Swing Pie

package com.sky.java.chat;

import java.awt.Color;  
import java.awt.Graphics;  
import java.awt.Graphics2D;  
import java.awt.RenderingHints;  
import java.awt.Toolkit;  
import java.awt.geom.Arc2D;  
import java.awt.geom.Area;  
import java.awt.geom.GeneralPath;  
import java.awt.geom.Point2D;  
import java.util.ArrayList;  
import java.util.List;  
  
import javax.swing.JFrame;  
import javax.swing.JPanel;  
  
/** 
 * 绘制带阴影的饼图 
 *  
 * @author Biao 
 */  
@SuppressWarnings("serial")  
public class Pie extends JPanel {  
    // 饼图中每一个部分的百分比  
    private double[] percents = { 10.72, 15.38, 3.74, 10.26, 6.56, 5.69, 10.72, 15.38, 6.15, 18.0 };  
    // 饼图的颜色  
    private Color[] pieColors;  
      
    public Pie() {  
        List<Color> colors = new ArrayList<Color>();  
        colors.add(getColorFromHex("#169800"));  
        colors.add(getColorFromHex("#00E500"));  
        colors.add(getColorFromHex("#D0F15A"));  
        colors.add(getColorFromHex("#FF7321"));  
        colors.add(getColorFromHex("#E2FF55"));  
        colors.add(getColorFromHex("#AA6A2D"));  
        colors.add(getColorFromHex("#BFDD89"));  
        colors.add(getColorFromHex("#D718A5"));  
        colors.add(getColorFromHex("#00DBFF"));  
        colors.add(getColorFromHex("#00FF00"));  
          
        pieColors = colors.toArray(new Color[0]);  
    }  
      
    public static Color getColorFromHex(String hex) {  
        try {  
            return new Color(Integer.valueOf(hex.substring(1), 16));  
        } catch (Exception e) {  
            return Color.BLACK;  
        }  
    }  
  
    @Override  
    protected void paintComponent(Graphics g) {  
        super.paintComponent(g);  
        Graphics2D g2d = (Graphics2D) g;  
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);  
        int w = 380;  
        int h = (int) (w * 0.618);  
        fillPies(g2d, percents, 30, 30, w, h);  
    }  
  
    private void fillPies(Graphics2D g2d, double[] percents, int x, int y, int w, int h) {  
        int colorIndex = 0;  
        double startAngle = 0;  
        double arcAngle = 0;  
  
        // 一次性绘制完阴影，然后再绘制饼图的效果比绘制饼图的同时绘制它的阴影好  
        for (int i = 0; i < percents.length; ++i) {  
            arcAngle = percents[i] * 3.6;  
  
            if (i + 1 == percents.length) {  
                arcAngle = 360 - startAngle;  
            }
  
            Arc2D.Double arcTop = new Arc2D.Double(x, y, w, h, startAngle, arcAngle, Arc2D.PIE);  
  
            g2d.setColor(pieColors[colorIndex].darker());  
            g2d.fill(buildShadow(arcTop));  
  
            colorIndex = (colorIndex + 1) % pieColors.length;  
            startAngle += arcAngle;  
        }  
  
        colorIndex = 0;  
        startAngle = 0;  
        for (int i = 0; i < percents.length; ++i) {  
            arcAngle = percents[i] * 3.6;  
  
            if (i + 1 == percents.length) {  
                arcAngle = 360 - startAngle;  
            }  
  
            Arc2D.Double arcTop = new Arc2D.Double(x, y, w, h, startAngle, arcAngle, Arc2D.PIE);  
  
            g2d.setColor(pieColors[colorIndex]);  
            g2d.fill(arcTop);  
  
            colorIndex = (colorIndex + 1) % pieColors.length;  
            startAngle += arcAngle;  
        }  
    }  
  
    private Area buildShadow(Arc2D arc) {  
        int shadowDapth = 10;  
        Arc2D arcBottom = new Arc2D.Double(arc.getX(), arc.getY() + shadowDapth, arc.getWidth(),  
            arc.getHeight() + 0, arc.getAngleStart(), arc.getAngleExtent(), Arc2D.CHORD);  
  
        Point2D topLeft = new Point2D.Double(arc.getStartPoint().getX(), arc.getStartPoint().getY());  
        Point2D topRight = new Point2D.Double(arc.getEndPoint().getX(), arc.getEndPoint().getY());  
        Point2D bottomLeft = new Point2D.Double(arcBottom.getStartPoint().getX(), arcBottom  
            .getStartPoint().getY());  
        Point2D bottomRight = new Point2D.Double(arcBottom.getEndPoint().getX(), arcBottom  
            .getEndPoint().getY());  
  
        double[] xpoints = { topLeft.getX(), topRight.getX(), bottomRight.getX(), bottomLeft.getX() };  
        double[] ypoints = { topLeft.getY(), topRight.getY(), bottomRight.getY(), bottomLeft.getY() };  
  
        GeneralPath path = new GeneralPath();  
        path.moveTo(xpoints[0], ypoints[0]);  
        path.lineTo(xpoints[1], ypoints[1]);  
        path.lineTo(xpoints[2], ypoints[2]);  
        path.lineTo(xpoints[3], ypoints[3]);  
        path.closePath();  
  
        Area area = new Area(arcBottom);  
        area.add(new Area(path));  
  
        return area;  
    }  
  
    private static void createGuiAndShow() {  
        JFrame frame = new JFrame("");  
        frame.getContentPane().add(new Pie());  
  
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
        int sw = Toolkit.getDefaultToolkit().getScreenSize().width;  
        int sh = Toolkit.getDefaultToolkit().getScreenSize().height;  
        int w = 500;  
        int h = 400;  
        int x = (sw - w) / 2;  
        int y = (sh - h) / 2 - 40;  
        x = x > 0 ? x : 0;  
        y = y > 0 ? y : 0;  
        frame.setBounds(x, y, w, h);  
        frame.setVisible(true);  
    }  
  
    public static void main(String[] args) {  
        createGuiAndShow();  
    }  
}