checkbox.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 a Checkbox component.
 *
 * @author Dieter Wimberger
 * @version 2.0 (16/07/2006)
 */
public class Checkbox extends ActiveComponent {

  //Members
  private String m_Text = "";
  private boolean m_Selected = false;
  private String m_Mark;
  private String m_LeftBracket;
  private String m_RightBracket;


  /**
   * Constructs a checkbox instance.
   */
  public Checkbox(BasicTerminalIO io, String name) {
    super(io, name);
    setBoxStyle(SQUARED_BOXSTYLE);
    setMarkStyle(LARGE_CHECKMARK);
  }//constructor

  /**
   * Method to set the checkbox`s state.
   *
   * @param b boolean that represents the state (true equals selected, false equals not selected).
   */
  public void setSelected(boolean b) throws IOException {
    m_Selected = b;
    drawMark();
  }//setSelected

  /**
   * Accessor method for the state of the checkbox instance.
   *
   * @return boolean that represents the state (true equals selected, false equals not selected).
   */
  public boolean isSelected() {
    return m_Selected;
  }//isSelected

  /**
   * Mutator method for the text property of the checkbox item.
   * This text will be placed like a label, naturally you can
   * leave this text empty and place a label if used in a form.
   *
   * @param str String that represents the text that will be displayed right
   *            of the checkbox.
   */
  public void setText(String str) {
    m_Text = str;
  }//setText

  /**
   * Mutator method for the boxstyle property of the checkbox.
   * The *_BOXSTYLE constants should be passed as parameter.
   *
   * @param style int that represents one of the defined constants for boxstyles.
   */
  public void setBoxStyle(int style) {
    switch (style) {
      case ROUND_BOXSTYLE:
        m_LeftBracket = "(";
        m_RightBracket = ")";
        break;
      case EDGED_BOXSTYLE:
        m_LeftBracket = "<";
        m_RightBracket = ">";
        break;
      case SQUARED_BOXSTYLE:
      default:
        m_LeftBracket = "[";
        m_RightBracket = "]";
    }
  }//setBoxStyle

  /**
   * Mutator method for the markstyle property of the checkbox.
   * The *_CHECKMARK constants should be passed as parameter.
   *
   * @param style int that represents one of the defined constants for checkmarks.
   */
  public void setMarkStyle(int style) {
    switch (style) {
      case SMALL_CHECKMARK:
        m_Mark = "x";
        break;
      case LARGE_CHECKMARK:
      default:
        m_Mark = "X";
    }
  }//setMarkStyle

  /**
   * Method that will make the checkbox active, reading and processing input.
   */
  public void run() throws IOException {
    int in = 0;
    draw();
    m_IO.flush();
    do {
      //get next key
      in = m_IO.read();
      switch (in) {
        case SPACE:
          setSelected(!m_Selected);	//toggle actual state, will redraw mark
          break;
        case BasicTerminalIO.TABULATOR:
        case BasicTerminalIO.ENTER:
          in = -1;
          break;
        default:
          m_IO.bell();
      }
      m_IO.flush();
    } while (in != -1);
  }//run

  /**
   * Method that draws the component.
   */
  public void draw() throws IOException {
    StringBuffer sbuf = new StringBuffer();
    sbuf.append(" ");			//1/1
    sbuf.append(m_LeftBracket);	//1/2
    if (m_Selected) {
      sbuf.append(m_Mark);	//1/3
    } else {
      sbuf.append(" ");
    }
    sbuf.append(m_RightBracket);	//1/4
    sbuf.append(" ");			//1/5
    sbuf.append(m_Text);		//1/5+myText.length

    if (m_Position != null) {
      m_IO.setCursor(m_Position.getRow(), m_Position.getColumn());
    }

    m_IO.write(sbuf.toString());
    m_IO.moveLeft(3 + m_Text.length()); //thats the mark position
    m_IO.flush();
  }//draw

  private void drawMark() throws IOException {
    if (m_Position != null) {
      m_IO.storeCursor();
      m_IO.setCursor(m_Position.getRow(), m_Position.getColumn());
      m_IO.moveRight(2);
    }
    if (m_Selected) {
      m_IO.write(m_Mark);
    } else {
      m_IO.write(" ");
    }
    if (m_Position == null) {
      m_IO.moveLeft(1); //back to mark position
    } else {
      m_IO.restoreCursor();
    }
    m_IO.flush();
  }//drawMark


  public static final int SMALL_CHECKMARK = 10;
  public static final int LARGE_CHECKMARK = 11;

  public static final int SQUARED_BOXSTYLE = 1;
  public static final int ROUND_BOXSTYLE = 2;
  public static final int EDGED_BOXSTYLE = 3;
  private static final int SPACE = 32;

}//class Checkbox