How to convert JScrollPane like JLabel

Question

I have to change JScrollPane to something like JLabel . I used this code here:

myJScroll.setBorder(null);
myJScroll.setEnabled(false);
myJScroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_NEVER);
myJScroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);

But with setEnable(false) , it has another color that covers this pane.

How can I change this color to another color?

Answer 1

A JScrollPane contains a Viewport component that is opaque by default. You can set a custom background color for the Viewport :

myJScroll.getViewport().setBackground(Color.BLUE);

or make the viewport non-opaque:

myJScroll.getViewport().setOpaque(false);

and depending on your needs, you may also want to make the JScrollPane non-opaque (to get the true background color of the parent component of the scrollpane:

myJScroll.setOpaque(false);

Also keep in mind the opacity and default background color of the component that is being added to the viewport.

For instance, try this as a test case:

import java.awt.BorderLayout;
import java.awt.Color;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

public class ScrollPaneTest extends JPanel
{
    private static final long serialVersionUID = 1L;

    public ScrollPaneTest()
    {
        super(new BorderLayout());

        JPanel myScrolledComponent = new JPanel(new BorderLayout());
        myScrolledComponent.setBackground(Color.YELLOW);
        myScrolledComponent.setOpaque(false);
        myScrolledComponent.add(new JLabel("Some text"), BorderLayout.CENTER);

        JScrollPane myJScroll = new JScrollPane(myScrolledComponent);
        myJScroll.setBackground(Color.CYAN);
        myJScroll.setOpaque(false);

        myJScroll.setBorder(null);
        myJScroll.setEnabled(false);
        myJScroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_NEVER);
        myJScroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);

        myJScroll.getViewport().setBackground(Color.MAGENTA);
        myJScroll.getViewport().setOpaque(false);

        super.add(myJScroll, BorderLayout.CENTER);

        return;
    }

    @SuppressWarnings("deprecation")
    public static void main(String[] args)
    {
        JFrame f = new JFrame();
        f.setBackground(Color.BLUE);
        ScrollPaneTest test = new ScrollPaneTest();
        test.setBackground(Color.RED);
        f.add(test);
        f.pack();
        f.show();
    }
}

The above class will display the JLabel text with a red background (transparent all the way to the ScrollPaneTest component.

A second example based on your comment:

import java.awt.BorderLayout;
import java.awt.Color;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

public class ScrollPaneTest2 extends JScrollPane
{
    private static final long serialVersionUID = 1L;

    public ScrollPaneTest2()
    {
        super();
        super.setBackground(Color.CYAN);

        super.getViewport().setBackground(Color.MAGENTA);
        super.getViewport().setOpaque(false);

        return;
    }

    @SuppressWarnings("deprecation")
    public static void main(String[] args)
    {
        JFrame f = new JFrame();
        f.setBackground(Color.BLUE);
        ScrollPaneTest2 scrollPane = new ScrollPaneTest2();
        scrollPane.setBackground(Color.RED);
        f.add(scrollPane);

        JPanel myScrolledComponent = new JPanel(new BorderLayout());
        myScrolledComponent.setBackground(Color.YELLOW);
        myScrolledComponent.setOpaque(false);
        myScrolledComponent.add(new JLabel("Some text"), BorderLayout.CENTER);

        scrollPane.getViewport().setView(myScrolledComponent);

        scrollPane.setBorder(null);
        scrollPane.setEnabled(false);
        scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_NEVER);
        scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);

        f.pack();
        f.show();
    }
}