001 /* FileSystemView.java --
002 Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.swing.filechooser;
039
040 import java.io.File;
041 import java.io.IOException;
042 import java.util.ArrayList;
043
044 import javax.swing.Icon;
045 import javax.swing.JFileChooser;
046
047
048 /**
049 * The base class providing a view of the file system for use by the
050 * {@link JFileChooser} component.
051 */
052 public abstract class FileSystemView
053 {
054 /** The instance returned by {@link #getFileSystemView()}. */
055 private static FileSystemView defaultFileSystemView;
056
057 /**
058 * Creates a new file object with the given name in the specified directory.
059 *
060 * @param dir the directory (<code>null</code> permitted).
061 * @param filename the file name.
062 *
063 * @return A new file object.
064 */
065 public File createFileObject(File dir, String filename)
066 {
067 return new File(dir, filename);
068 }
069
070 /**
071 * Creates a new file object from the specified path.
072 *
073 * @param path the path.
074 *
075 * @return A new file object.
076 */
077 public File createFileObject(String path)
078 {
079 File f = new File(path);
080 if (isFileSystemRoot(f))
081 f = this.createFileSystemRoot(f);
082 return f;
083 }
084
085 /**
086 * DOCUMENT ME!
087 *
088 * @param f DOCUMENT ME!
089 *
090 * @return DOCUMENT ME!
091 */
092 protected File createFileSystemRoot(File f)
093 {
094 File[] roots = File.listRoots();
095 if (roots == null)
096 return null;
097 return roots[0];
098 }
099
100 /**
101 * Creates a new folder with a unique name in the specified directory and
102 * returns a {@link File} object representing the new directory.
103 *
104 * @param containingDir the directory to contain the new folder
105 * (<code>null</code> not permitted).
106 *
107 * @return A {@link File} object representing the new directory.
108 *
109 * @throws IOException if an exception occurs while creating the new
110 * directory.
111 */
112 public abstract File createNewFolder(File containingDir)
113 throws IOException;
114
115 /**
116 * DOCUMENT ME!
117 *
118 * @param parent DOCUMENT ME!
119 * @param fileName DOCUMENT ME!
120 *
121 * @return DOCUMENT ME!
122 */
123 public File getChild(File parent, String fileName)
124 {
125 // FIXME: Handle the case when parent and child are special folders.
126 return new File(parent, fileName);
127 }
128
129 /**
130 * Returns the default directory.
131 *
132 * @return The default directory.
133 */
134 public File getDefaultDirectory()
135 {
136 return getHomeDirectory();
137 }
138
139 /**
140 * Returns an array containing the files in the given directory. The
141 * <code>useFileHiding</code> controls whether or not hidden files are
142 * included in the result.
143 *
144 * @param dir the directory (if <code>null</code>
145 * @param useFileHiding a flag that controls whether or not hidden files are
146 * included in the result (pass in <code>true</code> to
147 * exclude hidden files).
148 *
149 * @return The files in the given directory (possibly <code>null</code>).
150 */
151 public File[] getFiles(File dir, boolean useFileHiding)
152 {
153 if (dir == null || dir.listFiles() == null)
154 return null;
155 File[] files = dir.listFiles();
156 if (! useFileHiding)
157 return files;
158 ArrayList trim = new ArrayList();
159 for (int i = 0; i < files.length; i++)
160 if (! files[i].isHidden())
161 trim.add(files[i]);
162 File[] value = (File[]) trim.toArray(new File[trim.size()]);
163 return value;
164 }
165
166 /**
167 * Returns a default {@link FileSystemView} appropriate for the platform.
168 *
169 * @return A default {@link FileSystemView} appropriate for the platform.
170 */
171 public static FileSystemView getFileSystemView()
172 {
173 if (defaultFileSystemView == null)
174 {
175 // FIXME: We need to support other file systems too.
176 defaultFileSystemView = new UnixFileSystemView();
177 }
178 return defaultFileSystemView;
179 }
180
181 /**
182 * Returns the home directory for the current user.
183 *
184 * @return The home directory for the current user.
185 */
186 public File getHomeDirectory()
187 {
188 return createFileObject(System.getProperty("user.home"));
189 }
190
191 /**
192 * Returns the parent directory for the given file/directory.
193 *
194 * @param f the file/directory.
195 *
196 * @return The parent directory (or <code>null</code> if there is no parent
197 * directory).
198 */
199 public File getParentDirectory(File f)
200 {
201 if (f == null)
202 return null;
203 return f.getParentFile();
204 }
205
206 /**
207 * Returns an array containing the file system roots. On Unix-like platforms,
208 * this array will contain just a single item ("/"), while other platforms
209 * may return multiple roots.
210 * <p>
211 * This method is implemented to return <code>null</code>, subclasses must
212 * override this method.
213 *
214 * @return An array containing the file system roots.
215 */
216 public File[] getRoots()
217 {
218 // subclass
219 return null;
220 }
221
222 /**
223 * Returns the name of a file as it would be displayed by the underlying
224 * system.
225 *
226 * @param f the file.
227 *
228 * @return the name of a file as it would be displayed by the underlying
229 * system
230 *
231 * @specnote The specification suggests that the information here is
232 * fetched from a ShellFolder class. This seems to be a non public
233 * private file handling class. We simply return File.getName()
234 * here and leave special handling to subclasses.
235 */
236 public String getSystemDisplayName(File f)
237 {
238 String name = null;
239 if (f != null)
240 name = f.getName();
241 return name;
242 }
243
244 /**
245 * Returns the icon that would be displayed for the given file by the
246 * underlying system. This implementation returns <code>null</code>,
247 * subclasses must override.
248 *
249 * @param f the file.
250 *
251 * @return <code>null</code>.
252 */
253 public Icon getSystemIcon(File f)
254 {
255 return null;
256 }
257
258 /**
259 * Returns the type description of a file that would be displayed by the
260 * underlying system. This implementation returns <code>null</code>,
261 * subclasses must override.
262 *
263 * @param f the file.
264 *
265 * @return <code>null</code>.
266 */
267 public String getSystemTypeDescription(File f)
268 {
269 return null;
270 }
271
272 /**
273 * DOCUMENT ME!
274 *
275 * @param dir DOCUMENT ME!
276 *
277 * @return DOCUMENT ME!
278 */
279 public boolean isComputerNode(File dir)
280 {
281 return false;
282 }
283
284 /**
285 * Returns <code>true</code> if the given directory represents a disk
286 * drive, and <code>false</code> otherwise. This default implementation
287 * always returns <code>false</code>.
288 *
289 * @param dir the directory.
290 *
291 * @return <code>false</code>.
292 */
293 public boolean isDrive(File dir)
294 {
295 return false;
296 }
297
298 /**
299 * Returns <code>true</code> if <code>f</code> is a file or directory, and
300 * <code>false</code> otherwise.
301 *
302 * @param f the file/directory.
303 *
304 * @return <code>true</code> if <code>f</code> is a file or directory, and
305 * <code>false</code> otherwise.
306 */
307 public boolean isFileSystem(File f)
308 {
309 return (f.isFile() || f.isDirectory());
310 }
311
312 /**
313 * Returns <code>true</code> if the given directory is a file system root,
314 * and <code>false</code> otherwise.
315 *
316 * @param dir the directory.
317 *
318 * @return <code>true</code> if the given directory is a file system root,
319 * and <code>false</code> otherwise.
320 */
321 public boolean isFileSystemRoot(File dir)
322 {
323 File[] roots = File.listRoots();
324 if (roots == null || dir == null)
325 return false;
326 String filename = dir.getAbsolutePath();
327 for (int i = 0; i < roots.length; i++)
328 if (roots[i].getAbsolutePath().equals(filename))
329 return true;
330 return false;
331 }
332
333 /**
334 * Returns <code>true</code> if the given directory represents a floppy
335 * drive, and <code>false</code> otherwise. This default implementation
336 * always returns <code>false</code>.
337 *
338 * @param dir the directory.
339 *
340 * @return <code>false</code>.
341 */
342 public boolean isFloppyDrive(File dir)
343 {
344 return false;
345 }
346
347 /**
348 * Returns <code>true</code> if the given file is hidden, and
349 * <code>false</code> otherwise.
350 *
351 * @param f the file.
352 *
353 * @return <code>true</code> if the given file is hidden, and
354 * <code>false</code> otherwise.
355 */
356 public boolean isHiddenFile(File f)
357 {
358 return f.isHidden();
359 }
360
361 /**
362 * Returns <code>true</code> if <code>folder</code> is the parent of
363 * <code>file</code>, and <code>false</code> otherwise.
364 *
365 * @param folder the folder (<code>null</code> not permitted).
366 * @param file the file (<code>null</code> not permitted).
367 *
368 * @return <code>true</code> if <code>folder</code> is the parent of
369 * <code>file</code>, and <code>false</code> otherwise.
370 */
371 public boolean isParent(File folder, File file)
372 {
373 File parent = file.getParentFile();
374 if (parent == null)
375 return false;
376 return folder.equals(parent);
377 }
378
379 /**
380 * DOCUMENT ME!
381 *
382 * @param f DOCUMENT ME!
383 *
384 * @return DOCUMENT ME!
385 */
386 public boolean isRoot(File f)
387 {
388 // These are not file system roots.
389 return false;
390 }
391
392 /**
393 * Returns <code>true</code> if the file is traversable, and
394 * <code>false</code> otherwise. Here, all directories are considered
395 * traversable, and files are considered non-traversable.
396 *
397 * @param f the file or directory (<code>null</code> not permitted).
398 *
399 * @return <code>true</code> if the file is traversable, and
400 * <code>false</code> otherwise.
401 */
402 public Boolean isTraversable(File f)
403 {
404 // Tested. A directory where the user has no permission to rwx is still
405 // traversable. (No files are listed when you traverse the directory)
406 // My best guess is that as long as it's a directory, the file is
407 // traversable.
408 return Boolean.valueOf(f.isDirectory());
409 }
410 }