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