//  MenuDemoApplication.java  (c) 2006 Kari Laitinen

//  http://www.naturalprogramming.com

//  2006-10-03  File created.
//  2006-10-04  Last modification.

//  See the notes at the end of this file.

//  This program demonstrates how menus can be built for a Java
//  application.

//  The menus are built into a MenuDemoFrame object.
//  Menus cannot be built into a JPanel-based component.

import java.awt.* ;
import java.awt.event.*;

import javax.swing.* ;

class MenuDemoFrame extends JFrame implements ActionListener
{
   static final int WINDOW_WIDTH   =  500 ;
   static final int WINDOW_HEIGHT  =  400 ;

   JMenuItem  file_open_menu_item  =  new  JMenuItem( "Open" ) ;
   JMenuItem  file_save_menu_item  =  new  JMenuItem( "Save" ) ;
   JMenuItem  file_exit_menu_item  =  new  JMenuItem( "Exit" ) ;

   JMenuItem  edit_copy_menu_item  =  new  JMenuItem( "Copy" ) ;
   JMenuItem  edit_paste_menu_item =  new  JMenuItem( "Paste" ) ;

   JCheckBoxMenuItem  cyan_background_menu_item  =
                           new JCheckBoxMenuItem( "Cyan background" ) ;

   JRadioButtonMenuItem  small_text_menu_item  =
                                   new JRadioButtonMenuItem( "Small" ) ;
   JRadioButtonMenuItem  medium_text_menu_item  =
                                   new JRadioButtonMenuItem( "Medium" ) ;
   JRadioButtonMenuItem  large_text_menu_item  =
                                   new JRadioButtonMenuItem( "Large" ) ;

   JMenuItem  about_menu_item  =  new  JMenuItem( "About" ) ;

   String  last_selected_menu_item  =  "NO SELECTIONS MADE." ;


   public MenuDemoFrame()
   {
      getContentPane().setBackground( Color.white ) ;

      setSize( WINDOW_WIDTH, WINDOW_HEIGHT ) ;

      setTitle( "GUI APPLICATION WITH MENUS" ) ;

      file_open_menu_item.setMnemonic( 'O' ) ;
      file_open_menu_item.addActionListener( this ) ;
      file_save_menu_item.setMnemonic( 'S' ) ;
      file_save_menu_item.addActionListener( this ) ;
      file_exit_menu_item.setMnemonic( 'x' ) ;
      file_exit_menu_item.addActionListener( this ) ;

      JMenu  file_menu  =  new  JMenu( "File" ) ;
      file_menu.setMnemonic( 'F' ) ;

      file_menu.add( file_open_menu_item ) ;
      file_menu.add( file_save_menu_item ) ;
      file_menu.add( file_exit_menu_item ) ;

      edit_copy_menu_item.addActionListener( this ) ;
      edit_paste_menu_item.addActionListener( this ) ;

      JMenu  edit_menu  =  new  JMenu( "Edit" ) ;

      edit_menu.add( edit_copy_menu_item ) ;
      edit_menu.add( edit_paste_menu_item ) ;

      JMenu  settings_menu  =  new  JMenu( "Settings" ) ;

      cyan_background_menu_item.addActionListener( this ) ;

      settings_menu.add( cyan_background_menu_item ) ;

      small_text_menu_item.addActionListener( this ) ;
      medium_text_menu_item.addActionListener( this ) ;
      large_text_menu_item.addActionListener( this ) ;

      medium_text_menu_item.setSelected( true ) ;

      ButtonGroup  text_size_button_group  =  new  ButtonGroup() ;

      text_size_button_group.add( small_text_menu_item ) ;
      text_size_button_group.add( medium_text_menu_item ) ;
      text_size_button_group.add( large_text_menu_item ) ;

      JMenu  text_size_menu  =  new  JMenu( "Text size" ) ;
      
      text_size_menu.add( small_text_menu_item ) ;
      text_size_menu.add( medium_text_menu_item ) ;
      text_size_menu.add( large_text_menu_item ) ;

      settings_menu.add( text_size_menu ) ;

      JMenu  help_menu  =  new  JMenu( "Help" ) ;

      about_menu_item.addActionListener( this ) ;
      help_menu.add( about_menu_item ) ;

      JMenuBar menubar_of_this_window  =  new JMenuBar() ;

      menubar_of_this_window.add( file_menu ) ;
      menubar_of_this_window.add( edit_menu ) ;
      menubar_of_this_window.add( settings_menu ) ;
      menubar_of_this_window.add( help_menu ) ;

      setJMenuBar( menubar_of_this_window ) ;

      setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ) ;
   }


   //  The following method reacts to the menu selections.
   //  In most cases the only reaction is that the text that
   //  appears on the screen is changed.
   //  Background color is set to cyan if that selection is made.
   //  Help -> About selection brings a message dialog to the screen.
   //  File -> Exit selection terminates the application.

   public void actionPerformed( ActionEvent event )
   {
      if ( event.getSource() instanceof JMenuItem )
      {
         JMenuItem selected_menu_item  = (JMenuItem) event.getSource() ;

         last_selected_menu_item  =  selected_menu_item.getText() ;

         if ( cyan_background_menu_item.isSelected() == true )
         {
            getContentPane().setBackground( Color.cyan ) ;
         }
         else
         {
            getContentPane().setBackground( Color.white ) ;
         }

         if ( selected_menu_item  ==  file_exit_menu_item )
         {
            setVisible( false ) ;
            System.exit( 0 ) ;
         }
         else if ( selected_menu_item  ==  about_menu_item )
         {
            JOptionPane.showMessageDialog( this, 
                                 "This is a simple GUI application"
                               + "\nwith menus.",
                                 "About", JOptionPane.PLAIN_MESSAGE ) ;
         }

         repaint() ;
      }
   }


   public void paint( Graphics graphics )
   {
      super.paint( graphics ) ;

      if ( small_text_menu_item.isSelected() == true )
      {
         graphics.setFont( new Font( "Serif", Font.PLAIN, 10 ) ) ;
      }

      if ( medium_text_menu_item.isSelected() == true )
      {
         graphics.setFont( new Font( "Serif", Font.PLAIN, 14 ) ) ;
      }

      if ( large_text_menu_item.isSelected() == true )
      {
         graphics.setFont( new Font( "Serif", Font.PLAIN, 18 ) ) ;
      }

      graphics.drawString( "Last selected menu item: \""
                        +   last_selected_menu_item  +  "\"",
                           100, 200 ) ;
   }
}

public class MenuDemoApplication
{
   public static void main( String[] not_in_use )
   {
      MenuDemoFrame  this_application_window  =
                                     new  MenuDemoFrame() ;

      this_application_window.setVisible( true ) ;
   }
}


/*******

    The statement at the end of the MenuDemoFrame constructor

       setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ) ;

    makes the program terminate when the window is closed.

    Another possibility to program this feature would be to
    make the MenuDemoFrame class implement the WindowListener interface.
    In addition the constructor should contain the statement

      addWindowListener( this ) ;

    and the class should have the methods

   //  A method belonging to the WindowListener interface

   public void windowClosing( WindowEvent event )
   {
      setVisible( false ) ;
      System.exit( 0 ) ;
   }

   //  Other methods required by the WindowListener interface:
   public void windowActivated( WindowEvent event ) {}
   public void windowClosed( WindowEvent event ) {}
   public void windowDeactivated( WindowEvent event ) {}
   public void windowDeiconified( WindowEvent event ) {}
   public void windowIconified( WindowEvent event )  { }
   public void windowOpened( WindowEvent event ) {}

*****/