modules: add new module-default-nodes-api

This is to provide easy access to default nodes from the scripts

modules/module-default-nodes-api.c

@@ -0,0 +1,194 @@
+/* WirePlumber
+ *
+ * Copyright © 2021 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <wp/wp.h>
+#include <pipewire/keys.h>
+#include "module-default-nodes/common.h"
+
+struct _WpDefaultNodesApi
+{
+  WpPlugin parent;
+
+  gchar *defaults[N_DEFAULT_NODES];
+  WpObjectManager *metadatas_om;
+  WpObjectManager *nodes_om;
+  GSource *idle_source;
+};
+
+enum {
+  ACTION_GET_DEFAULT_NODE,
+  SIGNAL_CHANGED,
+  N_SIGNALS
+};
+
+static guint signals[N_SIGNALS] = {0};
+
+G_DECLARE_FINAL_TYPE (WpDefaultNodesApi, wp_default_nodes_api,
+                      WP, DEFAULT_NODES_API, WpPlugin)
+G_DEFINE_TYPE (WpDefaultNodesApi, wp_default_nodes_api, WP_TYPE_PLUGIN)
+
+static void
+wp_default_nodes_api_init (WpDefaultNodesApi * self)
+{
+}
+
+static gboolean
+emit_changed_cb (gpointer data)
+{
+  WpDefaultNodesApi *self = data;
+
+  g_signal_emit (self, signals[SIGNAL_CHANGED], 0);
+
+  g_clear_pointer (&self->idle_source, g_source_unref);
+  return G_SOURCE_REMOVE;
+}
+
+static void
+schedule_changed_notification (WpDefaultNodesApi *self)
+{
+  g_autoptr (WpCore) core = wp_object_get_core (WP_OBJECT (self));
+  g_return_if_fail (core);
+  wp_core_idle_add (core, &self->idle_source, emit_changed_cb, self, NULL);
+}
+
+static void
+on_metadata_changed (WpMetadata *m, guint32 subject,
+    const gchar *key, const gchar *type, const gchar *value, gpointer d)
+{
+  WpDefaultNodesApi * self = WP_DEFAULT_NODES_API (d);
+  gint node_t = -1;
+  gchar name[1024];
+
+  if (subject == 0) {
+    for (gint i = 0; i < N_DEFAULT_NODES; i++) {
+      if (!g_strcmp0 (key, DEFAULT_KEY[i])) {
+        node_t = i;
+        break;
+      }
+    }
+  }
+
+  if (node_t != -1) {
+    g_clear_pointer (&self->defaults[node_t], g_free);
+
+    if (value && !g_strcmp0 (type, "Spa:String:JSON") &&
+        json_object_find (value, "name", name, sizeof(name)) == 0)
+    {
+      self->defaults[node_t] = g_strdup (name);
+    }
+
+    schedule_changed_notification (self);
+  }
+}
+
+static void
+on_metadata_added (WpObjectManager *om, WpMetadata *metadata, gpointer d)
+{
+  WpDefaultNodesApi * self = WP_DEFAULT_NODES_API (d);
+  g_autoptr (WpCore) core = wp_object_get_core (WP_OBJECT (self));
+  g_return_if_fail (core);
+
+  /* Handle the changed signal */
+  g_signal_connect_object (metadata, "changed",
+      G_CALLBACK (on_metadata_changed), self, 0);
+
+  /* Create the nodes object manager */
+  self->nodes_om = wp_object_manager_new ();
+  wp_object_manager_add_interest (self->nodes_om, WP_TYPE_NODE, NULL);
+  wp_object_manager_request_object_features (self->nodes_om, WP_TYPE_NODE,
+      WP_PIPEWIRE_OBJECT_FEATURES_MINIMAL);
+  wp_core_install_object_manager (core, self->nodes_om);
+}
+
+static void
+wp_default_nodes_api_enable (WpPlugin * plugin, WpTransition * transition)
+{
+  WpDefaultNodesApi * self = WP_DEFAULT_NODES_API (plugin);
+  g_autoptr (WpCore) core = wp_object_get_core (WP_OBJECT (plugin));
+  g_return_if_fail (core);
+
+  /* Create the metadatas object manager */
+  self->metadatas_om = wp_object_manager_new ();
+  wp_object_manager_add_interest (self->metadatas_om, WP_TYPE_METADATA,
+      WP_CONSTRAINT_TYPE_PW_GLOBAL_PROPERTY, "metadata.name", "=s", "default",
+      NULL);
+  wp_object_manager_request_object_features (self->metadatas_om,
+      WP_TYPE_METADATA, WP_OBJECT_FEATURES_ALL);
+  g_signal_connect_object (self->metadatas_om, "object-added",
+      G_CALLBACK (on_metadata_added), self, 0);
+  wp_core_install_object_manager (core, self->metadatas_om);
+
+  wp_object_update_features (WP_OBJECT (self), WP_PLUGIN_FEATURE_ENABLED, 0);
+}
+
+static void
+wp_default_nodes_api_disable (WpPlugin * plugin)
+{
+  WpDefaultNodesApi * self = WP_DEFAULT_NODES_API (plugin);
+
+  if (self->idle_source)
+    g_source_destroy (self->idle_source);
+  g_clear_pointer (&self->idle_source, g_source_unref);
+
+  g_clear_object (&self->metadatas_om);
+  g_clear_object (&self->nodes_om);
+}
+
+static guint
+wp_default_nodes_api_get_default_node (WpDefaultNodesApi * self,
+    const gchar * media_class)
+{
+  gint node_t = -1;
+  for (gint i = 0; i < N_DEFAULT_NODES; i++) {
+    if (!g_strcmp0 (media_class, MEDIA_CLASS[i])) {
+      node_t = i;
+      break;
+    }
+  }
+  if (node_t != -1 && self->defaults[node_t]) {
+    g_autoptr (WpNode) node = wp_object_manager_lookup (self->nodes_om,
+        WP_TYPE_NODE,
+        WP_CONSTRAINT_TYPE_PW_PROPERTY,
+        PW_KEY_NODE_NAME, "=s", self->defaults[node_t],
+        WP_CONSTRAINT_TYPE_PW_PROPERTY,
+        PW_KEY_MEDIA_CLASS, "=s", MEDIA_CLASS[node_t],
+        NULL);
+    return wp_proxy_get_bound_id (WP_PROXY (node));
+  }
+  return SPA_ID_INVALID;
+}
+
+static void
+wp_default_nodes_api_class_init (WpDefaultNodesApiClass * klass)
+{
+  WpPluginClass *plugin_class = (WpPluginClass *) klass;
+
+  plugin_class->enable = wp_default_nodes_api_enable;
+  plugin_class->disable = wp_default_nodes_api_disable;
+
+  signals[ACTION_GET_DEFAULT_NODE] = g_signal_new_class_handler (
+      "get-default-node", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+      (GCallback) wp_default_nodes_api_get_default_node,
+      NULL, NULL, NULL,
+      G_TYPE_UINT, 1, G_TYPE_STRING);
+
+  signals[SIGNAL_CHANGED] = g_signal_new (
+      "changed", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
+}
+
+WP_PLUGIN_EXPORT gboolean
+wireplumber__module_init (WpCore * core, GVariant * args, GError ** error)
+{
+  wp_plugin_register (g_object_new (wp_default_nodes_api_get_type (),
+          "name", "default-nodes-api",
+          "core", core,
+          NULL));
+  return TRUE;
+}