Learn Java Now/Learn_Java_Now_Microsoft_1996.iso/JavaNow/Code/Chap15/Stock3/Stock.class

Java Class File | 1996-07-29 | 5.2 KB | 188 lines

import java.applet.Applet;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.ImageObserver;
import java.util.Random;

public class Stock extends Applet implements Runnable {
   Thread m_Stock;
   int m_fps = 10;
   final String PARAM_fps = "fps";
   private Random m_r = new Random();
   private double[] m_dValue;
   private int m_nSize;
   private int m_nMax;
   private Image m_image;
   private Graphics m_g;
   Dimension m_dimImage;
   private static final int m_PIXELS_PER_POINT = 3;

   public void start() {
      if (this.m_Stock == null) {
         this.m_Stock = new Thread(this);
         this.m_Stock.start();
      }

   }

   private static int IndexToX(int nWidth, int nIndex) {
      return nWidth - 1 - 3 * nIndex;
   }

   public String[][] getParameterInfo() {
      String[][] info = new String[][]{{"fps", "int", "Frame rate"}};
      return info;
   }

   public void stop() {
      if (this.m_Stock != null) {
         this.m_Stock.stop();
         this.m_Stock = null;
      }

   }

   private void PaintFrame(Graphics g) {
      Dimension d = ((Component)this).size();
      int nWidth = d.width;
      int nHeight = d.height;
      g.drawString(Integer.toString(this.m_nMax), 5, 10);
      g.drawString("0", 5, d.height - 10);
      g.drawLine(0, nHeight - 1, nWidth, nHeight - 1);
      g.drawLine(0, nHeight - 1, 0, 0);

      for(int nMark = 50; nMark < this.m_nMax; nMark += 50) {
         int nL = 3;
         if (nMark % 100 == 0) {
            nL = 6;
         }

         int nH = this.ValueToY(nHeight, (double)nMark);
         g.drawLine(0, nH, nL, nH);
      }

   }

   private void ResizeArray(int nWidth) {
      int nNumPts = XToIndex(nWidth);
      if (nNumPts != this.m_nSize) {
         double[] dNewArray = new double[nNumPts];
         int nNumToCopy = Math.min(nNumPts, this.m_nSize);

         for(int i = 0; i < nNumToCopy; ++i) {
            dNewArray[i] = this.m_dValue[i];
         }

         this.m_dValue = dNewArray;
         this.m_nSize = nNumPts;
      }
   }

   private synchronized void PaintData(Graphics g) {
      Dimension d = ((Component)this).size();
      int nWidth = d.width;
      int nHeight = d.height;
      this.ResizeArray(d.width);

      for(int i = 0; i < this.m_nSize; ++i) {
         int x = IndexToX(nWidth, i);
         int y = this.ValueToY(nHeight, this.m_dValue[i]);
         g.drawLine(x - 1, y, x + 1, y);
         g.drawLine(x, y - 1, x, y + 1);
      }

   }

   private void ResizeImage() {
      Dimension dim = ((Component)this).size();
      int nWidth = dim.width;
      int nHeight = dim.height;
      if (this.m_dimImage == null || this.m_dimImage.width != nWidth || this.m_dimImage.height != nHeight) {
         this.m_dimImage = new Dimension(nWidth, nHeight);
         this.m_image = ((Component)this).createImage(nWidth, nHeight);
         this.m_g = this.m_image.getGraphics();
      }
   }

   public void finalize() {
   }

   private synchronized void AddValue(double dValue) {
      for(int i = this.m_nSize - 1; i > 0; --i) {
         this.m_dValue[i] = this.m_dValue[i - 1];
      }

      for(this.m_dValue[0] = dValue; dValue >= (double)this.m_nMax; this.m_nMax += 50) {
      }

   }

   public String getAppletInfo() {
      return "Name: Stock\r\n" + "Author: Stephan R. Davis\r\n" + "Created for Learn Java Now (c)";
   }

   private static int XToIndex(int nWidth) {
      return nWidth / 3;
   }

   private int ValueToY(int nHeight, double dValue) {
      return nHeight - (int)dValue * nHeight / this.m_nMax;
   }

   public void run() {
      int nSleepTime = 1000 / this.m_fps;
      double dValue = this.m_dValue[0];
      if (dValue == (double)0.0F) {
         dValue = (double)50.0F;
      }

      while(true) {
         try {
            dValue += (double)2.0F * this.m_r.nextGaussian() + 0.2;
            this.AddValue(dValue);
            ((Component)this).repaint();
            Thread.sleep((long)nSleepTime);
         } catch (InterruptedException var6) {
            this.stop();
         }
      }
   }

   public void destroy() {
   }

   public void init() {
      String param = ((Applet)this).getParameter("fps");
      if (param != null) {
         this.m_fps = Integer.parseInt(param);
      }

      Dimension dim = ((Component)this).size();
      int m_nSize = XToIndex(dim.width);
      this.m_dValue = new double[m_nSize];
      this.m_nMax = 100;
   }

   public void paint(Graphics g) {
      if (this.m_image != null) {
         g.drawImage(this.m_image, 0, 0, (ImageObserver)null);
      }

   }

   public void update(Graphics g) {
      this.ResizeImage();
      Color colFG = ((Component)this).getForeground();
      Color colBG = ((Component)this).getBackground();
      this.m_g.setColor(colBG);
      this.m_g.fillRect(0, 0, this.m_dimImage.width, this.m_dimImage.height);
      this.m_g.setColor(colFG);
      this.PaintFrame(this.m_g);
      this.PaintData(this.m_g);
      this.paint(g);
   }
}