package net.havercan.geometry2D;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;

public class ShowCircle extends JApplet                  
{  private DrawCanvas       canvas;
   private Graphics2D       g;
   private Ellipse2D.Double circle;   

   public ShowCircle()
       {canvas = new DrawCanvas();
        canvas.setPreferredSize(new Dimension(600, 400));
        this.setContentPane(canvas);
        circle = new Ellipse2D.Double(); 
       }

   private class DrawCanvas extends JPanel
       {@Override public void paint(Graphics g0)
         {double circle_r = 128.0;
          double circle_x = 0.5*this.getWidth();
          double circle_y = 0.5*this.getHeight();
          g = (Graphics2D)g0;
          super.paintComponent(g);
          circle.setFrame(circle_x-circle_r, circle_y-circle_r, 2.0*circle_r, 2.0*circle_r);
          setBackground(Color.WHITE);
          g.setColor(Color.BLUE);
          g.fill(circle);
         }
       }
      
   public static void main(String[] args)
       {SwingUtilities.invokeLater
         (new Runnable()
            {@Override public void run()
              {JApplet ja = new ShowCircle();
               JFrame  jf = new JFrame();
               jf.add(ja);
               jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
               jf.setTitle("Java Swing 2d Circle demonstration");
               jf.pack();
               jf.setVisible(true);
              }
            }
         );
       }
    
   public void init()
       {try {javax.swing.SwingUtilities.invokeAndWait(new Runnable() {public void run() {new ShowCircle();}});}
        catch(Exception e) {System.err.println("ShowCircle applet did not initialize: "+e.getMessage());}
       }
}