How to change Scroll Bar color

[Nishan Patel]

Hi,

I want to change color of Swing scroll bar horizontal and vertical scroll bar color. I worked on that a lot but I am unable to find solution for that.

So can anyone know how to change color of that scroll bar. Please find attached image for more detail.

[Campbell Ritchie]

Don't know. . . . but I need practice writing Actions.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.JTextField;
import javax.swing.JTextPane;

import static java.awt.BorderLayout.*;
import static java.awt.Color.*;
import static javax.swing.AbstractAction.*;

public class ScrollBarDemo
{
    private JFrame frame;
    private JScrollPane pane;
    private JButton horizontalButton;
    private JScrollBar horizontal;
    private JButton verticalButton;
    private JScrollBar vertical;
    private JPanel panel;
    Color[] colours;
    
    public ScrollBarDemo(String title)
    {
        frame = new JFrame(title);
        pane = new JScrollPane(panel = new JPanel(new BorderLayout()));
        panel.add(new JTextPane(), NORTH);
        panel.add(new JTextField(), SOUTH);
        colours = new Color[]{
                BLACK, WHITE, GREEN, BLUE, RED, ORANGE, MAGENTA, YELLOW,
                CYAN, DARK_GRAY, LIGHT_GRAY,};
                
        horizontal = pane.getHorizontalScrollBar();
        AbstractAction horizontalAction = new AbstractAction()        
        {
            int i = 0;
            int j = colours.length - 1;
            
            @Override public void actionPerformed(ActionEvent e)
            {
                horizontal.setBackground(colours[i++]);
                i %= colours.length;
                horizontal.setForeground(colours[j--]);
                if (j < 0) j += colours.length;
            }
        };
        horizontalAction.putValue(NAME, "Horizontal");
        horizontalAction.putValue(MNEMONIC_KEY, KeyEvent.VK_H);
        horizontalAction.putValue
                (SHORT_DESCRIPTION, "Change colour of vertical scroll bar");
        horizontalButton = new JButton(horizontalAction);
        
        vertical = pane.getVerticalScrollBar();
        AbstractAction verticalAction = new AbstractAction()        
        {
            int i = 0;
            int j = colours.length - 1;
            
            @Override public void actionPerformed(ActionEvent e)
            {
                vertical.setBackground(colours[i++]);
                i %= colours.length;
                vertical.setForeground(colours[j--]);
                if (j < 0) j += colours.length;
            }
        };
        horizontalAction.putValue(NAME, "Vertical");
        horizontalAction.putValue(MNEMONIC_KEY, KeyEvent.VK_V);
        horizontalAction.putValue(
                SHORT_DESCRIPTION, "Change colour of vertical scroll bar");
        verticalButton = new JButton(verticalAction);
        
        frame.add(pane, CENTER);
        frame.add(verticalButton, WEST);
        frame.add(horizontalButton, EAST);
        frame.setBounds(250, 150, 150, 150);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    public static void main(final String[] args)
    {
        SwingUtilities.invokeLater(
            new Runnable()
            {
                public void run()
                {
                    new ScrollBarDemo(args.length > 0 ? args[0] : "Scroll");
                }
            }
        );
    }
}

Write some text into the two text components to get the scroll bars to appear.

No, you tell me why I get a colour change in the scroll bar at the bottom if I click the "vertical" button, and vice versa. Also see what you can make of the javax.swing.plaf.ScrollBarUI class. Also why the scroll handles don't change colour.

[Campbell Ritchie]

I think I have worked out why I am getting the wrong bar changing colour