001    /*
002     * Copyright (C) 2012 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.shell;
021    
022    import java.io.IOException;
023    
024    /**
025     * The interaction context extends the screen context and provides interaction with the client.
026     *
027     * @param <E> the element generic type
028     */
029    public interface InteractionContext<E> extends ScreenContext<E> {
030    
031      /**
032       * Take control of the alternate buffer. When the alternate buffer is already used
033       * nothing happens. The buffer switch should occur when then {@link #flush()} method
034       * is invoked.
035       *
036       * @return true if the alternate buffer is shown
037       */
038      boolean takeAlternateBuffer() throws IOException;
039    
040      /**
041       * Release control of the alternate buffer. When the normal buffer is already used
042       * nothing happens. The buffer switch should occur when then {@link #flush()} method
043       * is invoked.
044       *
045       * @return true if the usual buffer is shown
046       */
047      boolean releaseAlternateBuffer() throws IOException;
048    
049      /**
050       * Returns a generic property, usually this property is resolved by the
051       * shell client.
052       *
053       * @param propertyName the property name
054       * @return the property value
055       */
056      String getProperty(String propertyName);
057    
058      /**
059       * Display a message and read a line on the console. If no line can be read
060       * then null is returned.
061       *
062       * @param msg the message to display before reading a line
063       * @param echo wether or not the line read should be echoed when typing
064       * @return the line read
065       */
066      String readLine(String msg, boolean echo);
067    
068    }