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