2 * Copyright (C) 2006 Stefan Kost <ensonic@users.sf.net>
4 * gstpreset.c: helper interface for element presets
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
23 * @short_description: helper interface for element presets
25 * This interface offers methods to query and manipulate parameter preset sets.
26 * A preset is a bunch of property settings, together with meta data and a name.
27 * The name of a preset serves as key for subsequent method calls to manipulate
29 * All instances of one type will share the list of presets. The list is created
30 * on demand, if presets are not used, the list is not created.
32 * The interface comes with a default implementation that serves most plugins.
33 * Wrapper plugins will override most methods to implement support for the
34 * native preset format of those wrapped plugins.
35 * One method that is useful to be overridden is gst_preset_get_property_names().
36 * With that one can control which properties are saved and in which order.
38 * The default implementation supports presets located in a system directory,
39 * application specific directory and in the users home directory. When getting
40 * a list of presets individual presets are read and overlaid in 1) system,
41 * 2) application and 3) user order. Whenever an earlier entry is newer, the
42 * later entries will be updated.
47 * - we need to avoid two instances writing the preset file
48 * -> flock(fileno()), http://www.ecst.csuchico.edu/~beej/guide/ipc/flock.html
50 * -> better save the new file to a tempfile and then rename?
51 * - we like to know when any other instance makes changes to the keyfile
52 * - then ui can be updated
53 * - and we make sure that we don't lose edits
54 * -> its the same problem actually, once for inside a process, once system-
56 * - can we use a lock inside a names shared memory segment?
58 * - should there be a 'preset-list' property to get the preset list
59 * (and to connect a notify:: to to listen for changes)
60 * we could use gnome_vfs_monitor_add() to monitor the user preset_file.
62 * - should there be a 'preset-name' property so that we can set a preset via
63 * gst-launch, or should we handle this with special syntax in gst-launch:
64 * gst-launch element preset:<preset-name> property=value ...
65 * - this would allow to have preset-bundles too (a preset on bins that
66 * specifies presets for children
69 #include "gst_private.h"
71 #include "gstpreset.h"
72 #include "gstchildproxy.h"
79 #include <glib/gstdio.h>
82 #define WIN32_LEAN_AND_MEAN
85 extern HMODULE _priv_gst_dll_handle;
88 #define GST_CAT_DEFAULT preset_debug
89 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
91 /* defines for keyfile usage, this group contains the element type name and
92 * version these presets belong to. */
93 #define PRESET_HEADER "_presets_"
95 /* keys of the preset header section */
96 #define PRESET_HEADER_ELEMENT_NAME "element-name"
97 #define PRESET_HEADER_VERSION "version"
99 static GQuark preset_user_path_quark = 0;
100 static GQuark preset_app_path_quark = 0;
101 static GQuark preset_system_path_quark = 0;
102 static GQuark preset_quark = 0;
104 /* the application can set a custom path that is checked in addition to standard
105 * system and user dirs. This helps to develop new presets first local to the
108 static gchar *preset_app_dir = NULL;
110 /* default iface implementation */
112 static gboolean gst_preset_default_save_presets_file (GstPreset * preset);
116 * @preset: a #GObject that implements #GstPreset
117 * @preset_user_path: (out) (allow-none): location for path or %NULL
118 * @preset_app_path: (out) (allow-none): location for path or %NULL
119 * @preset_system_path: (out) (allow-none): location for path or %NULL
121 * Fetch the preset_path for user local, application specific and system wide
122 * settings. Don't free after use.
124 * Returns: %FALSE if no paths could be found.
127 preset_get_paths (GstPreset * preset, const gchar ** preset_user_path,
128 const gchar ** preset_app_path, const gchar ** preset_system_path)
130 GType type = G_TYPE_FROM_INSTANCE (preset);
132 const gchar *element_name;
134 /* we use the element name when we must construct the paths */
135 element_name = G_OBJECT_TYPE_NAME (preset);
136 GST_INFO_OBJECT (preset, "element_name: '%s'", element_name);
138 if (preset_user_path) {
139 /* preset user path requested, see if we have it cached in the qdata */
140 if (!(preset_path = g_type_get_qdata (type, preset_user_path_quark))) {
143 /* user presets go in user's XDG data directory. */
144 preset_dir = g_build_filename (g_get_user_data_dir (),
145 "gstreamer-" GST_API_VERSION, "presets", NULL);
146 GST_INFO_OBJECT (preset, "user_preset_dir: '%s'", preset_dir);
148 g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s.prs", preset_dir,
150 GST_INFO_OBJECT (preset, "user_preset_path: '%s'", preset_path);
152 g_mkdir_with_parents (preset_dir, 0755);
155 /* cache the preset path to the type */
156 g_type_set_qdata (type, preset_user_path_quark, preset_path);
158 *preset_user_path = preset_path;
161 if (preset_app_path) {
162 if (preset_app_dir) {
163 if (!(preset_path = g_type_get_qdata (type, preset_system_path_quark))) {
164 preset_path = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s.prs",
165 preset_app_dir, element_name);
166 GST_INFO_OBJECT (preset, "application_preset_path: '%s'", preset_path);
168 /* cache the preset path to the type */
169 g_type_set_qdata (type, preset_app_path_quark, preset_path);
171 *preset_app_path = preset_path;
173 *preset_app_path = NULL;
177 if (preset_system_path) {
178 /* preset system path requested, see if we have it cached in the qdata */
179 if (!(preset_path = g_type_get_qdata (type, preset_system_path_quark))) {
182 /* system presets in '$GST_DATADIR/gstreamer-1.0/presets/GstAudioPanorama.prs' */
185 g_win32_get_package_installation_directory_of_module
186 (_priv_gst_dll_handle);
188 g_build_filename (basedir, "share", "gstreamer-" GST_API_VERSION,
192 preset_dir = g_build_filename (GST_DATADIR, "gstreamer-" GST_API_VERSION,
195 GST_INFO_OBJECT (preset, "system_preset_dir: '%s'", preset_dir);
196 preset_path = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s.prs",
197 preset_dir, element_name);
198 GST_INFO_OBJECT (preset, "system_preset_path: '%s'", preset_path);
200 g_mkdir_with_parents (preset_dir, 0755);
203 /* cache the preset path to the type */
204 g_type_set_qdata (type, preset_system_path_quark, preset_path);
206 *preset_system_path = preset_path;
212 preset_skip_property (GParamSpec * property)
214 if (((property->flags & G_PARAM_READWRITE) != G_PARAM_READWRITE) ||
215 (property->flags & G_PARAM_CONSTRUCT_ONLY))
217 /* FIXME: skip GST_PARAM_NOT_PRESETABLE, see #522205 */
222 preset_parse_version (const gchar * str_version)
224 guint major, minor, micro, nano;
227 major = minor = micro = nano = 0;
229 /* parse version (e.g. 0.10.15.1) to guint64 */
230 num = sscanf (str_version, "%u.%u.%u.%u", &major, &minor, µ, &nano);
231 /* make sure we have at least "major.minor" */
235 version = ((((major << 8 | minor) << 8) | micro) << 8) | nano;
236 GST_DEBUG ("version %s -> %" G_GUINT64_FORMAT, str_version, version);
239 return G_GUINT64_CONSTANT (0);
243 preset_open_and_parse_header (GstPreset * preset, const gchar * preset_path,
244 guint64 * preset_version)
247 GError *error = NULL;
249 const gchar *element_name;
252 in = g_key_file_new ();
254 res = g_key_file_load_from_file (in, preset_path,
255 G_KEY_FILE_KEEP_COMMENTS | G_KEY_FILE_KEEP_TRANSLATIONS, &error);
256 if (!res || error != NULL)
259 /* element type name and preset name must match or we are dealing with a wrong
261 element_name = G_OBJECT_TYPE_NAME (preset);
263 g_key_file_get_value (in, PRESET_HEADER, PRESET_HEADER_ELEMENT_NAME,
266 if (!name || strcmp (name, element_name))
271 /* get the version now so that the caller can check it */
272 if (preset_version) {
274 g_key_file_get_value (in, PRESET_HEADER, PRESET_HEADER_VERSION, NULL);
275 *preset_version = preset_parse_version (str);
284 GST_WARNING_OBJECT (preset, "Unable to read preset file %s: %s",
285 preset_path, error->message);
286 g_error_free (error);
287 g_key_file_free (in);
292 GST_WARNING_OBJECT (preset,
293 "Wrong element name in preset file %s. Expected %s, got %s",
294 preset_path, element_name, GST_STR_NULL (name));
296 g_key_file_free (in);
302 preset_merge (GKeyFile * system, GKeyFile * user)
305 gchar **groups, **keys;
306 gsize i, j, num_groups, num_keys;
308 /* copy file comment if there is any */
309 if ((str = g_key_file_get_comment (user, NULL, NULL, NULL))) {
310 g_key_file_set_comment (system, NULL, NULL, str, NULL);
314 /* get groups in user and copy into system */
315 groups = g_key_file_get_groups (user, &num_groups);
316 for (i = 0; i < num_groups; i++) {
317 /* copy group comment if there is any */
318 if ((str = g_key_file_get_comment (user, groups[i], NULL, NULL))) {
319 g_key_file_set_comment (system, groups[i], NULL, str, NULL);
323 /* ignore private groups */
324 if (groups[i][0] == '_')
327 /* if group already exists in system, remove and re-add keys from user */
328 if (g_key_file_has_group (system, groups[i])) {
329 g_key_file_remove_group (system, groups[i], NULL);
332 keys = g_key_file_get_keys (user, groups[i], &num_keys, NULL);
333 for (j = 0; j < num_keys; j++) {
334 /* copy key comment if there is any */
335 if ((str = g_key_file_get_comment (user, groups[i], keys[j], NULL))) {
336 g_key_file_set_comment (system, groups[i], keys[j], str, NULL);
339 str = g_key_file_get_value (user, groups[i], keys[j], NULL);
340 g_key_file_set_value (system, groups[i], keys[j], str);
348 /* reads the user and system presets files and merges them together. This
349 * function caches the GKeyFile on the element type. If there is no existing
350 * preset file, a new in-memory GKeyFile will be created. */
352 preset_get_keyfile (GstPreset * preset)
355 GType type = G_TYPE_FROM_INSTANCE (preset);
357 /* first see if the have a cached version for the type */
358 if (!(presets = g_type_get_qdata (type, preset_quark))) {
359 const gchar *preset_user_path, *preset_app_path, *preset_system_path;
360 guint64 version_system = G_GUINT64_CONSTANT (0);
361 guint64 version_app = G_GUINT64_CONSTANT (0);
362 guint64 version_user = G_GUINT64_CONSTANT (0);
363 guint64 version = G_GUINT64_CONSTANT (0);
364 gboolean merged = FALSE;
365 GKeyFile *in_user, *in_app = NULL, *in_system;
367 preset_get_paths (preset, &preset_user_path, &preset_app_path,
368 &preset_system_path);
370 /* try to load the user, app and system presets, we do this to get the
371 * versions of all files. */
372 in_user = preset_open_and_parse_header (preset, preset_user_path,
374 if (preset_app_path) {
375 in_app = preset_open_and_parse_header (preset, preset_app_path,
378 in_system = preset_open_and_parse_header (preset, preset_system_path,
381 /* compare version to check for merge */
384 version = version_system;
387 /* if system version is higher, merge */
388 if (version > version_app) {
389 preset_merge (presets, in_app);
390 g_key_file_free (in_app);
393 g_key_file_free (presets);
395 version = version_system;
399 /* if system or app version is higher, merge */
400 if (version > version_user) {
401 preset_merge (presets, in_user);
402 g_key_file_free (in_user);
406 g_key_file_free (presets);
412 /* we did not load a user, app or system presets file, create a new one */
413 presets = g_key_file_new ();
414 g_key_file_set_string (presets, PRESET_HEADER, PRESET_HEADER_ELEMENT_NAME,
415 G_OBJECT_TYPE_NAME (preset));
418 /* attach the preset to the type */
419 g_type_set_qdata (type, preset_quark, (gpointer) presets);
422 gst_preset_default_save_presets_file (preset);
428 /* get a list of all supported preset names for an element */
430 gst_preset_default_get_preset_names (GstPreset * preset)
436 /* get the presets from the type */
437 if (!(presets = preset_get_keyfile (preset)))
440 /* get the groups, which are also the preset names */
441 if (!(groups = g_key_file_get_groups (presets, &num_groups)))
444 /* remove all private group names starting with '_' from the array */
445 for (i = 0; i < num_groups; i++) {
446 if (groups[i][0] == '_') {
447 /* free private group */
449 /* move last element of list down */
451 /* move last element into removed element */
452 groups[i] = groups[num_groups];
453 groups[num_groups] = NULL;
456 /* sort the array now */
457 g_qsort_with_data (groups, num_groups, sizeof (gchar *),
458 (GCompareDataFunc) strcmp, NULL);
465 GST_WARNING_OBJECT (preset, "Could not load presets");
470 GST_WARNING_OBJECT (preset, "Could not find preset groups");
475 /* get a list of all property names that are used for presets */
477 gst_preset_default_get_property_names (GstPreset * preset)
480 guint i, j = 0, n_props;
481 GObjectClass *gclass;
482 gboolean is_child_proxy;
483 gchar **result = NULL;
485 gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
486 is_child_proxy = GST_IS_CHILD_PROXY (preset);
488 /* get a list of object properties */
489 props = g_object_class_list_properties (gclass, &n_props);
491 /* allocate array big enough to hold the worst case, including a terminating
493 result = g_new (gchar *, n_props + 1);
495 /* now filter out the properties that we can use for presets */
496 GST_DEBUG_OBJECT (preset, " filtering properties: %u", n_props);
497 for (i = 0; i < n_props; i++) {
498 if (preset_skip_property (props[i]))
500 GST_DEBUG_OBJECT (preset, " using: %s", props[i]->name);
501 result[j++] = g_strdup (props[i]->name);
506 if (is_child_proxy) {
510 n_children = gst_child_proxy_get_children_count ((GstChildProxy *) preset);
511 for (c = 0; c < n_children; c++) {
512 child = gst_child_proxy_get_child_by_index ((GstChildProxy *) preset, c);
513 gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (child));
515 props = g_object_class_list_properties (gclass, &n_props);
517 /* resize property name array */
518 result = g_renew (gchar *, result, j + n_props + 1);
520 /* now filter out the properties that we can use for presets */
521 GST_DEBUG_OBJECT (preset, " filtering properties: %u", n_props);
522 for (i = 0; i < n_props; i++) {
523 if (preset_skip_property (props[i]))
525 GST_DEBUG_OBJECT (preset, " using: %s::%s",
526 GST_OBJECT_NAME (child), props[i]->name);
527 result[j++] = g_strdup_printf ("%s::%s", GST_OBJECT_NAME (child),
533 g_object_unref (child);
537 GST_INFO_OBJECT (preset, "object has no properties");
544 /* load the presets of @name for the instance @preset. Returns %FALSE if something
547 gst_preset_default_load_preset (GstPreset * preset, const gchar * name)
552 GObjectClass *gclass;
553 gboolean is_child_proxy;
555 /* get the presets from the type */
556 if (!(presets = preset_get_keyfile (preset)))
559 /* get the preset name */
560 if (!g_key_file_has_group (presets, name))
563 GST_DEBUG_OBJECT (preset, "loading preset : '%s'", name);
565 /* get the properties that we can configure in this element */
566 if (!(props = gst_preset_get_property_names (preset)))
569 gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
570 is_child_proxy = GST_IS_CHILD_PROXY (preset);
572 /* for each of the property names, find the preset parameter and try to
573 * configure the property with its value */
574 for (i = 0; props[i]; i++) {
576 GValue gvalue = { 0, };
577 GParamSpec *property = NULL;
579 /* check if we have a settings for this element property */
580 if (!(str = g_key_file_get_value (presets, name, props[i], NULL))) {
581 /* the element has a property but the parameter is not in the keyfile */
582 GST_WARNING_OBJECT (preset, "parameter '%s' not in preset", props[i]);
586 GST_DEBUG_OBJECT (preset, "setting value '%s' for property '%s'", str,
589 if (is_child_proxy) {
590 gst_child_proxy_lookup ((GstChildProxy *) preset, props[i], NULL,
593 property = g_object_class_find_property (gclass, props[i]);
596 /* the parameter was in the keyfile, the element said it supported it but
597 * then the property was not found in the element. This should not happen. */
598 GST_WARNING_OBJECT (preset, "property '%s' not in object", props[i]);
603 /* try to deserialize the property value from the keyfile and set it as
604 * the object property */
605 g_value_init (&gvalue, property->value_type);
606 if (gst_value_deserialize (&gvalue, str)) {
607 if (is_child_proxy) {
608 gst_child_proxy_set_property ((GstChildProxy *) preset, props[i],
611 g_object_set_property ((GObject *) preset, props[i], &gvalue);
614 GST_WARNING_OBJECT (preset,
615 "deserialization of value '%s' for property '%s' failed", str,
618 g_value_unset (&gvalue);
628 GST_WARNING_OBJECT (preset, "no presets");
633 GST_WARNING_OBJECT (preset, "no preset named '%s'", name);
638 GST_INFO_OBJECT (preset, "no properties");
643 /* save the presets file. A copy of the existing presets file is stored in a
646 gst_preset_default_save_presets_file (GstPreset * preset)
649 const gchar *preset_path;
650 GError *error = NULL;
651 gchar *bak_file_name;
652 gboolean backup = TRUE;
656 preset_get_paths (preset, &preset_path, NULL, NULL);
658 /* get the presets from the type */
659 if (!(presets = preset_get_keyfile (preset)))
662 GST_DEBUG_OBJECT (preset, "saving preset file: '%s'", preset_path);
664 /* create backup if possible */
665 bak_file_name = g_strdup_printf ("%s.bak", preset_path);
666 if (g_file_test (bak_file_name, G_FILE_TEST_EXISTS)) {
667 if (g_unlink (bak_file_name)) {
669 GST_INFO_OBJECT (preset, "cannot remove old backup file : %s",
674 if (g_rename (preset_path, bak_file_name)) {
675 GST_INFO_OBJECT (preset, "cannot backup file : %s -> %s", preset_path,
679 g_free (bak_file_name);
681 /* update gstreamer version */
682 g_key_file_set_string (presets, PRESET_HEADER, PRESET_HEADER_VERSION,
685 /* get new contents, wee need this to save it */
686 if (!(data = g_key_file_to_data (presets, &data_size, &error)))
690 if (!g_file_set_contents (preset_path, data, data_size, &error))
700 GST_WARNING_OBJECT (preset,
701 "no presets, trying to unlink possibly existing preset file: '%s'",
703 g_unlink (preset_path);
708 GST_WARNING_OBJECT (preset, "can not get the keyfile contents: %s",
710 g_error_free (error);
716 GST_WARNING_OBJECT (preset, "Unable to store preset file %s: %s",
717 preset_path, error->message);
718 g_error_free (error);
724 /* save the preset with the given name */
726 gst_preset_default_save_preset (GstPreset * preset, const gchar * name)
731 GObjectClass *gclass;
732 gboolean is_child_proxy;
734 GST_INFO_OBJECT (preset, "saving new preset: %s", name);
736 /* get the presets from the type */
737 if (!(presets = preset_get_keyfile (preset)))
740 /* take copies of current gobject properties from preset */
741 if (!(props = gst_preset_get_property_names (preset)))
744 gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
745 is_child_proxy = GST_IS_CHILD_PROXY (preset);
747 /* loop over the object properties and store the property value in the
749 for (i = 0; props[i]; i++) {
750 GValue gvalue = { 0, };
752 GParamSpec *property = NULL;
754 if (is_child_proxy) {
755 gst_child_proxy_lookup ((GstChildProxy *) preset, props[i], NULL,
758 property = g_object_class_find_property (gclass, props[i]);
761 /* the element said it supported the property but then it does not have
762 * that property. This should not happen. */
763 GST_WARNING_OBJECT (preset, "property '%s' not in object", props[i]);
767 g_value_init (&gvalue, property->value_type);
768 if (is_child_proxy) {
769 gst_child_proxy_get_property ((GstChildProxy *) preset, props[i],
772 g_object_get_property ((GObject *) preset, props[i], &gvalue);
775 if ((str = gst_value_serialize (&gvalue))) {
776 g_key_file_set_string (presets, name, props[i], (gpointer) str);
779 GST_WARNING_OBJECT (preset, "serialization for property '%s' failed",
782 g_value_unset (&gvalue);
784 GST_INFO_OBJECT (preset, " saved");
787 /* save updated version */
788 return gst_preset_default_save_presets_file (preset);
793 GST_WARNING_OBJECT (preset, "no presets");
798 GST_INFO_OBJECT (preset, "no properties");
803 /* copies all keys and comments from one group to another, deleting the old
806 gst_preset_default_rename_preset (GstPreset * preset, const gchar * old_name,
807 const gchar * new_name)
814 /* get the presets from the type */
815 if (!(presets = preset_get_keyfile (preset)))
818 if (!g_key_file_has_group (presets, old_name))
821 /* copy group comment if there is any */
822 if ((str = g_key_file_get_comment (presets, old_name, NULL, NULL))) {
823 g_key_file_set_comment (presets, new_name, NULL, str, NULL);
827 /* get all keys from the old group and copy them in the new group */
828 keys = g_key_file_get_keys (presets, old_name, &num_keys, NULL);
829 for (i = 0; i < num_keys; i++) {
830 /* copy key comment if there is any */
831 if ((str = g_key_file_get_comment (presets, old_name, keys[i], NULL))) {
832 g_key_file_set_comment (presets, new_name, keys[i], str, NULL);
836 str = g_key_file_get_value (presets, old_name, keys[i], NULL);
837 g_key_file_set_value (presets, new_name, keys[i], str);
842 /* remove old group */
843 g_key_file_remove_group (presets, old_name, NULL);
845 /* save updated version */
846 return gst_preset_default_save_presets_file (preset);
851 GST_WARNING_OBJECT (preset, "no presets");
856 GST_WARNING_OBJECT (preset, "no preset named %s", old_name);
861 /* delete a group from the keyfile */
863 gst_preset_default_delete_preset (GstPreset * preset, const gchar * name)
867 /* get the presets from the type */
868 if (!(presets = preset_get_keyfile (preset)))
872 if (!g_key_file_has_group (presets, name))
875 /* remove the group */
876 g_key_file_remove_group (presets, name, NULL);
878 /* save updated version */
879 return gst_preset_default_save_presets_file (preset);
884 GST_WARNING_OBJECT (preset, "no presets");
889 GST_WARNING_OBJECT (preset, "no preset named %s", name);
895 gst_preset_default_set_meta (GstPreset * preset, const gchar * name,
896 const gchar * tag, const gchar * value)
901 /* get the presets from the type */
902 if (!(presets = preset_get_keyfile (preset)))
905 key = g_strdup_printf ("_meta/%s", tag);
906 if (value && *value) {
907 g_key_file_set_value (presets, name, key, value);
909 g_key_file_remove_key (presets, name, key, NULL);
913 /* save updated keyfile */
914 return gst_preset_default_save_presets_file (preset);
919 GST_WARNING_OBJECT (preset, "no presets");
924 /* the caller must free @value after usage */
926 gst_preset_default_get_meta (GstPreset * preset, const gchar * name,
927 const gchar * tag, gchar ** value)
932 /* get the presets from the type */
933 if (!(presets = preset_get_keyfile (preset)))
936 key = g_strdup_printf ("_meta/%s", tag);
937 *value = g_key_file_get_value (presets, name, key, NULL);
945 GST_WARNING_OBJECT (preset, "no presets");
954 * gst_preset_get_preset_names:
955 * @preset: a #GObject that implements #GstPreset
957 * Get a copy of preset names as a %NULL terminated string array.
959 * Returns: (transfer full) (array zero-terminated=1) (element-type gchar*):
960 * list with names, use g_strfreev() after usage.
963 gst_preset_get_preset_names (GstPreset * preset)
965 g_return_val_if_fail (GST_IS_PRESET (preset), NULL);
967 return (GST_PRESET_GET_INTERFACE (preset)->get_preset_names (preset));
971 * gst_preset_get_property_names:
972 * @preset: a #GObject that implements #GstPreset
974 * Get a the names of the GObject properties that can be used for presets.
976 * Returns: (transfer full) (array zero-terminated=1) (element-type gchar*): an
977 * array of property names which should be freed with g_strfreev() after use.
980 gst_preset_get_property_names (GstPreset * preset)
982 g_return_val_if_fail (GST_IS_PRESET (preset), NULL);
984 return (GST_PRESET_GET_INTERFACE (preset)->get_property_names (preset));
988 * gst_preset_load_preset:
989 * @preset: a #GObject that implements #GstPreset
990 * @name: preset name to load
992 * Load the given preset.
994 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
997 gst_preset_load_preset (GstPreset * preset, const gchar * name)
999 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1000 g_return_val_if_fail (name, FALSE);
1002 return (GST_PRESET_GET_INTERFACE (preset)->load_preset (preset, name));
1006 * gst_preset_save_preset:
1007 * @preset: a #GObject that implements #GstPreset
1008 * @name: preset name to save
1010 * Save the current object settings as a preset under the given name. If there
1011 * is already a preset by this @name it will be overwritten.
1013 * Returns: %TRUE for success, %FALSE
1016 gst_preset_save_preset (GstPreset * preset, const gchar * name)
1018 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1019 g_return_val_if_fail (name, FALSE);
1021 return (GST_PRESET_GET_INTERFACE (preset)->save_preset (preset, name));
1025 * gst_preset_rename_preset:
1026 * @preset: a #GObject that implements #GstPreset
1027 * @old_name: current preset name
1028 * @new_name: new preset name
1030 * Renames a preset. If there is already a preset by the @new_name it will be
1033 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with @old_name
1036 gst_preset_rename_preset (GstPreset * preset, const gchar * old_name,
1037 const gchar * new_name)
1039 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1040 g_return_val_if_fail (old_name, FALSE);
1041 g_return_val_if_fail (new_name, FALSE);
1043 return (GST_PRESET_GET_INTERFACE (preset)->rename_preset (preset, old_name,
1048 * gst_preset_delete_preset:
1049 * @preset: a #GObject that implements #GstPreset
1050 * @name: preset name to remove
1052 * Delete the given preset.
1054 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
1057 gst_preset_delete_preset (GstPreset * preset, const gchar * name)
1059 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1060 g_return_val_if_fail (name, FALSE);
1062 return (GST_PRESET_GET_INTERFACE (preset)->delete_preset (preset, name));
1066 * gst_preset_set_meta:
1067 * @preset: a #GObject that implements #GstPreset
1068 * @name: preset name
1069 * @tag: meta data item name
1070 * @value: (allow-none): new value
1072 * Sets a new @value for an existing meta data item or adds a new item. Meta
1073 * data @tag names can be something like e.g. "comment". Supplying %NULL for the
1074 * @value will unset an existing value.
1076 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
1079 gst_preset_set_meta (GstPreset * preset, const gchar * name, const gchar * tag,
1080 const gchar * value)
1082 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1083 g_return_val_if_fail (name, FALSE);
1084 g_return_val_if_fail (tag, FALSE);
1086 return GST_PRESET_GET_INTERFACE (preset)->set_meta (preset, name, tag, value);
1090 * gst_preset_get_meta:
1091 * @preset: a #GObject that implements #GstPreset
1092 * @name: preset name
1093 * @tag: meta data item name
1094 * @value: (out callee-allocates): value
1096 * Gets the @value for an existing meta data @tag. Meta data @tag names can be
1097 * something like e.g. "comment". Returned values need to be released when done.
1099 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
1100 * or no value for the given @tag
1103 gst_preset_get_meta (GstPreset * preset, const gchar * name, const gchar * tag,
1106 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1107 g_return_val_if_fail (name, FALSE);
1108 g_return_val_if_fail (tag, FALSE);
1109 g_return_val_if_fail (value, FALSE);
1111 return GST_PRESET_GET_INTERFACE (preset)->get_meta (preset, name, tag, value);
1115 * gst_preset_set_app_dir:
1116 * @app_dir: the application specific preset dir
1118 * Sets an extra directory as an absolute path that should be considered when
1119 * looking for presets. Any presets in the application dir will shadow the
1122 * Returns: %TRUE for success, %FALSE if the dir already has been set
1125 gst_preset_set_app_dir (const gchar * app_dir)
1127 g_return_val_if_fail (app_dir, FALSE);
1129 if (!preset_app_dir) {
1130 preset_app_dir = g_strdup (app_dir);
1137 * gst_preset_get_app_dir:
1139 * Gets the directory for application specific presets if set by the
1142 * Returns: (nullable): the directory or %NULL, don't free or modify
1146 gst_preset_get_app_dir (void)
1148 return preset_app_dir;
1151 /* class internals */
1154 gst_preset_class_init (GstPresetInterface * iface)
1156 iface->get_preset_names = gst_preset_default_get_preset_names;
1157 iface->get_property_names = gst_preset_default_get_property_names;
1159 iface->load_preset = gst_preset_default_load_preset;
1160 iface->save_preset = gst_preset_default_save_preset;
1161 iface->rename_preset = gst_preset_default_rename_preset;
1162 iface->delete_preset = gst_preset_default_delete_preset;
1164 iface->set_meta = gst_preset_default_set_meta;
1165 iface->get_meta = gst_preset_default_get_meta;
1169 gst_preset_base_init (gpointer g_class)
1171 static gboolean initialized = FALSE;
1174 /* init default implementation */
1175 GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "preset",
1176 GST_DEBUG_FG_WHITE | GST_DEBUG_BG_BLACK, "preset interface");
1178 /* create quarks for use with g_type_{g,s}et_qdata() */
1179 preset_quark = g_quark_from_static_string ("GstPreset::presets");
1180 preset_user_path_quark =
1181 g_quark_from_static_string ("GstPreset::user_path");
1182 preset_app_path_quark = g_quark_from_static_string ("GstPreset::app_path");
1183 preset_system_path_quark =
1184 g_quark_from_static_string ("GstPreset::system_path");
1187 /* create interface properties, each element would need to override this
1188 * g_object_class_override_property(gobject_class, PROP_PRESET_NAME, "preset-name");
1189 * and in _set_property() do
1190 * case PROP_PRESET_NAME: {
1191 * gchar *name = g_value_get_string (value);
1193 * gst_preset_load_preset(preset, name);
1196 g_object_interface_install_property (g_class,
1197 g_param_spec_string ("preset-name",
1198 "preset-name property",
1199 "load given preset", NULL, G_PARAM_WRITABLE));
1207 gst_preset_get_type (void)
1209 static volatile gsize type = 0;
1211 if (g_once_init_enter (&type)) {
1213 const GTypeInfo info = {
1214 sizeof (GstPresetInterface),
1215 (GBaseInitFunc) gst_preset_base_init, /* base_init */
1216 NULL, /* base_finalize */
1217 (GClassInitFunc) gst_preset_class_init, /* class_init */
1218 NULL, /* class_finalize */
1219 NULL, /* class_data */
1221 0, /* n_preallocs */
1222 NULL /* instance_init */
1224 _type = g_type_register_static (G_TYPE_INTERFACE, "GstPreset", &info, 0);
1225 g_once_init_leave (&type, _type);