001    /* java.beans.Visibility
002       Copyright (C) 1998, 1999 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package 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    
056    public 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    }