	public static void main(String[] args) {
		new SoundLevels();
	}
}