fix(wireplumber): waybar crashes when default node changes

In order to fix the issue, the default node name is cached rather than
the default node id. This is due to ids being unstable. So now when the
object manager is installed (ie ready), the default node name is
retrieved and stored for later.

Now when the mixer changed signal is emitted, the id of the changed node
is used to get the node from the object manager. The nodes name is
grabbed off that node and compared against the default node name, if
they match the volume is updated. Some safeguarding has been added such
that if the node cannot be found off the object manager, it's ignored.

Additionally, the "changed" signal on the default nodes api is now
utilized to update the default node name if it has changed. This way if
the default node changes, the module will be updated with the correct
volume and node.nick.

This adds additional debug logging for helping diagnose wireplumber
issues.

This also adds the wireplumber man page entry to the main waybar
supported section.

include/modules/wireplumber.hpp

@@ -20,15 +20,19 @@ class Wireplumber : public ALabel {
   void loadRequiredApiModules();
   void prepare();
   void activatePlugins();
-  static void updateVolume(waybar::modules::Wireplumber* self);
+  static void updateVolume(waybar::modules::Wireplumber* self, uint32_t id);
-  static void updateNodeName(waybar::modules::Wireplumber* self);
+  static void updateNodeName(waybar::modules::Wireplumber* self, uint32_t id);
-  static uint32_t getDefaultNodeId(waybar::modules::Wireplumber* self);
   static void onPluginActivated(WpObject* p, GAsyncResult* res, waybar::modules::Wireplumber* self);
   static void onObjectManagerInstalled(waybar::modules::Wireplumber* self);
+  static void onMixerChanged(waybar::modules::Wireplumber* self, uint32_t id);
+  static void onDefaultNodesApiChanged(waybar::modules::Wireplumber* self);
 
   WpCore* wp_core_;
   GPtrArray* apis_;
   WpObjectManager* om_;
+  WpPlugin* mixer_api_;
+  WpPlugin* def_nodes_api_;
+  gchar* default_node_name_;
   uint32_t pending_plugins_;
   bool muted_;
   double volume_;

man/waybar.5.scd.in

@@ -277,6 +277,7 @@ A module group is defined by specifying a module named "group/some-group-name".
 - *waybar-sway-scratchpad(5)*
 - *waybar-sway-window(5)*
 - *waybar-sway-workspaces(5)*
+- *waybar-wireplumber(5)*
 - *waybar-wlr-taskbar(5)*
 - *waybar-wlr-workspaces(5)*
 - *waybar-temperature(5)*

src/modules/wireplumber.cpp

@@ -1,15 +1,22 @@
 #include "modules/wireplumber.hpp"
 
+#include <spdlog/spdlog.h>
+
+bool isValidNodeId(uint32_t id) { return id > 0 && id < G_MAXUINT32; }
+
 waybar::modules::Wireplumber::Wireplumber(const std::string& id, const Json::Value& config)
     : ALabel(config, "wireplumber", id, "{volume}%"),
       wp_core_(nullptr),
       apis_(nullptr),
       om_(nullptr),
+      mixer_api_(nullptr),
+      def_nodes_api_(nullptr),
+      default_node_name_(nullptr),
       pending_plugins_(0),
       muted_(false),
       volume_(0.0),
       node_id_(0) {
-  wp_init(WP_INIT_ALL);
+  wp_init(WP_INIT_PIPEWIRE);
   wp_core_ = wp_core_new(NULL, NULL);
   apis_ = g_ptr_array_new_with_free_func(g_object_unref);
   om_ = wp_object_manager_new();
@@ -18,10 +25,15 @@ waybar::modules::Wireplumber::Wireplumber(const std::string& id, const Json::Val
 
   loadRequiredApiModules();
 
+  spdlog::debug("[{}]: connecting to pipewire...", this->name_);
+
   if (!wp_core_connect(wp_core_)) {
+    spdlog::error("[{}]: Could not connect to PipeWire", this->name_);
     throw std::runtime_error("Could not connect to PipeWire\n");
   }
 
+  spdlog::debug("[{}]: connected!", this->name_);
+
   g_signal_connect_swapped(om_, "installed", (GCallback)onObjectManagerInstalled, this);
 
   activatePlugins();
@@ -33,33 +45,26 @@ waybar::modules::Wireplumber::~Wireplumber() {
   g_clear_pointer(&apis_, g_ptr_array_unref);
   g_clear_object(&om_);
   g_clear_object(&wp_core_);
+  g_clear_object(&mixer_api_);
+  g_clear_object(&def_nodes_api_);
+  g_free(&default_node_name_);
 }
 
-uint32_t waybar::modules::Wireplumber::getDefaultNodeId(waybar::modules::Wireplumber* self) {
+void waybar::modules::Wireplumber::updateNodeName(waybar::modules::Wireplumber* self, uint32_t id) {
-  uint32_t id;
+  spdlog::debug("[{}]: updating node name with node.id {}", self->name_, id);
-  g_autoptr(WpPlugin) def_nodes_api = wp_plugin_find(self->wp_core_, "default-nodes-api");
 
-  if (!def_nodes_api) {
+  if (!isValidNodeId(id)) {
-    throw std::runtime_error("Default nodes API is not loaded\n");
+    spdlog::warn("[{}]: '{}' is not a valid node ID. Ignoring node name update.", self->name_, id);
+    return;
   }
 
-  g_signal_emit_by_name(def_nodes_api, "get-default-node", "Audio/Sink", &id);
+  auto proxy = static_cast<WpProxy*>(wp_object_manager_lookup(
-
+      self->om_, WP_TYPE_GLOBAL_PROXY, WP_CONSTRAINT_TYPE_G_PROPERTY, "bound-id", "=u", id, NULL));
-  if (id <= 0 || id >= G_MAXUINT32) {
-    auto err = fmt::format("'{}' is not a valid ID (returned by default-nodes-api)\n", id);
-    throw std::runtime_error(err);
-  }
-
-  return id;
-}
-
-void waybar::modules::Wireplumber::updateNodeName(waybar::modules::Wireplumber* self) {
-  auto proxy = static_cast<WpProxy*>(
-      wp_object_manager_lookup(self->om_, WP_TYPE_GLOBAL_PROXY, WP_CONSTRAINT_TYPE_G_PROPERTY,
-                               "bound-id", "=u", self->node_id_, NULL));
 
   if (!proxy) {
-    throw std::runtime_error(fmt::format("Object '{}' not found\n", self->node_id_));
+    auto err = fmt::format("Object '{}' not found\n", id);
+    spdlog::error("[{}]: {}", self->name_, err);
+    throw std::runtime_error(err);
   }
 
   g_autoptr(WpProperties) properties =
@@ -73,15 +78,24 @@ void waybar::modules::Wireplumber::updateNodeName(waybar::modules::Wireplumber*
   auto description = wp_properties_get(properties, "node.description");
 
   self->node_name_ = nick ? nick : description;
+  spdlog::debug("[{}]: Updating node name to: {}", self->name_, self->node_name_);
 }
 
-void waybar::modules::Wireplumber::updateVolume(waybar::modules::Wireplumber* self) {
+void waybar::modules::Wireplumber::updateVolume(waybar::modules::Wireplumber* self, uint32_t id) {
+  spdlog::debug("[{}]: updating volume", self->name_);
   double vol;
   GVariant* variant = NULL;
-  g_autoptr(WpPlugin) mixer_api = wp_plugin_find(self->wp_core_, "mixer-api");
+
-  g_signal_emit_by_name(mixer_api, "get-volume", self->node_id_, &variant);
+  if (!isValidNodeId(id)) {
+    spdlog::error("[{}]: '{}' is not a valid node ID. Ignoring volume update.", self->name_, id);
+    return;
+  }
+
+  g_signal_emit_by_name(self->mixer_api_, "get-volume", id, &variant);
+
   if (!variant) {
-    auto err = fmt::format("Node {} does not support volume\n", self->node_id_);
+    auto err = fmt::format("Node {} does not support volume\n", id);
+    spdlog::error("[{}]: {}", self->name_, err);
     throw std::runtime_error(err);
   }
 
@@ -93,22 +107,121 @@ void waybar::modules::Wireplumber::updateVolume(waybar::modules::Wireplumber* se
   self->dp.emit();
 }
 
+void waybar::modules::Wireplumber::onMixerChanged(waybar::modules::Wireplumber* self, uint32_t id) {
+  spdlog::debug("[{}]: (onMixerChanged) - id: {}", self->name_, id);
+
+  g_autoptr(WpNode) node = static_cast<WpNode*>(wp_object_manager_lookup(
+      self->om_, WP_TYPE_NODE, WP_CONSTRAINT_TYPE_G_PROPERTY, "bound-id", "=u", id, NULL));
+
+  if (!node) {
+    spdlog::warn("[{}]: (onMixerChanged) - Object with id {} not found", self->name_, id);
+    return;
+  }
+
+  const gchar* name = wp_pipewire_object_get_property(WP_PIPEWIRE_OBJECT(node), "node.name");
+
+  if (g_strcmp0(self->default_node_name_, name) != 0) {
+    spdlog::debug(
+        "[{}]: (onMixerChanged) - ignoring mixer update for node: id: {}, name: {} as it is not "
+        "the default node: {}",
+        self->name_, id, name, self->default_node_name_);
+    return;
+  }
+
+  spdlog::debug("[{}]: (onMixerChanged) - Need to update volume for node with id {} and name {}",
+                self->name_, id, name);
+  updateVolume(self, id);
+}
+
+void waybar::modules::Wireplumber::onDefaultNodesApiChanged(waybar::modules::Wireplumber* self) {
+  spdlog::debug("[{}]: (onDefaultNodesApiChanged)", self->name_);
+
+  uint32_t default_node_id;
+  g_signal_emit_by_name(self->def_nodes_api_, "get-default-node", "Audio/Sink", &default_node_id);
+
+  if (!isValidNodeId(default_node_id)) {
+    spdlog::warn("[{}]: '{}' is not a valid node ID. Ignoring node change.", self->name_,
+                 default_node_id);
+    return;
+  }
+
+  g_autoptr(WpNode) node = static_cast<WpNode*>(
+      wp_object_manager_lookup(self->om_, WP_TYPE_NODE, WP_CONSTRAINT_TYPE_G_PROPERTY, "bound-id",
+                               "=u", default_node_id, NULL));
+
+  if (!node) {
+    spdlog::warn("[{}]: (onDefaultNodesApiChanged) - Object with id {} not found", self->name_,
+                 default_node_id);
+    return;
+  }
+
+  const gchar* default_node_name =
+      wp_pipewire_object_get_property(WP_PIPEWIRE_OBJECT(node), "node.name");
+
+  spdlog::debug(
+      "[{}]: (onDefaultNodesApiChanged) - got the following default node: Node(name: {}, id: {})",
+      self->name_, default_node_name, default_node_id);
+
+  if (g_strcmp0(self->default_node_name_, default_node_name) == 0) {
+    spdlog::debug(
+        "[{}]: (onDefaultNodesApiChanged) - Default node has not changed. Node(name: {}, id: {}). "
+        "Ignoring.",
+        self->name_, self->default_node_name_, default_node_id);
+    return;
+  }
+
+  spdlog::debug(
+      "[{}]: (onDefaultNodesApiChanged) - Default node changed to -> Node(name: {}, id: {})",
+      self->name_, default_node_name, default_node_id);
+
+  self->default_node_name_ = g_strdup(default_node_name);
+  updateVolume(self, default_node_id);
+  updateNodeName(self, default_node_id);
+}
+
 void waybar::modules::Wireplumber::onObjectManagerInstalled(waybar::modules::Wireplumber* self) {
-  self->node_id_ =
+  spdlog::debug("[{}]: onObjectManagerInstalled", self->name_);
-      self->config_["node-id"].isInt() ? self->config_["node-id"].asInt() : getDefaultNodeId(self);
 
-  g_autoptr(WpPlugin) mixer_api = wp_plugin_find(self->wp_core_, "mixer-api");
+  self->def_nodes_api_ = wp_plugin_find(self->wp_core_, "default-nodes-api");
 
-  updateVolume(self);
+  if (!self->def_nodes_api_) {
-  updateNodeName(self);
+    spdlog::error("[{}]: default nodes api is not loaded.", self->name_);
-  g_signal_connect_swapped(mixer_api, "changed", (GCallback)updateVolume, self);
+    throw std::runtime_error("Default nodes API is not loaded\n");
+  }
+
+  self->mixer_api_ = wp_plugin_find(self->wp_core_, "mixer-api");
+
+  if (!self->mixer_api_) {
+    spdlog::error("[{}]: mixer api is not loaded.", self->name_);
+    throw std::runtime_error("Mixer api is not loaded\n");
+  }
+
+  uint32_t default_node_id;
+  g_signal_emit_by_name(self->def_nodes_api_, "get-default-configured-node-name", "Audio/Sink",
+                        &self->default_node_name_);
+  g_signal_emit_by_name(self->def_nodes_api_, "get-default-node", "Audio/Sink", &default_node_id);
+
+  if (self->default_node_name_) {
+    spdlog::debug("[{}]: (onObjectManagerInstalled) - default configured node name: {} and id: {}",
+                  self->name_, self->default_node_name_, default_node_id);
+  }
+
+  updateVolume(self, default_node_id);
+  updateNodeName(self, default_node_id);
+
+  g_signal_connect_swapped(self->mixer_api_, "changed", (GCallback)onMixerChanged, self);
+  g_signal_connect_swapped(self->def_nodes_api_, "changed", (GCallback)onDefaultNodesApiChanged,
+                           self);
 }
 
 void waybar::modules::Wireplumber::onPluginActivated(WpObject* p, GAsyncResult* res,
                                                      waybar::modules::Wireplumber* self) {
+  auto plugin_name = wp_plugin_get_name(WP_PLUGIN(p));
+  spdlog::debug("[{}]: onPluginActivated: {}", self->name_, plugin_name);
   g_autoptr(GError) error = NULL;
 
   if (!wp_object_activate_finish(p, res, &error)) {
+    spdlog::error("[{}]: error activating plugin: {}", self->name_, error->message);
     throw std::runtime_error(error->message);
   }
 
@@ -118,6 +231,7 @@ void waybar::modules::Wireplumber::onPluginActivated(WpObject* p, GAsyncResult*
 }
 
 void waybar::modules::Wireplumber::activatePlugins() {
+  spdlog::debug("[{}]: activating plugins", name_);
   for (uint16_t i = 0; i < apis_->len; i++) {
     WpPlugin* plugin = static_cast<WpPlugin*>(g_ptr_array_index(apis_, i));
     pending_plugins_++;
@@ -127,13 +241,13 @@ void waybar::modules::Wireplumber::activatePlugins() {
 }
 
 void waybar::modules::Wireplumber::prepare() {
-  wp_object_manager_add_interest(om_, WP_TYPE_NODE, NULL);
+  spdlog::debug("[{}]: preparing object manager", name_);
-  wp_object_manager_add_interest(om_, WP_TYPE_GLOBAL_PROXY, NULL);
+  wp_object_manager_add_interest(om_, WP_TYPE_NODE, WP_CONSTRAINT_TYPE_PW_PROPERTY, "media.class",
-  wp_object_manager_request_object_features(om_, WP_TYPE_GLOBAL_PROXY,
+                                 "=s", "Audio/Sink", NULL);
-                                            WP_PIPEWIRE_OBJECT_FEATURES_MINIMAL);
 }
 
 void waybar::modules::Wireplumber::loadRequiredApiModules() {
+  spdlog::debug("[{}]: loading required modules", name_);
   g_autoptr(GError) error = NULL;
 
   if (!wp_core_load_component(wp_core_, "libwireplumber-module-default-nodes-api", "module", NULL,