立体柱状图的实现

前几天自己写了个平面的柱状图的实现,呵呵!现在花了一点时间,将其其升级为了立体柱状图.还是用的JApplet做的试图,现在没加双缓冲,所以看到的是一个一个的出现的,有时间的话我再好好把这两个类重构下,加个双缓冲,呵呵!效果如图:

示例代码如下:

package com.lazy.histogram;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;

import javax.swing.JApplet;

/**
 * 
 * @author lazy_p
 * @version 1.0
 *
 */
public class Histogram extends JApplet {

 private static final long serialVersionUID = 3562814718711641084L;
 private final int histogramWidth = 15; // 柱宽
 private int histogramPitch = 10;// 间距
 private float scaling = 0.0f;
 private int maxStrWidth = 0; // 字符串需要的最大宽度

 public Histogram() {
 }

 @Override
 public void paint(Graphics g) {

  // setSize(200, 250);

  int[] b = new int[] { 100, 1000, 1200, 900 };
  Color[] color = new Color[] { Color.red, Color.green, Color.lightGray,
    Color.BLUE };
  paintHistogram(g, b, new String[] { "香蕉", "萝卜", "菠萝菠萝蜜", "西瓜" }, color);
 }

 /**
  * 画基面
  * 
  * @param g
  */
 private void paintBase(Graphics g) {

  g.drawPolygon(new int[] { 10, 40, 40, 10 }, new int[] { 30, 10,
    this.getHeight() - 30, this.getHeight() - 10 }, 4);
  g.setColor(new Color(100, 100, 100, 20));
  g.fillPolygon(new int[] { 10, 40, 40, 10 }, new int[] { 30, 10,
    this.getHeight() - 30, this.getHeight() - 10 }, 4);

  g.setColor(Color.BLACK);
  g.drawPolygon(new int[] { 10, 40, this.getWidth() - 10,
    this.getWidth() - 30 }, new int[] { this.getHeight() - 10,
    this.getHeight() - 30, this.getHeight() - 30,
    this.getHeight() - 10 }, 4);
  g.setColor(new Color(100, 100, 100, 20));
  g.fillPolygon(new int[] { 10, 40, this.getWidth() - 10,
    this.getWidth() - 30 }, new int[] { this.getHeight() - 10,
    this.getHeight() - 30, this.getHeight() - 30,
    this.getHeight() - 10 }, 4);
 }

 private void paintHistogram(Graphics g, int[] b, String[] str, Color[] color) {

  int hWidth = this.getWidth();
  int hHeight = this.getHeight();

  FontMetrics metrics = this
    .getFontMetrics(new Font(null, Font.PLAIN, 12));
  setSize(calculate(hHeight, str, b, metrics));

  paintBase(g); // 画基平面

  int len = b.length;

  for (int i = 0; i < len; ++i) {

   // //////////////////////画比例////////////////////////////
   g.setColor(trans(color[i], 255));
   Font font = new Font(null, Font.PLAIN, 12);

   g
     .drawString(b[i] + "", (20 + (histogramPitch
       + histogramWidth + (maxStrWidth >> 1))
       * i)
       + ((histogramWidth - metrics.stringWidth(String
         .valueOf(b[i]))) >> 1), (int) (this
       .getHeight() - 25 - b[i] * scaling));

   g.setColor(trans(color[i], 150));

   int x = histogramWidth
     + (histogramWidth + histogramPitch + (maxStrWidth >> 1))
     * i;
   // //////////////////画上面////////////////////////////
   if (i == 0)
    x += 10; // 画第一个立方方柱时
   g.drawPolygon(new int[] { x, 5 + x, 20 + x, 15 + x }, new int[] {
     (int) (this.getHeight() - 15 - b[i] * scaling),
     (int) (this.getHeight() - 25 - b[i] * scaling),
     (int) (this.getHeight() - 25 - b[i] * scaling),
     (int) (this.getHeight() - 15 - b[i] * scaling) }, 4);
   g.fillPolygon(new int[] { x, 5 + x, 20 + x, 15 + x }, new int[] {
     (int) (this.getHeight() - 15 - b[i] * scaling),
     (int) (this.getHeight() - 25 - b[i] * scaling),
     (int) (this.getHeight() - 25 - b[i] * scaling),
     (int) (this.getHeight() - 15 - b[i] * scaling) }, 4);

   // ////////////////////////画左侧面//////////////////////////////////
   // g.setColor(trans(color[i], 20));
   // g.drawPolygon(new int[] { 15 + 25 * i, 20 + 25 * i, 20 + 25 * i,
   // 15 + 25 * i }, new int[] {
   // this.getHeight() - 15 - b[i],
   // this.getHeight() - 25 - b[i], this.getHeight() - 25,
   // this.getHeight() - 15 }, 4);
   // g.setColor(trans(color[i], 20));
   // g.fillPolygon(new int[] { 15 + 25 * i, 20 + 25 * i, 20 + 25 * i,
   // 15 + 25 * i }, new int[] {
   // this.getHeight() - 15 - b[i],
   // this.getHeight() - 25 - b[i], this.getHeight() - 25,
   // this.getHeight() - 15 }, 4);
   ////////////////////////////////画后面/////////////////////////////////
   // g.setColor(trans(color[i], 20));
   // g.drawRect(20 + 25 * i, this.getHeight() - 25 - b[i], 15,
   // b[i]);
   // g.fillRect(20 + 25 * i, this.getHeight() - 25 - b[i], 15,
   // b[i]);

   // ////////////////////////画前面部分///////////////////////////
   g.drawRect(x, (int) (this.getHeight() - 15 - b[i] * scaling),
     histogramWidth, (int) (b[i] * scaling));
   // System.out.println((int) (b[i] * scaling));
   g.fillRect(x, (int) (this.getHeight() - 15 - b[i] * scaling),
     histogramWidth, (int) (b[i] * scaling));

   // ////////////////////////画右侧面/////////////////////////////////
   g.drawPolygon(new int[] { 15 + x, 20 + x, 20 + x, 15 + x },
     new int[] { (int) (this.getHeight() - 15 - b[i] * scaling),
       (int) (this.getHeight() - 25 - b[i] * scaling),
       this.getHeight() - 25, this.getHeight() - 15 }, 4);

   g.fillPolygon(new int[] { 15 + x, 20 + x, 20 + x, 15 + x },
     new int[] { (int) (this.getHeight() - 15 - b[i] * scaling),
       (int) (this.getHeight() - 25 - b[i] * scaling),
       this.getHeight() - 25, this.getHeight() - 15 }, 4);

   g.setColor(trans(color[i], 255));
   g.drawString(str[i] + "", (5 + x)
     + ((histogramWidth - this.getFontMetrics(font).stringWidth(
       str[i])) >> 1), this.getHeight() - 2);
  }
 }

 /**
  * 给颜色加上透明度
  * 
  * @param color
  * @param alpha
  *            透明值(0-256)
  * @return Color
  * 
  */
 private Color trans(Color color, int alpha) {

  int rgb = color.getRGB();

  int r = (rgb >> 16) & 0xff;
  int g = (rgb >> 8) & 0xff;
  int b = rgb & 0xff;

  return new Color(r, g, b, alpha);
 }

 private Dimension calculate(int h, String[] str, int[] b,
   FontMetrics metrics) {

  int len = b.length;
  int max = -1;
  for (int i = 0; i < len; ++i) {
   if (b[i] > max)
    max = b[i];
  }

  int height = h;

  if (max > this.getHeight()) {
   scaling = (float) this.getHeight() / (max + 300); // 加了个任意数300,
   // 是为了让立方柱的高度始终小于整个applet的高度
  }

  len = str.length;
  for (int i = 0; i < len; ++i) {
   if (metrics.stringWidth(str[i]) > maxStrWidth)
    maxStrWidth = metrics.stringWidth(str[i]);
  }

  int width = b.length
    * ((maxStrWidth >> 1) + histogramPitch + histogramWidth) + 20;

  // System.out.println(width);

// return new Dimension(width, height+20);//如果这样写会有个很奇怪的现象出现,不知道为什么?郁闷.....
  return new Dimension(width, height);
 }
}