package swingExamples;

import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 * The main panel for the Multicaster main frame
 */
class MulticastPanel extends JPanel
    implements ActionListener
{
  public MulticastPanel()
  {
    m_newButton = new JButton("Create Frame");
    m_newButton.addActionListener(this);
    add(m_newButton);
    
    m_closeAllButton = new JButton("Close All");
    m_closeAllButton.setEnabled(false);
    add(m_closeAllButton);
    
    // Listens for SimpleFrames to close
    m_windowListener = new WindowAdapter()
    {
      public void windowClosing(WindowEvent ev)
      {
        // One fewer SimpleFrame visible
        if (--m_totalFrameCount == 0)
        {
          // Once there are no more SimpleFrames left,
          // disable the Close All button.
          m_closeAllButton.setEnabled(false);
        }
      }
    };
  }
  
  public void actionPerformed(ActionEvent event)
  {
    Object source = event.getSource();
    if (source == m_newButton)
    {
      // Create Frame button click causes 
      // a SimpleFrame to be created
      SimpleFrame frame = new SimpleFrame(++m_nextFrameNo);
      // Keeps track of how many SimpleFrames 
      // are currently up.
      m_totalFrameCount++;
      // SimpleFrame listens for Close All button clicks.
      m_closeAllButton.addActionListener(frame);
      // At least one SimpleFrame up, so enable the 
      // Close All button.
      m_closeAllButton.setEnabled(true);
      // Listens for SimpleFrame to close
      frame.addWindowListener(m_windowListener);
      // Makes SimpleFrame visible
      frame.setVisible(true);
    }
  }
  
  /////////// Private data //////////
  private JButton m_newButton;
  private JButton m_closeAllButton;
  private WindowListener m_windowListener;
  
  private static int m_nextFrameNo = 0; 
          // Frame number for next frame
  private static int m_totalFrameCount = 0; 
          // Count of frames currently visible
}

/**
 * Frame to be displayed when user clicks on 
 * "Create Frame" button.
 */
class SimpleFrame extends JFrame
    implements ActionListener
{
  SimpleFrame(int frameNumber)
  {
    setSize(300, 200);
    // Calculate an offset to locate the SimpleFrame 
    // on the screen
    int offset = 30 * ( (frameNumber - 1) % 10);
    setLocation(offset, offset);
    // Give it a title
    setTitle("Frame " + frameNumber);
  }
  
  public void actionPerformed(ActionEvent ev)
  {
    // This method is invoked by a Close All button click
    
    // Make the frame invisible
    setVisible(false);
    // The above doesn't generate an event, so create one 
    // and dispatch it so that the window listener is informed
    dispatchEvent(new WindowEvent(
        this, 
        WindowEvent.WINDOW_CLOSING));
    // Get rid of this frame's resources
    dispose();
  }
}

/**
 * The "main" frame class
 */
class MulticastFrame extends JFrame
{
  public MulticastFrame()
  {
    setTitle("MulticastTest");
    setSize(100, 50);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    Container contentPane = getContentPane();
    contentPane.add(new MulticastPanel());
    pack(); // Size, based on contents of frame
  }
}

public class Multicaster
{
  public static void main(String[] args)
  {
    MulticastFrame frame = new MulticastFrame();
    frame.setVisible(true);
  }
}