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 org.crsh.text.ScreenContext; 023 024 import java.io.IOException; 025 026 /** 027 * The interaction context extends the screen context and provides interaction with the client. 028 */ 029 public interface InteractionContext extends ScreenContext { 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, this method call can be blocking until the user provides 060 * a value. If no line can be read 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 * @throws java.io.IOException any io exception 066 * @throws java.lang.InterruptedException the thread was interrupted while waiting for the user value 067 * @throws java.lang.IllegalStateException if reading a line is not at the appropriate time 068 */ 069 String readLine(String msg, boolean echo) throws IOException, InterruptedException, IllegalStateException; 070 071 }