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 #include "gioalias.h"
  34
  35 /**
  36  * SECTION:gfilenamecompleter
  37  * @short_description: Filename Completer
  38  * @include: gio/gio.h
  39  *
  40  * Completes partial file and directory names given a partial string by
  41  * looking in the file system for clues. Can return a list of possible
  42  * completion strings for widget implementations.
  43  *
  44  **/
  45
  46 enum {
  47   GOT_COMPLETION_DATA,
  48   LAST_SIGNAL
  49 };
  50
  51 static guint signals[LAST_SIGNAL] = { 0 };
  52
  53 typedef struct {
  54   GFilenameCompleter *completer;
  55   GFileEnumerator *enumerator;
  56   GCancellable *cancellable;
  57   gboolean should_escape;
  58   GFile *dir;
  59   GList *basenames;
  60   gboolean dirs_only;
  61 } LoadBasenamesData;
  62
  63 struct _GFilenameCompleter {
  64   GObject parent;
  65
  66   GFile *basenames_dir;
  67   gboolean basenames_are_escaped;
  68   GList *basenames;
  69   gboolean dirs_only;
  70
  71   LoadBasenamesData *basename_loader;
  72 };
  73
  74 G_DEFINE_TYPE (GFilenameCompleter, g_filename_completer, G_TYPE_OBJECT);
  75
  76 static void cancel_load_basenames (GFilenameCompleter *completer);
  77
  78 static void
  79 g_filename_completer_finalize (GObject *object)
  80 {
  81   GFilenameCompleter *completer;
  82
  83   completer = G_FILENAME_COMPLETER (object);
  84
  85   cancel_load_basenames (completer);
  86
  87   if (completer->basenames_dir)
  88     g_object_unref (completer->basenames_dir);
  89
  90   g_list_foreach (completer->basenames, (GFunc)g_free, NULL);
  91   g_list_free (completer->basenames);
  92
  93   G_OBJECT_CLASS (g_filename_completer_parent_class)->finalize (object);
  94 }
  95
  96 static void
  97 g_filename_completer_class_init (GFilenameCompleterClass *klass)
  98 {
  99   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 100
 101   gobject_class->finalize = g_filename_completer_finalize;
 102   /**
 103    * GFilenameCompleter::got-completion-data:
 104    *
 105    * Emitted when the file name completion information comes available.
 106    **/
 107   signals[GOT_COMPLETION_DATA] = g_signal_new (I_("got-completion-data"),
 108                                           G_TYPE_FILENAME_COMPLETER,
 109                                           G_SIGNAL_RUN_LAST,
 110                                           G_STRUCT_OFFSET (GFilenameCompleterClass, got_completion_data),
 111                                           NULL, NULL,
 112                                           g_cclosure_marshal_VOID__VOID,
 113                                           G_TYPE_NONE, 0);
 114 }
 115
 116 static void
 117 g_filename_completer_init (GFilenameCompleter *completer)
 118 {
 119 }
 120
 121 /**
 122  * g_filename_completer_new:
 123  *
 124  * Creates a new filename completer.
 125  *
 126  * Returns: a #GFilenameCompleter.
 127  **/
 128 GFilenameCompleter *
 129 g_filename_completer_new (void)
 130 {
 131   return g_object_new (G_TYPE_FILENAME_COMPLETER, NULL);
 132 }
 133
 134 static char *
 135 longest_common_prefix (char *a, char *b)
 136 {
 137   char *start;
 138
 139   start = a;
 140
 141   while (g_utf8_get_char (a) == g_utf8_get_char (b))
 142     {
 143       a = g_utf8_next_char (a);
 144       b = g_utf8_next_char (b);
 145     }
 146
 147   return g_strndup (start, a - start);
 148 }
 149
 150 static void
 151 load_basenames_data_free (LoadBasenamesData *data)
 152 {
 153   if (data->enumerator)
 154     g_object_unref (data->enumerator);
 155
 156   g_object_unref (data->cancellable);
 157   g_object_unref (data->dir);
 158
 159   g_list_foreach (data->basenames, (GFunc)g_free, NULL);
 160   g_list_free (data->basenames);
 161
 162   g_free (data);
 163 }
 164
 165 static void
 166 got_more_files (GObject *source_object,
 167                 GAsyncResult *res,
 168                 gpointer user_data)
 169 {
 170   LoadBasenamesData *data = user_data;
 171   GList *infos, *l;
 172   GFileInfo *info;
 173   const char *name;
 174   gboolean append_slash;
 175   char *t;
 176   char *basename;
 177
 178   if (data->completer == NULL)
 179     {
 180       /* Was cancelled */
 181       load_basenames_data_free (data);
 182       return;
 183     }
 184
 185   infos = g_file_enumerator_next_files_finish (data->enumerator, res, NULL);
 186
 187   for (l = infos; l != NULL; l = l->next)
 188     {
 189       info = l->data;
 190
 191       if (data->dirs_only &&
 192           g_file_info_get_file_type (info) != G_FILE_TYPE_DIRECTORY)
 193         {
 194           g_object_unref (info);
 195           continue;
 196         }
 197
 198       append_slash = g_file_info_get_file_type (info) == G_FILE_TYPE_DIRECTORY;
 199       name = g_file_info_get_name (info);
 200       if (name == NULL)
 201         {
 202           g_object_unref (info);
 203           continue;
 204         }
 205
 206
 207       if (data->should_escape)
 208         basename = g_uri_escape_string (name,
 209                                         G_URI_RESERVED_CHARS_ALLOWED_IN_PATH,
 210                                         TRUE);
 211       else
 212         /* If not should_escape, must be a local filename, convert to utf8 */
 213         basename = g_filename_to_utf8 (name, -1, NULL, NULL, NULL);
 214
 215       if (basename)
 216         {
 217           if (append_slash)
 218             {
 219               t = basename;
 220               basename = g_strconcat (basename, "/", NULL);
 221               g_free (t);
 222             }
 223
 224           data->basenames = g_list_prepend (data->basenames, basename);
 225         }
 226
 227       g_object_unref (info);
 228     }
 229
 230   g_list_free (infos);
 231
 232   if (infos)
 233     {
 234       /* Not last, get more files */
 235       g_file_enumerator_next_files_async (data->enumerator,
 236                                           100,
 237                                           0,
 238                                           data->cancellable,
 239                                           got_more_files, data);
 240     }
 241   else
 242     {
 243       data->completer->basename_loader = NULL;
 244
 245       if (data->completer->basenames_dir)
 246         g_object_unref (data->completer->basenames_dir);
 247       g_list_foreach (data->completer->basenames, (GFunc)g_free, NULL);
 248       g_list_free (data->completer->basenames);
 249
 250       data->completer->basenames_dir = g_object_ref (data->dir);
 251       data->completer->basenames = data->basenames;
 252       data->completer->basenames_are_escaped = data->should_escape;
 253       data->basenames = NULL;
 254
 255       g_file_enumerator_close_async (data->enumerator, 0, NULL, NULL, NULL);
 256
 257       g_signal_emit (data->completer, signals[GOT_COMPLETION_DATA], 0);
 258       load_basenames_data_free (data);
 259     }
 260 }
 261
 262
 263 static void
 264 got_enum (GObject *source_object,
 265           GAsyncResult *res,
 266           gpointer user_data)
 267 {
 268   LoadBasenamesData *data = user_data;
 269
 270   if (data->completer == NULL)
 271     {
 272       /* Was cancelled */
 273       load_basenames_data_free (data);
 274       return;
 275     }
 276
 277   data->enumerator = g_file_enumerate_children_finish (G_FILE (source_object), res, NULL);
 278
 279   if (data->enumerator == NULL)
 280     {
 281       data->completer->basename_loader = NULL;
 282
 283       if (data->completer->basenames_dir)
 284         g_object_unref (data->completer->basenames_dir);
 285       g_list_foreach (data->completer->basenames, (GFunc)g_free, NULL);
 286       g_list_free (data->completer->basenames);
 287
 288       /* Mark uptodate with no basenames */
 289       data->completer->basenames_dir = g_object_ref (data->dir);
 290       data->completer->basenames = NULL;
 291       data->completer->basenames_are_escaped = data->should_escape;
 292
 293       load_basenames_data_free (data);
 294       return;
 295     }
 296
 297   g_file_enumerator_next_files_async (data->enumerator,
 298                                       100,
 299                                       0,
 300                                       data->cancellable,
 301                                       got_more_files, data);
 302 }
 303
 304 static void
 305 schedule_load_basenames (GFilenameCompleter *completer,
 306                          GFile *dir,
 307                          gboolean should_escape)
 308 {
 309   LoadBasenamesData *data;
 310
 311   cancel_load_basenames (completer);
 312
 313   data = g_new0 (LoadBasenamesData, 1);
 314   data->completer = completer;
 315   data->cancellable = g_cancellable_new ();
 316   data->dir = g_object_ref (dir);
 317   data->should_escape = should_escape;
 318   data->dirs_only = completer->dirs_only;
 319
 320   completer->basename_loader = data;
 321
 322   g_file_enumerate_children_async (dir,
 323                                    G_FILE_ATTRIBUTE_STANDARD_NAME "," G_FILE_ATTRIBUTE_STANDARD_TYPE,
 324                                    0, 0,
 325                                    data->cancellable,
 326                                    got_enum, data);
 327 }
 328
 329 static void
 330 cancel_load_basenames (GFilenameCompleter *completer)
 331 {
 332   LoadBasenamesData *loader;
 333
 334   if (completer->basename_loader)
 335     {
 336       loader = completer->basename_loader;
 337       loader->completer = NULL;
 338
 339       g_cancellable_cancel (loader->cancellable);
 340
 341       completer->basename_loader = NULL;
 342     }
 343 }
 344
 345
 346 /* Returns a list of possible matches and the basename to use for it */
 347 static GList *
 348 init_completion (GFilenameCompleter *completer,
 349                  const char *initial_text,
 350                  char **basename_out)
 351 {
 352   gboolean should_escape;
 353   GFile *file, *parent;
 354   char *basename;
 355   char *t;
 356   int len;
 357
 358   *basename_out = NULL;
 359
 360   should_escape = ! (g_path_is_absolute (initial_text) || *initial_text == '~');
 361
 362   len = strlen (initial_text);
 363
 364   if (len > 0 &&
 365       initial_text[len - 1] == '/')
 366     return NULL;
 367
 368   file = g_file_parse_name (initial_text);
 369   parent = g_file_get_parent (file);
 370   if (parent == NULL)
 371     {
 372       g_object_unref (file);
 373       return NULL;
 374     }
 375
 376   if (completer->basenames_dir == NULL ||
 377       completer->basenames_are_escaped != should_escape ||
 378       !g_file_equal (parent, completer->basenames_dir))
 379     {
 380       schedule_load_basenames (completer, parent, should_escape);
 381       g_object_unref (file);
 382       return NULL;
 383     }
 384
 385   basename = g_file_get_basename (file);
 386   if (should_escape)
 387     {
 388       t = basename;
 389       basename = g_uri_escape_string (basename, G_URI_RESERVED_CHARS_ALLOWED_IN_PATH, TRUE);
 390       g_free (t);
 391     }
 392   else
 393     {
 394       t = basename;
 395       basename = g_filename_to_utf8 (basename, -1, NULL, NULL, NULL);
 396       g_free (t);
 397
 398       if (basename == NULL)
 399         return NULL;
 400     }
 401
 402   *basename_out = basename;
 403
 404   return completer->basenames;
 405 }
 406
 407 /**
 408  * g_filename_completer_get_completion_suffix:
 409  * @completer: the filename completer.
 410  * @initial_text: text to be completed.
 411  *
 412  * Obtains a completion for @initial_text from @completer.
 413  *
 414  * Returns: a completed string, or %NULL if no completion exists.
 415  *     This string is not owned by GIO, so remember to g_free() it
 416  *     when finished.
 417  **/
 418 char *
 419 g_filename_completer_get_completion_suffix (GFilenameCompleter *completer,
 420                                             const char *initial_text)
 421 {
 422   GList *possible_matches, *l;
 423   char *prefix;
 424   char *suffix;
 425   char *possible_match;
 426   char *lcp;
 427
 428   g_return_val_if_fail (G_IS_FILENAME_COMPLETER (completer), NULL);
 429   g_return_val_if_fail (initial_text != NULL, NULL);
 430
 431   possible_matches = init_completion (completer, initial_text, &prefix);
 432
 433   suffix = NULL;
 434
 435   for (l = possible_matches; l != NULL; l = l->next)
 436     {
 437       possible_match = l->data;
 438
 439       if (g_str_has_prefix (possible_match, prefix))
 440         {
 441           if (suffix == NULL)
 442             suffix = g_strdup (possible_match + strlen (prefix));
 443           else
 444             {
 445               lcp = longest_common_prefix (suffix,
 446                                            possible_match + strlen (prefix));
 447               g_free (suffix);
 448               suffix = lcp;
 449
 450               if (*suffix == 0)
 451                 break;
 452             }
 453         }
 454     }
 455
 456   g_free (prefix);
 457
 458   return suffix;
 459 }
 460
 461 /**
 462  * g_filename_completer_get_completions:
 463  * @completer: the filename completer.
 464  * @initial_text: text to be completed.
 465  *
 466  * Gets an array of completion strings for a given initial text.
 467  *
 468  * Returns: array of strings with possible completions for @initial_text.
 469  * This array must be freed by g_strfreev() when finished.
 470  **/
 471 char **
 472 g_filename_completer_get_completions (GFilenameCompleter *completer,
 473                                       const char         *initial_text)
 474 {
 475   GList *possible_matches, *l;
 476   char *prefix;
 477   char *possible_match;
 478   GPtrArray *res;
 479
 480   g_return_val_if_fail (G_IS_FILENAME_COMPLETER (completer), NULL);
 481   g_return_val_if_fail (initial_text != NULL, NULL);
 482
 483   possible_matches = init_completion (completer, initial_text, &prefix);
 484
 485   res = g_ptr_array_new ();
 486   for (l = possible_matches; l != NULL; l = l->next)
 487     {
 488       possible_match = l->data;
 489
 490       if (g_str_has_prefix (possible_match, prefix))
 491         g_ptr_array_add (res,
 492                          g_strconcat (initial_text, possible_match + strlen (prefix), NULL));
 493     }
 494
 495   g_free (prefix);
 496
 497   g_ptr_array_add (res, NULL);
 498
 499   return (char**)g_ptr_array_free (res, FALSE);
 500 }
 501
 502 /**
 503  * g_filename_completer_set_dirs_only:
 504  * @completer: the filename completer.
 505  * @dirs_only: a #gboolean.
 506  *
 507  * If @dirs_only is %TRUE, @completer will only
 508  * complete directory names, and not file names.
 509  **/
 510 void
 511 g_filename_completer_set_dirs_only (GFilenameCompleter *completer,
 512                                     gboolean dirs_only)
 513 {
 514   g_return_if_fail (G_IS_FILENAME_COMPLETER (completer));
 515
 516   completer->dirs_only = dirs_only;
 517 }
 518
 519 #define __G_FILENAME_COMPLETER_C__
 520 #include "gioaliasdef.c"