/*

 * Copyright 1996-1998 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.beans;

/**

 * Under some circumstances a bean may be run on servers where a GUI

 * is not available.  This interface can be used to query a bean to

 * determine whether it absolutely needs a gui, and to advise the

 * bean whether a GUI is available.

 * <p>

 * This interface is for expert developers, and is not needed

 * for normal simple beans.  To avoid confusing end-users we

 * avoid using getXXX setXXX design patterns for these methods.

 */

public interface Visibility {

    /**

     * Determines whether this bean needs a GUI.

     *

     * @return True if the bean absolutely needs a GUI available in

     *          order to get its work done.

     */

    boolean needsGui();

    /**

     * This method instructs the bean that it should not use the Gui.

     */

    void dontUseGui();

    /**

     * This method instructs the bean that it is OK to use the Gui.

     */

    void okToUseGui();

    /**

     * Determines whether this bean is avoiding using a GUI.

     *

     * @return true if the bean is currently avoiding use of the Gui.

     *   e.g. due to a call on dontUseGui().

     */

    boolean avoidingGui();

}