//  AlarmclockKL.java  Copyright (c) 2005 Kari Laitinen

//  http://www.naturalprogramming.com

//  2005-06-21   File created.
//  2005-06-21   Last modification.

//  This is a solution to Exercise 16-8.

import java.util.* ;

class  ThreadToMeasureTimeAndAlarm  extends  Thread
{
   int  alarm_hour ;
   int  alarm_minute ;

   boolean  must_measure_time_and_alarm   =  true ;

   public ThreadToMeasureTimeAndAlarm( int given_alarm_hour,
                                       int given_alarm_minute )
   {
      alarm_hour    =  given_alarm_hour ;
      alarm_minute  =  given_alarm_minute ;
   }

   public void stop_this_thread()
   {
      must_measure_time_and_alarm  =  false ;
   }

   public void run()
   {
      boolean  it_is_time_to_give_alarm  =  false ;

      while ( must_measure_time_and_alarm  ==  true  &&
              it_is_time_to_give_alarm     ==  false )
      {
         Calendar  current_time  =  new  GregorianCalendar() ;

         int current_hour    =  current_time.get( Calendar.HOUR_OF_DAY ) ;
         int current_minute  =  current_time.get( Calendar.MINUTE ) ;

         if ( current_hour    ==  alarm_hour  &&
              current_minute  ==  alarm_minute )
         {
            it_is_time_to_give_alarm  =  true ;
         }

         System.out.printf( "\r  Current time:  %02d:%02d",
                            current_hour, current_minute ) ;
         System.out.printf( "     Alarm time:  %02d:%02d",
                            alarm_hour, alarm_minute ) ;
         try
         {
            Thread.sleep( 5000 ) ; // Check time once in every 5 seconds.
         }
         catch ( InterruptedException  caught_exception )
         {
         }
      }

      while ( must_measure_time_and_alarm  ==  true )
      {
         System.out.print( "\u0007" ) ;  // Output the Alert sound 0x07

         try
         {
            Thread.sleep( 1000 ) ;   // Alert is given once a second.
         }
         catch ( InterruptedException  caught_exception )
         {
         }
      }

   }
}

class AlarmclockKL
{
   public static void main( String[] not_in_use )
   {
      Scanner keyboard = new Scanner( System.in ) ;

      System.out.print( "\n Give alarm hour between 0 ... 23   : " ) ;

      int alarm_hour  =  Integer.parseInt( keyboard.nextLine() ) ;

      System.out.print( "\n Give alarm minute between 0 ... 59 : " ) ;

      int alarm_minute  =  Integer.parseInt( keyboard.nextLine() ) ;

      System.out.print( "\n Press the Enter key to stop the alarm sound "
                  +  "\n or deactivate the alarm clock.\n\n" ) ;

      ThreadToMeasureTimeAndAlarm thread_to_measure_time_and_alarm  = 
               new ThreadToMeasureTimeAndAlarm( alarm_hour, alarm_minute ) ;

      thread_to_measure_time_and_alarm.start() ;

      String  any_string_from_keyboard  =  keyboard.nextLine() ;

      thread_to_measure_time_and_alarm.stop_this_thread() ;
   }
}