visibility.java

来自「《移动Agent技术》一书的所有章节源代码。」· Java 代码 · 共 61 行

/*
 * @(#)Visibility.java	1.5 96/12/06  
 * 
 * Copyright (c) 1996 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the confidential and proprietary information of Sun
 * Microsystems, Inc. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Sun.
 * 
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
 * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 * 
 * CopyrightVersion bdk_beta
 * 
 */

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 {

    /**
     * @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();

    /**
     * @return true if the bean is currently avoiding use of the Gui.
     *   e.g. due to a call on dontUseGui().
     */
    boolean avoidingGui();

}