001    /*
002     * Copyright (C) 2010 eXo Platform SAS.
003     *
004     * This is free software; you can redistribute it and/or modify it
005     * under the terms of the GNU Lesser General Public License as
006     * published by the Free Software Foundation; either version 2.1 of
007     * the License, or (at your option) any later version.
008     *
009     * This software is distributed in the hope that it will be useful,
010     * but WITHOUT ANY WARRANTY; without even the implied warranty of
011     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012     * Lesser General Public License for more details.
013     *
014     * You should have received a copy of the GNU Lesser General Public
015     * License along with this software; if not, write to the Free
016     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018     */
019    
020    package org.crsh.term.console;
021    
022    import java.io.IOException;
023    
024    /**
025     * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
026     * @version $Revision$
027     */
028    public abstract class ViewReader implements Appendable {
029    
030      public abstract ViewReader append(char c) throws IOException;
031    
032      public abstract ViewReader append(CharSequence s) throws IOException;
033    
034      public abstract ViewReader append(CharSequence csq, int start, int end) throws IOException;
035    
036      /**
037       * Replace all the characters before the cursor by the provided char sequence.
038       *
039       * @param s the new char sequence
040       * @return the l
041       * @throws IOException any IOException
042       */
043      public abstract CharSequence replace(CharSequence s) throws IOException;
044    
045      /**
046       * Delete the char under the cursor or return -1 if no char was deleted.
047       *
048       * @return the deleted char
049       * @throws IOException any IOException
050       */
051      public abstract int del() throws IOException;
052    
053      public abstract boolean moveRight() throws IOException;
054    
055      public abstract boolean moveLeft() throws IOException;
056    }