JDialog: accessing its "title bar"

[Claude Moore]

Hi there,

I need to add a custom handler for double-click on a JDialog's title bar. I need the component to be reactive only if user clicks twice on the title bar; the problem is I don't know how (and I did not find anything useful on the matter) access that part of the component. Can anyone suggest me how to achieve this ?

[Michael Dunn]

this works, but the 'JDialog.setDefaultLookAndFeelDecorated(true)' is a bit ugly

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class Testing
{
  public void buildGUI()
  {
    JDialog.setDefaultLookAndFeelDecorated(true);
    JDialog d = new JDialog();
    d.setSize(400,200);
    d.setLocationRelativeTo(null);
    d.setVisible(true);
    d.addWindowListener(new WindowAdapter(){
      public void windowClosing(WindowEvent we){
        System.exit(0);
      }
    });
    d.getLayeredPane().getComponent(1).addMouseListener(new MouseAdapter(){
      public void mousePressed(MouseEvent me){
        if(me.getClickCount() == 2) System.out.println("Title bar double-clicked");
      }
    });
  }
  public static void main(String[] args)
  {
    SwingUtilities.invokeLater(new Runnable(){
      public void run(){
        new Testing().buildGUI();
      }
    });
  }
}

[Claude Moore]

Michael,

thank you so much for your reply and providing me a sample. In a nutshell, the part of the code that gives you a reference to JDialog's title is

d.getLayeredPane().getComponent(1)

Your code works, anyway there's another problem: I cannot drag dialog's window anymore. It seems "frozen". It's like if adding a MouseListener to d.getLayeredPane().getComponent(1) inhibits default drag handler...

[Michael Dunn]

it would probably consume the mouseEvent that would normally pass to the default listener handling the dragging.

add your own mouseMotionListener for dragging

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class Testing
{
  Point startPt;//<----------------------added
  public void buildGUI()
  {
    JDialog.setDefaultLookAndFeelDecorated(true);
    final JDialog d = new JDialog();
    d.setSize(400,200);
    d.setLocationRelativeTo(null);
    d.setVisible(true);
    d.addWindowListener(new WindowAdapter(){
      public void windowClosing(WindowEvent we){
        System.exit(0);
      }
    });
    d.getLayeredPane().getComponent(1).addMouseListener(new MouseAdapter(){
      public void mousePressed(MouseEvent me){
        startPt = me.getPoint();//<----------------------added
        if(me.getClickCount() == 2) System.out.println("Title bar double-clicked");
      }
    });
    d.getLayeredPane().getComponent(1).addMouseMotionListener(new MouseMotionAdapter(){
      public void mouseDragged(MouseEvent me){
        Point dragPt = me.getPoint();
        d.setLocation(d.getX()+dragPt.x-startPt.x,d.getY()+dragPt.y-startPt.y);
      }
    });
  }
  public static void main(String[] args)
  {
    SwingUtilities.invokeLater(new Runnable(){
      public void run(){
        new Testing().buildGUI();
      }
    });
  }
}

[Darryl Burke]

Or add the custom listener to the dialog (which is where the original drag handler is added).

    final Component titleBar = dialog.getLayeredPane().getComponent(1);
    dialog.addMouseListener(new MouseAdapter() {

      @Override
      public void mousePressed(MouseEvent me) {
        Point pointInTitleBarSpace
                = SwingUtilities.convertPoint((Component) me.getSource(),me.getPoint(), titleBar);
        if (me.getClickCount() == 2 && titleBar.getBounds().contains(pointInTitleBarSpace)) {
          System.out.println("Title bar double-clicked");
        }
      }
    });

Took a fair amount of sleuthing through the sources to find the handler.

[Claude Moore]

Thak you so much, I've tested Michael's second post code and it works greatly.