gstreamer/gst/gstpreset.c
2009-10-15 12:16:05 +03:00

1117 lines
32 KiB
C

/* GStreamer
* Copyright (C) 2006 Stefan Kost <ensonic@users.sf.net>
*
* gstpreset.c: helper interface for element presets
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstpreset
* @short_description: helper interface for element presets
*
* This interface offers methods to query and manipulate parameter preset sets.
* A preset is a bunch of property settings, together with meta data and a name.
* The name of a preset serves as key for subsequent method calls to manipulate
* single presets.
* All instances of one type will share the list of presets. The list is created
* on demand, if presets are not used, the list is not created.
*
* The interface comes with a default implementation that serves most plugins.
* Wrapper plugins will override most methods to implement support for the
* native preset format of those wrapped plugins.
* One method that is useful to be overridden is gst_preset_get_property_names().
* With that one can control which properties are saved and in which order.
*/
/* FIXME:
* - non racyness
* - we need to avoid two instances writing the preset file
* -> flock(fileno()), http://www.ecst.csuchico.edu/~beej/guide/ipc/flock.html
* -> open exclusive
* -> better save the new file to a tempfile and then rename?
* - we like to know when any other instance makes changes to the keyfile
* - then ui can be updated
* - and we make sure that we don't lose edits
* -> its the same problem actually, once for inside a process, once system-
* wide
* - can we use a lock inside a names shared memory segment?
*
* - need to add support for GstChildProxy
* we can do this in a next iteration, the format is flexible enough
* http://www.buzztard.org/index.php/Preset_handling_interface
*
* - should there be a 'preset-list' property to get the preset list
* (and to connect a notify:: to to listen for changes)
* we could use gnome_vfs_monitor_add() to monitor the user preset_file.
*
* - should there be a 'preset-name' property so that we can set a preset via
* gst-launch, or should we handle this with special syntax in gst-launch:
* gst-launch element preset:<preset-name> property=value ...
* - this would alloow to hanve preset-bundles too (a preset on bins that
* specifies presets for children
*
* - GstChildProxy suport
* - if we stick with GParamSpec **_list_properties()
* we need to use g_param_spec_set_qdata() to specify the instance on each GParamSpec
* OBJECT_LOCK(obj); // ChildProxy needs GstIterator support
* num=gst_child_proxy_get_children_count(obj);
* for(i=0;i<num;i++) {
* child=gst_child_proxy_get_child_by_index(obj,i);
* // v1 ----
* g_object_class_list_properties(child,&num);
* // foreach prop
* // g_param_spec_set_qdata(prop, quark, (gpointer)child);
* // add to result
* // v2 ----
* // children have to implement preset-iface too tag the returned GParamSpec* with the owner
* props=gst_preset_list_properties(child);
* // add props to result
* }
* OBJECT_UNLOCK(obj);
*
*/
#include "gst_private.h"
#include "gstpreset.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <glib/gstdio.h>
#define GST_CAT_DEFAULT preset_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
/* defines for keyfile usage, this group contains the element type name and
* version these presets belong to. */
#define PRESET_HEADER "_presets_"
/* keys of the preset header section */
#define PRESET_HEADER_ELEMENT_NAME "element-name"
#define PRESET_HEADER_VERSION "version"
static GQuark preset_user_path_quark = 0;
static GQuark preset_system_path_quark = 0;
static GQuark preset_quark = 0;
/*static GQuark property_list_quark = 0;*/
/* default iface implementation */
static gboolean gst_preset_default_save_presets_file (GstPreset * preset);
/*
* preset_get_paths:
* @preset: a #GObject that implements #GstPreset
* @preset_user_path: location for path or %NULL
* @preset_system_path: location for path or %NULL
*
* Fetch the preset_path for user local and system wide settings. Don't free
* after use.
*
* Returns: %FALSE if no paths could be found.
*/
static gboolean
preset_get_paths (GstPreset * preset, const gchar ** preset_user_path,
const gchar ** preset_system_path)
{
GType type = G_TYPE_FROM_INSTANCE (preset);
gchar *preset_path;
const gchar *element_name;
/* we use the element name when we must contruct the paths */
element_name = G_OBJECT_TYPE_NAME (preset);
GST_INFO_OBJECT (preset, "element_name: '%s'", element_name);
if (preset_user_path) {
/* preset user path requested, see if we have it cached in the qdata */
if (!(preset_path = g_type_get_qdata (type, preset_user_path_quark))) {
gchar *preset_dir;
/* user presets go in '$HOME/.gstreamer-0.10/presets/GstSimSyn.prs' */
preset_dir = g_build_filename (g_get_home_dir (),
".gstreamer-" GST_MAJORMINOR, "presets", NULL);
GST_INFO_OBJECT (preset, "user_preset_dir: '%s'", preset_dir);
preset_path =
g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s.prs", preset_dir,
element_name);
GST_INFO_OBJECT (preset, "user_preset_path: '%s'", preset_path);
/* create dirs */
g_mkdir_with_parents (preset_dir, 0755);
g_free (preset_dir);
/* cache the preset path to the type */
g_type_set_qdata (type, preset_user_path_quark, preset_path);
}
*preset_user_path = preset_path;
}
if (preset_system_path) {
/* preset system path requested, see if we have it cached in the qdata */
if (!(preset_path = g_type_get_qdata (type, preset_system_path_quark))) {
gchar *preset_dir;
/* system presets in '$GST_DATADIR/gstreamer-0.10/presets/GstAudioPanorama.prs' */
preset_dir = g_build_filename (GST_DATADIR, "gstreamer-" GST_MAJORMINOR,
"presets", NULL);
GST_INFO_OBJECT (preset, "system_preset_dir: '%s'", preset_dir);
preset_path = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s.prs",
preset_dir, element_name);
GST_INFO_OBJECT (preset, "system_preset_path: '%s'", preset_path);
/* create dirs */
g_mkdir_with_parents (preset_dir, 0755);
g_free (preset_dir);
/* cache the preset path to the type */
g_type_set_qdata (type, preset_system_path_quark, preset_path);
}
*preset_system_path = preset_path;
}
return TRUE;
}
static gboolean
preset_skip_property (GParamSpec * property)
{
if (((property->flags & G_PARAM_READWRITE) != G_PARAM_READWRITE) ||
(property->flags & G_PARAM_CONSTRUCT_ONLY))
return TRUE;
/* FIXME: skip GST_PARAM_NOT_PRESETABLE, see #522205 */
return FALSE;
}
/* caller must free @preset_version after use */
static GKeyFile *
preset_open_and_parse_header (GstPreset * preset, const gchar * preset_path,
gchar ** preset_version)
{
GKeyFile *in;
GError *error = NULL;
gboolean res;
const gchar *element_name;
gchar *name;
in = g_key_file_new ();
res = g_key_file_load_from_file (in, preset_path,
G_KEY_FILE_KEEP_COMMENTS | G_KEY_FILE_KEEP_TRANSLATIONS, &error);
if (!res || error != NULL)
goto load_error;
/* element type name and preset name must match or we are dealing with a wrong
* preset file */
element_name = G_OBJECT_TYPE_NAME (preset);
name =
g_key_file_get_value (in, PRESET_HEADER, PRESET_HEADER_ELEMENT_NAME,
NULL);
if (!name || strcmp (name, element_name))
goto wrong_name;
g_free (name);
/* get the version now so that the caller can check it */
if (preset_version)
*preset_version =
g_key_file_get_value (in, PRESET_HEADER, PRESET_HEADER_VERSION, NULL);
return in;
/* ERRORS */
load_error:
{
GST_WARNING_OBJECT (preset, "Unable to read preset file %s: %s",
preset_path, error->message);
g_error_free (error);
g_key_file_free (in);
return NULL;
}
wrong_name:
{
GST_WARNING_OBJECT (preset,
"Wrong element name in preset file %s. Expected %s, got %s",
preset_path, element_name, GST_STR_NULL (name));
g_free (name);
g_key_file_free (in);
return NULL;
}
}
static guint64
preset_parse_version (const gchar * str_version)
{
gint major, minor, micro, nano, num;
major = minor = micro = nano = 0;
/* parse version (e.g. 0.10.15.1) to guint64 */
num = sscanf (str_version, "%d.%d.%d.%d", &major, &minor, &micro, &nano);
/* make sure we have atleast "major.minor" */
if (num > 1) {
guint64 version;
version = ((((major << 8 | minor) << 8) | micro) << 8) | nano;
GST_DEBUG ("version %s -> %" G_GUINT64_FORMAT, str_version, version);
return version;
}
return G_GUINT64_CONSTANT (0);
}
static void
preset_merge (GKeyFile * system, GKeyFile * user)
{
gchar *str;
gchar **groups, **keys;
gsize i, j, num_groups, num_keys;
/* copy file comment if there is any */
if ((str = g_key_file_get_comment (user, NULL, NULL, NULL))) {
g_key_file_set_comment (system, NULL, NULL, str, NULL);
g_free (str);
}
/* get groups in user and copy into system */
groups = g_key_file_get_groups (user, &num_groups);
for (i = 0; i < num_groups; i++) {
/* copy group comment if there is any */
if ((str = g_key_file_get_comment (user, groups[i], NULL, NULL))) {
g_key_file_set_comment (system, groups[i], NULL, str, NULL);
g_free (str);
}
/* ignore private groups */
if (groups[i][0] == '_')
continue;
/* if group already exists in system, remove and re-add keys from user */
if (g_key_file_has_group (system, groups[i])) {
g_key_file_remove_group (system, groups[i], NULL);
}
keys = g_key_file_get_keys (user, groups[i], &num_keys, NULL);
for (j = 0; j < num_keys; j++) {
/* copy key comment if there is any */
if ((str = g_key_file_get_comment (user, groups[i], keys[j], NULL))) {
g_key_file_set_comment (system, groups[i], keys[j], str, NULL);
g_free (str);
}
str = g_key_file_get_value (user, groups[i], keys[j], NULL);
g_key_file_set_value (system, groups[i], keys[j], str);
g_free (str);
}
g_strfreev (keys);
}
g_strfreev (groups);
}
/* reads the user and system presets files and merges them together. This
* function caches the GKeyFile on the element type. If there is no existing
* preset file, a new in-memory GKeyFile will be created. */
static GKeyFile *
preset_get_keyfile (GstPreset * preset)
{
GKeyFile *presets;
GType type = G_TYPE_FROM_INSTANCE (preset);
/* first see if the have a cached version for the type */
if (!(presets = g_type_get_qdata (type, preset_quark))) {
const gchar *preset_user_path, *preset_system_path;
gchar *str_version_user = NULL, *str_version_system = NULL;
gboolean updated_from_system = FALSE;
GKeyFile *in_user, *in_system;
preset_get_paths (preset, &preset_user_path, &preset_system_path);
/* try to load the user and system presets, we do this to get the versions
* of both files. */
in_user = preset_open_and_parse_header (preset, preset_user_path,
&str_version_user);
in_system = preset_open_and_parse_header (preset, preset_system_path,
&str_version_system);
/* compare version to check for merge */
if (in_system) {
/* keep system presets if there is no user preset or when the system
* version is higher than the user version. */
if (!in_user) {
presets = in_system;
} else if (preset_parse_version (str_version_system) >
preset_parse_version (str_version_user)) {
presets = in_system;
updated_from_system = TRUE;
}
}
if (in_user) {
if (updated_from_system) {
/* merge user on top of system presets */
preset_merge (presets, in_user);
g_key_file_free (in_user);
} else {
/* keep user presets */
presets = in_user;
}
}
if (!in_user && !in_system) {
/* we did not load a user or system presets file, create a new one */
presets = g_key_file_new ();
g_key_file_set_string (presets, PRESET_HEADER, PRESET_HEADER_ELEMENT_NAME,
G_OBJECT_TYPE_NAME (preset));
}
g_free (str_version_user);
g_free (str_version_system);
/* attach the preset to the type */
g_type_set_qdata (type, preset_quark, (gpointer) presets);
if (updated_from_system) {
gst_preset_default_save_presets_file (preset);
}
}
return presets;
}
/* get a list of all supported preset names for an element */
static gchar **
gst_preset_default_get_preset_names (GstPreset * preset)
{
GKeyFile *presets;
gsize i, num_groups;
gchar **groups;
/* get the presets from the type */
if (!(presets = preset_get_keyfile (preset)))
goto no_presets;
/* get the groups, which are also the preset names */
if (!(groups = g_key_file_get_groups (presets, &num_groups)))
goto no_groups;
/* remove all private group names starting with '_' from the array */
for (i = 0; i < num_groups; i++) {
if (groups[i][0] == '_') {
/* free private group */
g_free (groups[i]);
/* move last element of list down */
num_groups--;
/* move last element into removed element */
groups[i] = groups[num_groups];
groups[num_groups] = NULL;
}
}
/* sort the array now */
g_qsort_with_data (groups, num_groups, sizeof (gchar *),
(GCompareDataFunc) strcmp, NULL);
return groups;
/* ERRORS */
no_presets:
{
GST_WARNING_OBJECT (preset, "Could not load presets");
return NULL;
}
no_groups:
{
GST_WARNING_OBJECT (preset, "Could not find preset groups");
return NULL;
}
}
/* get a list of all property names that are used for presets */
static gchar **
gst_preset_default_get_property_names (GstPreset * preset)
{
GParamSpec **props;
guint i, j, n_props;
GObjectClass *gclass;
gchar **result;
gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
/* get a list of normal properties.
* FIXME, change this for childproxy support. */
props = g_object_class_list_properties (gclass, &n_props);
if (!props)
goto no_properties;
/* allocate array big enough to hold the worst case, including a terminating
* NULL pointer. */
result = g_new (gchar *, n_props + 1);
/* now filter out the properties that we can use for presets */
GST_DEBUG_OBJECT (preset, " filtering properties: %u", n_props);
for (i = j = 0; i < n_props; i++) {
if (preset_skip_property (props[i]))
continue;
/* copy and increment out pointer */
result[j++] = g_strdup (props[i]->name);
}
result[j] = NULL;
g_free (props);
return result;
/* ERRORS */
no_properties:
{
GST_INFO_OBJECT (preset, "object has no properties");
return NULL;
}
}
/* load the presets of @name for the instance @preset. Returns %FALSE if something
* failed. */
static gboolean
gst_preset_default_load_preset (GstPreset * preset, const gchar * name)
{
GKeyFile *presets;
gchar **props;
guint i;
GObjectClass *gclass;
/* get the presets from the type */
if (!(presets = preset_get_keyfile (preset)))
goto no_presets;
/* get the preset name */
if (!g_key_file_has_group (presets, name))
goto no_group;
GST_DEBUG_OBJECT (preset, "loading preset : '%s'", name);
/* get the properties that we can configure in this element */
if (!(props = gst_preset_get_property_names (preset)))
goto no_properties;
gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
/* for each of the property names, find the preset parameter and try to
* configure the property with its value */
for (i = 0; props[i]; i++) {
gchar *str;
GValue gvalue = { 0, };
GParamSpec *property;
/* check if we have a settings for this element property */
if (!(str = g_key_file_get_value (presets, name, props[i], NULL))) {
/* the element has a property but the parameter is not in the keyfile */
GST_WARNING_OBJECT (preset, "parameter '%s' not in preset", props[i]);
continue;
}
GST_DEBUG_OBJECT (preset, "setting value '%s' for property '%s'", str,
props[i]);
/* FIXME, change for childproxy to get the property and element. */
if (!(property = g_object_class_find_property (gclass, props[i]))) {
/* the parameter was in the keyfile, the element said it supported it but
* then the property was not found in the element. This should not happen. */
GST_WARNING_OBJECT (preset, "property '%s' not in object", props[i]);
g_free (str);
continue;
}
/* try to deserialize the property value from the keyfile and set it as
* the object property */
g_value_init (&gvalue, property->value_type);
if (gst_value_deserialize (&gvalue, str)) {
/* FIXME, change for childproxy support */
g_object_set_property (G_OBJECT (preset), props[i], &gvalue);
} else {
GST_WARNING_OBJECT (preset,
"deserialization of value '%s' for property '%s' failed", str,
props[i]);
}
g_value_unset (&gvalue);
g_free (str);
}
g_strfreev (props);
return TRUE;
/* ERRORS */
no_presets:
{
GST_WARNING_OBJECT (preset, "no presets");
return FALSE;
}
no_group:
{
GST_WARNING_OBJECT (preset, "no preset named '%s'", name);
return FALSE;
}
no_properties:
{
GST_INFO_OBJECT (preset, "no properties");
return FALSE;
}
}
/* save the presets file. A copy of the existing presets file is stored in a
* .bak file */
static gboolean
gst_preset_default_save_presets_file (GstPreset * preset)
{
GKeyFile *presets;
const gchar *preset_path;
GError *error = NULL;
gchar *bak_file_name;
gboolean backup = TRUE;
gchar *data;
gsize data_size;
preset_get_paths (preset, &preset_path, NULL);
/* get the presets from the type */
if (!(presets = preset_get_keyfile (preset)))
goto no_presets;
GST_DEBUG_OBJECT (preset, "saving preset file: '%s'", preset_path);
/* create backup if possible */
bak_file_name = g_strdup_printf ("%s.bak", preset_path);
if (g_file_test (bak_file_name, G_FILE_TEST_EXISTS)) {
if (g_unlink (bak_file_name)) {
backup = FALSE;
GST_INFO_OBJECT (preset, "cannot remove old backup file : %s",
bak_file_name);
}
}
if (backup) {
if (g_rename (preset_path, bak_file_name)) {
GST_INFO_OBJECT (preset, "cannot backup file : %s -> %s", preset_path,
bak_file_name);
}
}
g_free (bak_file_name);
/* update gstreamer version */
g_key_file_set_string (presets, PRESET_HEADER, PRESET_HEADER_VERSION,
PACKAGE_VERSION);
/* get new contents, wee need this to save it */
if (!(data = g_key_file_to_data (presets, &data_size, &error)))
goto convert_failed;
/* write presets */
if (!g_file_set_contents (preset_path, data, data_size, &error))
goto write_failed;
g_free (data);
return TRUE;
/* ERRORS */
no_presets:
{
GST_WARNING_OBJECT (preset,
"no presets, trying to unlink possibly existing preset file: '%s'",
preset_path);
g_unlink (preset_path);
return FALSE;
}
convert_failed:
{
GST_WARNING_OBJECT (preset, "can not get the keyfile contents: %s",
error->message);
g_error_free (error);
g_free (data);
return FALSE;
}
write_failed:
{
GST_WARNING_OBJECT (preset, "Unable to store preset file %s: %s",
preset_path, error->message);
g_error_free (error);
g_free (data);
return FALSE;
}
}
/* save the preset with the given name */
static gboolean
gst_preset_default_save_preset (GstPreset * preset, const gchar * name)
{
GKeyFile *presets;
gchar **props;
guint i;
GObjectClass *gclass;
GST_INFO_OBJECT (preset, "saving new preset: %s", name);
/* get the presets from the type */
if (!(presets = preset_get_keyfile (preset)))
goto no_presets;
/* take copies of current gobject properties from preset */
if (!(props = gst_preset_get_property_names (preset)))
goto no_properties;
gclass = G_OBJECT_CLASS (GST_ELEMENT_GET_CLASS (preset));
/* loop over the object properties and store the property value in the
* keyfile */
for (i = 0; props[i]; i++) {
GValue gvalue = { 0, };
gchar *str;
GParamSpec *property;
/* FIXME, change for childproxy to get the property and element. */
if (!(property = g_object_class_find_property (gclass, props[i]))) {
/* the element said it supported the property but then it does not have
* that property. This should not happen. */
GST_WARNING_OBJECT (preset, "property '%s' not in object", props[i]);
continue;
}
g_value_init (&gvalue, property->value_type);
/* FIXME, change for childproxy */
g_object_get_property (G_OBJECT (preset), props[i], &gvalue);
if ((str = gst_value_serialize (&gvalue))) {
g_key_file_set_string (presets, name, props[i], (gpointer) str);
g_free (str);
} else {
GST_WARNING_OBJECT (preset, "serialization for property '%s' failed",
props[i]);
}
g_value_unset (&gvalue);
}
GST_INFO_OBJECT (preset, " saved");
g_strfreev (props);
/* save updated version */
return gst_preset_default_save_presets_file (preset);
/* ERRORS */
no_presets:
{
GST_WARNING_OBJECT (preset, "no presets");
return FALSE;
}
no_properties:
{
GST_INFO_OBJECT (preset, "no properties");
return FALSE;
}
}
/* copies all keys and comments from one group to another, deleting the old
* group. */
static gboolean
gst_preset_default_rename_preset (GstPreset * preset, const gchar * old_name,
const gchar * new_name)
{
GKeyFile *presets;
gchar *str;
gchar **keys;
gsize i, num_keys;
/* get the presets from the type */
if (!(presets = preset_get_keyfile (preset)))
goto no_presets;
if (!g_key_file_has_group (presets, old_name))
goto no_group;
/* copy group comment if there is any */
if ((str = g_key_file_get_comment (presets, old_name, NULL, NULL))) {
g_key_file_set_comment (presets, new_name, NULL, str, NULL);
g_free (str);
}
/* get all keys from the old group and copy them in the new group */
keys = g_key_file_get_keys (presets, old_name, &num_keys, NULL);
for (i = 0; i < num_keys; i++) {
/* copy key comment if there is any */
if ((str = g_key_file_get_comment (presets, old_name, keys[i], NULL))) {
g_key_file_set_comment (presets, new_name, keys[i], str, NULL);
g_free (str);
}
/* copy key value */
str = g_key_file_get_value (presets, old_name, keys[i], NULL);
g_key_file_set_value (presets, new_name, keys[i], str);
g_free (str);
}
g_strfreev (keys);
/* remove old group */
g_key_file_remove_group (presets, old_name, NULL);
/* save updated version */
return gst_preset_default_save_presets_file (preset);
/* ERRORS */
no_presets:
{
GST_WARNING_OBJECT (preset, "no presets");
return FALSE;
}
no_group:
{
GST_WARNING_OBJECT (preset, "no preset named %s", old_name);
return FALSE;
}
}
/* delete a group from the keyfile */
static gboolean
gst_preset_default_delete_preset (GstPreset * preset, const gchar * name)
{
GKeyFile *presets;
/* get the presets from the type */
if (!(presets = preset_get_keyfile (preset)))
goto no_presets;
/* get the group */
if (!g_key_file_has_group (presets, name))
goto no_group;
/* remove the group */
g_key_file_remove_group (presets, name, NULL);
/* save updated version */
return gst_preset_default_save_presets_file (preset);
/* ERRORS */
no_presets:
{
GST_WARNING_OBJECT (preset, "no presets");
return FALSE;
}
no_group:
{
GST_WARNING_OBJECT (preset, "no preset named %s", name);
return FALSE;
}
}
static gboolean
gst_preset_default_set_meta (GstPreset * preset, const gchar * name,
const gchar * tag, const gchar * value)
{
GKeyFile *presets;
gchar *key;
/* get the presets from the type */
if (!(presets = preset_get_keyfile (preset)))
goto no_presets;
key = g_strdup_printf ("_meta/%s", tag);
if (value && *value) {
g_key_file_set_value (presets, name, key, value);
} else {
g_key_file_remove_key (presets, name, key, NULL);
}
g_free (key);
/* save updated keyfile */
return gst_preset_default_save_presets_file (preset);
/* ERRORS */
no_presets:
{
GST_WARNING_OBJECT (preset, "no presets");
return FALSE;
}
}
/* the caller must free @value after usage */
static gboolean
gst_preset_default_get_meta (GstPreset * preset, const gchar * name,
const gchar * tag, gchar ** value)
{
GKeyFile *presets;
gchar *key;
/* get the presets from the type */
if (!(presets = preset_get_keyfile (preset)))
goto no_presets;
key = g_strdup_printf ("_meta/%s", tag);
*value = g_key_file_get_value (presets, name, key, NULL);
g_free (key);
return TRUE;
/* ERRORS */
no_presets:
{
GST_WARNING_OBJECT (preset, "no presets");
*value = NULL;
return FALSE;
}
}
/* wrapper */
/**
* gst_preset_get_preset_names:
* @preset: a #GObject that implements #GstPreset
*
* Get a copy of preset names as a NULL terminated string array.
*
* Returns: list with names, ue g_strfreev() after usage.
*
* Since: 0.10.20
*/
gchar **
gst_preset_get_preset_names (GstPreset * preset)
{
g_return_val_if_fail (GST_IS_PRESET (preset), NULL);
return (GST_PRESET_GET_INTERFACE (preset)->get_preset_names (preset));
}
/**
* gst_preset_get_property_names:
* @preset: a #GObject that implements #GstPreset
*
* Get a the names of the GObject properties that can be used for presets.
*
* Returns: an array of property names which should be freed with g_strfreev() after use.
*
* Since: 0.10.20
*/
gchar **
gst_preset_get_property_names (GstPreset * preset)
{
g_return_val_if_fail (GST_IS_PRESET (preset), NULL);
return (GST_PRESET_GET_INTERFACE (preset)->get_property_names (preset));
}
/**
* gst_preset_load_preset:
* @preset: a #GObject that implements #GstPreset
* @name: preset name to load
*
* Load the given preset.
*
* Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
*
* Since: 0.10.20
*/
gboolean
gst_preset_load_preset (GstPreset * preset, const gchar * name)
{
g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
g_return_val_if_fail (name, FALSE);
return (GST_PRESET_GET_INTERFACE (preset)->load_preset (preset, name));
}
/**
* gst_preset_save_preset:
* @preset: a #GObject that implements #GstPreset
* @name: preset name to save
*
* Save the current object settings as a preset under the given name. If there
* is already a preset by this @name it will be overwritten.
*
* Returns: %TRUE for success, %FALSE
*
* Since: 0.10.20
*/
gboolean
gst_preset_save_preset (GstPreset * preset, const gchar * name)
{
g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
g_return_val_if_fail (name, FALSE);
return (GST_PRESET_GET_INTERFACE (preset)->save_preset (preset, name));
}
/**
* gst_preset_rename_preset:
* @preset: a #GObject that implements #GstPreset
* @old_name: current preset name
* @new_name: new preset name
*
* Renames a preset. If there is already a preset by the @new_name it will be
* overwritten.
*
* Returns: %TRUE for success, %FALSE if e.g. there is no preset with @old_name
*
* Since: 0.10.20
*/
gboolean
gst_preset_rename_preset (GstPreset * preset, const gchar * old_name,
const gchar * new_name)
{
g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
g_return_val_if_fail (old_name, FALSE);
g_return_val_if_fail (new_name, FALSE);
return (GST_PRESET_GET_INTERFACE (preset)->rename_preset (preset, old_name,
new_name));
}
/**
* gst_preset_delete_preset:
* @preset: a #GObject that implements #GstPreset
* @name: preset name to remove
*
* Delete the given preset.
*
* Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
*
* Since: 0.10.20
*/
gboolean
gst_preset_delete_preset (GstPreset * preset, const gchar * name)
{
g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
g_return_val_if_fail (name, FALSE);
return (GST_PRESET_GET_INTERFACE (preset)->delete_preset (preset, name));
}
/**
* gst_preset_set_meta:
* @preset: a #GObject that implements #GstPreset
* @name: preset name
* @tag: meta data item name
* @value: new value
*
* Sets a new @value for an existing meta data item or adds a new item. Meta
* data @tag names can be something like e.g. "comment". Supplying %NULL for the
* @value will unset an existing value.
*
* Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
*
* Since: 0.10.20
*/
gboolean
gst_preset_set_meta (GstPreset * preset, const gchar * name, const gchar * tag,
const gchar * value)
{
g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
g_return_val_if_fail (name, FALSE);
g_return_val_if_fail (tag, FALSE);
return GST_PRESET_GET_INTERFACE (preset)->set_meta (preset, name, tag, value);
}
/**
* gst_preset_get_meta:
* @preset: a #GObject that implements #GstPreset
* @name: preset name
* @tag: meta data item name
* @value: value
*
* Gets the @value for an existing meta data @tag. Meta data @tag names can be
* something like e.g. "comment". Returned values need to be released when done.
*
* Returns: %TRUE for success, %FALSE if e.g. there is no preset with that @name
* or no value for the given @tag
*
* Since: 0.10.20
*/
gboolean
gst_preset_get_meta (GstPreset * preset, const gchar * name, const gchar * tag,
gchar ** value)
{
g_return_val_if_fail (GST_IS_PRESET (preset), FALSE);
g_return_val_if_fail (name, FALSE);
g_return_val_if_fail (tag, FALSE);
g_return_val_if_fail (value, FALSE);
return GST_PRESET_GET_INTERFACE (preset)->get_meta (preset, name, tag, value);
}
/* class internals */
static void
gst_preset_class_init (GstPresetInterface * iface)
{
iface->get_preset_names = gst_preset_default_get_preset_names;
iface->get_property_names = gst_preset_default_get_property_names;
iface->load_preset = gst_preset_default_load_preset;
iface->save_preset = gst_preset_default_save_preset;
iface->rename_preset = gst_preset_default_rename_preset;
iface->delete_preset = gst_preset_default_delete_preset;
iface->set_meta = gst_preset_default_set_meta;
iface->get_meta = gst_preset_default_get_meta;
}
static void
gst_preset_base_init (gpointer g_class)
{
static gboolean initialized = FALSE;
if (!initialized) {
/* init default implementation */
GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "preset",
GST_DEBUG_FG_WHITE | GST_DEBUG_BG_BLACK, "preset interface");
/* create quarks for use with g_type_{g,s}et_qdata() */
preset_quark = g_quark_from_static_string ("GstPreset::presets");
preset_user_path_quark =
g_quark_from_static_string ("GstPreset::user_path");
preset_system_path_quark =
g_quark_from_static_string ("GstPreset::system_path");
#if 0
property_list_quark = g_quark_from_static_string ("GstPreset::properties");
/* create interface properties, each element would need to override this
* g_object_class_override_property(gobject_class, PROP_PRESET_NAME, "preset-name");
* and in _set_property() do
* case PROP_PRESET_NAME: {
* gchar *name = g_value_get_string (value);
* if (name)
* gst_preset_load_preset(preset, name);
* } break;
*/
g_object_interface_install_property (g_class,
g_param_spec_string ("preset-name",
"preset-name property",
"load given preset", NULL, G_PARAM_WRITABLE));
#endif
initialized = TRUE;
}
}
GType
gst_preset_get_type (void)
{
static volatile gsize type = 0;
if (g_once_init_enter (&type)) {
GType _type;
const GTypeInfo info = {
sizeof (GstPresetInterface),
(GBaseInitFunc) gst_preset_base_init, /* base_init */
NULL, /* base_finalize */
(GClassInitFunc) gst_preset_class_init, /* class_init */
NULL, /* class_finalize */
NULL, /* class_data */
0,
0, /* n_preallocs */
NULL /* instance_init */
};
_type = g_type_register_static (G_TYPE_INTERFACE, "GstPreset", &info, 0);
g_once_init_leave (&type, _type);
}
return type;
}