JComponent: setOpaque(boolean isOpaque)
import java.awt.Color;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainClass extends JFrame {
public MainClass() {
super("Opaque JPanel Demo");
setSize(400, 200);
setDefaultCloseOperation(EXIT_ON_CLOSE);
JPanel opaque = createNested(true);
JPanel notOpaque = createNested(false);
getContentPane().setLayout(new FlowLayout());
getContentPane().add(opaque);
getContentPane().add(notOpaque);
}
public static void main(String[] args) {
MainClass oe = new MainClass();
oe.setVisible(true);
}
public JPanel createNested(boolean opaque) {
JPanel outer = new JPanel(new FlowLayout());
JPanel inner = new JPanel(new FlowLayout());
outer.setBackground(Color.white);
inner.setBackground(Color.black);
inner.setOpaque(opaque);
inner.setBorder(BorderFactory.createLineBorder(Color.gray));
inner.add(new JButton("Button"));
outer.add(inner);
return outer;
}
}
Related examples in the same category