old-autovect-branch/libjava/classpath/javax/swing/filechooser/FileSystemView.java

   1 /* FileSystemView.java --
   2    Copyright (C) 2002, 2004, 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package javax.swing.filechooser;
  39
  40 import java.io.File;
  41 import java.io.IOException;
  42 import java.util.ArrayList;
  43
  44 import javax.swing.Icon;
  45 import javax.swing.JFileChooser;
  46
  47
  48 /**
  49  * The base class providing a view of the file system for use by the
  50  * {@link JFileChooser} component.
  51  */
  52 public abstract class FileSystemView
  53 {
  54   /** The instance returned by {@link #getFileSystemView()}. */
  55   private static FileSystemView defaultFileSystemView;
  56
  57   /**
  58    * Creates a new file object with the given name in the specified directory.
  59    *
  60    * @param dir  the directory (<code>null</code> permitted).
  61    * @param filename  the file name.
  62    *
  63    * @return A new file object.
  64    */
  65   public File createFileObject(File dir, String filename)
  66   {
  67     return new File(dir, filename);
  68   }
  69
  70   /**
  71    * Creates a new file object from the specified path.
  72    *
  73    * @param path  the path.
  74    *
  75    * @return A new file object.
  76    */
  77   public File createFileObject(String path)
  78   {
  79     return new File(path);
  80   }
  81
  82   /**
  83    * DOCUMENT ME!
  84    *
  85    * @param f DOCUMENT ME!
  86    *
  87    * @return DOCUMENT ME!
  88    */
  89   protected File createFileSystemRoot(File f)
  90   {
  91     File[] roots = File.listRoots();
  92     if (roots == null)
  93       return null;
  94     return roots[0];
  95   }
  96
  97   /**
  98    * Creates a new folder with a unique name in the specified directory and
  99    * returns a {@link File} object representing the new directory.
 100    *
 101    * @param containingDir  the directory to contain the new folder
 102    *                       (<code>null</code> not permitted).
 103    *
 104    * @return A {@link File} object representing the new directory.
 105    *
 106    * @throws IOException if an exception occurs while creating the new
 107    *                     directory.
 108    */
 109   public abstract File createNewFolder(File containingDir)
 110                                 throws IOException;
 111
 112   /**
 113    * DOCUMENT ME!
 114    *
 115    * @param parent DOCUMENT ME!
 116    * @param fileName DOCUMENT ME!
 117    *
 118    * @return DOCUMENT ME!
 119    */
 120   public File getChild(File parent, String fileName)
 121   {
 122     // FIXME: Handle the case when parent and child are special folders.
 123     return new File(parent, fileName);
 124   }
 125
 126   /**
 127    * Returns the default directory.
 128    *
 129    * @return The default directory.
 130    */
 131   public File getDefaultDirectory()
 132   {
 133     return getHomeDirectory();
 134   }
 135
 136   /**
 137    * Returns an array containing the files in the given directory.  The
 138    * <code>useFileHiding</code> controls whether or not hidden files are
 139    * included in the result.
 140    *
 141    * @param dir  the directory (if <code>null</code>
 142    * @param useFileHiding  a flag that controls whether or not hidden files are
 143    *                       included in the result (pass in <code>true</code> to
 144    *                       exclude hidden files).
 145    *
 146    * @return The files in the given directory (possibly <code>null</code>).
 147    */
 148   public File[] getFiles(File dir, boolean useFileHiding)
 149   {
 150     if (dir == null || dir.listFiles() == null)
 151       return null;
 152     File[] files = dir.listFiles();
 153     if (! useFileHiding)
 154       return files;
 155     ArrayList trim = new ArrayList();
 156     for (int i = 0; i < files.length; i++)
 157       if (! files[i].isHidden())
 158         trim.add(files[i]);
 159     File[] value = (File[]) trim.toArray(new File[trim.size()]);
 160     return value;
 161   }
 162
 163   /**
 164    * Returns a default {@link FileSystemView} appropriate for the platform.
 165    *
 166    * @return A default {@link FileSystemView} appropriate for the platform.
 167    */
 168   public static FileSystemView getFileSystemView()
 169   {
 170     if (defaultFileSystemView == null)
 171       {
 172         if (File.separator.equals("/"))
 173           defaultFileSystemView = new UnixFileSystemView();
 174         // FIXME: need to implement additional views
 175         // else if (File.Separator.equals("\"))
 176         //   return new Win32FileSystemView();
 177         // else
 178         //   return new GenericFileSystemView();
 179       }
 180     return defaultFileSystemView;
 181   }
 182
 183   /**
 184    * Returns the home directory for the current user.
 185    *
 186    * @return The home directory for the current user.
 187    */
 188   public File getHomeDirectory()
 189   {
 190     return createFileObject(System.getProperty("user.home"));
 191   }
 192
 193   /**
 194    * Returns the parent directory for the given file/directory.
 195    *
 196    * @param f  the file/directory.
 197    *
 198    * @return The parent directory (or <code>null</code> if there is no parent
 199    *         directory).
 200    */
 201   public File getParentDirectory(File f)
 202   {
 203     if (f == null)
 204       return null;
 205     return f.getParentFile();
 206   }
 207
 208   /**
 209    * Returns an array containing the file system roots.  On Unix-like platforms,
 210    * this array will contain just a single item ("/"), while other platforms
 211    * may return multiple roots.
 212    * <p>
 213    * This method is implemented to return <code>null</code>, subclasses must
 214    * override this method.
 215    *
 216    * @return An array containing the file system roots.
 217    */
 218   public File[] getRoots()
 219   {
 220     // subclass
 221     return null;
 222   }
 223
 224   /**
 225    * Returns the name of a file as it would be displayed by the underlying
 226    * system.  This implementation returns <code>null</code>, subclasses must
 227    * override.
 228    *
 229    * @param f  the file.
 230    *
 231    * @return <code>null</code>.
 232    */
 233   public String getSystemDisplayName(File f)
 234   {
 235     return null;
 236   }
 237
 238   /**
 239    * Returns the icon that would be displayed for the given file by the
 240    * underlying system.  This implementation returns <code>null</code>,
 241    * subclasses must override.
 242    *
 243    * @param f  the file.
 244    *
 245    * @return <code>null</code>.
 246    */
 247   public Icon getSystemIcon(File f)
 248   {
 249     return null;
 250   }
 251
 252   /**
 253    * Returns the type description of a file that would be displayed by the
 254    * underlying system.  This implementation returns <code>null</code>,
 255    * subclasses must override.
 256    *
 257    * @param f  the file.
 258    *
 259    * @return <code>null</code>.
 260    */
 261   public String getSystemTypeDescription(File f)
 262   {
 263     return null;
 264   }
 265
 266   /**
 267    * DOCUMENT ME!
 268    *
 269    * @param dir DOCUMENT ME!
 270    *
 271    * @return DOCUMENT ME!
 272    */
 273   public boolean isComputerNode(File dir)
 274   {
 275     return false;
 276   }
 277
 278   /**
 279    * Returns <code>true</code> if the given directory represents a disk
 280    * drive, and <code>false</code> otherwise.  This default implementation
 281    * always returns <code>false</code>.
 282    *
 283    * @param dir  the directory.
 284    *
 285    * @return <code>false</code>.
 286    */
 287   public boolean isDrive(File dir)
 288   {
 289     return false;
 290   }
 291
 292   /**
 293    * Returns <code>true</code> if <code>f</code> is a file or directory, and
 294    * <code>false</code> otherwise.
 295    *
 296    * @param f  the file/directory.
 297    *
 298    * @return <code>true</code> if <code>f</code> is a file or directory, and
 299    * <code>false</code> otherwise.
 300    */
 301   public boolean isFileSystem(File f)
 302   {
 303     return (f.isFile() || f.isDirectory());
 304   }
 305
 306   /**
 307    * Returns <code>true</code> if the given directory is a file system root,
 308    * and <code>false</code> otherwise.
 309    *
 310    * @param dir  the directory.
 311    *
 312    * @return <code>true</code> if the given directory is a file system root,
 313    *          and <code>false</code> otherwise.
 314    */
 315   public boolean isFileSystemRoot(File dir)
 316   {
 317     File[] roots = File.listRoots();
 318     if (roots == null || dir == null)
 319       return false;
 320     String filename = dir.getAbsolutePath();
 321     for (int i = 0; i < roots.length; i++)
 322       if (roots[i].getAbsolutePath().equals(filename))
 323         return true;
 324     return false;
 325   }
 326
 327   /**
 328    * Returns <code>true</code> if the given directory represents a floppy
 329    * drive, and <code>false</code> otherwise.  This default implementation
 330    * always returns <code>false</code>.
 331    *
 332    * @param dir  the directory.
 333    *
 334    * @return <code>false</code>.
 335    */
 336   public boolean isFloppyDrive(File dir)
 337   {
 338     return false;
 339   }
 340
 341   /**
 342    * Returns <code>true</code> if the given file is hidden, and
 343    * <code>false</code> otherwise.
 344    *
 345    * @param f  the file.
 346    *
 347    * @return <code>true</code> if the given file is hidden, and
 348    *         <code>false</code> otherwise.
 349    */
 350   public boolean isHiddenFile(File f)
 351   {
 352     return f.isHidden();
 353   }
 354
 355   /**
 356    * Returns <code>true</code> if <code>folder</code> is the parent of
 357    * <code>file</code>, and <code>false</code> otherwise.
 358    *
 359    * @param folder  the folder (<code>null</code> not permitted).
 360    * @param file  the file (<code>null</code> not permitted).
 361    *
 362    * @return <code>true</code> if <code>folder</code> is the parent of
 363    *         <code>file</code>, and <code>false</code> otherwise.
 364    */
 365   public boolean isParent(File folder, File file)
 366   {
 367     File parent = file.getParentFile();
 368     if (parent == null)
 369       return false;
 370     return folder.equals(parent);
 371   }
 372
 373   /**
 374    * DOCUMENT ME!
 375    *
 376    * @param f DOCUMENT ME!
 377    *
 378    * @return DOCUMENT ME!
 379    */
 380   public boolean isRoot(File f)
 381   {
 382     // These are not file system roots.
 383     return false;
 384   }
 385
 386   /**
 387    * Returns <code>true</code> if the file is traversable, and
 388    * <code>false</code> otherwise.  Here, all directories are considered
 389    * traversable, and files are considered non-traversable.
 390    *
 391    * @param f  the file or directory (<code>null</code> not permitted).
 392    *
 393    * @return <code>true</code> if the file is traversable, and
 394    *         <code>false</code> otherwise.
 395    */
 396   public Boolean isTraversable(File f)
 397   {
 398     // Tested. A directory where the user has no permission to rwx is still
 399     // traversable. (No files are listed when you traverse the directory)
 400     // My best guess is that as long as it's a directory, the file is
 401     // traversable.
 402     return Boolean.valueOf(f.isDirectory());
 403   }
 404 }