ShellCommand.java

/*
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version. You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

package org.aitools.programd.interfaces.shell;

/**
 * A <code>ShellCommand</code> is a command that can be executed from the {@link Shell}.
 * 
 * @author <a href="mailto:noel@aitools.org">Noel Bush</a>
 */
abstract public class ShellCommand {

  /** The command string for the shell command (so it can be returned via a get method). */
  private String _commandString;

  /** The argument template for the shell command (so it can be returned via a get method). */
  private String _argumentTemplate;

  /** The help line for the shell command (so it can be returned via a get method). */
  private String _helpLine;

  /**
   * Creates a <code>ShellCommand</code> that handles the given command string.
   * 
   * @param commandString the command string to handle
   * @param argumentTemplate the argument template to use
   * @param helpLine the help line to provide when asked
   */
  public ShellCommand(String commandString, String argumentTemplate, String helpLine) {
    this._commandString = commandString;
    this._argumentTemplate = argumentTemplate;
    this._helpLine = helpLine;
  }

  /**
   * Returns the argument template for this command.
   * 
   * @return the argument template for this command
   */
  public String getArgumentTemplate() {
    return this._argumentTemplate;
  }

  /**
   * Returns the command to which this responds.
   * 
   * @return the command to which this responds
   */
  public String getCommandString() {
    return this._commandString;
  }

  /**
   * Returns a line of help for this command.
   * 
   * @return a line of help for this command
   */
  public String getHelpLine() {
    return this._helpLine;
  }

  /**
   * Handles the given command line.
   * 
   * @param commandLine the command line to handle
   * @param shell the shell that got the command
   */
  abstract public void handle(String commandLine, Shell shell);

  /**
   * Indicates whether the ShellCommand handles a command contained in the given line.
   * 
   * @param commandLine the line of text received
   * @return whether the ShellCommand handles this
   */
  abstract public boolean handles(String commandLine);
}