insertb.java

Java 入门书的源码

//Copyright (c) 1998, Arthur Gittleman
//This example is provided WITHOUT ANY WARRANTY either expressed or implied.

/* Add an insertNext method to insert
 * each value in order as soon as the 
 * user enters it
 */

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;

public class InsertB extends Applet implements ActionListener{
  public static int ITEM_SIZE = 10;
  public static int CHART_SIZE 	= 100;
  private TextField number = new TextField(5);
  private DrawOn canvas = new DrawOn();
  private int [] item = new int[ITEM_SIZE];
  private int count = 0;

  public void init() { 
    add(number); 
    canvas.setSize(CHART_SIZE,CHART_SIZE);
    canvas.setBackground(Color.pink);
    add(canvas);
    number.addActionListener(this);
  }
  public void actionPerformed(ActionEvent event) {
    item[count] = new Integer(number.getText()).intValue();
    number.setText("");
    insertNext(item,count++);
    canvas.repaint();
  }   
  public void insertNext(int [] data, int size) {
      int current = data[size]; 
      int j = 0;
      while (current > data[j]) j++;
      for (int k=size; k>j; k--)
        data[k] = data[k-1];
      data[j] = current; 
  }
  class DrawOn extends Canvas {
    public void paint(Graphics g) {
      if (count > 0){
        int width = CHART_SIZE/count;
        for (int i=0; i<count; i++)
          g.fillRect(i*width,CHART_SIZE-item[i],width,item[i]);
      }
    }
  }
}