mypanel.java~13~

很好得jbuilder100例源代码

package transparency;

import java.awt.*;
import javax.swing.JPanel;
import java.awt.geom.*;

/**
 * Title:
 * Description:
 * Copyright:    Copyright (c) 2001
 * Company:
 * @author
 * @version 1.0
 */

public class MyPanel extends JPanel {
  BorderLayout borderLayout1 = new BorderLayout();
  private static int gap=5, width=40, offset=15,
                     deltaX=gap+width+offset;//90
  private Rectangle
    yellowSquare = new Rectangle(gap+offset, gap+offset, width, width),
    greenSquare = new Rectangle(gap, gap, width, width);

  public MyPanel() {
    try {
      jbInit();
    }
    catch(Exception ex) {
      ex.printStackTrace();
    }
  }
  void jbInit() throws Exception {
    this.setLayout(borderLayout1);
  }

  private AlphaComposite makeComposite(float alpha) {
    int type = AlphaComposite.SRC_OVER;
    return(AlphaComposite.getInstance(type, alpha));
  }

  private void drawSquares(Graphics2D g2d, float alpha) {
    Composite originalComposite = g2d.getComposite();
    g2d.setPaint(Color.yellow);
    g2d.fill(yellowSquare);
    g2d.setComposite(makeComposite(alpha));
    g2d.setPaint(Color.green);
    g2d.fill(greenSquare);
    g2d.setComposite(originalComposite);
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D)g;
    for(int i=0; i<11; i++) {
      drawSquares(g2d, i*0.1F);
      g2d.translate(deltaX, 0);
    }
  }

}