editline.java

java telnet 服务器实现 .

//License
/***
 * Java TelnetD library (embeddable telnet daemon)
 * Copyright (c) 2000-2005 Dieter Wimberger 
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the author nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *  
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS
 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 ***/

package net.wimpi.telnetd.io.toolkit;

import net.wimpi.telnetd.io.BasicTerminalIO;

import java.io.IOException;

/**
 * Class that implements an Editline
 *
 * @author Dieter Wimberger
 * @version 2.0 (16/07/2006)
 */
class Editline {

  //Aggregations (inner class!)
  private Buffer m_Buffer;
  //Members
  private BasicTerminalIO m_IO;
  private int m_Cursor = 0;
  private boolean m_InsertMode = true;
  private int m_LastSize = 0;
  private boolean m_HardWrapped = false;
  private char m_LastRead;
  private int m_LastCursPos = 0;

  /**
   * Constructs an Editline.
   */
  public Editline(BasicTerminalIO io) {
    m_IO = io;
    //allways full length
    m_Buffer = new Buffer(m_IO.getColumns() - 1);
    m_Cursor = 0;
    m_InsertMode = true;
  }//constructor

  /**
   * Accessor method for line buffer size.
   *
   * @ return int that represents the number of chars in the fields buffer.
   */
  public int size() {
    return m_Buffer.size();
  }//getSize

  public String getValue() {
    return m_Buffer.toString();
  }//getValue

  public void setValue(String str)
      throws BufferOverflowException, IOException {

    storeSize();
    //buffer
    m_Buffer.clear();
    //cursor
    m_Cursor = 0;

    //screen
    m_IO.moveLeft(m_LastSize);
    m_IO.eraseToEndOfLine();
    append(str);
  }//setValue

  public void clear() throws IOException {

    storeSize();
    //Buffer
    m_Buffer.clear();
    //Cursor
    m_Cursor = 0;
    //Screen
    draw();
  }//clear

  public String getSoftwrap()
      throws IndexOutOfBoundsException, IOException {

    //Wrap from Buffer
    String content = m_Buffer.toString();
    int idx = content.lastIndexOf(" ");
    if (idx == -1) {
      content = "";
    } else {
      //System.out.println("Line:softwrap:lastspace:"+idx);
      content = content.substring(idx + 1, content.length());

      //System.out.println("Line:softwrap:wraplength:"+content.length());

      //Cursor
      //remeber relative cursor pos
      m_Cursor = size();
      m_Cursor = m_Cursor - content.length();

      //buffer
      for (int i = 0; i < content.length(); i++) {
        m_Buffer.removeCharAt(m_Cursor);
      }

      //screen
      m_IO.moveLeft(content.length());
      m_IO.eraseToEndOfLine();

      //System.out.println("Line:softwrap:buffercontent:"+buf.toString());
    }
    return content + getLastRead();
  }//getSoftWrap


  public String getHardwrap()
      throws IndexOutOfBoundsException, IOException {

    //Buffer
    String content = m_Buffer.toString();
    content = content.substring(m_Cursor, content.length());
    //System.out.println("buffer:tostring:"+buf.toString()+":");
    //System.out.println("buffer:size:"+buf.size());
    int lastsize = m_Buffer.size();
    for (int i = m_Cursor; i < lastsize; i++) {
      m_Buffer.removeCharAt(m_Cursor);
      //System.out.println("buffer:removing char #"+i);
    }
    //System.out.println("buffer:tostring:"+buf.toString()+":");
    //cursor stays
    //screen
    m_IO.eraseToEndOfLine();
    return content;
  }//getHardWrap

  private void setCharAt(int pos, char ch)
      throws IndexOutOfBoundsException, IOException {

    //buffer
    m_Buffer.setCharAt(pos, ch);
    //cursor
    //implements overwrite mode no change
    //screen
    draw();
  }//setCharAt

  private void insertCharAt(int pos, char ch)
      throws BufferOverflowException, IndexOutOfBoundsException, IOException {

    storeSize();
    //buffer
    m_Buffer.ensureSpace(1);
    m_Buffer.insertCharAt(pos, ch);
    //cursor adjustment (so that it stays in "same" pos)
    if (m_Cursor >= pos) {
      m_Cursor++;
    }
    //screen
    draw();
  }//insertCharAt

  private void removeCharAt(int pos)
      throws IndexOutOfBoundsException, IOException {

    storeSize();
    //buffer
    m_Buffer.removeCharAt(pos);

    //cursor
    if (m_Cursor > pos) {
      m_Cursor--;
    }
    //screen
    draw();

  }//removeChatAt

  private void insertStringAt(int pos, String str)
      throws BufferOverflowException, IndexOutOfBoundsException, IOException {

    storeSize();
    //buffer
    m_Buffer.ensureSpace(str.length());
    for (int i = 0; i < str.length(); i++) {
      m_Buffer.insertCharAt(pos, str.charAt(i));
      //Cursor
      m_Cursor++;
    }
    //screen
    draw();

  }//insertStringAt

  public void append(char ch)
      throws BufferOverflowException, IOException {

    storeSize();
    //buffer
    m_Buffer.ensureSpace(1);
    m_Buffer.append(ch);
    //cursor
    m_Cursor++;
    //screen
    m_IO.write(ch);
  }//append(char)

  public void append(String str)
      throws BufferOverflowException, IOException {

    storeSize();
    //buffer
    m_Buffer.ensureSpace(str.length());
    for (int i = 0; i < str.length(); i++) {
      m_Buffer.append(str.charAt(i));
      //Cursor
      m_Cursor++;
    }
    //screen
    m_IO.write(str);
  }//append(String)

  public int getCursorPosition() {
    return m_Cursor;
  }//getCursorPosition

  public void setCursorPosition(int pos) {

    if (m_Buffer.size() < pos) {
      m_Cursor = m_Buffer.size();
    } else {
      m_Cursor = pos;
    }
    //System.out.println("Editline:cursor:"+Cursor);
  }//setCursorPosition

  private char getLastRead() {
    return m_LastRead;
  }//getLastRead

  private void setLastRead(char ch) {
    m_LastRead = ch;
  }//setLastRead


  public boolean isInInsertMode() {
    return m_InsertMode;
  }//isInInsertMode

  public void setInsertMode(boolean b) {
    m_InsertMode = b;
  }//setInsertMode

  public boolean isHardwrapped() {
    return m_HardWrapped;
  }//isHardwrapped

  public void setHardwrapped(boolean b) {
    m_HardWrapped = b;
  }//setHardwrapped

  /**
   * Method that will be
   * reading and processing input.
   */
  public int run() throws IOException {
    int in = 0;
    //draw();
    //myIO.flush();
    do {
      //get next key
      in = m_IO.read();
      //store cursorpos
      m_LastCursPos = m_Cursor;

      switch (in) {
        case BasicTerminalIO.LEFT:
          if (!moveLeft()) {
            return in;
          }
          break;
        case BasicTerminalIO.RIGHT:
          if (!moveRight()) {
            return in;
          }
          break;
        case BasicTerminalIO.BACKSPACE:
          try {
            if (m_Cursor == 0) {
              return in;
            } else {
              removeCharAt(m_Cursor - 1);
            }
          } catch (IndexOutOfBoundsException ioobex) {
            m_IO.bell();
          }
          break;
        case BasicTerminalIO.DELETE:
          try {
            removeCharAt(m_Cursor);
          } catch (IndexOutOfBoundsException ioobex) {
            m_IO.bell();
          }
          break;
        case BasicTerminalIO.ENTER:
        case BasicTerminalIO.UP:
        case BasicTerminalIO.DOWN:
        case BasicTerminalIO.TABULATOR:
          return in;
        default:
          try {
            handleCharInput(in);
          } catch (BufferOverflowException boex) {
            setLastRead((char) in);
            return in;
          }
      }
      m_IO.flush();
    } while (true);
  }//run


  public void draw() throws IOException {
    //System.out.println("DEBUG: Buffer="+buf.toString());
    //System.out.println("DEBUG: Cursor="+Cursor);
    //System.out.println("DEBUG: lastcurspos="+lastcurspos);


    /*
    int diff=lastSize-buf.size();
    StringBuffer output=new StringBuffer(buf.toString());
    if(diff>0){
            for (int i=0;i<diff;i++) {
                output.append(" ");
            }
    }
    */

    m_IO.moveLeft(m_LastCursPos);
    m_IO.eraseToEndOfLine();
    m_IO.write(m_Buffer.toString());
    //adjust screen cursor hmm
    if (m_Cursor < m_Buffer.size()) {
      m_IO.moveLeft(m_Buffer.size() - m_Cursor);
    }
  }//draw

  private boolean moveRight() throws IOException {
    //cursor
    if (m_Cursor < m_Buffer.size()) {
      m_Cursor++;
      //screen
      m_IO.moveRight(1);
      return true;
    } else {
      return false;
    }
  }//moveRight

  private boolean moveLeft() throws IOException {
    //cursor
    if (m_Cursor > 0) {
      m_Cursor--;
      //screen
      m_IO.moveLeft(1);
      return true;
    } else {
      return false;
    }
  }//moveLeft

  private boolean isCursorAtEnd() {
    return (m_Cursor == m_Buffer.size());
  }//isCursorAtEnd

  private void handleCharInput(int ch)
      throws BufferOverflowException, IOException {

    if (isCursorAtEnd()) {
      append((char) ch);
    } else {
      if (isInInsertMode()) {
        try {
          insertCharAt(m_Cursor, (char) ch);
        } catch (BufferOverflowException ex) {
          //ignore buffer overflow on insert
          m_IO.bell();
        }
      } else {
        setCharAt(m_Cursor, (char) ch);
      }
    }
  }//handleCharInput

  private void storeSize() {
    m_LastSize = m_Buffer.size();
  }//storeSize


  //inner class Buffer
  class Buffer extends CharBuffer {

    public Buffer(int size) {
      super(size);
    }//constructor

  }//class Buffer

}//class Editfield