gio/gappinfo.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 "gappinfo.h"
  25 #include "glibintl.h"
  26 #include <gioerror.h>
  27 #include <gfile.h>
  28
  29
  30 /**
  31  * SECTION:gappinfo
  32  * @short_description: Application information and launch contexts
  33  * @include: gio/gio.h
  34  *
  35  * #GAppInfo and #GAppLaunchContext are used for describing and launching
  36  * applications installed on the system.
  37  *
  38  * As of GLib 2.20, URIs will always be converted to POSIX paths
  39  * (using g_file_get_path()) when using g_app_info_launch() even if
  40  * the application requested an URI and not a POSIX path. For example
  41  * for an desktop-file based application with Exec key <literal>totem
  42  * &percnt;U</literal> and a single URI,
  43  * <literal>sftp://foo/file.avi</literal>, then
  44  * <literal>/home/user/.gvfs/sftp on foo/file.avi</literal> will be
  45  * passed. This will only work if a set of suitable GIO extensions
  46  * (such as gvfs 2.26 compiled with FUSE support), is available and
  47  * operational; if this is not the case, the URI will be passed
  48  * unmodified to the application. Some URIs, such as
  49  * <literal>mailto:</literal>, of course cannot be mapped to a POSIX
  50  * path (in gvfs there's no FUSE mount for it); such URIs will be
  51  * passed unmodified to the application.
  52  *
  53  * Specifically for gvfs 2.26 and later, the POSIX URI will be mapped
  54  * back to the GIO URI in the #GFile constructors (since gvfs
  55  * implements the #GVfs extension point). As such, if the application
  56  * needs to examine the URI, it needs to use g_file_get_uri() or
  57  * similar on #GFile. In other words, an application cannot assume
  58  * that the URI passed to e.g. g_file_new_for_commandline_arg() is
  59  * equal to the result of g_file_get_uri(). The following snippet
  60  * illustrates this:
  61  *
  62  * <programlisting>
  63  * GFile *f;
  64  * char *uri;
  65  *
  66  * file = g_file_new_for_commandline_arg (uri_from_commandline);
  67  *
  68  * uri = g_file_get_uri (file);
  69  * strcmp (uri, uri_from_commandline) == 0; // FALSE
  70  * g_free (uri);
  71  *
  72  * if (g_file_has_uri_scheme (file, "cdda"))
  73  *   {
  74  *     // do something special with uri
  75  *   }
  76  * g_object_unref (file);
  77  * </programlisting>
  78  *
  79  * This code will work when both <literal>cdda://sr0/Track
  80  * 1.wav</literal> and <literal>/home/user/.gvfs/cdda on sr0/Track
  81  * 1.wav</literal> is passed to the application. It should be noted
  82  * that it's generally not safe for applications to rely on the format
  83  * of a particular URIs. Different launcher applications (e.g. file
  84  * managers) may have different ideas of what a given URI means.
  85  *
  86  **/
  87
  88 typedef GAppInfoIface GAppInfoInterface;
  89 G_DEFINE_INTERFACE (GAppInfo, g_app_info, G_TYPE_OBJECT)
  90
  91 static void
  92 g_app_info_default_init (GAppInfoInterface *iface)
  93 {
  94 }
  95
  96
  97 /**
  98  * g_app_info_dup:
  99  * @appinfo: a #GAppInfo.
 100  *
 101  * Creates a duplicate of a #GAppInfo.
 102  *
 103  * Returns: (transfer full): a duplicate of @appinfo.
 104  **/
 105 GAppInfo *
 106 g_app_info_dup (GAppInfo *appinfo)
 107 {
 108   GAppInfoIface *iface;
 109
 110   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 111
 112   iface = G_APP_INFO_GET_IFACE (appinfo);
 113
 114   return (* iface->dup) (appinfo);
 115 }
 116
 117 /**
 118  * g_app_info_equal:
 119  * @appinfo1: the first #GAppInfo.
 120  * @appinfo2: the second #GAppInfo.
 121  *
 122  * Checks if two #GAppInfo<!-- -->s are equal.
 123  *
 124  * Returns: %TRUE if @appinfo1 is equal to @appinfo2. %FALSE otherwise.
 125  **/
 126 gboolean
 127 g_app_info_equal (GAppInfo *appinfo1,
 128                   GAppInfo *appinfo2)
 129 {
 130   GAppInfoIface *iface;
 131
 132   g_return_val_if_fail (G_IS_APP_INFO (appinfo1), FALSE);
 133   g_return_val_if_fail (G_IS_APP_INFO (appinfo2), FALSE);
 134
 135   if (G_TYPE_FROM_INSTANCE (appinfo1) != G_TYPE_FROM_INSTANCE (appinfo2))
 136     return FALSE;
 137
 138   iface = G_APP_INFO_GET_IFACE (appinfo1);
 139
 140   return (* iface->equal) (appinfo1, appinfo2);
 141 }
 142
 143 /**
 144  * g_app_info_get_id:
 145  * @appinfo: a #GAppInfo.
 146  *
 147  * Gets the ID of an application. An id is a string that
 148  * identifies the application. The exact format of the id is
 149  * platform dependent. For instance, on Unix this is the
 150  * desktop file id from the xdg menu specification.
 151  *
 152  * Note that the returned ID may be %NULL, depending on how
 153  * the @appinfo has been constructed.
 154  *
 155  * Returns: a string containing the application's ID.
 156  **/
 157 const char *
 158 g_app_info_get_id (GAppInfo *appinfo)
 159 {
 160   GAppInfoIface *iface;
 161
 162   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 163
 164   iface = G_APP_INFO_GET_IFACE (appinfo);
 165
 166   return (* iface->get_id) (appinfo);
 167 }
 168
 169 /**
 170  * g_app_info_get_name:
 171  * @appinfo: a #GAppInfo.
 172  *
 173  * Gets the installed name of the application.
 174  *
 175  * Returns: the name of the application for @appinfo.
 176  **/
 177 const char *
 178 g_app_info_get_name (GAppInfo *appinfo)
 179 {
 180   GAppInfoIface *iface;
 181
 182   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 183
 184   iface = G_APP_INFO_GET_IFACE (appinfo);
 185
 186   return (* iface->get_name) (appinfo);
 187 }
 188
 189 /**
 190  * g_app_info_get_display_name:
 191  * @appinfo: a #GAppInfo.
 192  *
 193  * Gets the display name of the application. The display name is often more
 194  * descriptive to the user than the name itself.
 195  *
 196  * Returns: the display name of the application for @appinfo, or the name if
 197  * no display name is available.
 198  *
 199  * Since: 2.24
 200  **/
 201 const char *
 202 g_app_info_get_display_name (GAppInfo *appinfo)
 203 {
 204   GAppInfoIface *iface;
 205
 206   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 207
 208   iface = G_APP_INFO_GET_IFACE (appinfo);
 209
 210   if (iface->get_display_name == NULL)
 211     return (* iface->get_name) (appinfo);
 212
 213   return (* iface->get_display_name) (appinfo);
 214 }
 215
 216 /**
 217  * g_app_info_get_description:
 218  * @appinfo: a #GAppInfo.
 219  *
 220  * Gets a human-readable description of an installed application.
 221  *
 222  * Returns: a string containing a description of the
 223  * application @appinfo, or %NULL if none.
 224  **/
 225 const char *
 226 g_app_info_get_description (GAppInfo *appinfo)
 227 {
 228   GAppInfoIface *iface;
 229
 230   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 231
 232   iface = G_APP_INFO_GET_IFACE (appinfo);
 233
 234   return (* iface->get_description) (appinfo);
 235 }
 236
 237 /**
 238  * g_app_info_get_executable:
 239  * @appinfo: a #GAppInfo
 240  *
 241  * Gets the executable's name for the installed application.
 242  *
 243  * Returns: a string containing the @appinfo's application
 244  * binaries name
 245  **/
 246 const char *
 247 g_app_info_get_executable (GAppInfo *appinfo)
 248 {
 249   GAppInfoIface *iface;
 250
 251   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 252
 253   iface = G_APP_INFO_GET_IFACE (appinfo);
 254
 255   return (* iface->get_executable) (appinfo);
 256 }
 257
 258
 259 /**
 260  * g_app_info_get_commandline:
 261  * @appinfo: a #GAppInfo
 262  *
 263  * Gets the commandline with which the application will be
 264  * started.
 265  *
 266  * Returns: a string containing the @appinfo's commandline,
 267  *     or %NULL if this information is not available
 268  *
 269  * Since: 2.20
 270  **/
 271 const char *
 272 g_app_info_get_commandline (GAppInfo *appinfo)
 273 {
 274   GAppInfoIface *iface;
 275
 276   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 277
 278   iface = G_APP_INFO_GET_IFACE (appinfo);
 279
 280   if (iface->get_commandline)
 281     return (* iface->get_commandline) (appinfo);
 282
 283   return NULL;
 284 }
 285
 286 /**
 287  * g_app_info_set_as_default_for_type:
 288  * @appinfo: a #GAppInfo.
 289  * @content_type: the content type.
 290  * @error: a #GError.
 291  *
 292  * Sets the application as the default handler for a given type.
 293  *
 294  * Returns: %TRUE on success, %FALSE on error.
 295  **/
 296 gboolean
 297 g_app_info_set_as_default_for_type (GAppInfo    *appinfo,
 298                                     const char  *content_type,
 299                                     GError     **error)
 300 {
 301   GAppInfoIface *iface;
 302
 303   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 304   g_return_val_if_fail (content_type != NULL, FALSE);
 305
 306   iface = G_APP_INFO_GET_IFACE (appinfo);
 307
 308   return (* iface->set_as_default_for_type) (appinfo, content_type, error);
 309 }
 310
 311 /**
 312  * g_app_info_set_as_last_used_for_type:
 313  * @appinfo: a #GAppInfo.
 314  * @content_type: the content type.
 315  * @error: a #GError.
 316  *
 317  * Sets the application as the last used application for a given type.
 318  * This will make the application appear as first in the list returned
 319  * by g_app_info_get_recommended_for_type(), regardless of the default
 320  * application for that content type.
 321  *
 322  * Returns: %TRUE on success, %FALSE on error.
 323  **/
 324 gboolean
 325 g_app_info_set_as_last_used_for_type (GAppInfo    *appinfo,
 326                                       const char  *content_type,
 327                                       GError     **error)
 328 {
 329   GAppInfoIface *iface;
 330
 331   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 332   g_return_val_if_fail (content_type != NULL, FALSE);
 333
 334   iface = G_APP_INFO_GET_IFACE (appinfo);
 335
 336   return (* iface->set_as_last_used_for_type) (appinfo, content_type, error);
 337 }
 338
 339 /**
 340  * g_app_info_set_as_default_for_extension:
 341  * @appinfo: a #GAppInfo.
 342  * @extension: a string containing the file extension (without the dot).
 343  * @error: a #GError.
 344  *
 345  * Sets the application as the default handler for the given file extension.
 346  *
 347  * Returns: %TRUE on success, %FALSE on error.
 348  **/
 349 gboolean
 350 g_app_info_set_as_default_for_extension (GAppInfo    *appinfo,
 351                                          const char  *extension,
 352                                          GError     **error)
 353 {
 354   GAppInfoIface *iface;
 355
 356   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 357   g_return_val_if_fail (extension != NULL, FALSE);
 358
 359   iface = G_APP_INFO_GET_IFACE (appinfo);
 360
 361   if (iface->set_as_default_for_extension)
 362     return (* iface->set_as_default_for_extension) (appinfo, extension, error);
 363
 364   g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 365                        "g_app_info_set_as_default_for_extension not supported yet");
 366   return FALSE;
 367 }
 368
 369
 370 /**
 371  * g_app_info_add_supports_type:
 372  * @appinfo: a #GAppInfo.
 373  * @content_type: a string.
 374  * @error: a #GError.
 375  *
 376  * Adds a content type to the application information to indicate the
 377  * application is capable of opening files with the given content type.
 378  *
 379  * Returns: %TRUE on success, %FALSE on error.
 380  **/
 381 gboolean
 382 g_app_info_add_supports_type (GAppInfo    *appinfo,
 383                               const char  *content_type,
 384                               GError     **error)
 385 {
 386   GAppInfoIface *iface;
 387
 388   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 389   g_return_val_if_fail (content_type != NULL, FALSE);
 390
 391   iface = G_APP_INFO_GET_IFACE (appinfo);
 392
 393   if (iface->add_supports_type)
 394     return (* iface->add_supports_type) (appinfo, content_type, error);
 395
 396   g_set_error_literal (error, G_IO_ERROR,
 397                        G_IO_ERROR_NOT_SUPPORTED,
 398                        "g_app_info_add_supports_type not supported yet");
 399
 400   return FALSE;
 401 }
 402
 403
 404 /**
 405  * g_app_info_can_remove_supports_type:
 406  * @appinfo: a #GAppInfo.
 407  *
 408  * Checks if a supported content type can be removed from an application.
 409  *
 410  * Returns: %TRUE if it is possible to remove supported
 411  *     content types from a given @appinfo, %FALSE if not.
 412  **/
 413 gboolean
 414 g_app_info_can_remove_supports_type (GAppInfo *appinfo)
 415 {
 416   GAppInfoIface *iface;
 417
 418   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 419
 420   iface = G_APP_INFO_GET_IFACE (appinfo);
 421
 422   if (iface->can_remove_supports_type)
 423     return (* iface->can_remove_supports_type) (appinfo);
 424
 425   return FALSE;
 426 }
 427
 428
 429 /**
 430  * g_app_info_remove_supports_type:
 431  * @appinfo: a #GAppInfo.
 432  * @content_type: a string.
 433  * @error: a #GError.
 434  *
 435  * Removes a supported type from an application, if possible.
 436  *
 437  * Returns: %TRUE on success, %FALSE on error.
 438  **/
 439 gboolean
 440 g_app_info_remove_supports_type (GAppInfo    *appinfo,
 441                                  const char  *content_type,
 442                                  GError     **error)
 443 {
 444   GAppInfoIface *iface;
 445
 446   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 447   g_return_val_if_fail (content_type != NULL, FALSE);
 448
 449   iface = G_APP_INFO_GET_IFACE (appinfo);
 450
 451   if (iface->remove_supports_type)
 452     return (* iface->remove_supports_type) (appinfo, content_type, error);
 453
 454   g_set_error_literal (error, G_IO_ERROR,
 455                        G_IO_ERROR_NOT_SUPPORTED,
 456                        "g_app_info_remove_supports_type not supported yet");
 457
 458   return FALSE;
 459 }
 460
 461 /**
 462  * g_app_info_get_supported_types:
 463  * @appinfo: a #GAppInfo that can handle files
 464  *
 465  * Retrieves the list of content types that @app_info claims to support.
 466  * If this information is not provided by the environment, this function
 467  * will return %NULL.
 468  * This function does not take in consideration associations added with
 469  * g_app_info_add_supports_type(), but only those exported directly by
 470  * the application.
 471  *
 472  * Returns: (transfer none) (array zero-terminated=1) (element-type utf8):
 473  *    a list of content types.
 474  *
 475  * Since: 2.34
 476  */
 477 const char **
 478 g_app_info_get_supported_types (GAppInfo *appinfo)
 479 {
 480   GAppInfoIface *iface;
 481
 482   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 483
 484   iface = G_APP_INFO_GET_IFACE (appinfo);
 485
 486   if (iface->get_supported_types)
 487     return iface->get_supported_types (appinfo);
 488   else
 489     return NULL;
 490 }
 491
 492
 493 /**
 494  * g_app_info_get_icon:
 495  * @appinfo: a #GAppInfo.
 496  *
 497  * Gets the icon for the application.
 498  *
 499  * Returns: (transfer none): the default #GIcon for @appinfo or %NULL
 500  * if there is no default icon.
 501  **/
 502 GIcon *
 503 g_app_info_get_icon (GAppInfo *appinfo)
 504 {
 505   GAppInfoIface *iface;
 506
 507   g_return_val_if_fail (G_IS_APP_INFO (appinfo), NULL);
 508
 509   iface = G_APP_INFO_GET_IFACE (appinfo);
 510
 511   return (* iface->get_icon) (appinfo);
 512 }
 513
 514
 515 /**
 516  * g_app_info_launch:
 517  * @appinfo: a #GAppInfo
 518  * @files: (allow-none) (element-type GFile): a #GList of #GFile objects
 519  * @launch_context: (allow-none): a #GAppLaunchContext or %NULL
 520  * @error: a #GError
 521  *
 522  * Launches the application. Passes @files to the launched application
 523  * as arguments, using the optional @launch_context to get information
 524  * about the details of the launcher (like what screen it is on).
 525  * On error, @error will be set accordingly.
 526  *
 527  * To launch the application without arguments pass a %NULL @files list.
 528  *
 529  * Note that even if the launch is successful the application launched
 530  * can fail to start if it runs into problems during startup. There is
 531  * no way to detect this.
 532  *
 533  * Some URIs can be changed when passed through a GFile (for instance
 534  * unsupported URIs with strange formats like mailto:), so if you have
 535  * a textual URI you want to pass in as argument, consider using
 536  * g_app_info_launch_uris() instead.
 537  *
 538  * The launched application inherits the environment of the launching
 539  * process, but it can be modified with g_app_launch_context_setenv() and
 540  * g_app_launch_context_unsetenv().
 541  *
 542  * On UNIX, this function sets the <envar>GIO_LAUNCHED_DESKTOP_FILE</envar>
 543  * environment variable with the path of the launched desktop file and
 544  * <envar>GIO_LAUNCHED_DESKTOP_FILE_PID</envar> to the process
 545  * id of the launched process. This can be used to ignore
 546  * <envar>GIO_LAUNCHED_DESKTOP_FILE</envar>, should it be inherited
 547  * by further processes. The <envar>DISPLAY</envar> and
 548  * <envar>DESKTOP_STARTUP_ID</envar> environment variables are also
 549  * set, based on information provided in @launch_context.
 550  *
 551  * Returns: %TRUE on successful launch, %FALSE otherwise.
 552  **/
 553 gboolean
 554 g_app_info_launch (GAppInfo           *appinfo,
 555                    GList              *files,
 556                    GAppLaunchContext  *launch_context,
 557                    GError            **error)
 558 {
 559   GAppInfoIface *iface;
 560
 561   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 562
 563   iface = G_APP_INFO_GET_IFACE (appinfo);
 564
 565   return (* iface->launch) (appinfo, files, launch_context, error);
 566 }
 567
 568
 569 /**
 570  * g_app_info_supports_uris:
 571  * @appinfo: a #GAppInfo.
 572  *
 573  * Checks if the application supports reading files and directories from URIs.
 574  *
 575  * Returns: %TRUE if the @appinfo supports URIs.
 576  **/
 577 gboolean
 578 g_app_info_supports_uris (GAppInfo *appinfo)
 579 {
 580   GAppInfoIface *iface;
 581
 582   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 583
 584   iface = G_APP_INFO_GET_IFACE (appinfo);
 585
 586   return (* iface->supports_uris) (appinfo);
 587 }
 588
 589
 590 /**
 591  * g_app_info_supports_files:
 592  * @appinfo: a #GAppInfo.
 593  *
 594  * Checks if the application accepts files as arguments.
 595  *
 596  * Returns: %TRUE if the @appinfo supports files.
 597  **/
 598 gboolean
 599 g_app_info_supports_files (GAppInfo *appinfo)
 600 {
 601   GAppInfoIface *iface;
 602
 603   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 604
 605   iface = G_APP_INFO_GET_IFACE (appinfo);
 606
 607   return (* iface->supports_files) (appinfo);
 608 }
 609
 610
 611 /**
 612  * g_app_info_launch_uris:
 613  * @appinfo: a #GAppInfo
 614  * @uris: (allow-none) (element-type utf8): a #GList containing URIs to launch.
 615  * @launch_context: (allow-none): a #GAppLaunchContext or %NULL
 616  * @error: a #GError
 617  *
 618  * Launches the application. This passes the @uris to the launched application
 619  * as arguments, using the optional @launch_context to get information
 620  * about the details of the launcher (like what screen it is on).
 621  * On error, @error will be set accordingly.
 622  *
 623  * To launch the application without arguments pass a %NULL @uris list.
 624  *
 625  * Note that even if the launch is successful the application launched
 626  * can fail to start if it runs into problems during startup. There is
 627  * no way to detect this.
 628  *
 629  * Returns: %TRUE on successful launch, %FALSE otherwise.
 630  **/
 631 gboolean
 632 g_app_info_launch_uris (GAppInfo           *appinfo,
 633                         GList              *uris,
 634                         GAppLaunchContext  *launch_context,
 635                         GError            **error)
 636 {
 637   GAppInfoIface *iface;
 638
 639   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 640
 641   iface = G_APP_INFO_GET_IFACE (appinfo);
 642
 643   return (* iface->launch_uris) (appinfo, uris, launch_context, error);
 644 }
 645
 646
 647 /**
 648  * g_app_info_should_show:
 649  * @appinfo: a #GAppInfo.
 650  *
 651  * Checks if the application info should be shown in menus that
 652  * list available applications.
 653  *
 654  * Returns: %TRUE if the @appinfo should be shown, %FALSE otherwise.
 655  **/
 656 gboolean
 657 g_app_info_should_show (GAppInfo *appinfo)
 658 {
 659   GAppInfoIface *iface;
 660
 661   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 662
 663   iface = G_APP_INFO_GET_IFACE (appinfo);
 664
 665   return (* iface->should_show) (appinfo);
 666 }
 667
 668 /**
 669  * g_app_info_launch_default_for_uri:
 670  * @uri: the uri to show
 671  * @launch_context: (allow-none): an optional #GAppLaunchContext.
 672  * @error: a #GError.
 673  *
 674  * Utility function that launches the default application
 675  * registered to handle the specified uri. Synchronous I/O
 676  * is done on the uri to detect the type of the file if
 677  * required.
 678  *
 679  * Returns: %TRUE on success, %FALSE on error.
 680  **/
 681 gboolean
 682 g_app_info_launch_default_for_uri (const char         *uri,
 683                                    GAppLaunchContext  *launch_context,
 684                                    GError            **error)
 685 {
 686   char *uri_scheme;
 687   GAppInfo *app_info = NULL;
 688   GList l;
 689   gboolean res;
 690
 691   /* g_file_query_default_handler() calls
 692    * g_app_info_get_default_for_uri_scheme() too, but we have to do it
 693    * here anyway in case GFile can't parse @uri correctly.
 694    */
 695   uri_scheme = g_uri_parse_scheme (uri);
 696   if (uri_scheme && uri_scheme[0] != '\0')
 697     app_info = g_app_info_get_default_for_uri_scheme (uri_scheme);
 698   g_free (uri_scheme);
 699
 700   if (!app_info)
 701     {
 702       GFile *file;
 703
 704       file = g_file_new_for_uri (uri);
 705       app_info = g_file_query_default_handler (file, NULL, error);
 706       g_object_unref (file);
 707       if (app_info == NULL)
 708         return FALSE;
 709
 710       /* We still use the original @uri rather than calling
 711        * g_file_get_uri(), because GFile might have modified the URI
 712        * in ways we don't want (eg, removing the fragment identifier
 713        * from a file: URI).
 714        */
 715     }
 716
 717   l.data = (char *)uri;
 718   l.next = l.prev = NULL;
 719   res = g_app_info_launch_uris (app_info, &l,
 720                                 launch_context, error);
 721
 722   g_object_unref (app_info);
 723
 724   return res;
 725 }
 726
 727 /**
 728  * g_app_info_can_delete:
 729  * @appinfo: a #GAppInfo
 730  *
 731  * Obtains the information whether the #GAppInfo can be deleted.
 732  * See g_app_info_delete().
 733  *
 734  * Returns: %TRUE if @appinfo can be deleted
 735  *
 736  * Since: 2.20
 737  */
 738 gboolean
 739 g_app_info_can_delete (GAppInfo *appinfo)
 740 {
 741   GAppInfoIface *iface;
 742
 743   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 744
 745   iface = G_APP_INFO_GET_IFACE (appinfo);
 746
 747   if (iface->can_delete)
 748     return (* iface->can_delete) (appinfo);
 749
 750   return FALSE;
 751 }
 752
 753
 754 /**
 755  * g_app_info_delete:
 756  * @appinfo: a #GAppInfo
 757  *
 758  * Tries to delete a #GAppInfo.
 759  *
 760  * On some platforms, there may be a difference between user-defined
 761  * #GAppInfo<!-- -->s which can be deleted, and system-wide ones which
 762  * cannot. See g_app_info_can_delete().
 763  *
 764  * Virtual: do_delete
 765  * Returns: %TRUE if @appinfo has been deleted
 766  *
 767  * Since: 2.20
 768  */
 769 gboolean
 770 g_app_info_delete (GAppInfo *appinfo)
 771 {
 772   GAppInfoIface *iface;
 773
 774   g_return_val_if_fail (G_IS_APP_INFO (appinfo), FALSE);
 775
 776   iface = G_APP_INFO_GET_IFACE (appinfo);
 777
 778   if (iface->do_delete)
 779     return (* iface->do_delete) (appinfo);
 780
 781   return FALSE;
 782 }
 783
 784
 785 enum {
 786   LAUNCH_FAILED,
 787   LAUNCHED,
 788   LAST_SIGNAL
 789 };
 790
 791 struct _GAppLaunchContextPrivate {
 792   char **envp;
 793 };
 794
 795 static guint signals[LAST_SIGNAL] = { 0 };
 796
 797 G_DEFINE_TYPE_WITH_PRIVATE (GAppLaunchContext, g_app_launch_context, G_TYPE_OBJECT)
 798
 799 /**
 800  * g_app_launch_context_new:
 801  *
 802  * Creates a new application launch context. This is not normally used,
 803  * instead you instantiate a subclass of this, such as #GdkAppLaunchContext.
 804  *
 805  * Returns: a #GAppLaunchContext.
 806  **/
 807 GAppLaunchContext *
 808 g_app_launch_context_new (void)
 809 {
 810   return g_object_new (G_TYPE_APP_LAUNCH_CONTEXT, NULL);
 811 }
 812
 813 static void
 814 g_app_launch_context_finalize (GObject *object)
 815 {
 816   GAppLaunchContext *context = G_APP_LAUNCH_CONTEXT (object);
 817
 818   g_strfreev (context->priv->envp);
 819
 820   G_OBJECT_CLASS (g_app_launch_context_parent_class)->finalize (object);
 821 }
 822
 823 static void
 824 g_app_launch_context_class_init (GAppLaunchContextClass *klass)
 825 {
 826   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 827
 828   object_class->finalize = g_app_launch_context_finalize;
 829
 830   /*
 831    * GAppLaunchContext::launch-failed:
 832    * @context: the object emitting the signal
 833    * @startup_notify_id: the startup notification id for the failed launch
 834    *
 835    * The ::launch-failed signal is emitted when a #GAppInfo launch
 836    * fails. The startup notification id is provided, so that the launcher
 837    * can cancel the startup notification.
 838    *
 839    * Since: 2.36
 840    */
 841   signals[LAUNCH_FAILED] = g_signal_new ("launch-failed",
 842                                          G_OBJECT_CLASS_TYPE (object_class),
 843                                          G_SIGNAL_RUN_LAST,
 844                                          G_STRUCT_OFFSET (GAppLaunchContextClass, launch_failed),
 845                                          NULL, NULL, NULL,
 846                                          G_TYPE_NONE, 1, G_TYPE_STRING);
 847
 848   /*
 849    * GAppLaunchContext::launched:
 850    * @context: the object emitting the signal
 851    * @info: the #GAppInfo that was just launched
 852    * @platform_data: additional platform-specific data for this launch
 853    *
 854    * The ::launched signal is emitted when a #GAppInfo is successfully
 855    * launched. The @platform_data is an GVariant dictionary mapping
 856    * strings to variants (ie a{sv}), which contains additional,
 857    * platform-specific data about this launch. On UNIX, at least the
 858    * "pid" and "startup-notification-id" keys will be present.
 859    *
 860    * Since: 2.36
 861    */
 862   signals[LAUNCHED] = g_signal_new ("launched",
 863                                     G_OBJECT_CLASS_TYPE (object_class),
 864                                     G_SIGNAL_RUN_LAST,
 865                                     G_STRUCT_OFFSET (GAppLaunchContextClass, launched),
 866                                     NULL, NULL, NULL,
 867                                     G_TYPE_NONE, 2,
 868                                     G_TYPE_APP_INFO, G_TYPE_VARIANT);
 869 }
 870
 871 static void
 872 g_app_launch_context_init (GAppLaunchContext *context)
 873 {
 874   context->priv = g_app_launch_context_get_instance_private (context);
 875 }
 876
 877 /**
 878  * g_app_launch_context_setenv:
 879  * @context: a #GAppLaunchContext
 880  * @variable: the environment variable to set
 881  * @value: the value for to set the variable to.
 882  *
 883  * Arranges for @variable to be set to @value in the child's
 884  * environment when @context is used to launch an application.
 885  *
 886  * Since: 2.32
 887  */
 888 void
 889 g_app_launch_context_setenv (GAppLaunchContext *context,
 890                              const char        *variable,
 891                              const char        *value)
 892 {
 893   if (!context->priv->envp)
 894     context->priv->envp = g_get_environ ();
 895
 896   context->priv->envp =
 897     g_environ_setenv (context->priv->envp, variable, value, TRUE);
 898 }
 899
 900 /**
 901  * g_app_launch_context_unsetenv:
 902  * @context: a #GAppLaunchContext
 903  * @variable: the environment variable to remove
 904  *
 905  * Arranges for @variable to be unset in the child's environment
 906  * when @context is used to launch an application.
 907  *
 908  * Since: 2.32
 909  */
 910 void
 911 g_app_launch_context_unsetenv (GAppLaunchContext *context,
 912                                const char        *variable)
 913 {
 914   if (!context->priv->envp)
 915     context->priv->envp = g_get_environ ();
 916
 917   context->priv->envp =
 918     g_environ_unsetenv (context->priv->envp, variable);
 919 }
 920
 921 /**
 922  * g_app_launch_context_get_environment:
 923  * @context: a #GAppLaunchContext
 924  *
 925  * Gets the complete environment variable list to be passed to
 926  * the child process when @context is used to launch an application.
 927  * This is a %NULL-terminated array of strings, where each string has
 928  * the form <literal>KEY=VALUE</literal>.
 929  *
 930  * Return value: (array zero-terminated=1) (transfer full): the
 931  *     child's environment
 932  *
 933  * Since: 2.32
 934  */
 935 char **
 936 g_app_launch_context_get_environment (GAppLaunchContext *context)
 937 {
 938   if (!context->priv->envp)
 939     context->priv->envp = g_get_environ ();
 940
 941   return g_strdupv (context->priv->envp);
 942 }
 943
 944 /**
 945  * g_app_launch_context_get_display:
 946  * @context: a #GAppLaunchContext
 947  * @info: a #GAppInfo
 948  * @files: (element-type GFile): a #GList of #GFile objects
 949  *
 950  * Gets the display string for the @context. This is used to ensure new
 951  * applications are started on the same display as the launching
 952  * application, by setting the <envar>DISPLAY</envar> environment variable.
 953  *
 954  * Returns: a display string for the display.
 955  */
 956 char *
 957 g_app_launch_context_get_display (GAppLaunchContext *context,
 958                                   GAppInfo          *info,
 959                                   GList             *files)
 960 {
 961   GAppLaunchContextClass *class;
 962
 963   g_return_val_if_fail (G_IS_APP_LAUNCH_CONTEXT (context), NULL);
 964   g_return_val_if_fail (G_IS_APP_INFO (info), NULL);
 965
 966   class = G_APP_LAUNCH_CONTEXT_GET_CLASS (context);
 967
 968   if (class->get_display == NULL)
 969     return NULL;
 970
 971   return class->get_display (context, info, files);
 972 }
 973
 974 /**
 975  * g_app_launch_context_get_startup_notify_id:
 976  * @context: a #GAppLaunchContext
 977  * @info: a #GAppInfo
 978  * @files: (element-type GFile): a #GList of of #GFile objects
 979  *
 980  * Initiates startup notification for the application and returns the
 981  * <envar>DESKTOP_STARTUP_ID</envar> for the launched operation,
 982  * if supported.
 983  *
 984  * Startup notification IDs are defined in the <ulink
 985  * url="http://standards.freedesktop.org/startup-notification-spec/startup-notification-latest.txt">
 986  * FreeDesktop.Org Startup Notifications standard</ulink>.
 987  *
 988  * Returns: a startup notification ID for the application, or %NULL if
 989  *     not supported.
 990  **/
 991 char *
 992 g_app_launch_context_get_startup_notify_id (GAppLaunchContext *context,
 993                                             GAppInfo          *info,
 994                                             GList             *files)
 995 {
 996   GAppLaunchContextClass *class;
 997
 998   g_return_val_if_fail (G_IS_APP_LAUNCH_CONTEXT (context), NULL);
 999   g_return_val_if_fail (G_IS_APP_INFO (info), NULL);
1000
1001   class = G_APP_LAUNCH_CONTEXT_GET_CLASS (context);
1002
1003   if (class->get_startup_notify_id == NULL)
1004     return NULL;
1005
1006   return class->get_startup_notify_id (context, info, files);
1007 }
1008
1009
1010 /**
1011  * g_app_launch_context_launch_failed:
1012  * @context: a #GAppLaunchContext.
1013  * @startup_notify_id: the startup notification id that was returned by g_app_launch_context_get_startup_notify_id().
1014  *
1015  * Called when an application has failed to launch, so that it can cancel
1016  * the application startup notification started in g_app_launch_context_get_startup_notify_id().
1017  *
1018  **/
1019 void
1020 g_app_launch_context_launch_failed (GAppLaunchContext *context,
1021                                     const char        *startup_notify_id)
1022 {
1023   g_return_if_fail (G_IS_APP_LAUNCH_CONTEXT (context));
1024   g_return_if_fail (startup_notify_id != NULL);
1025
1026   g_signal_emit (context, signals[LAUNCH_FAILED], 0, startup_notify_id);
1027 }