1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.pdfbox.pdfviewer;
18
19 /**
20 * A tree model that uses a cos document.
21 *
22 *
23 * @author wurtz
24 * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
25 * @version $Revision: 1.9 $
26 */
27 import javax.swing.tree.TreePath;
28 import javax.swing.tree.TreeModel;
29
30 //import java.awt.event.*;
31 import javax.swing.event.TreeModelListener;
32
33 import org.apache.pdfbox.cos.COSArray;
34 import org.apache.pdfbox.cos.COSBase;
35 import org.apache.pdfbox.cos.COSDictionary;
36 import org.apache.pdfbox.cos.COSDocument;
37 import org.apache.pdfbox.cos.COSName;
38 import org.apache.pdfbox.cos.COSObject;
39
40 import org.apache.pdfbox.pdmodel.PDDocument;
41
42 import java.util.ArrayList;
43 import java.util.Collections;
44 import java.util.List;
45
46 /**
47 * A class to model a PDF document as a tree structure.
48 *
49 * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
50 * @version $Revision: 1.9 $
51 */
52 public class PDFTreeModel implements TreeModel
53 {
54 private PDDocument document;
55
56 /**
57 * constructor.
58 */
59 public PDFTreeModel()
60 {
61 //default constructor
62 }
63
64 /**
65 * Constructor to take a document.
66 *
67 * @param doc The document to display in the tree.
68 */
69 public PDFTreeModel(PDDocument doc)
70 {
71 setDocument(doc);
72 }
73
74 /**
75 * Set the document to display in the tree.
76 *
77 * @param doc The document to display in the tree.
78 */
79 public void setDocument(PDDocument doc)
80 {
81 document = doc;
82 }
83 /**
84 * Adds a listener for the <code>TreeModelEvent</code>
85 * posted after the tree changes.
86 *
87 * @param l the listener to add
88 * @see #removeTreeModelListener
89 *
90 */
91 public void addTreeModelListener(TreeModelListener l)
92 {
93 //required for interface
94 }
95
96 /**
97 * Returns the child of <code>parent</code> at index <code>index</code>
98 * in the parent's
99 * child array. <code>parent</code> must be a node previously obtained
100 * from this data source. This should not return <code>null</code>
101 * if <code>index</code>
102 * is a valid index for <code>parent</code> (that is <code>index >= 0 &&
103 * index < getChildCount(parent</code>)).
104 *
105 * @param parent a node in the tree, obtained from this data source
106 * @param index The index into the parent object to location the child object.
107 * @return the child of <code>parent</code> at index <code>index</code>
108 *
109 */
110 public Object getChild(Object parent, int index)
111 {
112 Object retval = null;
113 if( parent instanceof COSArray )
114 {
115 ArrayEntry entry = new ArrayEntry();
116 entry.setIndex( index );
117 entry.setValue( ((COSArray)parent).getObject( index ) );
118 retval = entry;
119 }
120 else if( parent instanceof COSDictionary )
121 {
122 COSDictionary dict = ((COSDictionary)parent);
123 List<COSName> keys = new ArrayList<COSName>(dict.keySet());
124 Collections.sort( keys );
125 Object key = keys.get( index );
126 Object value = dict.getDictionaryObject( (COSName)key );
127 MapEntry entry = new MapEntry();
128 entry.setKey( key );
129 entry.setValue( value );
130 retval = entry;
131 }
132 else if( parent instanceof MapEntry )
133 {
134 retval = getChild( ((MapEntry)parent).getValue(), index );
135 }
136 else if( parent instanceof ArrayEntry )
137 {
138 retval = getChild( ((ArrayEntry)parent).getValue(), index );
139 }
140 else if( parent instanceof COSDocument )
141 {
142 retval = ((COSDocument)parent).getObjects().get( index );
143 }
144 else if( parent instanceof COSObject )
145 {
146 retval = ((COSObject)parent).getObject();
147 }
148 else
149 {
150 throw new RuntimeException( "Unknown COS type " + parent.getClass().getName() );
151 }
152 return retval;
153 }
154
155 /** Returns the number of children of <code>parent</code>.
156 * Returns 0 if the node
157 * is a leaf or if it has no children. <code>parent</code> must be a node
158 * previously obtained from this data source.
159 *
160 * @param parent a node in the tree, obtained from this data source
161 * @return the number of children of the node <code>parent</code>
162 *
163 */
164 public int getChildCount(Object parent)
165 {
166 int retval = 0;
167 if( parent instanceof COSArray )
168 {
169 retval = ((COSArray)parent).size();
170 }
171 else if( parent instanceof COSDictionary )
172 {
173 retval = ((COSDictionary)parent).size();
174 }
175 else if( parent instanceof MapEntry )
176 {
177 retval = getChildCount( ((MapEntry)parent).getValue() );
178 }
179 else if( parent instanceof ArrayEntry )
180 {
181 retval = getChildCount( ((ArrayEntry)parent).getValue() );
182 }
183 else if( parent instanceof COSDocument )
184 {
185 retval = ((COSDocument)parent).getObjects().size();
186 }
187 else if( parent instanceof COSObject )
188 {
189 retval = 1;
190 }
191 return retval;
192 }
193
194 /** Returns the index of child in parent. If <code>parent</code>
195 * is <code>null</code> or <code>child</code> is <code>null</code>,
196 * returns -1.
197 *
198 * @param parent a note in the tree, obtained from this data source
199 * @param child the node we are interested in
200 * @return the index of the child in the parent, or -1 if either
201 * <code>child</code> or <code>parent</code> are <code>null</code>
202 *
203 */
204 public int getIndexOfChild(Object parent, Object child)
205 {
206 int retval = -1;
207 if( parent != null && child != null )
208 {
209 if( parent instanceof COSArray )
210 {
211 COSArray array = (COSArray)parent;
212 if( child instanceof ArrayEntry )
213 {
214 ArrayEntry arrayEntry = (ArrayEntry)child;
215 retval = arrayEntry.getIndex();
216 }
217 else
218 {
219 retval = array.indexOf( (COSBase)child );
220 }
221 }
222 else if( parent instanceof COSDictionary )
223 {
224 MapEntry entry = (MapEntry)child;
225 COSDictionary dict = (COSDictionary)parent;
226 List<COSName> keys = new ArrayList<COSName>(dict.keySet());
227 Collections.sort( keys );
228 for( int i=0; retval == -1 && i<keys.size(); i++ )
229 {
230 if( keys.get( i ).equals( entry.getKey() ) )
231 {
232 retval = i;
233 }
234 }
235 }
236 else if( parent instanceof MapEntry )
237 {
238 retval = getIndexOfChild( ((MapEntry)parent).getValue(), child );
239 }
240 else if( parent instanceof ArrayEntry )
241 {
242 retval = getIndexOfChild( ((ArrayEntry)parent).getValue(), child );
243 }
244 else if( parent instanceof COSDocument )
245 {
246 retval = ((COSDocument)parent).getObjects().indexOf( child );
247 }
248 else if( parent instanceof COSObject )
249 {
250 retval = 0;
251 }
252 else
253 {
254 throw new RuntimeException( "Unknown COS type " + parent.getClass().getName() );
255 }
256 }
257 return retval;
258 }
259
260 /** Returns the root of the tree. Returns <code>null</code>
261 * only if the tree has no nodes.
262 *
263 * @return the root of the tree
264 *
265 */
266 public Object getRoot()
267 {
268 return document.getDocument().getTrailer();
269 }
270
271 /** Returns <code>true</code> if <code>node</code> is a leaf.
272 * It is possible for this method to return <code>false</code>
273 * even if <code>node</code> has no children.
274 * A directory in a filesystem, for example,
275 * may contain no files; the node representing
276 * the directory is not a leaf, but it also has no children.
277 *
278 * @param node a node in the tree, obtained from this data source
279 * @return true if <code>node</code> is a leaf
280 *
281 */
282 public boolean isLeaf(Object node)
283 {
284 boolean isLeaf = !(node instanceof COSDictionary ||
285 node instanceof COSArray ||
286 node instanceof COSDocument ||
287 node instanceof COSObject ||
288 (node instanceof MapEntry && !isLeaf(((MapEntry)node).getValue()) ) ||
289 (node instanceof ArrayEntry && !isLeaf(((ArrayEntry)node).getValue()) ));
290 return isLeaf;
291 }
292
293 /** Removes a listener previously added with
294 * <code>addTreeModelListener</code>.
295 *
296 * @see #addTreeModelListener
297 * @param l the listener to remove
298 *
299 */
300
301 public void removeTreeModelListener(TreeModelListener l)
302 {
303 //required for interface
304 }
305
306 /** Messaged when the user has altered the value for the item identified
307 * by <code>path</code> to <code>newValue</code>.
308 * If <code>newValue</code> signifies a truly new value
309 * the model should post a <code>treeNodesChanged</code> event.
310 *
311 * @param path path to the node that the user has altered
312 * @param newValue the new value from the TreeCellEditor
313 *
314 */
315 public void valueForPathChanged(TreePath path, Object newValue)
316 {
317 //required for interface
318 }
319 }