//  MenuDemoApplet.java  (c) 2006 Kari Laitinen

//  http://www.naturalprogramming.com

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

//  This is an applet that provides menus for its user.

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

import javax.swing.* ;

public class MenuDemoApplet extends JApplet
                            implements ActionListener
{
   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 void init()
   {
      getContentPane().setBackground( Color.white ) ;


      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 ) ;
   }


   //  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 and File -> Exit selections bring a message
   //  box to the screen.


   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 )
         {
            JOptionPane.showMessageDialog( this, 
                                 "This is a Java applet."
                               + "\nFile -> Exit does not work in applets.",
                                 "About", JOptionPane.PLAIN_MESSAGE ) ;
         }
         else if ( selected_menu_item  ==  about_menu_item )
         {
            JOptionPane.showMessageDialog( this, 
                                 "This is a simpe GUI applet"
                               + "\nthat has 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 ) ;
   }
}