//  CurtainsApplet.java  Copyright (c) Kari Laitinen

//  http://www.naturalprogramming.com

//  2007-10-05  File created.
//  2008-02-03  Latest modification.

//  This program shows how JSlider and JSpinner GUI components can be used.

import java.awt.* ;
import javax.swing.* ;
import javax.swing.event.* ;

class CurtainsPanel extends JPanel implements ChangeListener
{
   //  The word WINDOW in the following constants refers to the 'window'
   //  that is drawn onto the screen by this program.

   static final Point WINDOW_UPPER_LEFT_CORNER  =  new  Point( 150, 50 ) ;
   static final int WINDOW_WIDTH  =  300, WINDOW_HEIGHT  =  350 ;

   JSlider left_curtain_slider  =  new  JSlider( SwingConstants.HORIZONTAL,
                                                 10, WINDOW_WIDTH / 2 + 10,
                                                 WINDOW_WIDTH / 4 ) ;

   JSlider right_curtain_slider  =  new  JSlider( SwingConstants.HORIZONTAL,
                                                  10, WINDOW_WIDTH / 2 + 10,
                                                  WINDOW_WIDTH / 4 ) ;

   JSpinner red_color_spinner  = 
               new JSpinner( new SpinnerNumberModel( 255, 0, 255, 5 ) ) ;
   JSpinner green_color_spinner  = 
               new JSpinner( new SpinnerNumberModel(  50, 0, 255, 5 ) ) ;
   JSpinner blue_color_spinner  = 
               new JSpinner( new SpinnerNumberModel( 255, 0, 255, 5 ) ) ;
   JSpinner alpha_value_spinner  = 
               new JSpinner( new SpinnerNumberModel( 240, 0, 255, 5 ) ) ;

   JLabel red_color_label   = new JLabel( "RED:" ) ;
   JLabel green_color_label = new JLabel( "GREEN:" ) ;
   JLabel blue_color_label  = new JLabel( "BLUE:" ) ;
   JLabel alpha_value_label = new JLabel( "ALPHA:" ) ;


   int  applet_width, applet_height ;


   public CurtainsPanel( int given_applet_width,
                         int given_applet_height )
   {
      applet_width  =  given_applet_width ;
      applet_height =  given_applet_height ;

      setLayout( new BorderLayout() ) ;

      JPanel operations_panel   =  new  JPanel( new GridLayout( 2, 1 ) ) ;
      JPanel curtain_adjustments_panel  =  new  JPanel() ;
      JPanel color_adjustments_panel    =  new  JPanel() ;

      right_curtain_slider.setInverted( true ) ;

      left_curtain_slider.addChangeListener( this ) ;
      right_curtain_slider.addChangeListener( this ) ;

      red_color_spinner.addChangeListener( this ) ;
      green_color_spinner.addChangeListener( this ) ;
      blue_color_spinner.addChangeListener( this ) ;
      alpha_value_spinner.addChangeListener( this ) ;

      curtain_adjustments_panel.add( left_curtain_slider ) ;
      curtain_adjustments_panel.add( right_curtain_slider ) ;

      color_adjustments_panel.add( red_color_label ) ;
      color_adjustments_panel.add( red_color_spinner ) ;
      color_adjustments_panel.add( green_color_label ) ;
      color_adjustments_panel.add( green_color_spinner ) ;
      color_adjustments_panel.add( blue_color_label ) ;
      color_adjustments_panel.add( blue_color_spinner ) ;
      color_adjustments_panel.add( alpha_value_label ) ;
      color_adjustments_panel.add( alpha_value_spinner ) ;

      operations_panel.add( curtain_adjustments_panel ) ;
      operations_panel.add( color_adjustments_panel ) ;

      add( "South", operations_panel ) ;
   }

   public void stateChanged( ChangeEvent event )
   {
      repaint() ;
   }


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

      graphics.setColor( Color.BLUE ) ;

      graphics.fillRect( WINDOW_UPPER_LEFT_CORNER.x, WINDOW_UPPER_LEFT_CORNER.y,
                         WINDOW_WIDTH, WINDOW_HEIGHT / 2 ) ;

      graphics.setColor( Color.GREEN ) ;

      graphics.fillRect( WINDOW_UPPER_LEFT_CORNER.x,
                         WINDOW_UPPER_LEFT_CORNER.y + WINDOW_HEIGHT / 2,
                         WINDOW_WIDTH, WINDOW_HEIGHT / 2 ) ;


      graphics.setColor( Color.YELLOW ) ;  //  Color for the "sun"

      graphics.fillOval( WINDOW_UPPER_LEFT_CORNER.x + 50,
                         WINDOW_UPPER_LEFT_CORNER.y + 50, 50, 50 ) ;

      graphics.setColor( Color.BLACK ) ;

      graphics.drawRect( WINDOW_UPPER_LEFT_CORNER.x, WINDOW_UPPER_LEFT_CORNER.y,
                         WINDOW_WIDTH, WINDOW_HEIGHT ) ;

      graphics.drawLine( WINDOW_UPPER_LEFT_CORNER.x - 10,
                         WINDOW_UPPER_LEFT_CORNER.y - 10,
                         WINDOW_UPPER_LEFT_CORNER.x + WINDOW_WIDTH + 10,
                         WINDOW_UPPER_LEFT_CORNER.y - 10 ) ;

      graphics.setColor( new Color( (Integer) red_color_spinner.getValue(),
                                    (Integer) green_color_spinner.getValue(),
                                    (Integer) blue_color_spinner.getValue(),
                                    (Integer) alpha_value_spinner.getValue())) ;

      graphics.fillRect( WINDOW_UPPER_LEFT_CORNER.x - 10,
                         WINDOW_UPPER_LEFT_CORNER.y - 10,
                         left_curtain_slider.getValue(),
                         WINDOW_HEIGHT + 20 ) ;

      graphics.fillRect( WINDOW_UPPER_LEFT_CORNER.x + WINDOW_WIDTH + 10
                           - right_curtain_slider.getValue(),
                         WINDOW_UPPER_LEFT_CORNER.y - 10,
                         right_curtain_slider.getValue(),
                         WINDOW_HEIGHT + 20 ) ;

      red_color_label.setForeground(
             new Color( (Integer) red_color_spinner.getValue(), 0, 0 ) ) ;
      green_color_label.setForeground(
             new Color( 0, (Integer) green_color_spinner.getValue(), 0 ) ) ;
      blue_color_label.setForeground(
             new Color( 0, 0, (Integer) blue_color_spinner.getValue() ) ) ;
   }
}

public class CurtainsApplet extends JApplet
{
   public void init()
   {
      getContentPane().add( new CurtainsPanel( getSize().width,
                                               getSize().height ) ) ; 
   }
}