How do I disable a JFrame's specific window control button in Java?

Question

The BA wants a window that

• has a close button
• has a maximize button
• has no enabled minimize button

He wants us, Java devs, to achieve what the C guys did which is this

Considering the requirements for window control buttons, it seems there's no way around JFrame. But how do I disable the minimize button? I will consider going for native methods, if it's the only way (the apps are installed on Windows PCs)

I can do something like this, but the minimize button stays enabled -- just the frame pops back up

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

public class NonMinimizableFrameDemo {

    public NonMinimizableFrameDemo() {
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 300);
        frame.setLocationRelativeTo(null);
        frame.addWindowListener(getWindowAdapter());
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(NonMinimizableFrameDemo::new);
    }
    private final JFrame frame = new JFrame();

    private WindowAdapter getWindowAdapter() {
        return new WindowAdapter() {

            @Override
            public void windowIconified(WindowEvent we) {
                frame.setState(JFrame.NORMAL);
                JOptionPane.showMessageDialog(frame, "Cant Minimize");
            }
        };
    }
}

Answer 1

A complicated option is to undecorate the JFrame and put an JInternalFrame inside. With a listener you have to maximize the parent JFrame when the JInternalFrame is maximized.

package fenster;

import java.awt.Toolkit;
import java.awt.event.MouseEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.EventObject;

import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.InternalFrameAdapter;
import javax.swing.event.InternalFrameEvent;
import javax.swing.event.MouseInputAdapter;

public class Test
{
   public Test()
   {
      initComponents();
   }

   public static void main(String[] args)
   {
      javax.swing.SwingUtilities.invokeLater(new Runnable()
      {
         @Override
         public void run()
         {
            new Test();
         }
      });
   }

   private JFrame frame;

   private void initComponents()
   {
      try
      {
         
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
      }
      catch (ClassNotFoundException | InstantiationException
        | IllegalAccessException | UnsupportedLookAndFeelException e)
      {
         // nothing
      }
  
      frame = new JFrame();
      frame.setUndecorated(true);
      frame.setResizable(true);
      frame.setSize(600, 400);
      frame.setLocationByPlatform(true);
      JInternalFrame iframe = new JInternalFrame();
      iframe.setResizable(true);
      iframe.setClosable(true);
      iframe.setMaximizable(true);
      iframe.setIconifiable(false);   
      iframe.setSize(600, 400);
      iframe.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
      iframe.addInternalFrameListener(getAdapter());
      iframe.addPropertyChangeListener(new MyPropertyChangeListener());
      iframe.addMouseMotionListener( new DragHandler() );
      frame.addMouseMotionListener( new DragHandler() );
      frame.add(iframe);
      iframe.setVisible(true);
      frame.setVisible(true);
   }

   private InternalFrameAdapter getAdapter()
   {
       return new InternalFrameAdapter()
       {
          @Override
          public void internalFrameClosing(InternalFrameEvent e)
          {
             System.exit(0);
          }
       };
    }

   private class MyPropertyChangeListener implements PropertyChangeListener
   {
      @Override
      public void propertyChange(PropertyChangeEvent evt)
      {
         dealWithEvent(evt);   
      }
   }

   private class DragHandler extends MouseInputAdapter
   {
       public void mouseDragged( MouseEvent evt )
       {
          dealWithEvent(evt);
       }
   }

   private void dealWithEvent (EventObject event)
   {      
      if(event instanceof PropertyChangeEvent)
      {
         PropertyChangeEvent e = (PropertyChangeEvent) event;
         if(e.getPropertyName().equalsIgnoreCase("maximum"))
         {
            if(Toolkit.getDefaultToolkit().getScreenSize().width == frame.getWidth())
            {
               frame.setExtendedState(JFrame.NORMAL);
            }
            else
            {
               frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
            }
         }
      }
      else if(event instanceof MouseEvent && ((MouseEvent) event).getY() < 200)
      {
         MouseEvent e = (MouseEvent) event;
         int x = e.getX();
         int y = e.getY();
         int screenX = frame.getX();
         int screenY = frame.getY();
         screenX += x;
         screenY += y;
         frame.setLocation( screenX, screenY );
      }
      else if(event instanceof MouseEvent && ((MouseEvent) event).getY() > 200)
      {
         MouseEvent e = (MouseEvent) event;
         frame.setSize(e.getX(), e.getY());
      }  
   }
}