Translucent JPopupMenu inside a Translucent Window - alternative?

Question

I'm not sure if this is possible, but is there a way to safely allow popups to be translucent even when the parent container is also translucent?

If not, what would be wise alternative to use or extend instead of JPopupMenu?

Note: Translucent refers to a component not 'having a background', similar to the effect of setOpaque(false);. Thanks.

From a forum answer by user camickr in 2009:

I don't know if transparency painting has changed in 1.6.0_10. Prior to that I believe transparency can only be achieved in lightweight components (ie. Swing does all the painting). JFrame, JWindow and JDialog are not lightweight because they use OS components.

In the case of a popup, it is lightweight when entirely contained within its parent frame. But a lightweight popup can not be painted outside the bounds of the frame so a JWindow (I believe) is used as the popup, which can't be transparent.

SSCCE: Showing translucent JWindow over the top of translucent JFrame

import com.sun.awt.AWTUtilities;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

public class OpaqueWindowSSCCE {

    private int countdown = 5;

    public static void main(String[] args) {
        new OpaqueWindowSSCCE();
    }

    public OpaqueWindowSSCCE() {
        final JFrame frame = new JFrame("OpaqueWindowSSCCE");
        final JWindow window = new JWindow();

        new Timer(1000, new ActionListener(){

            @Override
            public void actionPerformed(ActionEvent e) {
                if(--countdown == 0){
                    frame.dispose();
                    window.dispose();
                    System.exit(0);
                } else {
                    frame.repaint();
                }
            }

        }).start();

        frame.setContentPane(new JPanel() {

            @Override
            public void paintComponent(Graphics paramGraphics) {
                super.paintComponent(paramGraphics);
                Graphics2D g = (Graphics2D) paramGraphics.create();
                g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
                g.setColor(new Color(50, 50, 50));
                g.fillRoundRect(0, 0, getWidth(), getHeight(), 10, 10);
                g.setColor(new Color(180, 180, 180));
                g.drawString("Closing in " + countdown + " seconds", 20, 25);
            }
        });

        window.setContentPane(new JPanel() {

            @Override
            public void paintComponent(Graphics paramGraphics) {
                super.paintComponent(paramGraphics);
                Graphics2D g = (Graphics2D) paramGraphics.create();
                g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
                g.setColor(new Color(180, 180, 180));
                g.fillRoundRect(0, 0, getWidth(), getHeight(), 10, 10);
            }
        });

        frame.setUndecorated(true);

        ((JComponent) frame.getContentPane()).setOpaque(false);
        ((JComponent) window.getContentPane()).setOpaque(false);

        AWTUtilities.setWindowOpaque(frame, false);
        AWTUtilities.setWindowOpaque(window, false);

        window.setAlwaysOnTop(true);

        frame.setBounds(200,200,500,500);
        window.setBounds(600,600,200,200);
        frame.setVisible(true);
        window.setVisible(true);
    }
}

Hoffert

I guess this can be achieved, in the given context, that you are doing, with JWindow using this funciton setOpacity(). – Purree

Answer 1

Try this code part, I had used JWindow though

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

public class WindowExample
{
    private JWindow window;
    private JLabel updateLabel;
    private int count = 5;
    private Timer timer;
    private int x;
    private int y;
    private ActionListener timerAction = new ActionListener()
    {
        public void actionPerformed(ActionEvent ae)
        {
            updateLabel.setText("Closing Window in " + count + " seconds...");
            count--;
            if (count == 0)
            {
                timer.stop();
                window.setVisible(false);
                window.dispose();
            }   
        }
    };

    private void createAndDisplayGUI()
    {
        final JFrame frame = new JFrame("Window Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.setUndecorated(true);
        frame.setOpacity(0.5f);
        frame.addMouseListener(new MouseAdapter()
        {
            public void mouseClicked(MouseEvent me)
            {
                x = me.getX();
                y = me.getY();
                window = new JWindow();
                JPanel contentPane = new JPanel();
                JLabel positionLabel = new JLabel(
                    "X : " + me.getX() + " Y : " + me.getY());
                updateLabel = new JLabel("TImer");  
                contentPane.setLayout(new BorderLayout(5, 5));
                contentPane.add(updateLabel, BorderLayout.CENTER);
                contentPane.add(positionLabel, BorderLayout.PAGE_END);
                window.setContentPane(contentPane);
                window.setOpacity(0.5f);
                window.setSize(200, 100);
                window.setLocation(x + window.getWidth(), y + window.getHeight());
                window.setVisible(true);
                count = 5;
                timer = new Timer(1000, timerAction);
                timer.start();
            }
        });

        frame.setSize(500, 500);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                new WindowExample().createAndDisplayGUI();
            }
        });
    }
}

And here is the output :

WARNING I AM GETTING

C:\Mine\JAVA\J2SE>javac -d classes src\OpaqueWindowSSCCE.java
src\OpaqueWindowSSCCE.java:1: warning: AWTUtilities is internal proprietary API and may be removed i
n a future release
import com.sun.awt.AWTUtilities;
                  ^
src\OpaqueWindowSSCCE.java:68: warning: AWTUtilities is internal proprietary API and may be removed
in a future release
        AWTUtilities.setWindowOpaque(frame, false);
        ^
src\OpaqueWindowSSCCE.java:69: warning: AWTUtilities is internal proprietary API and may be removed
in a future release
        AWTUtilities.setWindowOpaque(window, false);
        ^
3 warnings

Purree

Thanks for the SSCCE! It's clear that JWindow is capable of displaying properly - the drawback is that I'll have to implement the showing and hiding to imitate that of a JPopupMenu, which wouldn't be too hard. – Hoffert

You are MOST WELCOME AND KEEP SMILING :-), yeah that's true, even in JPopUpMenu I guess you have to click at some other place to hide the previous :-), Just the advantage of JWindow is that we can add whatever we want to add to it, to show it to the user :-) – Purree

Yeah, but JPopUpMenu handles focus very nicely and will have to make sure it works well. For some reason I didn't think of JWindow at all... thanks, I'll give it a shot and come back to you. :D – Hoffert

Hmm this doesn't work though, because setting arbitrary OPACITY isn't the issue here. What I would like is for the popup to not have a background at all (so that round corners can be round). The key thing to note is that the JFrame is not opaque, via AWTUtilities.setWindowOpaque(frame, false); – Hoffert

@paranoid-android : Sorry for the late reply, some server issues came in. May you please provide some small working code that I can try my hands on, if it's not a big issue, it would be great :-) – Purree

@paranoid-android : Thankyou for this, MAY I ask you a simple question, as to why this warning coming to me, do check my answer for that. I am glad though, that my answer did helped you somewhere :-) WOWO, I learned something from your inputs too, how to paint rounded JWindow , that's impressive :-) – Purree