Transparent Panel with no artifacts

Question

I've very limited knowledge with overriding JComponent objects and painting in Java. What I'm trying to do is to create a function that I can call to set the transparency and avoid getting artifacts when buttons are clicked inside a panel. Basically I'm gonna be using this on a JPanel inside another panel. Like,

class panel1 extends JPanel(){
public panel1(){
    this.add(new panel2())
    //call the setPanelTransparency(this);
}

class panel2 extends JPanel(){
    this.setPreferredSize(new Dimension(500,500));
    this.setBorder(BorderFactory.createLineBorder(2,Color.RED);
}

How do I correct this method? I get errors when I tried to include it as method in panel1 class.

 public void setPanelTransparency(JPanel myPanel){

    protected void paintComponent ( Graphics g )
    {
        g.setColor ( getBackground () );
        g.fillRect ( 0, 0, getWidth (), getHeight () );
        super.paintComponent ( g );
    }

    });
    myPanel.setOpaque(false);
    myPanel.setBackground(new Color(49,43,31,60));
}

I'd appreciate any help. I would just like to know the simplest way to make Panels transparent without any risk of artifacts. I need a method that I can call. Also, I tried UIManager.put() but doesn't seem to apply properly without any artifacts.

I'd appreciate the simplest solution to applying transparency to my project so I can focus on creating the tables.

Answer 1

You can't use a method like setPanelTransparency() to override a method.

That panel needs to be a class on its own to override the paintComponent(...) method:

//public void setPanelTransparency(JPanel myPanel){
public class TransparentPanel extend JPanel 
{
    TransparentPanel()
    {
        setOpaque( false );
    }

    @Override
    protectect void paintComponent(...)
    ...
}

Then you just use the panel like:

TransparentPanel panel = new TransparentPanel();
panel.setBackground(...);
panel.add( new JTestField(10) );
frame.add( panel );

See Background With Transparency for more information on this approach and a different solution.