001/* IIOParamController.java --
002   Copyright (C) 2004  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.imageio;
040
041/**
042 * An interface to set image parameters.  An IIOParamController may be
043 * a GUI component, a database reader, command-line parser or any
044 * other means of getting parameter settings.  For exampe, a dialog
045 * box could implement IIOParamController to allow a user to adjust
046 * JPEG compression levels.
047 *
048 * The activate method should always behave modally; it should only
049 * return when the action has been either cancelled or completed.
050 *
051 * @author Michael Koch (konqueror@gmx.de)
052 */
053public interface IIOParamController
054{
055  /**
056   * Activates the controller.  A return value of false should mean
057   * that no changes were made to param.  A return value of true
058   * should mean that the image is ready to be read or written.
059   *
060   * @param param the <code>IIOParam</code> to be modified
061   *
062   * @return true if the <code>IIOParam</code> has been modified,
063   * false otherwise
064   *
065   * @exception IllegalArgumentException if param is null or is not an instance
066   * of the correct class
067   */
068  boolean activate(IIOParam param);
069}