//  RandomNumbersMIDlet.java  Copyright (c) Kari Laitinen

//  http://www.naturalprogramming.com/

//  2007-09-24  This file was created.
//  2008-06-05  Last modification.

//  This program demonstrates the following things:
//     -  ChoiceGroup class
//     -  class Random and its methods nextInt() and nextDouble()

//  This program requires a CLDC 1.1 phone.

//  When the user presses a numerical key, this program generates a
//  random number and shows it on the screen.
//  Via the Settings menu the user can select what kinds of random
//  numbers will be generated.

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.util.Random ;

class RandomNumbersCanvas extends Canvas
                          implements CommandListener
{
   Display  midlet_display ;

   int  generated_random_integer  =  0 ;

   double  generated_random_double  =  0 ;

   Form  settings_form  =  new  Form( "SETTINGS" ) ;

   String[]  integer_ranges  =  { "0 ... 9", "0 ... 99", "0 ... 999" } ;

   ChoiceGroup  integer_range_selection  =  new  ChoiceGroup(
                                            "Range for random integers:",
                                            Choice.EXCLUSIVE,
                                            integer_ranges, null ) ;


   String[]  double_selection_text  =  { "Show only a double value:" } ;

   ChoiceGroup  double_selection  =  new ChoiceGroup( "Generate random double:",
                                                      Choice.MULTIPLE,
                                                      double_selection_text,
                                                      null ) ;

   Command  command_to_make_settings  =
                       new  Command( "Settings", Command.SCREEN, 1 ) ;

   Command  command_to_exit_settings  = 
                       new  Command( "Exit settings", Command.SCREEN, 1 ) ;

   public RandomNumbersCanvas( Display given_display )
   {
      midlet_display  =  given_display ;

      settings_form.append( integer_range_selection ) ;
      settings_form.append( double_selection ) ;
      settings_form.addCommand( command_to_exit_settings ) ;
      settings_form.setCommandListener( this ) ;

      addCommand( command_to_make_settings ) ;
      setCommandListener( this ) ;
   }


   public void commandAction( Command     given_command,
                              Displayable current_display_content )
   {
      if ( given_command  ==  command_to_make_settings )
      {
         midlet_display.setCurrent( settings_form ) ;
      }
      else if ( given_command  ==  command_to_exit_settings )
      {
         midlet_display.setCurrent( this ) ;
      }
   }


   public void keyPressed( int key_code )
   {
      if ( key_code  >=  '0'  &&  key_code  <=  '9' )
      {
         Random  random_number_generator  =  new  Random() ;

         if ( double_selection.isSelected( 0 ) )
         {
            generated_random_double  =
                          random_number_generator.nextDouble() ;
         }
         else if ( integer_range_selection.getSelectedIndex()  ==  0 )
         {
            generated_random_integer  =
                        random_number_generator.nextInt( 10 ) ;
         }
         else if ( integer_range_selection.getSelectedIndex()  ==  1 )
         {
            generated_random_integer  =
                        random_number_generator.nextInt( 100 ) ;
         }
         else if ( integer_range_selection.getSelectedIndex()  ==  2 )
         {
            generated_random_integer  =
                        random_number_generator.nextInt( 1000 ) ;
         }
      }

      repaint() ;
   }


   protected void paint( Graphics graphics )
   {
      graphics.setColor( 255, 255, 255 ) ;  //  White color
      graphics.fillRect( 0, 0, getWidth(), getHeight() ) ;

      graphics.setColor( 0, 0, 0 ) ;  //  Black color

      graphics.drawString( "LAST GENERATED RANDOM NUMBER:",
                           10, 20, Graphics.TOP | Graphics.LEFT ) ;

      if ( double_selection.isSelected( 0 ) )
      {
         graphics.drawString( ""  +  generated_random_double,
                              10, 40, Graphics.TOP | Graphics.LEFT ) ;
      }
      else
      {
         graphics.drawString( ""  +  generated_random_integer,
                              10, 40, Graphics.TOP | Graphics.LEFT ) ;
      }
   }
}


public class RandomNumbersMIDlet extends MIDlet
{
   Display  midlet_display  =  Display.getDisplay( this ) ;
   RandomNumbersCanvas  random_numbers_canvas  =
                          new RandomNumbersCanvas( midlet_display ) ;

   protected void startApp() throws MIDletStateChangeException
   {
      midlet_display.setCurrent( random_numbers_canvas ) ;
   }

   protected void pauseApp()
   {
   }

   protected void destroyApp( boolean unconditional_destruction_required )
   {
   }
}