outputwindow.java

用java编写的IDE程序示例

/*
 * Created on 2004-5-25
 */
package yuchifang.javaIDE.editors;

import java.awt.Color;
import java.awt.Font;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;

import javax.swing.JEditorPane;
import javax.swing.text.BadLocationException;

import yuchifang.javaIDE.interfaces.IExecCaller;

/**
 * @author yuchifang
 */
public class OutputWindow extends JEditorPane implements IExecCaller
{
  private int lastOutputPos; //上一次做输出的位置
  private OutputStream output; //给应用程序提供的输入
  
  public OutputWindow()
  {
    setBackground(Color.WHITE);
    setForeground(Color.BLUE);
    setFont(new Font("宋体", Font.PLAIN, 12));
    
    addKeyListener(
      new KeyAdapter()
      {
        public void keyPressed(KeyEvent e)
        {
          if (e.isActionKey()) return;
          
          switch (e.getKeyCode())
          {
            case KeyEvent.VK_ENTER:
            {
             inputTriggered();
             break;
            }
            
            case KeyEvent.VK_BACK_SPACE:
            case KeyEvent.VK_DELETE:
            {
              if (cannotModify())
                e.consume();
              break;
            }
            
            case KeyEvent.VK_X:
            {
              if ((e.getModifiers() & KeyEvent.CTRL_MASK) != 0)
              {
                if (cannotModify())
                  e.consume();
              }
            }

            default :
              if (cannotModify())
                 e.consume();
          }//switch
        }//keyPressed
      }//new KeyAdapter
    );//add listener
  }
  
  /**
   * 判断编辑操作是否能够进行
   * 当所进行的操作不会影响到上一次输出或者输入结果时返回true
	 * @return true表示编辑操作可以进行
	 */
	protected boolean cannotModify()
	{
    return (getCaretPosition() <= lastOutputPos ||
            getSelectionStart() < lastOutputPos);
	}
  
	/**
	 * 当OutputWindow里面有Enter键按下时发生，表示用户输入了数据
	 */
	protected void inputTriggered()
	{
    int length = getDocument().getLength() - lastOutputPos;
    int pos = lastOutputPos;
    lastOutputPos = getDocument().getLength() + 1;//加上还没有记入文档的回车符
    String input = null;
    try
		{
			input = getDocument().getText(pos, length);
		} catch (BadLocationException e)
		{
			e.printStackTrace();
		}
    
    if (output != null)
    {
      try
			{
        BufferedWriter out = new BufferedWriter(new OutputStreamWriter(output));
				out.write(input);  //##如果是Compiler时敲回车会否出错？
        out.close();
			} catch (IOException e1)
			{
				e1.printStackTrace();
			}
    }
	}

	public void printResults(InputStream is)
	{
    BufferedReader br = new BufferedReader(new InputStreamReader(is));
    String line = null;
    try
    {
      while ((line = br.readLine()) != null)
      {
        print(line + "\r\n");
      }
    } catch (IOException e)
    {
      e.printStackTrace();
    }
	}

	public void clearResults()
	{
    setText("");
	}

	/**
	 * @param string
	 */
	synchronized public void print(String string)
	{
    int pos = getDocument().getLength();  //不能用getText()，那不准确
    setCaretPosition(pos);
    replaceSelection(string);
    lastOutputPos = getDocument().getLength();
	}

	public void setOutput(OutputStream os)
	{
    output = os;
	}
}