src/share/classes/java/beans/BeanInfo.java

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package java.beans;

/**
 * A bean implementor who wishes to provide explicit information about
 * their bean may provide a BeanInfo class that implements this BeanInfo
 * interface and provides explicit information about the methods,
 * properties, events, etc, of their  bean.
 * <p>
 * A bean implementor doesn't need to provide a complete set of
 * explicit information.  You can pick and choose which information
 * you want to provide and the rest will be obtained by automatic
 * analysis using low-level reflection of the bean classes' methods
 * and applying standard design patterns.
 * <p>
 * You get the opportunity to provide lots and lots of different
 * information as part of the various XyZDescriptor classes.  But
 * don't panic, you only really need to provide the minimal core
 * information required by the various constructors.
 * <P>
 * See also the SimpleBeanInfo class which provides a convenient
 * "noop" base class for BeanInfo classes, which you can override
 * for those specific places where you want to return explicit info.
 * <P>
 * To learn about all the behaviour of a bean see the Introspector class.
 */

public interface BeanInfo {

    /**
     * Gets the beans <code>BeanDescriptor</code>.
     *
     * @return  A BeanDescriptor providing overall information about
     * the bean, such as its displayName, its customizer, etc.  May
     * return null if the information should be obtained by automatic
     * analysis.
     */
    BeanDescriptor getBeanDescriptor();

    /**
     * Gets the beans <code>EventSetDescriptor</code>s.
     *
     * @return  An array of EventSetDescriptors describing the kinds of
     * events fired by this bean.  May return null if the information
     * should be obtained by automatic analysis.
     */
    EventSetDescriptor[] getEventSetDescriptors();

    /**
     * A bean may have a "default" event that is the event that will
     * mostly commonly be used by humans when using the bean.
     * @return Index of default event in the EventSetDescriptor array
     *          returned by getEventSetDescriptors.
     * <P>      Returns -1 if there is no default event.
     */
    int getDefaultEventIndex();

    /**
     * Returns descriptors for all properties of the bean.
     * May return {@code null} if the information
     * should be obtained by automatic analysis.
     * <p>
     * If a property is indexed, then its entry in the result array
     * will belong to the {@link IndexedPropertyDescriptor} subclass
     * of the {@link PropertyDescriptor} class.
     * A client of the {@code getPropertyDescriptors} method
     * can use "{@code instanceof}" to check
     * whether a given {@code PropertyDescriptor}
     * is an {@code IndexedPropertyDescriptor}.
     *
     * @return an array of {@code PropertyDescriptor}s
     *         describing all properties supported by the bean
     *         or {@code null}
     */
    PropertyDescriptor[] getPropertyDescriptors();

    /**
     * A bean may have a "default" property that is the property that will
     * mostly commonly be initially chosen for update by human's who are
     * customizing the bean.
     * @return  Index of default property in the PropertyDescriptor array
     *          returned by getPropertyDescriptors.
     * <P>      Returns -1 if there is no default property.
     */
    int getDefaultPropertyIndex();

    /**
     * Gets the beans <code>MethodDescriptor</code>s.
     *
     * @return An array of MethodDescriptors describing the externally
     * visible methods supported by this bean.  May return null if
     * the information should be obtained by automatic analysis.
     */
    MethodDescriptor[] getMethodDescriptors();

    /**
     * This method allows a BeanInfo object to return an arbitrary collection
     * of other BeanInfo objects that provide additional information on the
     * current bean.
     * <P>
     * If there are conflicts or overlaps between the information provided
     * by different BeanInfo objects, then the current BeanInfo takes precedence
     * over the getAdditionalBeanInfo objects, and later elements in the array
     * take precedence over earlier ones.
     *
     * @return an array of BeanInfo objects.  May return null.
     */
    BeanInfo[] getAdditionalBeanInfo();

    /**
     * This method returns an image object that can be used to
     * represent the bean in toolboxes, toolbars, etc.   Icon images
     * will typically be GIFs, but may in future include other formats.
     * <p>
     * Beans aren't required to provide icons and may return null from
     * this method.
     * <p>
     * There are four possible flavors of icons (16x16 color,
     * 32x32 color, 16x16 mono, 32x32 mono).  If a bean choses to only
     * support a single icon we recommend supporting 16x16 color.
     * <p>
     * We recommend that icons have a "transparent" background
     * so they can be rendered onto an existing background.
     *
     * @param  iconKind  The kind of icon requested.  This should be
     *    one of the constant values ICON_COLOR_16x16, ICON_COLOR_32x32,
     *    ICON_MONO_16x16, or ICON_MONO_32x32.
     * @return  An image object representing the requested icon.  May
     *    return null if no suitable icon is available.
     */
    java.awt.Image getIcon(int iconKind);

    /**
     * Constant to indicate a 16 x 16 color icon.
     */
    final static int ICON_COLOR_16x16 = 1;

    /**
     * Constant to indicate a 32 x 32 color icon.
     */
    final static int ICON_COLOR_32x32 = 2;

    /**
     * Constant to indicate a 16 x 16 monochrome icon.
     */
    final static int ICON_MONO_16x16 = 3;

    /**
     * Constant to indicate a 32 x 32 monochrome icon.
     */
    final static int ICON_MONO_32x32 = 4;
}