Make Java Swing Modal Dialog Behave Like Mac OSX Dialogs

Question

I am writing a small app that requires a ProgressBar to appear centred under the frame's TitleBar as is often seen in Mac OSX apps. I have two problems:

1. I have managed the positioning but I had to hard code the parent Frame's TitleBar height. Is there a 'soft' way to get the TitleBar's height?

In the Dialog's constructor:

 Dimension dimensionParentFrame = parent.getSize();
 Dimension dimensionDialog = getSize();
 int x = parent.getX() + ((dimensionParentFrame.width - dimensionDialog.width)/2);
 setLocation(x, parent.getY() + 22);              // TODO HARD CODE WARNING TITLE HEIGHT

2. Even though the Dialog is modal, I can still click on the parent Frame and move it. How can I make the Dialog 'stick' to the parent Frame? That is, when the parent Frame is moved the Dialog moves with it as if attached.

Any help/pointers would be much appreciated.

Here is the code:

    import javax.swing.JFrame;
    import javax.swing.JButton;
    import java.awt.BorderLayout;
    import java.awt.EventQueue;
    import java.awt.event.ActionListener;
    import java.awt.event.ActionEvent;


    public class ModalDialogDemoFrame extends JFrame
    {
      ModalDialogDemoFrame modalDialogDemo;
      public ModalDialogDemoFrame() 
      {
        modalDialogDemo = this;
        setBounds(100, 100, 400, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JButton buttonDialog = new JButton("Open Dialog");
        buttonDialog.addActionListener(new ActionListener() 
        {
          public void actionPerformed(ActionEvent arg0) 
          {
            // Create a Modal Dialog with this Frame as Parent.
            ModalDialog modalDialog = new ModalDialog(modalDialogDemo, true);
            modalDialog.setVisible(true);
          }
        });
        getContentPane().add(buttonDialog, BorderLayout.CENTER);
      }

      /**
       * @param args
       */
      public static void main(String[] args)
      {
        EventQueue.invokeLater(new Runnable()
        {
          public void run()
          {
            try
            {
              ModalDialogDemoFrame window = new ModalDialogDemoFrame();
              window.setVisible(true);
            }
            catch (Exception e)
            {
              e.printStackTrace();
            }
          }
        });
      }

    }

    import java.awt.Dimension;

    import javax.swing.JDialog;
    import javax.swing.JFrame;
    import javax.swing.JButton;
    import java.awt.BorderLayout;
    import java.awt.event.ActionListener;
    import java.awt.event.ActionEvent;


    public class ModalDialog extends JDialog
    {
      public ModalDialog(JFrame parent, boolean modal) 
      {
        super(parent, modal);
        Dimension dimensionParentFrame = parent.getSize();
        setSize(new Dimension((parent == null) ? 300 : dimensionParentFrame.width / 2, 75));
        Dimension dimensionDialog = getSize();
        int x = parent.getX() + ((dimensionParentFrame.width - dimensionDialog.width)/2);
        setLocation(x, parent.getY() + parent.getInsets().top);
        setUndecorated(true);
        setModal(modal);
        setModalityType(ModalityType.APPLICATION_MODAL);
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);

        JButton buttonClose = new JButton("Close");
        buttonClose.addActionListener(new ActionListener() 
        {
          public void actionPerformed(ActionEvent e) 
          {
            dispose();
          }
        });
        getContentPane().add(buttonClose, BorderLayout.CENTER);
      }

    }

Answer 1

int titleBarHeight = frame.getInsets().top;

Even though the Dialog is modal, I can still click on the parent Frame and move it.

Then you are doing something wrong because this should NOT happen.

Post your SSCCE that demonstrates the problem.