ajava.beans.Visibility Maven / Gradle / Ivy

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 * particular file as subject to the "Classpath" exception as provided
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * accompanied this code).
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package ajava.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.
 * 
 * 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();

}