I have a modal settings dialog which is a JDialog. In this settings window I placed some components including a button to yet another modal settings dialog which is also a JDialog. I made them JDialogs because that is the only way I know of to make a modal dialog.
The problem is this: when I create the main settings dialog I have to construct the JDialog either without a parent Frame or with a parent Frame. Since my main window is a JFrame, I can just pass that to the main settings dialog constructor. But when I want to create the second modal settings dialog which should have the main settings dialog as a parent, I can't find a way to get the (J)Frame of the JDialog. I do want to pass that main settings dialog as a parent so that the second settings dialog centers on it when it is shown. Let's assume the second settings dialog has no constructor for passing a location, just the constructors of the JDialog.
Is there a way to get the (J)Frame of a JDialog? Is there a design flaw in my setup and should I have used something else for these settings dialogs? (And if so, how should I make these alternative settings dialogs modal?)
Thank you for your help, Erik
UPDATE: Thank you all for your answers. They led me to understand that apparently it's not absolutely necessary to have an owner for a JDialog. I thought this was needed for the dialog to be able to disable the owner until the dialog is closed, but apparently the modality is independent of the owner. I also noticed that even with an owner the dialog still doesn't center on the owner, so now my code is like:
public class CustomDialog extends JDialog {
public CustomDialog(String title) {
setModal(true);
setResizable(false);
setTitle(title);
buildGUI();
}
public Result showDialog(Window parent) {
setLocationRelativeTo(parent);
setVisible(true);
return getResult();
}
}
This also allows for modal dialogs in modal dialogs.
Thanks for all your help!
Not sure what exactly you have as a problem, but here is an example on how you can have multiple modal dialogs:
import java.awt.BorderLayout;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class TestDialog {
protected static void initUI() {
JPanel pane = newPane("Label in frame");
JFrame frame = new JFrame("Title");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(pane);
frame.pack();
frame.setVisible(true);
}
public static JPanel newPane(String labelText) {
JPanel pane = new JPanel(new BorderLayout());
pane.add(newLabel(labelText));
pane.add(newButton("Open dialog"), BorderLayout.SOUTH);
return pane;
}
private static JButton newButton(String label) {
final JButton button = new JButton(label);
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Window parentWindow = SwingUtilities.windowForComponent(button);
JDialog dialog = new JDialog(parentWindow);
dialog.setLocationRelativeTo(button);
dialog.setModal(true);
dialog.add(newPane("Label in dialog"));
dialog.pack();
dialog.setVisible(true);
}
});
return button;
}
private static JLabel newLabel(String label) {
JLabel l = new JLabel(label);
l.setFont(l.getFont().deriveFont(24.0f));
return l;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
initUI();
}
});
}
}