Java tutorial
/* * Copyright (c) 1996, 2016, Oracle and/or its affiliates. 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. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.beans; import java.awt.Image; import java.awt.Toolkit; import java.awt.image.ImageProducer; import java.net.URL; import java.security.AccessController; import java.security.PrivilegedAction; /** * This is a support class to make it easier for people to provide * BeanInfo classes. * <p> * It defaults to providing "noop" information, and can be selectively * overriden to provide more explicit information on chosen topics. * When the introspector sees the "noop" values, it will apply low * level introspection and design patterns to automatically analyze * the target bean. * * @since 1.1 */ public class SimpleBeanInfo implements BeanInfo { /** * Deny knowledge about the class and customizer of the bean. * You can override this if you wish to provide explicit info. */ @Override public BeanDescriptor getBeanDescriptor() { return null; } /** * Deny knowledge of properties. You can override this * if you wish to provide explicit property info. */ @Override public PropertyDescriptor[] getPropertyDescriptors() { return null; } /** * Deny knowledge of a default property. You can override this * if you wish to define a default property for the bean. */ @Override public int getDefaultPropertyIndex() { return -1; } /** * Deny knowledge of event sets. You can override this * if you wish to provide explicit event set info. */ @Override public EventSetDescriptor[] getEventSetDescriptors() { return null; } /** * Deny knowledge of a default event. You can override this * if you wish to define a default event for the bean. */ @Override public int getDefaultEventIndex() { return -1; } /** * Deny knowledge of methods. You can override this * if you wish to provide explicit method info. */ @Override public MethodDescriptor[] getMethodDescriptors() { return null; } /** * Claim there are no other relevant BeanInfo objects. You * may override this if you want to (for example) return a * BeanInfo for a base class. */ @Override public BeanInfo[] getAdditionalBeanInfo() { return null; } /** * Claim there are no icons available. You can override * this if you want to provide icons for your bean. */ @Override public Image getIcon(final int iconKind) { final BeanDescriptor descriptor = getBeanDescriptor(); if (descriptor != null) { final Class<?> type = descriptor.getBeanClass(); if (type != null && type.getClassLoader() == null && type.getAnnotation(JavaBean.class) != null) { final String name = type.getName(); final int index = name.lastIndexOf('.'); if (name.substring(0, index).equals("javax.swing")) { final String className = type.getSimpleName(); switch (iconKind) { case ICON_COLOR_32x32: return loadImage(className, "Color32.gif"); case ICON_COLOR_16x16: return loadImage(className, "Color16.gif"); case ICON_MONO_32x32: return loadImage(className, "Mono32.gif"); case ICON_MONO_16x16: return loadImage(className, "Mono16.gif"); } } } } return null; } /** * This is a utility method to help in loading standard icon images. * * @param resourceName A pathname relative to the directory holding the * class file of the current class * @return an image object. May be null if the load failed. * @see java.beans.SimpleBeanInfo#loadImage(String) */ private Image loadStandardImage(final String resourceName) { return AccessController.doPrivileged((PrivilegedAction<Image>) () -> loadImage(resourceName)); } /** * This is a utility method to help in loading standard icon images. * * @param resourceName A pathname relative to the directory holding the * class file of the current class * @param suffix A {@code String} containing a file suffix (<i>e.g.</i>, * "Color32.gif" or "Mono32.gif") * @return an image object. May be null if the load failed. * @see java.beans.SimpleBeanInfo#loadImage(String) */ private Image loadImage(final String resourceName, final String suffix) { final String prefix = "/javax/swing/beaninfo/images/"; final Image image = loadStandardImage(prefix + resourceName + suffix); return image == null ? loadStandardImage(prefix + "JComponent" + suffix) : image; } /** * This is a utility method to help in loading icon images. It takes the * name of a resource file associated with the current object's class file * and loads an image object from that file. Typically images will be GIFs. * * @param resourceName A pathname relative to the directory holding the * class file of the current class. For example, "wombat.gif". * @return an image object or null if the resource is not found or the * resource could not be loaded as an Image */ public Image loadImage(final String resourceName) { try { final URL url = getClass().getResource(resourceName); if (url != null) { final ImageProducer ip = (ImageProducer) url.getContent(); if (ip != null) { return Toolkit.getDefaultToolkit().createImage(ip); } } } catch (final Exception ignored) { } return null; } }