titlebar.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 net.wimpi.telnetd.io.terminal.ColorHelper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.IOException;

/**
 * Class that implements a titlebar, for the top of the
 * Terminal Window.
 *
 * @author Dieter Wimberger
 * @version 2.0 (16/07/2006)
 */
public class Titlebar extends InertComponent {

  private static Log log = LogFactory.getLog(Titlebar.class);
  //Members
  private String m_Title;
  private int m_Align;
  private String m_BgColor;
  private String m_FgColor;


  /**
   * Constructor for a simple titlebar instance.
   */
  public Titlebar(BasicTerminalIO io, String name) {
    super(io, name);
  }//constructor


  /**
   * Mutator method for the titletext property of the titlebar component.
   *
   * @param text title String displayed in the titlebar.
   */
  public void setTitleText(String text) {
    m_Title = text;
  }//setTitleText

  /**
   * Accessor method for the titletext property of the titlebar component.
   *
   * @return String that is displayed when the bar is drawn.
   */
  public String getTitleText() {
    return m_Title;
  }//getTitleText

  /**
   * Mutator method for the alignment property.
   *
   * @param alignment integer, valid if one of  the ALIGN_* constants.
   */
  public void setAlignment(int alignment) {
    if (alignment < 1 || alignment > 3) {
      alignment = 2;	//left default
    } else {
      m_Align = alignment;
    }
  }//setAlignment

  /**
   * Mutator method for the SoregroundColor property.
   *
   * @param color String, valid if it is a ColorHelper color constant.
   */
  public void setForegroundColor(String color) {
    m_FgColor = color;
  }//setForegroundColor

  /**
   * Mutator method for the BackgroundColor property.
   *
   * @param color String, valid if it is a ColorHelper color constant.
   */
  public void setBackgroundColor(String color) {
    m_BgColor = color;
  }//setBackgroundColor


  /**
   * Method that draws the titlebar on the screen.
   */
  public void draw() throws IOException {
    m_IO.storeCursor();
    m_IO.homeCursor();
    m_IO.write(getBar());
    m_IO.restoreCursor();
  }//draw


  /**
   * Internal method that creates the true titlebarstring displayed
   * on the terminal.
   */
  private String getBar() {
    String ttitle = m_Title;
    //get actual screen width , remove the correction offset
    int width = m_IO.getColumns() - 1;
    //get actual titletext width
    int textwidth = (int) ColorHelper.getVisibleLength(m_Title);

    if (textwidth > width) ttitle = m_Title.substring(0, width);
    textwidth = (int) ColorHelper.getVisibleLength(ttitle);

    //prepare a buffer with enough space
    StringBuffer bar = new StringBuffer(width + textwidth);
    switch (m_Align) {
      case ALIGN_LEFT:
        bar.append(ttitle);
        appendSpaceString(bar, width - textwidth);
        break;
      case ALIGN_RIGHT:
        appendSpaceString(bar, width - textwidth);
        bar.append(ttitle);
        break;
      case ALIGN_CENTER:
        int left = ((width - textwidth != 0) ? ((width - textwidth) / 2) : (0));
        int right = width - textwidth - left;
        appendSpaceString(bar, left);
        bar.append(ttitle);
        appendSpaceString(bar, right);
    }
    //log.debug("Length of TB=" + bar.length());
    return ColorHelper.boldcolorizeText(bar.toString(), m_FgColor, m_BgColor);
  }//getBar


  private void appendSpaceString(StringBuffer sbuf, int length) {
    for (int i = 0; i < length; i++) {
      sbuf.append(" ");
    }
  }//appendSpaceString


  // Constant definitions

  public static final int ALIGN_RIGHT = 1;
  public static final int ALIGN_LEFT = 2;
  public static final int ALIGN_CENTER = 3;


}//class Titlebar