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/*
* Copyright (C) 2014 Michal Ratajsky <michal.ratajsky@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the licence, 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <glib.h>
#include <glib-object.h>
#include <gmodule.h>
#include "matemixer.h"
#include "matemixer-private.h"
#include "matemixer-backend-module.h"
static void mixer_load_modules (void);
static gint mixer_compare_modules (gconstpointer a, gconstpointer b);
static GList *mixer_modules = NULL;
static gboolean mixer_initialized = FALSE;
/**
* mate_mixer_init:
*
* Initializes the library. You must call this function before using any other
* function from the library.
*
* Returns: %TRUE on success, or %FALSE if the library installation is broken and
* does not provide support for any sound systems.
*/
gboolean
mate_mixer_init (void)
{
if (!mixer_initialized) {
mixer_load_modules ();
if (mixer_modules) {
GList *list;
list = mixer_modules;
while (list) {
GTypeModule *module = G_TYPE_MODULE (list->data);
GList *next = list->next;
/* Attempt to load the module and remove it from the list
* if it isn't usable */
if (!g_type_module_use (module)) {
g_object_unref (module);
mixer_modules = g_list_delete_link (mixer_modules, list);
}
list = next;
}
if (mixer_modules) {
/* Sort the usable modules by their priority */
mixer_modules = g_list_sort (mixer_modules, mixer_compare_modules);
mixer_initialized = TRUE;
} else
g_critical ("No usable backend modules have been found");
}
}
return mixer_initialized;
}
/**
* mate_mixer_deinit:
*
* Deinitializes the library. You should call this function when you do not need
* to use the library any longer or before exitting the application.
*/
void
mate_mixer_deinit (void)
{
GList *list;
if (!mixer_initialized)
return;
list = mixer_modules;
while (list) {
g_type_module_unuse (G_TYPE_MODULE (list->data));
list = list->next;
}
mixer_initialized = FALSE;
}
/* Internal function: return a list of loaded backend modules */
const GList *
mate_mixer_get_modules (void)
{
return (const GList *) mixer_modules;
}
/* Internal function: return TRUE if the library has been initialized */
gboolean
mate_mixer_is_initialized (void)
{
return mixer_initialized;
}
static void
mixer_load_modules (void)
{
static gboolean loaded = FALSE;
if (loaded)
return;
if (g_module_supported ()) {
GDir *dir;
GError *error = NULL;
/* Read the directory which contains module libraries and create a list
* of those that are likely to be usable backend modules */
dir = g_dir_open (LIBMATEMIXER_BACKEND_DIR, 0, &error);
if (dir != NULL) {
const gchar *name;
while ((name = g_dir_read_name (dir)) != NULL) {
gchar *file;
if (!g_str_has_suffix (name, "." G_MODULE_SUFFIX))
continue;
file = g_build_filename (LIBMATEMIXER_BACKEND_DIR, name, NULL);
mixer_modules = g_list_prepend (mixer_modules,
mate_mixer_backend_module_new (file));
g_free (file);
}
if (mixer_modules == NULL)
g_critical ("No backend modules have been found");
g_dir_close (dir);
} else {
g_critical ("%s", error->message);
g_error_free (error);
}
} else {
g_critical ("Unable to load backend modules: GModule is not supported in your system");
}
loaded = TRUE;
}
/* GCompareFunc function to sort backend modules by the priority, higher number means
* higher priority */
static gint
mixer_compare_modules (gconstpointer a, gconstpointer b)
{
const MateMixerBackendInfo *info1, *info2;
info1 = mate_mixer_backend_module_get_info (MATE_MIXER_BACKEND_MODULE (a));
info2 = mate_mixer_backend_module_get_info (MATE_MIXER_BACKEND_MODULE (b));
return info2->priority - info1->priority;
}
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