gio/gfilenamecompleter.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Alexander Larsson <alexl@redhat.com>
  19  */
  20
  21 #include "config.h"
  22 #include "gfilenamecompleter.h"
  23 #include "gfileenumerator.h"
  24 #include "gfileattribute.h"
  25 #include "gfile.h"
  26 #include "gfileinfo.h"
  27 #include "gcancellable.h"
  28 #include <string.h>
  29 #include "glibintl.h"
  30
  31
  32 /**
  33  * SECTION:gfilenamecompleter
  34  * @short_description: Filename Completer
  35  * @include: gio/gio.h
  36  *
  37  * Completes partial file and directory names given a partial string by
  38  * looking in the file system for clues. Can return a list of possible
  39  * completion strings for widget implementations.
  40  *
  41  **/
  42
  43 enum {
  44   GOT_COMPLETION_DATA,
  45   LAST_SIGNAL
  46 };
  47
  48 static guint signals[LAST_SIGNAL] = { 0 };
  49
  50 typedef struct {
  51   GFilenameCompleter *completer;
  52   GFileEnumerator *enumerator;
  53   GCancellable *cancellable;
  54   gboolean should_escape;
  55   GFile *dir;
  56   GList *basenames;
  57   gboolean dirs_only;
  58 } LoadBasenamesData;
  59
  60 struct _GFilenameCompleter {
  61   GObject parent;
  62
  63   GFile *basenames_dir;
  64   gboolean basenames_are_escaped;
  65   gboolean dirs_only;
  66   GList *basenames;
  67
  68   LoadBasenamesData *basename_loader;
  69 };
  70
  71 G_DEFINE_TYPE (GFilenameCompleter, g_filename_completer, G_TYPE_OBJECT)
  72
  73 static void cancel_load_basenames (GFilenameCompleter *completer);
  74
  75 static void
  76 g_filename_completer_finalize (GObject *object)
  77 {
  78   GFilenameCompleter *completer;
  79
  80   completer = G_FILENAME_COMPLETER (object);
  81
  82   cancel_load_basenames (completer);
  83
  84   if (completer->basenames_dir)
  85     g_object_unref (completer->basenames_dir);
  86
  87   g_list_free_full (completer->basenames, g_free);
  88
  89   G_OBJECT_CLASS (g_filename_completer_parent_class)->finalize (object);
  90 }
  91
  92 static void
  93 g_filename_completer_class_init (GFilenameCompleterClass *klass)
  94 {
  95   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  96
  97   gobject_class->finalize = g_filename_completer_finalize;
  98   /**
  99    * GFilenameCompleter::got-completion-data:
 100    *
 101    * Emitted when the file name completion information comes available.
 102    **/
 103   signals[GOT_COMPLETION_DATA] = g_signal_new (I_("got-completion-data"),
 104                                           G_TYPE_FILENAME_COMPLETER,
 105                                           G_SIGNAL_RUN_LAST,
 106                                           G_STRUCT_OFFSET (GFilenameCompleterClass, got_completion_data),
 107                                           NULL, NULL,
 108                                           g_cclosure_marshal_VOID__VOID,
 109                                           G_TYPE_NONE, 0);
 110 }
 111
 112 static void
 113 g_filename_completer_init (GFilenameCompleter *completer)
 114 {
 115 }
 116
 117 /**
 118  * g_filename_completer_new:
 119  *
 120  * Creates a new filename completer.
 121  *
 122  * Returns: a #GFilenameCompleter.
 123  **/
 124 GFilenameCompleter *
 125 g_filename_completer_new (void)
 126 {
 127   return g_object_new (G_TYPE_FILENAME_COMPLETER, NULL);
 128 }
 129
 130 static char *
 131 longest_common_prefix (char *a, char *b)
 132 {
 133   char *start;
 134
 135   start = a;
 136
 137   while (g_utf8_get_char (a) == g_utf8_get_char (b))
 138     {
 139       a = g_utf8_next_char (a);
 140       b = g_utf8_next_char (b);
 141     }
 142
 143   return g_strndup (start, a - start);
 144 }
 145
 146 static void
 147 load_basenames_data_free (LoadBasenamesData *data)
 148 {
 149   if (data->enumerator)
 150     g_object_unref (data->enumerator);
 151
 152   g_object_unref (data->cancellable);
 153   g_object_unref (data->dir);
 154
 155   g_list_free_full (data->basenames, g_free);
 156
 157   g_free (data);
 158 }
 159
 160 static void
 161 got_more_files (GObject *source_object,
 162                 GAsyncResult *res,
 163                 gpointer user_data)
 164 {
 165   LoadBasenamesData *data = user_data;
 166   GList *infos, *l;
 167   GFileInfo *info;
 168   const char *name;
 169   gboolean append_slash;
 170   char *t;
 171   char *basename;
 172
 173   if (data->completer == NULL)
 174     {
 175       /* Was cancelled */
 176       load_basenames_data_free (data);
 177       return;
 178     }
 179
 180   infos = g_file_enumerator_next_files_finish (data->enumerator, res, NULL);
 181
 182   for (l = infos; l != NULL; l = l->next)
 183     {
 184       info = l->data;
 185
 186       if (data->dirs_only &&
 187           g_file_info_get_file_type (info) != G_FILE_TYPE_DIRECTORY)
 188         {
 189           g_object_unref (info);
 190           continue;
 191         }
 192
 193       append_slash = g_file_info_get_file_type (info) == G_FILE_TYPE_DIRECTORY;
 194       name = g_file_info_get_name (info);
 195       if (name == NULL)
 196         {
 197           g_object_unref (info);
 198           continue;
 199         }
 200
 201
 202       if (data->should_escape)
 203         basename = g_uri_escape_string (name,
 204                                         G_URI_RESERVED_CHARS_ALLOWED_IN_PATH,
 205                                         TRUE);
 206       else
 207         /* If not should_escape, must be a local filename, convert to utf8 */
 208         basename = g_filename_to_utf8 (name, -1, NULL, NULL, NULL);
 209
 210       if (basename)
 211         {
 212           if (append_slash)
 213             {
 214               t = basename;
 215               basename = g_strconcat (basename, "/", NULL);
 216               g_free (t);
 217             }
 218
 219           data->basenames = g_list_prepend (data->basenames, basename);
 220         }
 221
 222       g_object_unref (info);
 223     }
 224
 225   g_list_free (infos);
 226
 227   if (infos)
 228     {
 229       /* Not last, get more files */
 230       g_file_enumerator_next_files_async (data->enumerator,
 231                                           100,
 232                                           0,
 233                                           data->cancellable,
 234                                           got_more_files, data);
 235     }
 236   else
 237     {
 238       data->completer->basename_loader = NULL;
 239
 240       if (data->completer->basenames_dir)
 241         g_object_unref (data->completer->basenames_dir);
 242       g_list_free_full (data->completer->basenames, g_free);
 243
 244       data->completer->basenames_dir = g_object_ref (data->dir);
 245       data->completer->basenames = data->basenames;
 246       data->completer->basenames_are_escaped = data->should_escape;
 247       data->basenames = NULL;
 248
 249       g_file_enumerator_close_async (data->enumerator, 0, NULL, NULL, NULL);
 250
 251       g_signal_emit (data->completer, signals[GOT_COMPLETION_DATA], 0);
 252       load_basenames_data_free (data);
 253     }
 254 }
 255
 256
 257 static void
 258 got_enum (GObject *source_object,
 259           GAsyncResult *res,
 260           gpointer user_data)
 261 {
 262   LoadBasenamesData *data = user_data;
 263
 264   if (data->completer == NULL)
 265     {
 266       /* Was cancelled */
 267       load_basenames_data_free (data);
 268       return;
 269     }
 270
 271   data->enumerator = g_file_enumerate_children_finish (G_FILE (source_object), res, NULL);
 272
 273   if (data->enumerator == NULL)
 274     {
 275       data->completer->basename_loader = NULL;
 276
 277       if (data->completer->basenames_dir)
 278         g_object_unref (data->completer->basenames_dir);
 279       g_list_free_full (data->completer->basenames, g_free);
 280
 281       /* Mark uptodate with no basenames */
 282       data->completer->basenames_dir = g_object_ref (data->dir);
 283       data->completer->basenames = NULL;
 284       data->completer->basenames_are_escaped = data->should_escape;
 285
 286       load_basenames_data_free (data);
 287       return;
 288     }
 289
 290   g_file_enumerator_next_files_async (data->enumerator,
 291                                       100,
 292                                       0,
 293                                       data->cancellable,
 294                                       got_more_files, data);
 295 }
 296
 297 static void
 298 schedule_load_basenames (GFilenameCompleter *completer,
 299                          GFile *dir,
 300                          gboolean should_escape)
 301 {
 302   LoadBasenamesData *data;
 303
 304   cancel_load_basenames (completer);
 305
 306   data = g_new0 (LoadBasenamesData, 1);
 307   data->completer = completer;
 308   data->cancellable = g_cancellable_new ();
 309   data->dir = g_object_ref (dir);
 310   data->should_escape = should_escape;
 311   data->dirs_only = completer->dirs_only;
 312
 313   completer->basename_loader = data;
 314
 315   g_file_enumerate_children_async (dir,
 316                                    G_FILE_ATTRIBUTE_STANDARD_NAME "," G_FILE_ATTRIBUTE_STANDARD_TYPE,
 317                                    0, 0,
 318                                    data->cancellable,
 319                                    got_enum, data);
 320 }
 321
 322 static void
 323 cancel_load_basenames (GFilenameCompleter *completer)
 324 {
 325   LoadBasenamesData *loader;
 326
 327   if (completer->basename_loader)
 328     {
 329       loader = completer->basename_loader;
 330       loader->completer = NULL;
 331
 332       g_cancellable_cancel (loader->cancellable);
 333
 334       completer->basename_loader = NULL;
 335     }
 336 }
 337
 338
 339 /* Returns a list of possible matches and the basename to use for it */
 340 static GList *
 341 init_completion (GFilenameCompleter *completer,
 342                  const char *initial_text,
 343                  char **basename_out)
 344 {
 345   gboolean should_escape;
 346   GFile *file, *parent;
 347   char *basename;
 348   char *t;
 349   int len;
 350
 351   *basename_out = NULL;
 352
 353   should_escape = ! (g_path_is_absolute (initial_text) || *initial_text == '~');
 354
 355   len = strlen (initial_text);
 356
 357   if (len > 0 &&
 358       initial_text[len - 1] == '/')
 359     return NULL;
 360
 361   file = g_file_parse_name (initial_text);
 362   parent = g_file_get_parent (file);
 363   if (parent == NULL)
 364     {
 365       g_object_unref (file);
 366       return NULL;
 367     }
 368
 369   if (completer->basenames_dir == NULL ||
 370       completer->basenames_are_escaped != should_escape ||
 371       !g_file_equal (parent, completer->basenames_dir))
 372     {
 373       schedule_load_basenames (completer, parent, should_escape);
 374       g_object_unref (file);
 375       return NULL;
 376     }
 377
 378   basename = g_file_get_basename (file);
 379   if (should_escape)
 380     {
 381       t = basename;
 382       basename = g_uri_escape_string (basename, G_URI_RESERVED_CHARS_ALLOWED_IN_PATH, TRUE);
 383       g_free (t);
 384     }
 385   else
 386     {
 387       t = basename;
 388       basename = g_filename_to_utf8 (basename, -1, NULL, NULL, NULL);
 389       g_free (t);
 390
 391       if (basename == NULL)
 392         return NULL;
 393     }
 394
 395   *basename_out = basename;
 396
 397   return completer->basenames;
 398 }
 399
 400 /**
 401  * g_filename_completer_get_completion_suffix:
 402  * @completer: the filename completer.
 403  * @initial_text: text to be completed.
 404  *
 405  * Obtains a completion for @initial_text from @completer.
 406  *
 407  * Returns: a completed string, or %NULL if no completion exists.
 408  *     This string is not owned by GIO, so remember to g_free() it
 409  *     when finished.
 410  **/
 411 char *
 412 g_filename_completer_get_completion_suffix (GFilenameCompleter *completer,
 413                                             const char *initial_text)
 414 {
 415   GList *possible_matches, *l;
 416   char *prefix;
 417   char *suffix;
 418   char *possible_match;
 419   char *lcp;
 420
 421   g_return_val_if_fail (G_IS_FILENAME_COMPLETER (completer), NULL);
 422   g_return_val_if_fail (initial_text != NULL, NULL);
 423
 424   possible_matches = init_completion (completer, initial_text, &prefix);
 425
 426   suffix = NULL;
 427
 428   for (l = possible_matches; l != NULL; l = l->next)
 429     {
 430       possible_match = l->data;
 431
 432       if (g_str_has_prefix (possible_match, prefix))
 433         {
 434           if (suffix == NULL)
 435             suffix = g_strdup (possible_match + strlen (prefix));
 436           else
 437             {
 438               lcp = longest_common_prefix (suffix,
 439                                            possible_match + strlen (prefix));
 440               g_free (suffix);
 441               suffix = lcp;
 442
 443               if (*suffix == 0)
 444                 break;
 445             }
 446         }
 447     }
 448
 449   g_free (prefix);
 450
 451   return suffix;
 452 }
 453
 454 /**
 455  * g_filename_completer_get_completions:
 456  * @completer: the filename completer.
 457  * @initial_text: text to be completed.
 458  *
 459  * Gets an array of completion strings for a given initial text.
 460  *
 461  * Returns: (array zero-terminated=1) (transfer full): array of strings with possible completions for @initial_text.
 462  * This array must be freed by g_strfreev() when finished.
 463  **/
 464 char **
 465 g_filename_completer_get_completions (GFilenameCompleter *completer,
 466                                       const char         *initial_text)
 467 {
 468   GList *possible_matches, *l;
 469   char *prefix;
 470   char *possible_match;
 471   GPtrArray *res;
 472
 473   g_return_val_if_fail (G_IS_FILENAME_COMPLETER (completer), NULL);
 474   g_return_val_if_fail (initial_text != NULL, NULL);
 475
 476   possible_matches = init_completion (completer, initial_text, &prefix);
 477
 478   res = g_ptr_array_new ();
 479   for (l = possible_matches; l != NULL; l = l->next)
 480     {
 481       possible_match = l->data;
 482
 483       if (g_str_has_prefix (possible_match, prefix))
 484         g_ptr_array_add (res,
 485                          g_strconcat (initial_text, possible_match + strlen (prefix), NULL));
 486     }
 487
 488   g_free (prefix);
 489
 490   g_ptr_array_add (res, NULL);
 491
 492   return (char**)g_ptr_array_free (res, FALSE);
 493 }
 494
 495 /**
 496  * g_filename_completer_set_dirs_only:
 497  * @completer: the filename completer.
 498  * @dirs_only: a #gboolean.
 499  *
 500  * If @dirs_only is %TRUE, @completer will only
 501  * complete directory names, and not file names.
 502  **/
 503 void
 504 g_filename_completer_set_dirs_only (GFilenameCompleter *completer,
 505                                     gboolean dirs_only)
 506 {
 507   g_return_if_fail (G_IS_FILENAME_COMPLETER (completer));
 508
 509   completer->dirs_only = dirs_only;
 510 }