JSlider Java

Introduction

The class JSlider is a component which lets the user graphically select a value by sliding a knob within a bounded interval.

Class Declaration

Following is the declaration for javax.swing.JSlider class −

public class JSlider
   extends JComponent
      implements SwingConstants, Accessible

Field

Following are the fields for javax.swing.JSlider class −

• protected ChangeEvent changeEvent − Only one ChangeEvent is needed per slider instance since the event's only (read-only) state is the source property.
• protected ChangeListener changeListener − The changeListener (no suffix) is the listener we add to the slider's model.
• protected int majorTickSpacing − The number of values between the major tick marks -- the larger marks that break up the minor tick marks.
• protected int minorTickSpacing − The number of values between the minor tick marks -- the smaller marks that occur between the major tick marks.
• protected int orientation − Whether the slider is horizontal or vertical The default is horizontal.
• protected BoundedRangeModel sliderModel − The data model that handles the numeric maximum value, minimum value, and current-position value for the slider.
• protected boolean snapToTicks − If true, the knob (and the data value it represents) resolve to the closest tick mark next to where the user positioned the knob.

Class Constructors

Sr.No.	Constructor & Description
1	JSlider() Creates a horizontal slider with the range 0 to 100 and an initial value of 50.
2	JSlider(BoundedRangeModel brm) Creates a horizontal slider using the specified BoundedRangeModel.
3	JSlider(int orientation) Creates a slider using the specified orientation with the range 0 to 100 and an initial value of 50.
4	JSlider(int min, int max) Creates a horizontal slider using the specified min and max with an initial value equal to the average of the min plus max.
5	JSlider(int min, int max, int value) Creates a horizontal slider using the specified min, max and value.
6	JSlider(int orientation, int min, int max, int value) Creates a slider with the specified orientation and the specified minimum, maximum, and initial values.

Class Methods

Here is the list of methods in Swing JSlider class.

Methods Inherited

This class inherits methods from the following classes −

• javax.swing.JComponent
• java.awt.Container
• java.awt.Component
• java.lang.Object

JSlider Example

import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class Main {
  public static void main(String[] args) {
    JFrame f = new JFrame();
    final JSlider slider = new JSlider(0, 150, 0);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    slider.setPreferredSize(new Dimension(150, 30));
    slider.addChangeListener(new ChangeListener() {
      public void stateChanged(ChangeEvent event) {
        int value = slider.getValue();
        if (value == 0) {
          System.out.println("0");
        } else if (value > 0 && value <= 30) {
          System.out.println("value > 0 && value <= 30");
        } else if (value > 30 && value < 80) {
          System.out.println("value > 30 && value < 80");
        } else {
          System.out.println("max");
        }
      }
    });
    f.add(slider);
    f.pack();
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}

ANOTHER JSLIDER CODE
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class JSliderDemo {
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;

   public JSliderDemo(){
      prepareGUI();
   }
   public static void main(String[] args){
      JSliderDemo  jSliderDemo = new JSliderDemo();      
      jSliderDemo.showSliderDemo();
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Java Swing Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      headerLabel = new JLabel("", JLabel.CENTER);        
      statusLabel = new JLabel("",JLabel.CENTER);    
      statusLabel.setSize(350,100);

      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }
   private void showSliderDemo(){
      headerLabel.setText("Control in action: JSlider"); 
      JSlider slider = new JSlider(JSlider.HORIZONTAL,0,100,10);
      
      slider.addChangeListener(new ChangeListener() {
         public void stateChanged(ChangeEvent e) {
            statusLabel.setText("Value : " + ((JSlider)e.getSource()).getValue());
         }
      });
      controlPanel.add(slider);      
      mainFrame.setVisible(true);     
   } 
}

THE OUTPUT IS