1 /* 2 * Copyright (c) 1996, 1998, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.beans; 27 28 /** 29 * Under some circumstances a bean may be run on servers where a GUI 30 * is not available. This interface can be used to query a bean to 31 * determine whether it absolutely needs a gui, and to advise the 32 * bean whether a GUI is available. 33 * <p> 34 * This interface is for expert developers, and is not needed 35 * for normal simple beans. To avoid confusing end-users we 36 * avoid using getXXX setXXX design patterns for these methods. 37 * 38 * @since 1.1 39 */ 40 41 public interface Visibility { 42 43 /** 44 * Determines whether this bean needs a GUI. 45 * 46 * @return True if the bean absolutely needs a GUI available in 47 * order to get its work done. 48 */ 49 boolean needsGui(); 50 51 /** 52 * This method instructs the bean that it should not use the Gui. 53 */ 54 void dontUseGui(); 55 56 /** 57 * This method instructs the bean that it is OK to use the Gui. 58 */ 59 void okToUseGui(); 60 61 /** 62 * Determines whether this bean is avoiding using a GUI. 63 * 64 * @return true if the bean is currently avoiding use of the Gui. 65 * e.g. due to a call on dontUseGui(). 66 */ 67 boolean avoidingGui(); 68 69 }