Question

I have a Problem:

I’m rendering a BufferedImage in a JFrame. Then i add a JButton to the same frame.
when i try to make the button transparent, the button becomes transparent, but disregarding its actual position, its always transparent like it is stuck in the top left corner of the frame.
I testet some different methods to make the button transparent, always with the same result.

any ideas?

thanks

public class TestPanel extends JPanel {

public TestPanel(){
    JButton foo = new JButton("test");
    foo.setBackground(new Color(0, 0, 0, 0));
    foo.setBounds(20, 100, 300, 50);
    this.add(foo);
}

public void paint(Graphics g){
    Graphics2D g2 = (Graphics2D) g;
    g2.drawImage(ImageFactory.getImg(), 0, 0, null); //get a BufferedImage
    g2.dispose();
}

}

Answer 1

I see several problems, even if I’m not sure on which of them cause your problem.I try to list them in order:

1. Your TestPanel doesn’t specify a LayoutManager (I hope you are specifying it somewhere else in your code).

2. You are extending a JPanel without call super paintComponent method (don’t use paint). You should do this before anything else in your paintComponent method:

   public void paintComponent(Graphics g){
       super.paintComponent(g); 
   }
   

3. remove the dispose method call. You must not destroy your graphic object.

EDIT:

1. this is a problem:

   foo.setBounds(20, 100, 300, 50);
   

   you are trying to explicitly set the bounds of your JButton. You shouldn’t do that. If you are using a LayoutManager it probably ignore this directive. If you are using a null layout this could be a problem too.