001/* java.beans.Visibility
002   Copyright (C) 1998, 1999 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 java.beans;
040
041/**
042 * Visibility is an interface a Bean may implement so that the environment
043 * can tell the Bean whether there is a GUI or not, and so that the Bean
044 * can tell the environment whether it needs one or can run without one.
045 * <P>
046 *
047 * Sun decided not to use standard Introspection patterns so that these
048 * methods did not get included when the Introspector made its sweep on
049 * the class.
050 *
051 * @author John Keiser
052 * @since JDK1.1
053 * @version 1.1.0, 29 Jul 1998
054 */
055
056public interface Visibility {
057        /**
058         * Tells whether the Bean can run without a GUI or not.
059         * @return false if Bean can run without a GUI, else true.
060         */
061        boolean needsGui();
062
063        /**
064         * Tells whether Bean is trying not to use the GUI.
065         * If needsGui() is true, this method should always return false.
066         * @return true if definitely not using GUI, otherwise false.
067         */
068        boolean avoidingGui();
069
070        /**
071         * Tells the Bean not to use GUI methods.
072         * If needsGUI() is false, then after this method is called,
073         * avoidingGui() should return true.
074         */
075        void dontUseGui();
076
077        /**
078         * Tells the Bean it may use the GUI.
079         * The Bean is not required to use the GUI in this case, it is
080         * merely being <EM>permitted</EM> to use it.  If needsGui() is
081         * false, avoidingGui() may return true or false after this method
082         * is called.
083         */
084        void okToUseGui();
085}