services/pipewire: ignore monitors in PwNodeLinkTracker

changelog/next.md

@@ -25,6 +25,7 @@ set shell id.
 
 - FreeBSD is now partially supported.
 - IPC operations filter available instances to the current display connection by default.
+- PwNodeLinkTracker ignores sound level monitoring programs.
 
 ## Bug Fixes
 

src/services/pipewire/node.cpp

@@ -164,6 +164,12 @@ void PwNode::initProps(const spa_dict* props) {
 		this->nick = nodeNick;
 	}
 
+	if (const auto* nodeCategory = spa_dict_lookup(props, PW_KEY_MEDIA_CATEGORY)) {
+		if (strcmp(nodeCategory, "Monitor") == 0 || strcmp(nodeCategory, "Manager") == 0) {
+			this->isMonitor = true;
+		}
+	}
+
 	if (const auto* serial = spa_dict_lookup(props, PW_KEY_OBJECT_SERIAL)) {
 		auto ok = false;
 		auto value = QString::fromUtf8(serial).toULongLong(&ok);

src/services/pipewire/node.hpp

@@ -236,6 +236,7 @@ public:
 	QString nick;
 	QMap<QString, QString> properties;
 	quint64 objectSerial = 0;
+	bool isMonitor = false;
 
 	PwNodeType::Flags type = PwNodeType::Untracked;
 

src/services/pipewire/qml.cpp

@@ -213,6 +213,7 @@ void PwNodeLinkTracker::updateLinks() {
 			    || (this->mNode->isSink() && link->inputNode() == this->mNode->id()))
 			{
 				auto* iface = PwLinkGroupIface::instance(link);
+				if (iface->target()->node()->isMonitor) return;
 
 				// do not connect twice
 				if (!this->mLinkGroups.contains(iface)) {
@@ -231,7 +232,7 @@ void PwNodeLinkTracker::updateLinks() {
 
 	for (auto* iface: this->mLinkGroups) {
 		// only disconnect no longer used nodes
-		if (!newLinks.contains(iface)) {
+		if (!newLinks.contains(iface) || iface->target()->node()->isMonitor) {
 			QObject::disconnect(iface, nullptr, this, nullptr);
 		}
 	}
@@ -271,6 +272,8 @@ void PwNodeLinkTracker::onLinkGroupCreated(PwLinkGroup* linkGroup) {
 	    || (this->mNode->isSink() && linkGroup->inputNode() == this->mNode->id()))
 	{
 		auto* iface = PwLinkGroupIface::instance(linkGroup);
+		if (iface->target()->node()->isMonitor) return;
+
 		QObject::connect(iface, &QObject::destroyed, this, &PwNodeLinkTracker::onLinkGroupDestroyed);
 		this->mLinkGroups.push_back(iface);
 		emit this->linkGroupsChanged();

src/services/pipewire/qml.hpp

@@ -171,13 +171,13 @@ private:
 	ObjectModel<PwLinkGroupIface> mLinkGroups {this};
 };
 
-///! Tracks all link connections to a given node.
+///! Tracks non-monitor link connections to a given node.
 class PwNodeLinkTracker: public QObject {
 	Q_OBJECT;
 	// clang-format off
 	/// The node to track connections to.
 	Q_PROPERTY(qs::service::pipewire::PwNodeIface* node READ node WRITE setNode NOTIFY nodeChanged);
-	/// Link groups connected to the given node.
+	/// Link groups connected to the given node, excluding monitors.
 	///
 	/// If the node is a sink, links which target the node will be tracked.
 	/// If the node is a source, links which source the node will be tracked.