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.
37 * When implementing support for read-only presets, one should set the vmethods
38 * for gst_preset_save_preset() and gst_preset_delete_preset() to %NULL.
39 * Applications can use gst_preset_is_editable() to check for that.
41 * The default implementation supports presets located in a system directory,
42 * application specific directory and in the users home directory. When getting
43 * a list of presets individual presets are read and overlaid in 1) system,
44 * 2) application and 3) user order. Whenever an earlier entry is newer, the
45 * later entries will be updated.
50 * - we need to avoid two instances writing the preset file
51 * -> flock(fileno()), http://www.ecst.csuchico.edu/~beej/guide/ipc/flock.html
53 * -> better save the new file to a tempfile and then rename?
54 * - we like to know when any other instance makes changes to the keyfile
55 * - then ui can be updated
56 * - and we make sure that we don't lose edits
57 * -> its the same problem actually, once for inside a process, once system-
59 * - can we use a lock inside a names shared memory segment?
61 * - should there be a 'preset-list' property to get the preset list
62 * (and to connect a notify:: to to listen for changes)
63 * we could use gnome_vfs_monitor_add() to monitor the user preset_file.
65 * - should there be a 'preset-name' property so that we can set a preset via
66 * gst-launch, or should we handle this with special syntax in gst-launch:
67 * gst-launch element preset:<preset-name> property=value ...
68 * - this would allow to have preset-bundles too (a preset on bins that
69 * specifies presets for children
72 #include "gst_private.h"
74 #include "gstpreset.h"
75 #include "gstchildproxy.h"
82 #include <glib/gstdio.h>
85 #define WIN32_LEAN_AND_MEAN
88 extern HMODULE _priv_gst_dll_handle;
91 #define GST_CAT_DEFAULT preset_debug
92 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
94 /* defines for keyfile usage, this group contains the element type name and
95 * version these presets belong to. */
96 #define PRESET_HEADER "_presets_"
98 /* keys of the preset header section */
99 #define PRESET_HEADER_ELEMENT_NAME "element-name"
100 #define PRESET_HEADER_VERSION "version"
102 static GQuark preset_user_path_quark = 0;
103 static GQuark preset_app_path_quark = 0;
104 static GQuark preset_system_path_quark = 0;
105 static GQuark preset_quark = 0;
107 /* the application can set a custom path that is checked in addition to standard
108 * system and user dirs. This helps to develop new presets first local to the
111 static gchar *preset_app_dir = NULL;
113 /* default iface implementation */
115 static gboolean gst_preset_default_save_presets_file (GstPreset * preset);
119 * @preset: a #GObject that implements #GstPreset
120 * @preset_user_path: (out) (allow-none): location for path or %NULL
121 * @preset_app_path: (out) (allow-none): location for path or %NULL
122 * @preset_system_path: (out) (allow-none): location for path or %NULL
124 * Fetch the preset_path for user local, application specific and system wide
125 * settings. Don't free after use.
127 * Returns: %FALSE if no paths could be found.
130 preset_get_paths (GstPreset * preset, const gchar ** preset_user_path,
131 const gchar ** preset_app_path, const gchar ** preset_system_path)
133 GType type = G_TYPE_FROM_INSTANCE (preset);
135 const gchar *element_name;
137 /* we use the element name when we must construct the paths */
138 element_name = G_OBJECT_TYPE_NAME (preset);
139 GST_INFO_OBJECT (preset, "element_name: '%s'", element_name);
141 if (preset_user_path) {
142 /* preset user path requested, see if we have it cached in the qdata */
143 if (!(preset_path = g_type_get_qdata (type, preset_user_path_quark))) {
146 /* user presets go in user's XDG data directory. */
147 preset_dir = g_build_filename (g_get_user_data_dir (),
148 "gstreamer-" GST_API_VERSION, "presets", NULL);
149 GST_INFO_OBJECT (preset, "user_preset_dir: '%s'", preset_dir);
151 g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s.prs", preset_dir,
153 GST_INFO_OBJECT (preset, "user_preset_path: '%s'", preset_path);
155 g_mkdir_with_parents (preset_dir, 0755);
158 /* cache the preset path to the type */
159 g_type_set_qdata (type, preset_user_path_quark, preset_path);
161 *preset_user_path = preset_path;
164 if (preset_app_path) {
165 if (preset_app_dir) {
166 if (!(preset_path = g_type_get_qdata (type, preset_system_path_quark))) {
167 preset_path = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s.prs",
168 preset_app_dir, element_name);
169 GST_INFO_OBJECT (preset, "application_preset_path: '%s'", preset_path);
171 /* cache the preset path to the type */
172 g_type_set_qdata (type, preset_app_path_quark, preset_path);
174 *preset_app_path = preset_path;
176 *preset_app_path = NULL;
180 if (preset_system_path) {
181 /* preset system path requested, see if we have it cached in the qdata */
182 if (!(preset_path = g_type_get_qdata (type, preset_system_path_quark))) {
185 /* system presets in '$GST_DATADIR/gstreamer-1.0/presets/GstAudioPanorama.prs' */
188 g_win32_get_package_installation_directory_of_module
189 (_priv_gst_dll_handle);
191 g_build_filename (basedir, "share", "gstreamer-" GST_API_VERSION,
195 preset_dir = g_build_filename (GST_DATADIR, "gstreamer-" GST_API_VERSION,
198 GST_INFO_OBJECT (preset, "system_preset_dir: '%s'", preset_dir);
199 preset_path = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s.prs",
200 preset_dir, element_name);
201 GST_INFO_OBJECT (preset, "system_preset_path: '%s'", preset_path);
203 g_mkdir_with_parents (preset_dir, 0755);
206 /* cache the preset path to the type */
207 g_type_set_qdata (type, preset_system_path_quark, preset_path);
209 *preset_system_path = preset_path;
215 preset_skip_property (GParamSpec * property)
217 if (((property->flags & G_PARAM_READWRITE) != G_PARAM_READWRITE) ||
218 (property->flags & G_PARAM_CONSTRUCT_ONLY))
220 /* FIXME: skip GST_PARAM_NOT_PRESETABLE, see #522205 */
225 preset_parse_version (const gchar * str_version)
227 guint major, minor, micro, nano;
230 major = minor = micro = nano = 0;
232 /* parse version (e.g. 0.10.15.1) to guint64 */
233 num = sscanf (str_version, "%u.%u.%u.%u", &major, &minor, µ, &nano);
234 /* make sure we have at least "major.minor" */
238 version = ((((major << 8 | minor) << 8) | micro) << 8) | nano;
239 GST_DEBUG ("version %s -> %" G_GUINT64_FORMAT, str_version, version);
242 return G_GUINT64_CONSTANT (0);
246 preset_open_and_parse_header (GstPreset * preset, const gchar * preset_path,
247 guint64 * preset_version)
250 GError *error = NULL;
252 const gchar *element_name;
255 in = g_key_file_new ();
257 res = g_key_file_load_from_file (in, preset_path,
258 G_KEY_FILE_KEEP_COMMENTS | G_KEY_FILE_KEEP_TRANSLATIONS, &error);
259 if (!res || error != NULL)
262 /* element type name and preset name must match or we are dealing with a wrong
264 element_name = G_OBJECT_TYPE_NAME (preset);
266 g_key_file_get_value (in, PRESET_HEADER, PRESET_HEADER_ELEMENT_NAME,
269 if (!name || strcmp (name, element_name))
274 /* get the version now so that the caller can check it */
275 if (preset_version) {
277 g_key_file_get_value (in, PRESET_HEADER, PRESET_HEADER_VERSION, NULL);
278 *preset_version = preset_parse_version (str);
287 GST_WARNING_OBJECT (preset, "Unable to read preset file %s: %s",
288 preset_path, error->message);
289 g_error_free (error);
290 g_key_file_free (in);
295 GST_WARNING_OBJECT (preset,
296 "Wrong element name in preset file %s. Expected %s, got %s",
297 preset_path, element_name, GST_STR_NULL (name));
299 g_key_file_free (in);
305 preset_merge (GKeyFile * system, GKeyFile * user)
308 gchar **groups, **keys;
309 gsize i, j, num_groups, num_keys;
311 /* copy file comment if there is any */
312 if ((str = g_key_file_get_comment (user, NULL, NULL, NULL))) {
313 g_key_file_set_comment (system, NULL, NULL, str, NULL);
317 /* get groups in user and copy into system */
318 groups = g_key_file_get_groups (user, &num_groups);
319 for (i = 0; i < num_groups; i++) {
320 /* copy group comment if there is any */
321 if ((str = g_key_file_get_comment (user, groups[i], NULL, NULL))) {
322 g_key_file_set_comment (system, groups[i], NULL, str, NULL);
326 /* ignore private groups */
327 if (groups[i][0] == '_')
330 /* if group already exists in system, remove and re-add keys from user */
331 if (g_key_file_has_group (system, groups[i])) {
332 g_key_file_remove_group (system, groups[i], NULL);
335 keys = g_key_file_get_keys (user, groups[i], &num_keys, NULL);
336 for (j = 0; j < num_keys; j++) {
337 /* copy key comment if there is any */
338 if ((str = g_key_file_get_comment (user, groups[i], keys[j], NULL))) {
339 g_key_file_set_comment (system, groups[i], keys[j], str, NULL);
342 str = g_key_file_get_value (user, groups[i], keys[j], NULL);
343 g_key_file_set_value (system, groups[i], keys[j], str);
351 /* reads the user and system presets files and merges them together. This
352 * function caches the GKeyFile on the element type. If there is no existing
353 * preset file, a new in-memory GKeyFile will be created. */
355 preset_get_keyfile (GstPreset * preset)
358 GType type = G_TYPE_FROM_INSTANCE (preset);
360 /* first see if the have a cached version for the type */
361 if (!(presets = g_type_get_qdata (type, preset_quark))) {
362 const gchar *preset_user_path, *preset_app_path, *preset_system_path;
363 guint64 version_system = G_GUINT64_CONSTANT (0);
364 guint64 version_app = G_GUINT64_CONSTANT (0);
365 guint64 version_user = G_GUINT64_CONSTANT (0);
366 guint64 version = G_GUINT64_CONSTANT (0);
367 gboolean merged = FALSE;
368 GKeyFile *in_user, *in_app = NULL, *in_system;
370 preset_get_paths (preset, &preset_user_path, &preset_app_path,
371 &preset_system_path);
373 /* try to load the user, app and system presets, we do this to get the
374 * versions of all files. */
375 in_user = preset_open_and_parse_header (preset, preset_user_path,
377 if (preset_app_path) {
378 in_app = preset_open_and_parse_header (preset, preset_app_path,
381 in_system = preset_open_and_parse_header (preset, preset_system_path,
384 /* compare version to check for merge */
387 version = version_system;
390 /* if system version is higher, merge */
391 if (version > version_app) {
392 preset_merge (presets, in_app);
393 g_key_file_free (in_app);
396 g_key_file_free (presets);
398 version = version_system;
402 /* if system or app version is higher, merge */
403 if (version > version_user) {
404 preset_merge (presets, in_user);
405 g_key_file_free (in_user);
409 g_key_file_free (presets);
415 /* we did not load a user, app or system presets file, create a new one */
416 presets = g_key_file_new ();
417 g_key_file_set_string (presets, PRESET_HEADER, PRESET_HEADER_ELEMENT_NAME,
418 G_OBJECT_TYPE_NAME (preset));
421 /* attach the preset to the type */
422 g_type_set_qdata (type, preset_quark, (gpointer) presets);
425 gst_preset_default_save_presets_file (preset);
431 /* get a list of all supported preset names for an element */
433 gst_preset_default_get_preset_names (GstPreset * preset)
439 /* get the presets from the type */
440 if (!(presets = preset_get_keyfile (preset)))
443 /* get the groups, which are also the preset names */
444 if (!(groups = g_key_file_get_groups (presets, &num_groups)))
447 /* remove all private group names starting with '_' from the array */
448 for (i = 0; i < num_groups; i++) {
449 if (groups[i][0] == '_') {
450 /* free private group */
452 /* move last element of list down */
454 /* move last element into removed element */
455 groups[i] = groups[num_groups];
456 groups[num_groups] = NULL;
459 /* sort the array now */
460 g_qsort_with_data (groups, num_groups, sizeof (gchar *),
461 (GCompareDataFunc) strcmp, NULL);
468 GST_WARNING_OBJECT (preset, "Could not load presets");
473 GST_WARNING_OBJECT (preset, "Could not find preset groups");
478 /* get a list of all property names that are used for presets */
480 gst_preset_default_get_property_names (GstPreset * preset)
483 guint i, j = 0, n_props;
484 GObjectClass *gclass;
485 gboolean is_child_proxy;
486 gchar **result = NULL;
488 gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
489 is_child_proxy = GST_IS_CHILD_PROXY (preset);
491 /* get a list of object properties */
492 props = g_object_class_list_properties (gclass, &n_props);
494 /* allocate array big enough to hold the worst case, including a terminating
496 result = g_new (gchar *, n_props + 1);
498 /* now filter out the properties that we can use for presets */
499 GST_DEBUG_OBJECT (preset, " filtering properties: %u", n_props);
500 for (i = 0; i < n_props; i++) {
501 if (preset_skip_property (props[i]))
503 GST_DEBUG_OBJECT (preset, " using: %s", props[i]->name);
504 result[j++] = g_strdup (props[i]->name);
509 if (is_child_proxy) {
513 n_children = gst_child_proxy_get_children_count ((GstChildProxy *) preset);
514 for (c = 0; c < n_children; c++) {
515 child = gst_child_proxy_get_child_by_index ((GstChildProxy *) preset, c);
516 gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (child));
518 props = g_object_class_list_properties (gclass, &n_props);
520 /* resize property name array */
521 result = g_renew (gchar *, result, j + n_props + 1);
523 /* now filter out the properties that we can use for presets */
524 GST_DEBUG_OBJECT (preset, " filtering properties: %u", n_props);
525 for (i = 0; i < n_props; i++) {
526 if (preset_skip_property (props[i]))
528 GST_DEBUG_OBJECT (preset, " using: %s::%s",
529 GST_OBJECT_NAME (child), props[i]->name);
530 result[j++] = g_strdup_printf ("%s::%s", GST_OBJECT_NAME (child),
536 g_object_unref (child);
540 GST_INFO_OBJECT (preset, "object has no properties");
547 /* load the presets of @name for the instance @preset. Returns %FALSE if something
550 gst_preset_default_load_preset (GstPreset * preset, const gchar * name)
555 GObjectClass *gclass;
556 gboolean is_child_proxy;
558 /* get the presets from the type */
559 if (!(presets = preset_get_keyfile (preset)))
562 /* get the preset name */
563 if (!g_key_file_has_group (presets, name))
566 GST_DEBUG_OBJECT (preset, "loading preset : '%s'", name);
568 /* get the properties that we can configure in this element */
569 if (!(props = gst_preset_get_property_names (preset)))
572 gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
573 is_child_proxy = GST_IS_CHILD_PROXY (preset);
575 /* for each of the property names, find the preset parameter and try to
576 * configure the property with its value */
577 for (i = 0; props[i]; i++) {
579 GValue gvalue = { 0, };
580 GParamSpec *property = NULL;
582 /* check if we have a settings for this element property */
583 if (!(str = g_key_file_get_value (presets, name, props[i], NULL))) {
584 /* the element has a property but the parameter is not in the keyfile */
585 GST_WARNING_OBJECT (preset, "parameter '%s' not in preset", props[i]);
589 GST_DEBUG_OBJECT (preset, "setting value '%s' for property '%s'", str,
592 if (is_child_proxy) {
593 gst_child_proxy_lookup ((GstChildProxy *) preset, props[i], NULL,
596 property = g_object_class_find_property (gclass, props[i]);
599 /* the parameter was in the keyfile, the element said it supported it but
600 * then the property was not found in the element. This should not happen. */
601 GST_WARNING_OBJECT (preset, "property '%s' not in object", props[i]);
606 /* try to deserialize the property value from the keyfile and set it as
607 * the object property */
608 g_value_init (&gvalue, property->value_type);
609 if (gst_value_deserialize (&gvalue, str)) {
610 if (is_child_proxy) {
611 gst_child_proxy_set_property ((GstChildProxy *) preset, props[i],
614 g_object_set_property ((GObject *) preset, props[i], &gvalue);
617 GST_WARNING_OBJECT (preset,
618 "deserialization of value '%s' for property '%s' failed", str,
621 g_value_unset (&gvalue);
631 GST_WARNING_OBJECT (preset, "no presets");
636 GST_WARNING_OBJECT (preset, "no preset named '%s'", name);
641 GST_INFO_OBJECT (preset, "no properties");
646 /* save the presets file. A copy of the existing presets file is stored in a
649 gst_preset_default_save_presets_file (GstPreset * preset)
652 const gchar *preset_path;
653 GError *error = NULL;
654 gchar *bak_file_name;
655 gboolean backup = TRUE;
659 preset_get_paths (preset, &preset_path, NULL, NULL);
661 /* get the presets from the type */
662 if (!(presets = preset_get_keyfile (preset)))
665 GST_DEBUG_OBJECT (preset, "saving preset file: '%s'", preset_path);
667 /* create backup if possible */
668 bak_file_name = g_strdup_printf ("%s.bak", preset_path);
669 if (g_file_test (bak_file_name, G_FILE_TEST_EXISTS)) {
670 if (g_unlink (bak_file_name)) {
672 GST_INFO_OBJECT (preset, "cannot remove old backup file : %s",
677 if (g_rename (preset_path, bak_file_name)) {
678 GST_INFO_OBJECT (preset, "cannot backup file : %s -> %s", preset_path,
682 g_free (bak_file_name);
684 /* update gstreamer version */
685 g_key_file_set_string (presets, PRESET_HEADER, PRESET_HEADER_VERSION,
688 /* get new contents, wee need this to save it */
689 if (!(data = g_key_file_to_data (presets, &data_size, &error)))
693 if (!g_file_set_contents (preset_path, data, data_size, &error))
703 GST_WARNING_OBJECT (preset,
704 "no presets, trying to unlink possibly existing preset file: '%s'",
706 g_unlink (preset_path);
711 GST_WARNING_OBJECT (preset, "can not get the keyfile contents: %s",
713 g_error_free (error);
719 GST_WARNING_OBJECT (preset, "Unable to store preset file %s: %s",
720 preset_path, error->message);
721 g_error_free (error);
727 /* save the preset with the given name */
729 gst_preset_default_save_preset (GstPreset * preset, const gchar * name)
734 GObjectClass *gclass;
735 gboolean is_child_proxy;
737 GST_INFO_OBJECT (preset, "saving new preset: %s", name);
739 /* get the presets from the type */
740 if (!(presets = preset_get_keyfile (preset)))
743 /* take copies of current gobject properties from preset */
744 if (!(props = gst_preset_get_property_names (preset)))
747 gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
748 is_child_proxy = GST_IS_CHILD_PROXY (preset);
750 /* loop over the object properties and store the property value in the
752 for (i = 0; props[i]; i++) {
753 GValue gvalue = { 0, };
755 GParamSpec *property = NULL;
757 if (is_child_proxy) {
758 gst_child_proxy_lookup ((GstChildProxy *) preset, props[i], NULL,
761 property = g_object_class_find_property (gclass, props[i]);
764 /* the element said it supported the property but then it does not have
765 * that property. This should not happen. */
766 GST_WARNING_OBJECT (preset, "property '%s' not in object", props[i]);
770 g_value_init (&gvalue, property->value_type);
771 if (is_child_proxy) {
772 gst_child_proxy_get_property ((GstChildProxy *) preset, props[i],
775 g_object_get_property ((GObject *) preset, props[i], &gvalue);
778 if ((str = gst_value_serialize (&gvalue))) {
779 g_key_file_set_string (presets, name, props[i], (gpointer) str);
782 GST_WARNING_OBJECT (preset, "serialization for property '%s' failed",
785 g_value_unset (&gvalue);
787 GST_INFO_OBJECT (preset, " saved");
790 /* save updated version */
791 return gst_preset_default_save_presets_file (preset);
796 GST_WARNING_OBJECT (preset, "no presets");
801 GST_INFO_OBJECT (preset, "no properties");
806 /* copies all keys and comments from one group to another, deleting the old
809 gst_preset_default_rename_preset (GstPreset * preset, const gchar * old_name,
810 const gchar * new_name)
817 /* get the presets from the type */
818 if (!(presets = preset_get_keyfile (preset)))
821 if (!g_key_file_has_group (presets, old_name))
824 /* copy group comment if there is any */
825 if ((str = g_key_file_get_comment (presets, old_name, NULL, NULL))) {
826 g_key_file_set_comment (presets, new_name, NULL, str, NULL);
830 /* get all keys from the old group and copy them in the new group */
831 keys = g_key_file_get_keys (presets, old_name, &num_keys, NULL);
832 for (i = 0; i < num_keys; i++) {
833 /* copy key comment if there is any */
834 if ((str = g_key_file_get_comment (presets, old_name, keys[i], NULL))) {
835 g_key_file_set_comment (presets, new_name, keys[i], str, NULL);
839 str = g_key_file_get_value (presets, old_name, keys[i], NULL);
840 g_key_file_set_value (presets, new_name, keys[i], str);
845 /* remove old group */
846 g_key_file_remove_group (presets, old_name, NULL);
848 /* save updated version */
849 return gst_preset_default_save_presets_file (preset);
854 GST_WARNING_OBJECT (preset, "no presets");
859 GST_WARNING_OBJECT (preset, "no preset named %s", old_name);
864 /* delete a group from the keyfile */
866 gst_preset_default_delete_preset (GstPreset * preset, const gchar * name)
870 /* get the presets from the type */
871 if (!(presets = preset_get_keyfile (preset)))
875 if (!g_key_file_has_group (presets, name))
878 /* remove the group */
879 g_key_file_remove_group (presets, name, NULL);
881 /* save updated version */
882 return gst_preset_default_save_presets_file (preset);
887 GST_WARNING_OBJECT (preset, "no presets");
892 GST_WARNING_OBJECT (preset, "no preset named %s", name);
898 gst_preset_default_set_meta (GstPreset * preset, const gchar * name,
899 const gchar * tag, const gchar * value)
904 /* get the presets from the type */
905 if (!(presets = preset_get_keyfile (preset)))
908 key = g_strdup_printf ("_meta/%s", tag);
909 if (value && *value) {
910 g_key_file_set_value (presets, name, key, value);
912 g_key_file_remove_key (presets, name, key, NULL);
916 /* save updated keyfile */
917 return gst_preset_default_save_presets_file (preset);
922 GST_WARNING_OBJECT (preset, "no presets");
927 /* the caller must free @value after usage */
929 gst_preset_default_get_meta (GstPreset * preset, const gchar * name,
930 const gchar * tag, gchar ** value)
935 /* get the presets from the type */
936 if (!(presets = preset_get_keyfile (preset)))
939 key = g_strdup_printf ("_meta/%s", tag);
940 *value = g_key_file_get_value (presets, name, key, NULL);
948 GST_WARNING_OBJECT (preset, "no presets");
957 * gst_preset_get_preset_names:
958 * @preset: a #GObject that implements #GstPreset
960 * Get a copy of preset names as a %NULL terminated string array.
962 * Returns: (transfer full) (array zero-terminated=1) (element-type gchar*):
963 * list with names, use g_strfreev() after usage.
966 gst_preset_get_preset_names (GstPreset * preset)
968 g_return_val_if_fail (GST_IS_PRESET (preset), NULL);
970 return (GST_PRESET_GET_INTERFACE (preset)->get_preset_names (preset));
974 * gst_preset_get_property_names:
975 * @preset: a #GObject that implements #GstPreset
977 * Get a the names of the GObject properties that can be used for presets.
979 * Returns: (transfer full) (array zero-terminated=1) (element-type gchar*): an
980 * array of property names which should be freed with g_strfreev() after use.
983 gst_preset_get_property_names (GstPreset * preset)
985 g_return_val_if_fail (GST_IS_PRESET (preset), NULL);
987 return (GST_PRESET_GET_INTERFACE (preset)->get_property_names (preset));
991 * gst_preset_load_preset:
992 * @preset: a #GObject that implements #GstPreset
993 * @name: preset name to load
995 * Load the given preset.
997 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
1000 gst_preset_load_preset (GstPreset * preset, const gchar * name)
1002 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1003 g_return_val_if_fail (name, FALSE);
1005 return (GST_PRESET_GET_INTERFACE (preset)->load_preset (preset, name));
1009 * gst_preset_save_preset:
1010 * @preset: a #GObject that implements #GstPreset
1011 * @name: preset name to save
1013 * Save the current object settings as a preset under the given name. If there
1014 * is already a preset by this @name it will be overwritten.
1016 * Returns: %TRUE for success, %FALSE
1019 gst_preset_save_preset (GstPreset * preset, const gchar * name)
1021 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1022 g_return_val_if_fail (name, FALSE);
1024 return (GST_PRESET_GET_INTERFACE (preset)->save_preset (preset, name));
1028 * gst_preset_rename_preset:
1029 * @preset: a #GObject that implements #GstPreset
1030 * @old_name: current preset name
1031 * @new_name: new preset name
1033 * Renames a preset. If there is already a preset by the @new_name it will be
1036 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with @old_name
1039 gst_preset_rename_preset (GstPreset * preset, const gchar * old_name,
1040 const gchar * new_name)
1042 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1043 g_return_val_if_fail (old_name, FALSE);
1044 g_return_val_if_fail (new_name, FALSE);
1046 return (GST_PRESET_GET_INTERFACE (preset)->rename_preset (preset, old_name,
1051 * gst_preset_delete_preset:
1052 * @preset: a #GObject that implements #GstPreset
1053 * @name: preset name to remove
1055 * Delete the given preset.
1057 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
1060 gst_preset_delete_preset (GstPreset * preset, const gchar * name)
1062 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1063 g_return_val_if_fail (name, FALSE);
1065 return (GST_PRESET_GET_INTERFACE (preset)->delete_preset (preset, name));
1069 * gst_preset_set_meta:
1070 * @preset: a #GObject that implements #GstPreset
1071 * @name: preset name
1072 * @tag: meta data item name
1073 * @value: (allow-none): new value
1075 * Sets a new @value for an existing meta data item or adds a new item. Meta
1076 * data @tag names can be something like e.g. "comment". Supplying %NULL for the
1077 * @value will unset an existing value.
1079 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
1082 gst_preset_set_meta (GstPreset * preset, const gchar * name, const gchar * tag,
1083 const gchar * value)
1085 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1086 g_return_val_if_fail (name, FALSE);
1087 g_return_val_if_fail (tag, FALSE);
1089 return GST_PRESET_GET_INTERFACE (preset)->set_meta (preset, name, tag, value);
1093 * gst_preset_get_meta:
1094 * @preset: a #GObject that implements #GstPreset
1095 * @name: preset name
1096 * @tag: meta data item name
1097 * @value: (out callee-allocates): value
1099 * Gets the @value for an existing meta data @tag. Meta data @tag names can be
1100 * something like e.g. "comment". Returned values need to be released when done.
1102 * Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
1103 * or no value for the given @tag
1106 gst_preset_get_meta (GstPreset * preset, const gchar * name, const gchar * tag,
1109 g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
1110 g_return_val_if_fail (name, FALSE);
1111 g_return_val_if_fail (tag, FALSE);
1112 g_return_val_if_fail (value, FALSE);
1114 return GST_PRESET_GET_INTERFACE (preset)->get_meta (preset, name, tag, value);
1118 * gst_preset_set_app_dir:
1119 * @app_dir: the application specific preset dir
1121 * Sets an extra directory as an absolute path that should be considered when
1122 * looking for presets. Any presets in the application dir will shadow the
1125 * Returns: %TRUE for success, %FALSE if the dir already has been set
1128 gst_preset_set_app_dir (const gchar * app_dir)
1130 g_return_val_if_fail (app_dir, FALSE);
1132 if (!preset_app_dir) {
1133 preset_app_dir = g_strdup (app_dir);
1140 * gst_preset_get_app_dir:
1142 * Gets the directory for application specific presets if set by the
1145 * Returns: (nullable): the directory or %NULL, don't free or modify
1149 gst_preset_get_app_dir (void)
1151 return preset_app_dir;
1155 * gst_preset_is_editable:
1156 * @preset: a #GObject that implements #GstPreset
1158 * Check if one can add new presets, change existing ones and remove presets.
1160 * Returns: %TRUE if presets are editable or %FALSE if they are static
1165 gst_preset_is_editable (GstPreset * preset)
1167 GstPresetInterface *iface = GST_PRESET_GET_INTERFACE (preset);
1169 return iface->save_preset && iface->delete_preset;
1172 /* class internals */
1175 gst_preset_class_init (GstPresetInterface * iface)
1177 iface->get_preset_names = gst_preset_default_get_preset_names;
1178 iface->get_property_names = gst_preset_default_get_property_names;
1180 iface->load_preset = gst_preset_default_load_preset;
1181 iface->save_preset = gst_preset_default_save_preset;
1182 iface->rename_preset = gst_preset_default_rename_preset;
1183 iface->delete_preset = gst_preset_default_delete_preset;
1185 iface->set_meta = gst_preset_default_set_meta;
1186 iface->get_meta = gst_preset_default_get_meta;
1190 gst_preset_base_init (gpointer g_class)
1192 static gboolean initialized = FALSE;
1195 /* init default implementation */
1196 GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "preset",
1197 GST_DEBUG_FG_WHITE | GST_DEBUG_BG_BLACK, "preset interface");
1199 /* create quarks for use with g_type_{g,s}et_qdata() */
1200 preset_quark = g_quark_from_static_string ("GstPreset::presets");
1201 preset_user_path_quark =
1202 g_quark_from_static_string ("GstPreset::user_path");
1203 preset_app_path_quark = g_quark_from_static_string ("GstPreset::app_path");
1204 preset_system_path_quark =
1205 g_quark_from_static_string ("GstPreset::system_path");
1208 /* create interface properties, each element would need to override this
1209 * g_object_class_override_property(gobject_class, PROP_PRESET_NAME, "preset-name");
1210 * and in _set_property() do
1211 * case PROP_PRESET_NAME: {
1212 * gchar *name = g_value_get_string (value);
1214 * gst_preset_load_preset(preset, name);
1217 g_object_interface_install_property (g_class,
1218 g_param_spec_string ("preset-name",
1219 "preset-name property",
1220 "load given preset", NULL, G_PARAM_WRITABLE));
1228 gst_preset_get_type (void)
1230 static volatile gsize type = 0;
1232 if (g_once_init_enter (&type)) {
1234 const GTypeInfo info = {
1235 sizeof (GstPresetInterface),
1236 (GBaseInitFunc) gst_preset_base_init, /* base_init */
1237 NULL, /* base_finalize */
1238 (GClassInitFunc) gst_preset_class_init, /* class_init */
1239 NULL, /* class_finalize */
1240 NULL, /* class_data */
1242 0, /* n_preallocs */
1243 NULL /* instance_init */
1245 _type = g_type_register_static (G_TYPE_INTERFACE, "GstPreset", &info, 0);
1246 g_once_init_leave (&type, _type);