//  DrawingLinesAWTApplication.java  (c) Kari Laitinen

//  http://www.naturalprogramming.com

//  2004-10-21  File created.
//  2007-02-28  Last modification.

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

public class DrawingLinesAWTApplication extends Frame
                                implements ActionListener,
                                           MouseListener,
                                           MouseMotionListener,
                                           WindowListener
{
   static final int WINDOW_WIDTH   =  500 ;
   static final int WINDOW_HEIGHT  =  400 ;

   final int MAXIMUM_NUMBER_OF_LINES = 10 ; 
   Point[] starting_points  =  new Point[ MAXIMUM_NUMBER_OF_LINES ] ;
   Point[] ending_points    =  new Point[ MAXIMUM_NUMBER_OF_LINES ] ;
   Point start_of_new_line ;
   Point end_of_new_line ;
   int   number_of_lines    =  0 ;

   MenuItem  edit_clear_menu_item  =  new  MenuItem( "Clear" ) ;

   DrawingLinesAWTApplication()
   {
      setBackground(Color.white);

      //  Event listeners must be registered.

      addMouseListener(this);
      addMouseMotionListener(this);

      // This class implements a WindowListener interface.

      addWindowListener( this ) ;

      setSize( WINDOW_WIDTH, WINDOW_HEIGHT ) ;

      setTitle( "DrawingLines Windows Application" ) ;

      edit_clear_menu_item.addActionListener( this ) ;

      Menu  edit_menu   =  new  Menu( "Edit" ) ;

      edit_menu.add( edit_clear_menu_item ) ;

      MenuBar menubar_of_this_window  =  new MenuBar() ;

      menubar_of_this_window.add( edit_menu ) ;

      setMenuBar( menubar_of_this_window ) ;

   }

   public void actionPerformed( ActionEvent event )
   {
      if ( event.getSource() instanceof MenuItem )
      {
         MenuItem valittu_menu_item  = (MenuItem) event.getSource() ;

         if ( valittu_menu_item  ==  edit_clear_menu_item )
         {
            number_of_lines  =  0 ;

            //  Poistetaan mahdollinen WINDOW FULL -otsikko.

            setTitle( "DrawingLines Windows Application" ) ;
         }

         repaint() ;
      }
   }


   //  The following dummy methods are needed
   //  to fully implement the listener interfaces.
   public void mouseMoved( MouseEvent event ) {}
   public void mouseClicked( MouseEvent event ) {}
   public void mouseEntered( MouseEvent event ) {}
   public void mouseExited( MouseEvent event ) {}

   public void mousePressed( MouseEvent event )
   {
      if ( number_of_lines  <  MAXIMUM_NUMBER_OF_LINES )
      {
          start_of_new_line  =  event.getPoint() ;
      }
   }

   public void mouseReleased( MouseEvent event )
   {
      if ( number_of_lines  <  MAXIMUM_NUMBER_OF_LINES ) 
      {
        starting_points[ number_of_lines ]  =  start_of_new_line;
        ending_points[ number_of_lines ]   =  event.getPoint() ;
        number_of_lines ++ ;
        end_of_new_line   = null ;
        start_of_new_line = null ;
        repaint() ;
      }
   }

   public void mouseDragged( MouseEvent event )
   {
      if ( number_of_lines  <  MAXIMUM_NUMBER_OF_LINES )
      {
         end_of_new_line = event.getPoint() ;
         repaint();
      }
   }

   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 ) {}



   public void paint( Graphics graphics )
   {
      for ( int line_index  =  0 ;
                line_index  <  number_of_lines ;
                line_index  ++ )
      {
         graphics.drawLine( starting_points[ line_index ].x,
                            starting_points[ line_index ].y,
                            ending_points[ line_index ].x,
                            ending_points[ line_index ].y ) ;
      }

      graphics.setColor( Color.red ) ;

      if ( end_of_new_line != null )
      {
         graphics.drawLine( start_of_new_line.x,
                            start_of_new_line.y,
                            end_of_new_line.x,
                            end_of_new_line.y ) ;
      }

      if ( number_of_lines  ==  MAXIMUM_NUMBER_OF_LINES )
      {
//         graphics.drawString( "Cannot draw more lines", 0, 300 ) ;
         setTitle( "WINDOW FULL" ) ;
      }

   }

   public static void main( String[] not_in_use )
   {
      DrawingLinesAWTApplication  this_application_window  =
                                new  DrawingLinesAWTApplication() ;

      this_application_window.setVisible( true ) ;
   }
}