/Users/lyon/j4p/src/j2d/file/ExtensionFileFilter.java
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1 // Modified by Glenn Josefiak
2 // Fairfield University
3 // SW513
4 // Spring 2003
5
6 package j2d.file;
7
8 /*
9 * Copyright (c) 2002 Sun Microsystems, Inc. All Rights Reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * -Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
18 * -Redistribution in binary form must reproduct the above copyright
19 * notice, this list of conditions and the following disclaimer in
20 * the documentation and/or other materials provided with the distribution.
21 *
22 * Neither the name of Sun Microsystems, Inc. or the names of contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * This software is provided "AS IS," without a warranty of any kind. ALL
27 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
28 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
29 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT
30 * BE LIABLE FOR ANY DAMAGES OR LIABILITIES SUFFERED BY LICENSEE AS A RESULT
31 * OF OR RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR ITS
32 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
33 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
34 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
35 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE SOFTWARE, EVEN
36 * IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
37 *
38 * You acknowledge that Software is not designed, licensed or intended for
39 * use in the design, construction, operation or maintenance of any nuclear
40 * facility.
41 */
42
43 /*
44 * @(#)ExampleFileFilter.java 1.13 02/06/13
45 */
46
47 import javax.swing.filechooser.FileFilter;
48 import java.io.File;
49 import java.util.Enumeration;
50 import java.util.Hashtable;
51
52 /**
53 * A convenience implementation of FileFilter that filters out
54 * all files except for those type extensions that it knows about.
55 * <p>
56 * Extensions are of the type ".foo", which is typically found on
57 * Windows and Unix boxes, but not on Macinthosh. Case is ignored.
58 * <p>
59 * Example - create a new filter that filerts out all files
60 * but gif and jpg image files:
61 *
62 * <pre>
63 * JFileChooser chooser = new JFileChooser();
64 * ExtensionFileFilter filter = new ExtensionFileFilter(
65 * new String{"gif", "jpg"}, "JPEG & GIF Images")
66 * chooser.addChoosableFileFilter(filter);
67 * chooser.showOpenDialog(this);
68 * </pre>
69 *
70 * @version 1.13 06/13/02
71 * @author Jeff Dinkins
72 */
73 public class ExtensionFileFilter
74 extends FileFilter {
75
76 private static String TYPE_UNKNOWN = "Type Unknown";
77 private static String HIDDEN_FILE = "Hidden File";
78
79 private Hashtable filters = null;
80 private String description = null;
81 private String fullDescription = null;
82 private boolean useExtensionsInDescription = true;
83
84 /**
85 * Creates a file filter. If no filters are added, then all
86 * files are accepted.
87 *
88 * @see #addExtension
89 */
90 public ExtensionFileFilter() {
91 this.filters = new Hashtable();
92 }
93
94 /**
95 * Creates a file filter that accepts files with the given extension.
96 * Example: new ExtensionFileFilter("jpg");
97 *
98 * @see #addExtension
99 */
100 public ExtensionFileFilter(String extension) {
101 this(extension,null);
102 }
103
104 /**
105 * Creates a file filter that accepts the given file type.
106 * Example: new ExtensionFileFilter("jpg", "JPEG Image Images");
107 *
108 * Note that the "." before the extension is not needed. If
109 * provided, it will be ignored.
110 *
111 * @see #addExtension
112 */
113 public ExtensionFileFilter(String extension, String description) {
114 this();
115 if(extension!=null) addExtension(extension);
116 if(description!=null) setDescription(description);
117 }
118
119 /**
120 * Creates a file filter from the given string array.
121 * Example: new ExtensionFileFilter(String {"gif", "jpg"});
122 *
123 * Note that the "." before the extension is not needed adn
124 * will be ignored.
125 *
126 * @see #addExtension
127 */
128 public ExtensionFileFilter(String[] filters) {
129 this(filters, null);
130 }
131
132 /**
133 * Creates a file filter from the given string array and description.
134 * Example: new ExtensionFileFilter(String {"gif", "jpg"}, "Gif and JPG Images");
135 *
136 * Note that the "." before the extension is not needed and will be ignored.
137 *
138 * @see #addExtension
139 */
140 public ExtensionFileFilter(String[] filters, String description) {
141 this();
142 for (int i = 0; i < filters.length; i++) {
143 // add filters one by one
144 addExtension(filters[i]);
145 }
146 if(description!=null) setDescription(description);
147 }
148
149 /**
150 * Return true if this file should be shown in the directory pane,
151 * false if it shouldn't.
152 *
153 * Files that begin with "." are ignored.
154 *
155 * @see #getExtension
156 * @see FileFilter#accepts
157 */
158 // public boolean accept(File f) {
159 // if(f != null) {
160 // if(f.isDirectory()) {
161 // return true;
162 // }
163 // String extension = getExtension(f);
164 // if(extension != null && filters.get(getExtension(f)) != null) {
165 // return true;
166 // };
167 // }
168 // return false;
169 // }
170
171 public boolean accept(File f) {
172 if(f != null) {
173 if(f.isDirectory()) {
174 return true;
175 }
176 String name = f.getName().toLowerCase();
177 Enumeration extensions = filters.keys();
178 if(extensions != null) {
179 while (extensions.hasMoreElements()) {
180 if (name.endsWith("." + (String) extensions.nextElement()))
181 return true;
182 }
183 }
184 }
185 return false;
186 }
187
188 /**
189 * Adds a filetype "dot" extension to filter against.
190 *
191 * For example: the following code will create a filter that filters
192 * out all files except those that end in ".jpg" and ".tif":
193 *
194 * ExtensionFileFilter filter = new ExtensionFileFilter();
195 * filter.addExtension("jpg");
196 * filter.addExtension("tif");
197 *
198 * Note that the "." before the extension is not needed and will be ignored.
199 */
200 public void addExtension(String extension) {
201 if(filters == null) {
202 filters = new Hashtable(5);
203 }
204 filters.put(extension.toLowerCase(), this);
205 fullDescription = null;
206 }
207
208
209 /**
210 * Returns the human readable description of this filter. For
211 * example: "JPEG and GIF Image Files (*.jpg, *.gif)"
212 *
213 * @see setDescription
214 * @see setExtensionListInDescription
215 * @see isExtensionListInDescription
216 * @see FileFilter#getDescription
217 */
218 public String getDescription() {
219 if(fullDescription == null) {
220 if(description == null || isExtensionListInDescription()) {
221 fullDescription = description==null ? "(" : description + " (";
222 // build the description from the extension list
223 Enumeration extensions = filters.keys();
224 if(extensions != null) {
225 fullDescription += "." + (String) extensions.nextElement();
226 while (extensions.hasMoreElements()) {
227 fullDescription += ", ." + (String) extensions.nextElement();
228 }
229 }
230 fullDescription += ")";
231 } else {
232 fullDescription = description;
233 }
234 }
235 return fullDescription;
236 }
237
238 /**
239 * Sets the human readable description of this filter. For
240 * example: filter.setDescription("Gif and JPG Images");
241 *
242 * @see setDescription
243 * @see setExtensionListInDescription
244 * @see isExtensionListInDescription
245 */
246 public void setDescription(String description) {
247 this.description = description;
248 fullDescription = null;
249 }
250
251 /**
252 * Determines whether the extension list (.jpg, .gif, etc) should
253 * show up in the human readable description.
254 *
255 * Only relevent if a description was provided in the constructor
256 * or using setDescription();
257 *
258 * @see getDescription
259 * @see setDescription
260 * @see isExtensionListInDescription
261 */
262 public void setExtensionListInDescription(boolean b) {
263 useExtensionsInDescription = b;
264 fullDescription = null;
265 }
266
267 /**
268 * Returns whether the extension list (.jpg, .gif, etc) should
269 * show up in the human readable description.
270 *
271 * Only relevent if a description was provided in the constructor
272 * or using setDescription();
273 *
274 * @see getDescription
275 * @see setDescription
276 * @see setExtensionListInDescription
277 */
278 public boolean isExtensionListInDescription() {
279 return useExtensionsInDescription;
280 }
281 }
282