modules: Add notifications-api module

This allows sending Desktop notifications using D-Bus.

modules/meson.build

@@ -58,6 +58,16 @@ shared_library(
   dependencies : [wp_dep, giounix_dep],
 )
 
+shared_library(
+  'wireplumber-module-notifications-api',
+  [
+    'module-notifications-api.c',
+  ],
+  install : true,
+  install_dir : wireplumber_module_dir,
+  dependencies : [wp_dep, giounix_dep],
+)
+
 shared_library(
   'wireplumber-module-si-audio-adapter',
   [

modules/module-notifications-api.c

@@ -0,0 +1,152 @@
+/* WirePlumber
+ *
+ * Copyright © 2021 Collabora Ltd.
+ *    @author Julian Bouzas <julian.bouzas@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <wp/wp.h>
+#include "dbus-connection-state.h"
+
+WP_DEFINE_LOCAL_LOG_TOPIC ("m-notification")
+
+#define DBUS_INTERFACE_NAME "org.freedesktop.Notifications"
+#define DBUS_OBJECT_PATH "/org/freedesktop/Notifications"
+
+enum
+{
+  ACTION_GET_DBUS,
+  ACTION_SEND,
+  LAST_SIGNAL
+};
+
+static guint signals[LAST_SIGNAL] = { 0 };
+
+struct _WpNotificationsPlugin
+{
+  WpPlugin parent;
+
+  WpPlugin *dbus;
+};
+
+G_DECLARE_FINAL_TYPE (WpNotificationsPlugin,
+    wp_notifications_plugin, WP, NOTIFICATIONS_PLUGIN,
+    WpPlugin)
+G_DEFINE_TYPE (WpNotificationsPlugin, wp_notifications_plugin,
+    WP_TYPE_PLUGIN)
+
+static gpointer
+wp_notifications_plugin_get_dbus (WpNotificationsPlugin *self)
+{
+  return self->dbus ? g_object_ref (self->dbus) : NULL;
+}
+
+static void
+wp_notifications_plugin_send (WpNotificationsPlugin *self,
+    const gchar *summary, const gchar *body_message)
+{
+  g_autoptr (GDBusConnection) conn = NULL;
+  g_autoptr (GError) error = NULL;
+  g_autoptr (GVariant) res = NULL;
+  GVariantBuilder hints;
+
+  g_object_get (self->dbus, "connection", &conn, NULL);
+  g_return_if_fail (conn);
+
+  /* Set urgency */
+  g_variant_builder_init (&hints, G_VARIANT_TYPE("a{sv}"));
+  g_variant_builder_add (&hints, "{sv}", "urgency", g_variant_new_byte (0));
+
+  /* Notify */
+  res = g_dbus_connection_call_sync (conn, DBUS_INTERFACE_NAME,
+      DBUS_OBJECT_PATH, DBUS_INTERFACE_NAME, "Notify",
+      g_variant_new("(susssasa{sv}i)", "wireplumber", 0, "", summary,
+          body_message, NULL, &hints, -1), NULL, G_DBUS_CALL_FLAGS_NONE, -1,
+          NULL, &error);
+  if (error) {
+    g_autofree gchar *remote_error = g_dbus_error_get_remote_error (error);
+    g_dbus_error_strip_remote_error (error);
+
+    wp_warning_object (self, "Notify: %s (%s)", error->message, remote_error);
+    return;
+  }
+}
+
+static void
+wp_notifications_plugin_init (WpNotificationsPlugin * self)
+{
+}
+
+static void
+wp_notifications_plugin_enable (WpPlugin * plugin,
+    WpTransition * transition)
+{
+  WpNotificationsPlugin *self = WP_NOTIFICATIONS_PLUGIN (plugin);
+  g_autoptr (WpCore) core = wp_object_get_core (WP_OBJECT (self));
+
+  self->dbus = wp_plugin_find (core, "dbus-connection");
+  if (!self->dbus) {
+    wp_transition_return_error (transition, g_error_new (WP_DOMAIN_LIBRARY,
+        WP_LIBRARY_ERROR_INVARIANT,
+        "dbus-connection module must be loaded before notifications"));
+    return;
+  }
+
+  wp_object_update_features (WP_OBJECT (self), WP_PLUGIN_FEATURE_ENABLED, 0);
+}
+
+static void
+wp_notifications_plugin_disable (WpPlugin * plugin)
+{
+  WpNotificationsPlugin *self = WP_NOTIFICATIONS_PLUGIN (plugin);
+
+  g_clear_object (&self->dbus);
+
+  wp_object_update_features (WP_OBJECT (self), 0, WP_PLUGIN_FEATURE_ENABLED);
+}
+
+static void
+wp_notifications_plugin_class_init (WpNotificationsPluginClass * klass)
+{
+  WpPluginClass *plugin_class = (WpPluginClass *) klass;
+
+  plugin_class->enable = wp_notifications_plugin_enable;
+  plugin_class->disable = wp_notifications_plugin_disable;
+
+  /**
+   * WpNotificationsPlugin::get-dbus:
+   *
+   * Returns: (transfer full): the dbus object
+   */
+  signals[ACTION_GET_DBUS] = g_signal_new_class_handler (
+      "get-dbus", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+      (GCallback) wp_notifications_plugin_get_dbus,
+      NULL, NULL, NULL,
+      G_TYPE_OBJECT, 0);
+
+  /**
+   * WpNotificationsPlugin::send:
+   *
+   * @brief
+   * @em summary: the summary
+   * @em body_message: The body message
+   */
+  signals[ACTION_SEND] = g_signal_new_class_handler (
+      "send", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+      (GCallback) wp_notifications_plugin_send,
+      NULL, NULL, NULL, G_TYPE_VARIANT,
+      2, G_TYPE_STRING, G_TYPE_STRING);
+}
+
+WP_PLUGIN_EXPORT GObject *
+wireplumber__module_init (WpCore * core, WpSpaJson * args, GError ** error)
+{
+  return G_OBJECT (g_object_new (
+      wp_notifications_plugin_get_type(),
+      "name", "notifications-api",
+      "core", core,
+      NULL));
+}

src/config/wireplumber.conf

@@ -335,6 +335,14 @@ wireplumber.components = [
     provides = api.file-monitor
   }
 
+  ## API to send D-Bus notifications
+  {
+    name = libwireplumber-module-notifications-api, type = module
+    provides = api.notifications
+    requires = [ support.dbus ]
+  }
+
+
   ## Provide the "default" pw_metadata
   {
     name = metadata.lua, type = script/lua