Java / Swing -> Creating a notification JFrame, and the error “The frame is displayable”

Question

Ok, I am not that versed in Java / Swing, and I am running into a problem. My application is throwing this error: \"Exception in thread \"AWT-EventQueue-0\" java.awt.Illegal

Answer 1

The error you are getting is calling setUndecorated(true) after the frame is made displayable by calling pack(). Call setUndecorated before pack and it should work.

Answer 2

• +1 thanks for this thread, your code solved quite correctly undecorated conatiner, everything is about correct ordering of methods (wooolaaa we are back to Java_1.4.2 edges)

• but bug still is there, isn't possible to create decorated JFrame with changed Look And Feel

• based on proper ordering of methods

import java.awt.*;
import javax.swing.*;

public class TranslucentWindow extends JFrame {

    private static final long serialVersionUID = 1L;

    public TranslucentWindow() {
        super("Test translucent window");
        setLayout(new FlowLayout());
        add(new JButton("test"));
        add(new JCheckBox("test"));
        add(new JRadioButton("test"));
        add(new JProgressBar(0, 100));
        JPanel panel = new JPanel() {
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(400, 300);
            }
            private static final long serialVersionUID = 1L;

            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                g.setColor(Color.red);
                g.fillRect(0, 0, getWidth(), getHeight());
            }
        };
        panel.add(new JLabel("Very long textxxxxxxxxxxxxxxxxxxxxx "));
        add(panel);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setUndecorated(true);
        pack();
        setLocationRelativeTo(null);
        setOpacity(0.70f);
    }

    public static void main(String[] args) {
        try {
            for (UIManager.LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        //JFrame.setDefaultLookAndFeelDecorated(true);
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                Window w = new TranslucentWindow();
                w.setVisible(true);
            }
        });
    }
}