Java Swing How to - Show JSlider value while dragging

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Question

We would like to know how to show JSlider value while dragging.

Answer

/*w w  w .j a v  a2 s.co  m*/
/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.util.Dictionary;
import java.util.Hashtable;

import javax.swing.ImageIcon;
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;

/**
 * @version 1.13 2007-06-12
 * @author Cay Horstmann
 */
public class Main
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(new Runnable()
         {
            public void run()
            {
               SliderTestFrame frame = new SliderTestFrame();
               frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               frame.setVisible(true);
            }
         });
   }
}

/**
 * A frame with many sliders and a text field to show slider values.
 */
class SliderTestFrame extends JFrame
{
   public SliderTestFrame()
   {
      setTitle("SliderTest");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      sliderPanel = new JPanel();
      sliderPanel.setLayout(new FlowLayout(FlowLayout.LEFT));

      // common listener for all sliders
      listener = new ChangeListener()
         {
            public void stateChanged(ChangeEvent event)
            {
               // update text field when the slider value changes
               JSlider source = (JSlider) event.getSource();
               textField.setText("" + source.getValue());
            }
         };

      // add a plain slider

      JSlider slider = new JSlider();
      addSlider(slider, "Plain");

      // add a slider with major and minor ticks

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      addSlider(slider, "Ticks");

      // add a slider that snaps to ticks

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setSnapToTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      addSlider(slider, "Snap to ticks");

      // add a slider with no track

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      slider.setPaintTrack(false);
      addSlider(slider, "No track");

      // add an inverted slider

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      slider.setInverted(true);
      addSlider(slider, "Inverted");

      // add a slider with numeric labels

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setPaintLabels(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);
      addSlider(slider, "Labels");

      // add a slider with alphabetic labels

      slider = new JSlider();
      slider.setPaintLabels(true);
      slider.setPaintTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(5);

      Dictionary<Integer, Component> labelTable = new Hashtable<Integer, Component>();
      labelTable.put(0, new JLabel("A"));
      labelTable.put(20, new JLabel("B"));
      labelTable.put(40, new JLabel("C"));
      labelTable.put(60, new JLabel("D"));
      labelTable.put(80, new JLabel("E"));
      labelTable.put(100, new JLabel("F"));

      slider.setLabelTable(labelTable);
      addSlider(slider, "Custom labels");

      // add a slider with icon labels

      slider = new JSlider();
      slider.setPaintTicks(true);
      slider.setPaintLabels(true);
      slider.setSnapToTicks(true);
      slider.setMajorTickSpacing(20);
      slider.setMinorTickSpacing(20);

      labelTable = new Hashtable<Integer, Component>();

      // add card images

      labelTable.put(0, new JLabel(new ImageIcon("nine.gif")));
      labelTable.put(20, new JLabel(new ImageIcon("ten.gif")));
      labelTable.put(40, new JLabel(new ImageIcon("jack.gif")));
      labelTable.put(60, new JLabel(new ImageIcon("queen.gif")));
      labelTable.put(80, new JLabel(new ImageIcon("king.gif")));
      labelTable.put(100, new JLabel(new ImageIcon("ace.gif")));

      slider.setLabelTable(labelTable);
      addSlider(slider, "Icon labels");

      // add the text field that displays the slider value

      textField = new JTextField();
      add(sliderPanel, BorderLayout.CENTER);
      add(textField, BorderLayout.SOUTH);
   }

   /**
    * Adds a slider to the slider panel and hooks up the listener
    * @param s the slider
    * @param description the slider description
    */
   public void addSlider(JSlider s, String description)
   {
      s.addChangeListener(listener);
      JPanel panel = new JPanel();
      panel.add(s);
      panel.add(new JLabel(description));
      sliderPanel.add(panel);
   }

   public static final int DEFAULT_WIDTH = 350;
   public static final int DEFAULT_HEIGHT = 450;

   private JPanel sliderPanel;
   private JTextField textField;
   private ChangeListener listener;
}

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