//  RectangleApplet.java  (c) 2005-2006 Kari Laitinen

//  http://www.naturalprogramming.com

//  2005-06-07  File created.
//  2006-10-23  Last modification.

//  This program shows how objects of classes JScrollBar, JRadioButton, and
//  ButtonGroup can be used in an applet.

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

public class RectangleApplet extends    JApplet
                             implements AdjustmentListener,
                                        ItemListener
{
   int  applet_width, applet_height ;

   int  rectangle_width, rectangle_height ;

   int  rectangle_center_point_x, rectangle_center_point_y ;

   JScrollBar  width_scrollbar, height_scrollbar ;

   Color  rectangle_color   =  Color.cyan ;

   JRadioButton  cyan_button, magenta_button, green_button,
                 lightGray_button ;

   ButtonGroup  color_selection_buttons  =  new  ButtonGroup() ;

   public void init()
   {
      setLayout( new BorderLayout() ) ;

      applet_width   =  getSize().width ;
      applet_height  =  getSize().height ;

      rectangle_center_point_x  =  applet_width / 2   ;
      rectangle_center_point_y  =  applet_height / 2  ;

      rectangle_width   =  applet_width  /  4 ;
      rectangle_height  =  applet_height  / 4 ;

      height_scrollbar  =  new  JScrollBar( Scrollbar.VERTICAL,
                                            rectangle_height, // initial value
                                            10,               // extent
                                            0,                // minimum value
                                            applet_height ) ; // maximum value

      height_scrollbar.addAdjustmentListener( this ) ;

      add( "East", height_scrollbar ) ;

      width_scrollbar   =  new  JScrollBar( Scrollbar.HORIZONTAL,
                                            rectangle_width,
                                            10,
                                            0,
                                            applet_width ) ;

      width_scrollbar.addAdjustmentListener( this ) ;

      JPanel  panel_for_buttons_and_scrollbar  =  new  JPanel() ;

      panel_for_buttons_and_scrollbar.add( width_scrollbar ) ;

      cyan_button       =  new JRadioButton( "cyan",      true ) ;
      magenta_button    =  new JRadioButton( "magenta",   false ) ;
      green_button      =  new JRadioButton( "green",     false ) ;
      lightGray_button  =  new JRadioButton( "lightGray", false ) ;

      color_selection_buttons.add( cyan_button ) ;
      color_selection_buttons.add( magenta_button ) ;
      color_selection_buttons.add( green_button ) ;
      color_selection_buttons.add( lightGray_button ) ;

      cyan_button.addItemListener( this ) ;
      magenta_button.addItemListener( this ) ;
      green_button.addItemListener( this ) ;
      lightGray_button.addItemListener( this ) ;

      panel_for_buttons_and_scrollbar.add( cyan_button ) ;
      panel_for_buttons_and_scrollbar.add( magenta_button ) ;
      panel_for_buttons_and_scrollbar.add( green_button ) ;
      panel_for_buttons_and_scrollbar.add( lightGray_button ) ;

      add( "South", panel_for_buttons_and_scrollbar ) ;
   }


   public void adjustmentValueChanged( AdjustmentEvent event )
   {
      if ( event.getSource()  ==  height_scrollbar )
      {
         rectangle_height  =  height_scrollbar.getValue() ;
      }
      else if ( event.getSource()  ==  width_scrollbar )
      {
         rectangle_width  =  width_scrollbar.getValue() ;
      }

      repaint() ;
   }

   public void itemStateChanged( ItemEvent event )
   {
      if ( event.getItemSelectable()  ==  cyan_button )
      {
         rectangle_color  =  Color.cyan ;
      }
      else if ( event.getItemSelectable()  ==  magenta_button )
      {
         rectangle_color  =  Color.magenta ;
      }
      else if ( event.getItemSelectable()  ==  green_button )
      {
         rectangle_color  =  Color.green ;
      }
      else if ( event.getItemSelectable()  ==  lightGray_button )
      {
         rectangle_color  =  Color.lightGray ;
      }

      repaint() ;
   }


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

      graphics.setColor( rectangle_color ) ;

      graphics.fillRect( 

             rectangle_center_point_x - rectangle_width / 2,

             rectangle_center_point_y - rectangle_height / 2,

             rectangle_width, rectangle_height ) ;

      graphics.setColor( Color.black ) ;

      graphics.drawRect( 

             rectangle_center_point_x - rectangle_width / 2,

             rectangle_center_point_y - rectangle_height / 2,

             rectangle_width, rectangle_height ) ;

      graphics.drawString( "Width: "   +  rectangle_width  +
                           "  Height: "  +  rectangle_height,
                           20, 20 ) ;

   }
}