path: root/module-volume-change-notify.c

#include <config.h>

#include <pulsecore/module.h>
#include <pulsecore/core-subscribe.h>
#include <pulse/introspect.h>

#include <dbus/dbus.h>

PA_MODULE_AUTHOR("Alexander Sulfrian");
PA_MODULE_DESCRIPTION("Module that notify you on volume changes of sinks.");
PA_MODULE_VERSION(PACKAGE_VERSION);
PA_MODULE_USAGE("");

struct userdata {
    pa_core *core;
    pa_module *module;
    pa_subscription *subscription;

    /* dbus stuff */
    DBusError dbus_error;
    DBusConnection *dbus_connection;
};

void sink_change_event_cb(pa_core *c, pa_subscription_event_type_t t,
                          uint32_t idx, void *userdata)
{
    pa_sink *s;
    char vol[PA_CVOLUME_SNPRINT_MAX];

    if (PA_SUBSCRIPTION_EVENT_CHANGE & t == 0)
        return;

    s = pa_idxset_get_by_index(c->sinks, idx);
    if (!s)
        return;

    pa_cvolume_snprint(vol, PA_CVOLUME_SNPRINT_MAX, &s->reference_volume);
    pa_log("Volume: %s %s", s->name, vol);
}

void pa__done(pa_module *m)
{
    struct userdata *u;

    if (!(u = m->userdata))
        return;

    pa_subscription_free(u->subscription);

    if (u->dbus_connection)
        dbus_connection_close(u->dbus_connection);

    pa_xfree(u);
}

int pa__init(pa_module* m)
{
    struct userdata *u;
    pa_subscription_mask_t mask;
    int ret;

    m->userdata = u = pa_xnew0(struct userdata, 1);
    u->core = m->core;
    u->module = m;

    mask = PA_SUBSCRIPTION_EVENT_SOURCE_OUTPUT | PA_SUBSCRIPTION_EVENT_CHANGE;
    u->subscription = pa_subscription_new(m->core, mask,
                                          sink_change_event_cb, u);

    /* initialize dbus */
    dbus_error_init(&u->dbus_error);
    u->dbus_connection = dbus_bus_get(DBUS_BUS_SESSION, &u->dbus_error);
    if (dbus_error_is_set(&u->dbus_error)) {
        pa_log("DBus Connection Error (%s)\n", u->dbus_error.message);
        dbus_error_free(&u->dbus_error);
    }

    if (!u->dbus_connection)
        goto fail;

    /* request a name on the bus */
    ret = dbus_bus_request_name(u->dbus_connection,
                                "org.PulseAudio.VolumeNotification",
                                DBUS_NAME_FLAG_REPLACE_EXISTING,
                                &u->dbus_error);

    if (dbus_error_is_set(&u->dbus_error)) {
        pa_log("DBus Name Error (%s)\n", u->dbus_error.message);
        dbus_error_free(&u->dbus_error);
    }

    if (DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER != ret) {
        goto fail;
    }

    return 0;

fail:
    pa__done(m);
    return -1;
}