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7  * to you under the Apache License, Version 2.0 (the
8  * "License"); you may not use this file except in compliance
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11  *   http://www.apache.org/licenses/LICENSE-2.0
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14  * software distributed under the License is distributed on an
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16  * KIND, either express or implied.  See the License for the
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18  * under the License.
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21 
22 package org.apache.openoffice.comp.sdbc.dbtools.comphelper;
23 
24 import com.sun.star.container.NoSuchElementException;
25 import com.sun.star.container.XEnumeration;
26 import com.sun.star.container.XNameAccess;
27 import com.sun.star.lang.EventObject;
28 import com.sun.star.lang.WrappedTargetException;
29 import com.sun.star.lang.XComponent;
30 import com.sun.star.lang.XEventListener;
31 import com.sun.star.lib.uno.helper.WeakBase;
32 import com.sun.star.uno.UnoRuntime;
33 
34 public class OEnumerationByName extends WeakBase implements XEnumeration, XEventListener {
35     private String[] names;
36     private int position;
37     private XNameAccess collection;
38     private boolean isListening;
39 
OEnumerationByName(XNameAccess collection)40     public OEnumerationByName(XNameAccess collection) {
41         this.collection = collection;
42         names = collection.getElementNames();
43         startDisposeListening();
44     }
45 
46     @Override
disposing(EventObject event)47     public void disposing(EventObject event) {
48         synchronized (this) {
49             if (event.Source == collection) {
50                 collection = null;
51             }
52         }
53     }
54 
55     @Override
hasMoreElements()56     public boolean hasMoreElements() {
57         synchronized (this) {
58             if (collection != null) {
59                 if (position < names.length) {
60                     return true;
61                 } else {
62                     stopDisposeListening();
63                     collection = null;
64                 }
65             }
66             return false;
67         }
68     }
69 
70     @Override
nextElement()71     public Object nextElement()
72             throws NoSuchElementException, WrappedTargetException {
73         Object value = null;
74         synchronized (this) {
75             if (collection != null) {
76                 if (position < names.length) {
77                     value = collection.getByName(names[position++]);
78                 }
79                 if (position >= names.length) {
80                     stopDisposeListening();
81                     collection = null;
82                 }
83             }
84         }
85         if (value == null) {
86             throw new NoSuchElementException();
87         }
88         return value;
89     }
90 
startDisposeListening()91     private void startDisposeListening() {
92         synchronized (this) {
93             if (isListening) {
94                 return;
95             }
96             XComponent component = UnoRuntime.queryInterface(XComponent.class, collection);
97             if (component != null) {
98                 component.addEventListener(this);
99                 isListening = true;
100             }
101         }
102     }
103 
stopDisposeListening()104     private void stopDisposeListening() {
105         synchronized (this) {
106             if (!isListening) {
107                 return;
108             }
109             XComponent component = UnoRuntime.queryInterface(XComponent.class, collection);
110             if (component != null) {
111                 component.removeEventListener(this);
112                 isListening = false;
113             }
114         }
115     }
116 }
117