shapes.java

经典的<<C how to program>一书第三版的例程。非常适合于C的初学者。

// Fig. 28.22: Shapes.java
// Demonstrating some Java2D shapes
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.awt.geom.*;
import java.awt.image.*;

public class Shapes extends JFrame {
   public Shapes() 
   {
      super( "Drawing 2D shapes" );

      setSize( 425, 160 );
      show();
   }

   public void paint( Graphics g )
   {
      // create 2D by casting g to Graphics2D
      Graphics2D g2d = ( Graphics2D ) g;

      // draw 2D ellipse filled with a blue-yellow gradient
      g2d.setPaint(
         new GradientPaint( 5, 30,         // x1, y1
                            Color.blue,    // initial Color
                            35, 100,       // x2, y2
                            Color.yellow,  // end Color
                            true ) );      // cyclic
      g2d.fill( new Ellipse2D.Double( 5, 30, 65, 100 ) );

      // draw 2D rectangle in red
      g2d.setPaint( Color.red );                  
      g2d.setStroke( new BasicStroke( 10.0f ) ); 
      g2d.draw(
         new Rectangle2D.Double( 80, 30, 65, 100 ) );

      // draw 2D rounded rectangle with a buffered background
      BufferedImage buffImage =
         new BufferedImage(
            10, 10, BufferedImage.TYPE_INT_RGB );

      Graphics2D gg = buffImage.createGraphics();   
      gg.setColor( Color.yellow ); // draw in yellow
      gg.fillRect( 0, 0, 10, 10 ); // draw a filled rectangle
      gg.setColor( Color.black );  // draw in black
      gg.drawRect( 1, 1, 6, 6 );   // draw a rectangle
      gg.setColor( Color.blue );   // draw in blue
      gg.fillRect( 1, 1, 3, 3 );   // draw a filled rectangle
      gg.setColor( Color.red );    // draw in red
      gg.fillRect( 4, 4, 3, 3 );   // draw a filled rectangle

      // paint buffImage onto the JFrame
      g2d.setPaint(
         new TexturePaint(
            buffImage, new Rectangle( 10, 10 ) ) );
      g2d.fill(
         new RoundRectangle2D.Double(
            155, 30, 75, 100, 50, 50 ) );

      // draw 2D pie-shaped arc in white
      g2d.setPaint( Color.white );
      g2d.setStroke( new BasicStroke( 6.0f ) ); 
      g2d.draw(
         new Arc2D.Double(
            240, 30, 75, 100, 0, 270, Arc2D.PIE ) );

      // draw 2D lines in green and yellow
      g2d.setPaint( Color.green );
      g2d.draw( new Line2D.Double( 395, 30, 320, 150 ) );

      float dashes[] = { 10 };

      g2d.setPaint( Color.yellow );    
      g2d.setStroke(
         new BasicStroke( 4,                      
                          BasicStroke.CAP_ROUND,  
                          BasicStroke.JOIN_ROUND, 
                          10, dashes, 0 ) );      
      g2d.draw( new Line2D.Double( 320, 30, 395, 150 ) );
   }

   public static void main( String args[] )
   {
      Shapes app = new Shapes();

      app.addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               System.exit( 0 );
            }
         }
      );
   }
}

/**************************************************************************
 * (C) Copyright 2000 by Deitel & Associates, Inc. and Prentice Hall.     *
 * All Rights Reserved.                                                   *
 *                                                                        *
 * DISCLAIMER: The authors and publisher of this book have used their     *
 * best efforts in preparing the book. These efforts include the          *
 * development, research, and testing of the theories and programs        *
 * to determine their effectiveness. The authors and publisher make       *
 * no warranty of any kind, expressed or implied, with regard to these    *
 * programs or to the documentation contained in these books. The authors *
 * and publisher shall not be liable in any event for incidental or       *
 * consequential damages in connection with, or arising out of, the       *
 * furnishing, performance, or use of these programs.                     *
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