Java Tutorial/Swing Event/ChangeListener

Get value of BoundedRangeModel in its change listener

import java.awt.BorderLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.BoundedRangeModel;
import javax.swing.JFrame;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Main extends JFrame {
  JSlider slider = new JSlider();
  BoundedRangeModel model = slider.getModel();
  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    getContentPane().add(slider, BorderLayout.CENTER);
    model.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        System.out.println("Value: " + model.getValue());
      }
    });
    pack();
    setVisible(true);
  }
  public static void main(String arg[]) {
    new Main();
  }
}

Listening to JMenu Events with a ChangeListener: register a ChangeListener with a JMenu

import java.awt.event.KeyEvent;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class ContructMenuWithAction {
  public static void main(final String args[]) {
    JFrame frame = new JFrame("MenuSample Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JMenuBar menuBar = new JMenuBar();
    // File Menu, F - Mnemonic
    JMenu fileMenu = new JMenu("File");
    fileMenu.setMnemonic(KeyEvent.VK_F);
    menuBar.add(fileMenu);
    fileMenu.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        System.out.println("File Menu Changed");
      }
    });
    // File->New, N - Mnemonic
    JMenuItem newMenuItem = new JMenuItem("New");
    fileMenu.add(newMenuItem);
    newMenuItem.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        System.out.println("new menu item changed");
      }
    });
    frame.setJMenuBar(menuBar);
    frame.setSize(350, 250);
    frame.setVisible(true);
  }
}

Registers a change listener on a slider that controls animation speed. The change listener ignores the change events until the user releases the slider.

import javax.swing.JFrame;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class RegisterChangeListenerToJSlider {
  public static void main(String[] a) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JSlider framesPerSecond = new JSlider(JSlider.HORIZONTAL, 10, 100, 20);
    framesPerSecond.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        JSlider source = (JSlider) e.getSource();
        if (!source.getValueIsAdjusting()) {
          int fps = (int) source.getValue();
          System.out.println(fps);
        }
      }
    });
    frame.add(framesPerSecond,"North");
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}

Tab change listener

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.JTextField;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Test extends JFrame {
  JTabbedPane tabs = new JTabbedPane();
  public Test() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JPanel p = new JPanel();
    p.add(new JButton("Button on Tab 0"));
    tabs.addTab("Tab 0", p);
    p = new JPanel();
    p.add(new JTextField("Text on Tab 1"));
    tabs.addTab("Tab 1", p);
    tabs.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        System.out.println("Tab=" + tabs.getSelectedIndex());
      }
    });
    getContentPane().add(tabs, "Center");
    pack();
  }
  public static void main(String[] args) {
    new Test().setVisible(true);
  }
}

Uses a change listener on a date-field spinner to change the color of the text as the spinner"s date changes.

import javax.swing.JFrame;
import javax.swing.JSpinner;
import javax.swing.SpinnerModel;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AddingChangeListenerToJSpinner {
  public static void main(String[] a) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final JSpinner dateSpinner = new JSpinner();
    dateSpinner.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        SpinnerModel dateModel = dateSpinner.getModel();
        System.out.println(dateModel.getValue());
      }
    });
    frame.add(dateSpinner,"North");
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}

Uses a change listener on the selection model of a color chooser to learn when the user changes the current color.

import java.awt.Color;
import javax.swing.JColorChooser;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AddingChangeListenerToJColorChooser {
  public static void main(String[] a) {
    final JColorChooser tcc = new JColorChooser();
    tcc.getSelectionModel().addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        System.out.println(tcc.getColor());
      }
    });
   tcc.showDialog(null,"title",Color.RED);
  }
}