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 }