BeanSupport


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3    * and Distribution License (the License). You may not use this file except in
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11   * If applicable, add the following below the CDDL Header, with the fields
12   * enclosed by brackets [] replaced by your own identifying information:
13   * "Portions Copyrighted [year] [name of copyright owner]"
14   *
15   * The Original Software is NetBeans. The Initial Developer of the Original
16   * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
17   * Microsystems, Inc. All Rights Reserved.
18   */
19  
20  package org.netbeans.modules.form;
21  
22  import java.awt.*;
23  import java.beans.*;
24  import java.lang.reflect.Method  ;
25  import java.lang.ref.Reference  ;
26  import java.lang.ref.SoftReference  ;
27  import java.util.*;
28  import org.netbeans.modules.form.fakepeer.FakePeerSupport;
29  import org.openide.util.Utilities;
30  
31  /**
32   * BeanSupport is a utility class with various static methods supporting
33   * operations with JavaBeans.
34   *
35   * @author Ian Formanek, Jan Stola
36   */
37  public class BeanSupport
38  {
39      public static final Object   NO_VALUE = new Object  ();
40  
41      // -----------------------------------------------------------------------------
42      // Private variables
43  
44      private static Map errorEmptyMap = new HashMap(3);
45      private static Map valuesCache = new HashMap(30);
46      private static Map instancesCache = new HashMap(30);
47      private static Map deviationsCache = new HashMap();
48  
49      // -----------------------------------------------------------------------------
50      // Public methods
51  
52      /**
53       * Utility method to create an instance of given class. Returns null on
54       * error.
55       * @param beanClass the class to create inctance of
56       * @return new instance of specified class or null if an error occured
57       * during instantiation
58       */
59      public static Object   createBeanInstance(Class   beanClass) {
60          try {
61              return CreationFactory.createDefaultInstance(beanClass);
62          }
63          catch (Exception   ex) {
64              if (Boolean.getBoolean("netbeans.debug.exceptions")) // NOI18N
65                  ex.printStackTrace();
66              System.err.println("[WARNING] BeanSupport cannot create default instance of: "+beanClass.getName());
67              return null;
68          }
69      }
70  
71  
72      /**
73       * Utility method to obtain an instance of specified beanClass. The
74       * instance is reused, and thus should only be used to obtain info about
75       * settings of default instances of the specified class.
76       * @param beanClass the class to create inctance of
77       * @return instance of specified class or null if an error occured during
78       * instantiation
79       */
80      public static Object   getDefaultInstance(Class   beanClass) {
81          Object   defInstance = instancesCache.get(beanClass);
82          if (defInstance == null) {
83              defInstance = createBeanInstance(beanClass);
84              if (defInstance instanceof Component) {
85                  FakePeerSupport.attachFakePeer((Component)defInstance);
86                  if (defInstance instanceof Container)
87                      FakePeerSupport.attachFakePeerRecursively(
88                                                      (Container)defInstance);
89              }
90  
91              // hack for JTextField - default background depends on whether
92              // the component is editable or not
93              if (defInstance instanceof javax.swing.JTextField  ) {
94                  Object  [] values = new Object  [2];
95                  javax.swing.JTextField   jtf = (javax.swing.JTextField  ) defInstance;
96                  values[0] = jtf.getBackground();
97                  jtf.setEditable(false);
98                  values[1] = jtf.getBackground();
99                  jtf.setEditable(true);
100 
101                 Map deviationMap = new HashMap();
102                 deviationMap.put(
103                     "background", // NOI18N
104                     new DefaultValueDeviation(values) {
105                         Object   getValue(Object   beanInstance) {
106                             return ((javax.swing.JTextField  )beanInstance).isEditable() ?
107                                    this.values[0] : this.values[1];
108                         }
109                     }
110                 );
111 
112                 deviationsCache.put(beanClass, deviationMap);
113             }
114 
115             instancesCache.put(beanClass, defInstance);
116         }
117         return defInstance;
118     }
119 
120     /**
121      * Utility method to obtain a default property values of specified JavaBean
122      * class.  The default values are property values immediately after the
123      * instance is created.  Because some AWT components initialize their
124      * properties only after the peer is created, these are treated specially
125      * and default values for those properties are provided
126      * explicitely(e.g. though the value of Font property of java.awt.Button is
127      * null after an instance of Button is created, this method will return the
128      * Font(Dialog, 12, PLAIN) as the default value).
129      *
130      * @param beanClass The Class of the JavaBean for which the default values
131      * are to be obtained
132      * @return Map containing pairs <PropertyName(String), value(Object)>
133      * @see #getDefaultPropertyValue
134      */
135     
136     public static Map getDefaultPropertyValues(Class   beanClass) {
137         Map defValues =(Map) valuesCache.get(beanClass);
138         if (defValues == null) {
139             Object   beanInstance = getDefaultInstance(beanClass);
140             if (beanInstance == null)
141                 return errorEmptyMap;
142             defValues = getPropertyValues(beanInstance);
143             valuesCache.put(beanClass, defValues);
144         }
145         return defValues;
146     }
147 
148     /**
149      * Utility method to obtain a default value of specified JavaBean class and
150      * property name.  The default values are property values immediately after
151      * the instance is created.  Because some AWT components initialize their
152      * properties only after the peer is created, these are treated specially
153      * and default values for those properties are provided
154      * explicitely(e.g. though the value of Font property of java.awt.Button is
155      * null after an instance of Button is created, this method will return the
156      * Font(Dialog, 12, PLAIN) as the default value).
157      *
158      * @param beanClass The Class of the JavaBean for which the default value
159      * is to be obtained
160      * @param beanClass The name of the propertyn for which the default value
161      * is to be obtained
162      * @return The default property value for specified property on specified
163      * JavaBean class
164      * @see #getDefaultPropertyValues
165      */
166     public static Object   getDefaultPropertyValue(Object   bean,
167                                                  String   propertyName)
168     {
169         Map deviationMap = (Map) deviationsCache.get(bean.getClass());
170         if (deviationMap != null) {
171             DefaultValueDeviation deviation = (DefaultValueDeviation)
172                                               deviationMap.get(propertyName);
173             if (deviation != null)
174                 return deviation.getValue(bean);
175         }
176 
177         Map valuesMap = getDefaultPropertyValues(bean.getClass());
178         Object   value = valuesMap.get(propertyName);
179         return value != null || valuesMap.containsKey(propertyName) ?
180                value : NO_VALUE;
181     }
182 
183     /**
184      * Utility method to obtain a current property values of given JavaBean instance.
185      * Only the properties specified in bean info(if it exists) are provided.
186      *
187      * @return Map containing pairs <PropertyName(String), value(Object)>
188      */
189     public static Map getPropertyValues(Object   beanInstance) {
190         if (beanInstance == null) {
191             return errorEmptyMap;
192         }
193 
194         BeanInfo info;
195         try {
196             info = FormUtils.getBeanInfo(beanInstance.getClass());
197         } catch (IntrospectionException ex) {
198             return errorEmptyMap;
199         }
200         PropertyDescriptor[] properties = info.getPropertyDescriptors();
201         HashMap defaultValues = new HashMap(properties.length * 2);
202 
203         for (int i = 0; i < properties.length; i++) {
204             defaultValues.put(properties[i].getName(), NO_VALUE);
205             
206             Method   readMethod = properties[i].getReadMethod();
207             if (readMethod != null) {
208                 try {
209                     Object   value = readMethod.invoke(beanInstance, new Object   [0]);
210                     defaultValues.put(properties[i].getName(), value);
211                 } catch (Exception   e) {
212                 }
213             } 
214         }
215 
216         return defaultValues;
217     }
218 
219     /** Utility method that obtains icon for a bean class.
220      * (This method is currently used only for obtaining default icons for AWT
221      *  components. Other icons should be provided by BeanInfo.)
222      */
223     public static Image getBeanIcon(Class   beanClass, int iconType) {
224         return getIconForDefault(beanClass);
225     }
226 
227     /** A utility method that returns a class of event adapter for
228      * specified listener. It works only on known listeners from java.awt.event.
229      * Null is returned for unknown listeners.
230      * @return class of an adapter for specified listener or null if
231      *               unknown/does not exist
232      */
233     public static Class   getAdapterForListener(Class   listener) {
234         if (java.awt.event.ComponentListener  .class.equals(listener))
235             return java.awt.event.ComponentAdapter  .class;
236         else if (java.awt.event.ContainerListener  .class.equals(listener))
237             return java.awt.event.ContainerAdapter  .class;
238         else if (java.awt.event.FocusListener  .class.equals(listener))
239             return java.awt.event.FocusAdapter  .class;
240         else if (java.awt.event.KeyListener  .class.equals(listener))
241             return java.awt.event.KeyAdapter  .class;
242         else if (java.awt.event.MouseListener  .class.equals(listener))
243             return java.awt.event.MouseAdapter  .class;
244         else if (java.awt.event.MouseMotionListener  .class.equals(listener))
245             return java.awt.event.MouseMotionAdapter  .class;
246         else if (java.awt.event.WindowListener  .class.equals(listener))
247             return java.awt.event.WindowAdapter  .class;
248         else return null; // not found
249     }
250 
251     // -----------------------------------------------------------------------------
252     // Private methods
253 
254     static Reference  <Map<String  ,Object  >> imageCache;
255 
256     private static synchronized Image getIconForDefault(Class   klass) {
257         Map<String  ,Object  > icons;
258         if ((imageCache == null) || ((icons = imageCache.get()) == null)) {
259             icons = createImageCache();
260             imageCache = new SoftReference  <Map<String  ,Object  >>(icons);
261         }
262         
263         String   name = klass.getName();
264         Object   img = icons.get(name);
265         
266         if (img == null) {
267             return null;
268         }
269         
270         if (img instanceof Image) {
271             return (Image) img;
272         } else {
273             Image image = Utilities.loadImage((String  )img);
274             icons.put(name, image);
275             return image;
276         }
277     }
278 
279     private static Map<String  , Object  > createImageCache() {
280         Map<String  , Object  > map = new HashMap<String  , Object  >();
281         
282         map.put("java.awt.Label", "org/netbeans/modules/form/beaninfo/awt/label.gif"); // NOI18N
283         map.put("java.awt.Button", "org/netbeans/modules/form/beaninfo/awt/button.gif"); // NOI18N
284         map.put("java.awt.TextField", "org/netbeans/modules/form/beaninfo/awt/textfield.gif"); // NOI18N
285         map.put("java.awt.TextArea", "org/netbeans/modules/form/beaninfo/awt/textarea.gif"); // NOI18N
286         map.put("java.awt.Checkbox", "org/netbeans/modules/form/beaninfo/awt/checkbox.gif"); // NOI18N
287         map.put("java.awt.Choice", "org/netbeans/modules/form/beaninfo/awt/choice.gif"); // NOI18N
288         map.put("java.awt.List", "org/netbeans/modules/form/beaninfo/awt/list.gif"); // NOI18N
289         map.put("java.awt.Scrollbar", "org/netbeans/modules/form/beaninfo/awt/scrollbar.gif"); // NOI18N
290         map.put("java.awt.ScrollPane", "org/netbeans/modules/form/beaninfo/awt/scrollpane.gif"); // NOI18N
291         map.put("java.awt.Panel", "org/netbeans/modules/form/beaninfo/awt/panel.gif"); // NOI18N
292         map.put("java.awt.Canvas", "org/netbeans/modules/form/beaninfo/awt/canvas.gif"); // NOI18N
293         map.put("java.awt.MenuBar", "org/netbeans/modules/form/beaninfo/awt/menubar.gif"); // NOI18N
294         map.put("java.awt.PopupMenu", "org/netbeans/modules/form/beaninfo/awt/popupmenu.gif"); // NOI18N
295         map.put("java.awt.Menu", "org/netbeans/modules/form/resources/menu.gif"); // NOI18N
296         map.put("java.awt.MenuItem", "org/netbeans/modules/form/resources/menuItem.gif"); // NOI18N
297         map.put("java.awt.CheckboxMenuItem", "org/netbeans/modules/form/resources/menuItemCheckbox.gif"); // NOI18N
298         map.put("org.netbeans.modulres.form.Separator", "org/netbeans/modules/form/resources/menuSeparator.gif"); // NOI18N
299 
300         map.put("java.applet.Applet", "org/netbeans/modules/form/resources/applet.gif"); // NOI18N
301         map.put("java.awt.Dialog", "org/netbeans/modules/form/resources/dialog.gif"); // NOI18N
302         map.put("java.awt.Frame", "org/netbeans/modules/form/resources/frame.gif"); // NOI18N
303 
304         return map;
305     }
306 
307     private static abstract class DefaultValueDeviation {
308         protected Object  [] values;
309         DefaultValueDeviation(Object  [] values) {
310             this.values = values;
311         }
312         abstract Object   getValue(Object   beanInstance);
313     }
314 }
315
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