// Based from Fig. 12.27: PanelDemo.java from Deitel Java HTP
//
// Using a JPanel to help lay out components.

// Note: the event handlers in this program use 3 different
// methods for adding the action listener.  This is done for
// demostration purposes.  Normally a single method should be
// chosen for a program and used throughout.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Mp2Gui extends JFrame 
                    implements ActionListener
{ 
 
   private JButton northButtons[]; 
   private JButton southButtons[];

   private JLabel emplId;
   private JTextField emplName;
   private JTextField dept;
   private JTextField startDate;

   public Mp2Gui()
   {
      super( "CS 441 MP2 GUI" );

      JMenuBar bar = new JMenuBar();  // create menubar
      setJMenuBar( bar );  // set the menubar for the JFrame

      // create File menu and Exit menu item
      JMenu fileMenu = new JMenu( "File" );
      fileMenu.setMnemonic( 'F' );

      JMenuItem exitItem = new JMenuItem( "eXit" );
      exitItem.setMnemonic( 'X' );
      exitItem.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               System.exit( 0 );
            }
         }
      );
      fileMenu.add( exitItem );

      // create Help menu and About menu item
      JMenu helpMenu = new JMenu( "Help" );
      helpMenu.setMnemonic( 'H' );

      JMenuItem aboutItem = new JMenuItem( "About..." );
      aboutItem.setMnemonic( 'A' );
      aboutItem.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               JOptionPane.showMessageDialog( Mp2Gui.this,
                  "This is an example\nof using menus",
                  "About", JOptionPane.PLAIN_MESSAGE );
            }
         }
      );
      helpMenu.add( aboutItem );

      bar.add( fileMenu );    // add File menu
      bar.add( helpMenu );    // add Help Menu


      // set up the main panel
      JPanel northButtonPanel;
      String northNames[] = {"Prev", "Next"};

      JPanel centerPanel;
      JLabel centerLabels [];
      String centerNames[] = {"Employee ID:", "Employee Name:", 
			       "Department:", "Start Date:"};

      JPanel southButtonPanel;
      String southNames[] = {"Add", "Modify", "Delete", "Quit"};

      Container c = getContentPane();

      // set up button in the north panel
      northButtonPanel = new JPanel();
      northButtons = new JButton[ northNames.length ];

      northButtonPanel.setLayout(
         new GridLayout( 1, northButtons.length ) );

      ButtonHandler handler = new ButtonHandler();

      for ( int i = 0; i < northButtons.length; i++ ) {
         northButtons[ i ] = new JButton( northNames[i] );
         northButtons[i].addActionListener (handler);
         northButtonPanel.add( northButtons[ i ] );
      }

      c.add( northButtonPanel, BorderLayout.NORTH );

      // set up the center Panel
      centerPanel = new JPanel();
      centerPanel.setLayout (
        new GridLayout(  centerNames.length, 2) );

      centerLabels = new JLabel [ centerNames.length ];
      for (int i = 0; i < centerLabels.length; i++ )
         {
          centerLabels[i] = new JLabel (centerNames[i]);
         }

       centerPanel.add (centerLabels[0]);
       emplId = new JLabel ();
       centerPanel.add (emplId);
       centerPanel.add (centerLabels[1]);
       emplName = new JTextField ();
       centerPanel.add (emplName);
       centerPanel.add (centerLabels[2]);
       dept = new JTextField ();
       centerPanel.add (dept);
       centerPanel.add (centerLabels[3]);
       startDate = new JTextField ();
       centerPanel.add (startDate);

      c.add( centerPanel, BorderLayout.CENTER );

      // set up the button in the south panel
      southButtonPanel = new JPanel();
      southButtons = new JButton[ southNames.length ];

      southButtonPanel.setLayout(
         new GridLayout( 1, southButtons.length ) );

      for ( int i = 0; i < southButtons.length; i++ ) {
         southButtons[ i ] = new JButton( southNames[i] );
         southButtons[i].addActionListener (this);
         southButtonPanel.add( southButtons[ i ] );
      }

      c.add( southButtonPanel, BorderLayout.SOUTH );

      setSize( 600, 200 );
      show();
   }

  // event handler for the South buttons
  public void actionPerformed( ActionEvent e )
   {
      JOptionPane.showMessageDialog (null,
	"You pressed button: " + e.getActionCommand() +
        "\n\nEmployee Number: " + emplId.getText () +
   	"\nEmployee Name:     " + emplName.getText() +
   	"\nDepartment:        " + dept.getText() +
   	"\nStart Date:        " + startDate.getText()  );

      String buttonText = e.getActionCommand();
      if (buttonText.equalsIgnoreCase("Quit"))
	{
         System.exit(0);
        }
   }



   public static void main( String args[] )
   {
      Mp2Gui app = new Mp2Gui();

      app.addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               System.exit( 0 );
            }
         }
      );
   }

 // inner class for buttoning handling events
 private class ButtonHandler implements ActionListener
  {

   // event handler for the NORTH buttons
   public void actionPerformed (ActionEvent e)
     {
      String id = emplId.getText();

      int num = 0;
      if (!id.equals (""))
         num = Integer.parseInt(id);

      // decrement or increment value based on which button was
      // pressed
      String buttonText = e.getActionCommand();
      if (buttonText.equalsIgnoreCase("Prev"))
         num--;
      else 
         num++;

      emplId.setText("" + num);

     }
  }

}