How do I know how many JFrames has opened ?

Question

Hi,
I've got an application which has a main form (JFrame).
Inside this main form there are buttons which opens others JFrames.
When I close the main form I need to show how many others Jframes has opened.
How do I know how many Jframes has opened in my whole application ?
and
How can I get them ?
Can someone help me, please ?
Thanks.
wmiro.

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class FrameTest
    static JLabel label;
    static int
        frameCount = 0,    // number of visible frames
        frameNumber = 0;   // consecutive frame number
    public static void main(String[] args)
        label = new JLabel("frame count = 0", JLabel.CENTER);
        JButton addButton = new JButton("add frame");
        addButton.addActionListener(new ActionListener()
            public void actionPerformed(ActionEvent e)
                makeNewFrame(++frameCount);
                label.setText("frame count = " + frameCount);
                label.repaint();
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.weightx = 1.0;
        gbc.fill = gbc.HORIZONTAL;
        panel.add(label, gbc);
        JPanel northPanel = new JPanel();
        northPanel.add(addButton);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(northPanel, "North");
        f.getContentPane().add(panel);
        f.setSize(175,120);
        f.setLocation(50,50);
        f.setVisible(true);
    private static void makeNewFrame(int count)
        final JFrame f = new JFrame(String.valueOf(++frameNumber));
        f.addWindowListener(new WindowAdapter()
            public void windowClosing(WindowEvent e)
                reportFrameClosing();
                f.dispose();
        f.getContentPane().add(new JLabel("frame " + frameNumber));
        f.setSize(140,70);
        f.setLocation(175 + count*40, 120 + count*80);
        f.setVisible(true);
    public static void reportFrameClosing()
        frameCount--;
        label.setText("frame count = " + frameCount);
        label.repaint();
}