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 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, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Alexander Larsson <alexl@redhat.com>
  21  */
  22
  23 #include "config.h"
  24 #include "gfilenamecompleter.h"
  25 #include "gfileenumerator.h"
  26 #include "gfileattribute.h"
  27 #include "gfile.h"
  28 #include "gfileinfo.h"
  29 #include "gcancellable.h"
  30 #include <string.h>
  31 #include "glibintl.h"
  32
  33
  34 /**
  35  * SECTION:gfilenamecompleter
  36  * @short_description: Filename Completer
  37  * @include: gio/gio.h
  38  *
  39  * Completes partial file and directory names given a partial string by
  40  * looking in the file system for clues. Can return a list of possible
  41  * completion strings for widget implementations.
  42  *
  43  **/
  44
  45 enum {
  46   GOT_COMPLETION_DATA,
  47   LAST_SIGNAL
  48 };
  49
  50 static guint signals[LAST_SIGNAL] = { 0 };
  51
  52 typedef struct {
  53   GFilenameCompleter *completer;
  54   GFileEnumerator *enumerator;
  55   GCancellable *cancellable;
  56   gboolean should_escape;
  57   GFile *dir;
  58   GList *basenames;
  59   gboolean dirs_only;
  60 } LoadBasenamesData;
  61
  62 struct _GFilenameCompleter {
  63   GObject parent;
  64
  65   GFile *basenames_dir;
  66   gboolean basenames_are_escaped;
  67   gboolean dirs_only;
  68   GList *basenames;
  69
  70   LoadBasenamesData *basename_loader;
  71 };
  72
  73 G_DEFINE_TYPE (GFilenameCompleter, g_filename_completer, G_TYPE_OBJECT);
  74
  75 static void cancel_load_basenames (GFilenameCompleter *completer);
  76
  77 static void
  78 g_filename_completer_finalize (GObject *object)
  79 {
  80   GFilenameCompleter *completer;
  81
  82   completer = G_FILENAME_COMPLETER (object);
  83
  84   cancel_load_basenames (completer);
  85
  86   if (completer->basenames_dir)
  87     g_object_unref (completer->basenames_dir);
  88
  89   g_list_foreach (completer->basenames, (GFunc)g_free, NULL);
  90   g_list_free (completer->basenames);
  91
  92   G_OBJECT_CLASS (g_filename_completer_parent_class)->finalize (object);
  93 }
  94
  95 static void
  96 g_filename_completer_class_init (GFilenameCompleterClass *klass)
  97 {
  98   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  99
 100   gobject_class->finalize = g_filename_completer_finalize;
 101   /**
 102    * GFilenameCompleter::got-completion-data:
 103    *
 104    * Emitted when the file name completion information comes available.
 105    **/
 106   signals[GOT_COMPLETION_DATA] = g_signal_new (I_("got-completion-data"),
 107                                           G_TYPE_FILENAME_COMPLETER,
 108                                           G_SIGNAL_RUN_LAST,
 109                                           G_STRUCT_OFFSET (GFilenameCompleterClass, got_completion_data),
 110                                           NULL, NULL,
 111                                           g_cclosure_marshal_VOID__VOID,
 112                                           G_TYPE_NONE, 0);
 113 }
 114
 115 static void
 116 g_filename_completer_init (GFilenameCompleter *completer)
 117 {
 118 }
 119
 120 /**
 121  * g_filename_completer_new:
 122  *
 123  * Creates a new filename completer.
 124  *
 125  * Returns: a #GFilenameCompleter.
 126  **/
 127 GFilenameCompleter *
 128 g_filename_completer_new (void)
 129 {
 130   return g_object_new (G_TYPE_FILENAME_COMPLETER, NULL);
 131 }
 132
 133 static char *
 134 longest_common_prefix (char *a, char *b)
 135 {
 136   char *start;
 137
 138   start = a;
 139
 140   while (g_utf8_get_char (a) == g_utf8_get_char (b))
 141     {
 142       a = g_utf8_next_char (a);
 143       b = g_utf8_next_char (b);
 144     }
 145
 146   return g_strndup (start, a - start);
 147 }
 148
 149 static void
 150 load_basenames_data_free (LoadBasenamesData *data)
 151 {
 152   if (data->enumerator)
 153     g_object_unref (data->enumerator);
 154
 155   g_object_unref (data->cancellable);
 156   g_object_unref (data->dir);
 157
 158   g_list_foreach (data->basenames, (GFunc)g_free, NULL);
 159   g_list_free (data->basenames);
 160
 161   g_free (data);
 162 }
 163
 164 static void
 165 got_more_files (GObject *source_object,
 166                 GAsyncResult *res,
 167                 gpointer user_data)
 168 {
 169   LoadBasenamesData *data = user_data;
 170   GList *infos, *l;
 171   GFileInfo *info;
 172   const char *name;
 173   gboolean append_slash;
 174   char *t;
 175   char *basename;
 176
 177   if (data->completer == NULL)
 178     {
 179       /* Was cancelled */
 180       load_basenames_data_free (data);
 181       return;
 182     }
 183
 184   infos = g_file_enumerator_next_files_finish (data->enumerator, res, NULL);
 185
 186   for (l = infos; l != NULL; l = l->next)
 187     {
 188       info = l->data;
 189
 190       if (data->dirs_only &&
 191           g_file_info_get_file_type (info) != G_FILE_TYPE_DIRECTORY)
 192         {
 193           g_object_unref (info);
 194           continue;
 195         }
 196
 197       append_slash = g_file_info_get_file_type (info) == G_FILE_TYPE_DIRECTORY;
 198       name = g_file_info_get_name (info);
 199       if (name == NULL)
 200         {
 201           g_object_unref (info);
 202           continue;
 203         }
 204
 205
 206       if (data->should_escape)
 207         basename = g_uri_escape_string (name,
 208                                         G_URI_RESERVED_CHARS_ALLOWED_IN_PATH,
 209                                         TRUE);
 210       else
 211         /* If not should_escape, must be a local filename, convert to utf8 */
 212         basename = g_filename_to_utf8 (name, -1, NULL, NULL, NULL);
 213
 214       if (basename)
 215         {
 216           if (append_slash)
 217             {
 218               t = basename;
 219               basename = g_strconcat (basename, "/", NULL);
 220               g_free (t);
 221             }
 222
 223           data->basenames = g_list_prepend (data->basenames, basename);
 224         }
 225
 226       g_object_unref (info);
 227     }
 228
 229   g_list_free (infos);
 230
 231   if (infos)
 232     {
 233       /* Not last, get more files */
 234       g_file_enumerator_next_files_async (data->enumerator,
 235                                           100,
 236                                           0,
 237                                           data->cancellable,
 238                                           got_more_files, data);
 239     }
 240   else
 241     {
 242       data->completer->basename_loader = NULL;
 243
 244       if (data->completer->basenames_dir)
 245         g_object_unref (data->completer->basenames_dir);
 246       g_list_foreach (data->completer->basenames, (GFunc)g_free, NULL);
 247       g_list_free (data->completer->basenames);
 248
 249       data->completer->basenames_dir = g_object_ref (data->dir);
 250       data->completer->basenames = data->basenames;
 251       data->completer->basenames_are_escaped = data->should_escape;
 252       data->basenames = NULL;
 253
 254       g_file_enumerator_close_async (data->enumerator, 0, NULL, NULL, NULL);
 255
 256       g_signal_emit (data->completer, signals[GOT_COMPLETION_DATA], 0);
 257       load_basenames_data_free (data);
 258     }
 259 }
 260
 261
 262 static void
 263 got_enum (GObject *source_object,
 264           GAsyncResult *res,
 265           gpointer user_data)
 266 {
 267   LoadBasenamesData *data = user_data;
 268
 269   if (data->completer == NULL)
 270     {
 271       /* Was cancelled */
 272       load_basenames_data_free (data);
 273       return;
 274     }
 275
 276   data->enumerator = g_file_enumerate_children_finish (G_FILE (source_object), res, NULL);
 277
 278   if (data->enumerator == NULL)
 279     {
 280       data->completer->basename_loader = NULL;
 281
 282       if (data->completer->basenames_dir)
 283         g_object_unref (data->completer->basenames_dir);
 284       g_list_foreach (data->completer->basenames, (GFunc)g_free, NULL);
 285       g_list_free (data->completer->basenames);
 286
 287       /* Mark uptodate with no basenames */
 288       data->completer->basenames_dir = g_object_ref (data->dir);
 289       data->completer->basenames = NULL;
 290       data->completer->basenames_are_escaped = data->should_escape;
 291
 292       load_basenames_data_free (data);
 293       return;
 294     }
 295
 296   g_file_enumerator_next_files_async (data->enumerator,
 297                                       100,
 298                                       0,
 299                                       data->cancellable,
 300                                       got_more_files, data);
 301 }
 302
 303 static void
 304 schedule_load_basenames (GFilenameCompleter *completer,
 305                          GFile *dir,
 306                          gboolean should_escape)
 307 {
 308   LoadBasenamesData *data;
 309
 310   cancel_load_basenames (completer);
 311
 312   data = g_new0 (LoadBasenamesData, 1);
 313   data->completer = completer;
 314   data->cancellable = g_cancellable_new ();
 315   data->dir = g_object_ref (dir);
 316   data->should_escape = should_escape;
 317   data->dirs_only = completer->dirs_only;
 318
 319   completer->basename_loader = data;
 320
 321   g_file_enumerate_children_async (dir,
 322                                    G_FILE_ATTRIBUTE_STANDARD_NAME "," G_FILE_ATTRIBUTE_STANDARD_TYPE,
 323                                    0, 0,
 324                                    data->cancellable,
 325                                    got_enum, data);
 326 }
 327
 328 static void
 329 cancel_load_basenames (GFilenameCompleter *completer)
 330 {
 331   LoadBasenamesData *loader;
 332
 333   if (completer->basename_loader)
 334     {
 335       loader = completer->basename_loader;
 336       loader->completer = NULL;
 337
 338       g_cancellable_cancel (loader->cancellable);
 339
 340       completer->basename_loader = NULL;
 341     }
 342 }
 343
 344
 345 /* Returns a list of possible matches and the basename to use for it */
 346 static GList *
 347 init_completion (GFilenameCompleter *completer,
 348                  const char *initial_text,
 349                  char **basename_out)
 350 {
 351   gboolean should_escape;
 352   GFile *file, *parent;
 353   char *basename;
 354   char *t;
 355   int len;
 356
 357   *basename_out = NULL;
 358
 359   should_escape = ! (g_path_is_absolute (initial_text) || *initial_text == '~');
 360
 361   len = strlen (initial_text);
 362
 363   if (len > 0 &&
 364       initial_text[len - 1] == '/')
 365     return NULL;
 366
 367   file = g_file_parse_name (initial_text);
 368   parent = g_file_get_parent (file);
 369   if (parent == NULL)
 370     {
 371       g_object_unref (file);
 372       return NULL;
 373     }
 374
 375   if (completer->basenames_dir == NULL ||
 376       completer->basenames_are_escaped != should_escape ||
 377       !g_file_equal (parent, completer->basenames_dir))
 378     {
 379       schedule_load_basenames (completer, parent, should_escape);
 380       g_object_unref (file);
 381       return NULL;
 382     }
 383
 384   basename = g_file_get_basename (file);
 385   if (should_escape)
 386     {
 387       t = basename;
 388       basename = g_uri_escape_string (basename, G_URI_RESERVED_CHARS_ALLOWED_IN_PATH, TRUE);
 389       g_free (t);
 390     }
 391   else
 392     {
 393       t = basename;
 394       basename = g_filename_to_utf8 (basename, -1, NULL, NULL, NULL);
 395       g_free (t);
 396
 397       if (basename == NULL)
 398         return NULL;
 399     }
 400
 401   *basename_out = basename;
 402
 403   return completer->basenames;
 404 }
 405
 406 /**
 407  * g_filename_completer_get_completion_suffix:
 408  * @completer: the filename completer.
 409  * @initial_text: text to be completed.
 410  *
 411  * Obtains a completion for @initial_text from @completer.
 412  *
 413  * Returns: a completed string, or %NULL if no completion exists.
 414  *     This string is not owned by GIO, so remember to g_free() it
 415  *     when finished.
 416  **/
 417 char *
 418 g_filename_completer_get_completion_suffix (GFilenameCompleter *completer,
 419                                             const char *initial_text)
 420 {
 421   GList *possible_matches, *l;
 422   char *prefix;
 423   char *suffix;
 424   char *possible_match;
 425   char *lcp;
 426
 427   g_return_val_if_fail (G_IS_FILENAME_COMPLETER (completer), NULL);
 428   g_return_val_if_fail (initial_text != NULL, NULL);
 429
 430   possible_matches = init_completion (completer, initial_text, &prefix);
 431
 432   suffix = NULL;
 433
 434   for (l = possible_matches; l != NULL; l = l->next)
 435     {
 436       possible_match = l->data;
 437
 438       if (g_str_has_prefix (possible_match, prefix))
 439         {
 440           if (suffix == NULL)
 441             suffix = g_strdup (possible_match + strlen (prefix));
 442           else
 443             {
 444               lcp = longest_common_prefix (suffix,
 445                                            possible_match + strlen (prefix));
 446               g_free (suffix);
 447               suffix = lcp;
 448
 449               if (*suffix == 0)
 450                 break;
 451             }
 452         }
 453     }
 454
 455   g_free (prefix);
 456
 457   return suffix;
 458 }
 459
 460 /**
 461  * g_filename_completer_get_completions:
 462  * @completer: the filename completer.
 463  * @initial_text: text to be completed.
 464  *
 465  * Gets an array of completion strings for a given initial text.
 466  *
 467  * Returns: (array zero-terminated=1) (transfer full): array of strings with possible completions for @initial_text.
 468  * This array must be freed by g_strfreev() when finished.
 469  **/
 470 char **
 471 g_filename_completer_get_completions (GFilenameCompleter *completer,
 472                                       const char         *initial_text)
 473 {
 474   GList *possible_matches, *l;
 475   char *prefix;
 476   char *possible_match;
 477   GPtrArray *res;
 478
 479   g_return_val_if_fail (G_IS_FILENAME_COMPLETER (completer), NULL);
 480   g_return_val_if_fail (initial_text != NULL, NULL);
 481
 482   possible_matches = init_completion (completer, initial_text, &prefix);
 483
 484   res = g_ptr_array_new ();
 485   for (l = possible_matches; l != NULL; l = l->next)
 486     {
 487       possible_match = l->data;
 488
 489       if (g_str_has_prefix (possible_match, prefix))
 490         g_ptr_array_add (res,
 491                          g_strconcat (initial_text, possible_match + strlen (prefix), NULL));
 492     }
 493
 494   g_free (prefix);
 495
 496   g_ptr_array_add (res, NULL);
 497
 498   return (char**)g_ptr_array_free (res, FALSE);
 499 }
 500
 501 /**
 502  * g_filename_completer_set_dirs_only:
 503  * @completer: the filename completer.
 504  * @dirs_only: a #gboolean.
 505  *
 506  * If @dirs_only is %TRUE, @completer will only
 507  * complete directory names, and not file names.
 508  **/
 509 void
 510 g_filename_completer_set_dirs_only (GFilenameCompleter *completer,
 511                                     gboolean dirs_only)
 512 {
 513   g_return_if_fail (G_IS_FILENAME_COMPLETER (completer));
 514
 515   completer->dirs_only = dirs_only;
 516 }