001 /* 002 * Copyright (C) 2003-2009 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.command; 021 022 import org.crsh.text.ShellPrintWriter; 023 024 /** 025 * The invocation context provided to a command during the invocation phase. 026 * It provides the various interactions that a command can perform with 027 * its context during its invocation. 028 * 029 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a> 030 * @version $Revision$ 031 */ 032 public interface InvocationContext<C, P> extends CommandContext { 033 034 /** 035 * Returns the term width in chars. When the value is not positive it means 036 * the value could not be determined. 037 * 038 * @return the term width 039 */ 040 int getWidth(); 041 042 /** 043 * Returns a generic property, usually this property is resolved by the 044 * shell client. 045 * 046 * @param propertyName the property name 047 * @return the property value 048 */ 049 String getProperty(String propertyName); 050 051 /** 052 * Display a message and read a line on the console. If no line can be read 053 * then null is returned. 054 * 055 * @param msg the message to display before reading a line 056 * @param echo wether or not the line read should be echoed when typing 057 * @return the line read 058 */ 059 String readLine(String msg, boolean echo); 060 061 /** 062 * Returns the writer for the output. 063 * 064 * @return the writer 065 */ 066 ShellPrintWriter getWriter(); 067 068 /** 069 * Returns true if the command is involved in a pipe operation and receives 070 * a stream. 071 * 072 * @return true if the command is involved in a pipe 073 */ 074 boolean isPiped(); 075 076 /** 077 * Returns an iterator over the stream of consumed items. 078 * 079 * @return the consumed items 080 * @throws IllegalStateException if the command is not involved in a 081 * pipe operation 082 */ 083 Iterable<C> consume() throws IllegalStateException; 084 085 /** 086 * Produce an item. 087 * 088 * @param product the item product 089 */ 090 void produce(P product); 091 092 }