i3/ipc: ensure monitor/workspace pointers are nulled on destroy

src/x11/i3/ipc/controller.cpp

@@ -276,7 +276,7 @@ void I3IpcController::handleWorkspaceEvent(I3IpcEvent* event) {
 
 		if (newWorkspace->bindableMonitor().value()) {
 			auto* monitor = newWorkspace->bindableMonitor().value();
-			monitor->setFocusedWorkspace(newWorkspace);
+			monitor->setActiveWorkspace(newWorkspace);
 			this->bFocusedMonitor = monitor;
 		}
 	} else if (change == "empty") {
@@ -286,13 +286,7 @@ void I3IpcController::handleWorkspaceEvent(I3IpcEvent* event) {
 
 		if (oldWorkspace != nullptr) {
 			qCInfo(logI3Ipc) << "Deleting" << oldWorkspace->bindableId().value() << name;
-
-			if (this->bFocusedWorkspace == oldWorkspace) {
-				this->bFocusedMonitor->setFocusedWorkspace(nullptr);
-			}
-
 			this->workspaces()->removeObject(oldWorkspace);
-
 			delete oldWorkspace;
 		} else {
 			qCInfo(logI3Ipc) << "Workspace" << name << "has already been deleted";

src/x11/i3/ipc/monitor.cpp

@@ -40,21 +40,37 @@ void I3Monitor::updateFromObject(const QVariantMap& obj) {
 	this->bHeight = rect.value("height").value<qint32>();
 	this->bScale = obj.value("scale").value<qreal>();
 
-	if (!this->bActiveWorkspace
+	auto* activeWorkspace = this->bActiveWorkspace.value();
-	    || activeWorkspaceName != this->bActiveWorkspace->bindableName().value())
+	if (!activeWorkspace || activeWorkspaceName != activeWorkspace->bindableName().value()) {
-	{
 		if (activeWorkspaceName.isEmpty()) {
-			this->bActiveWorkspace = nullptr;
+			activeWorkspace = nullptr;
 		} else {
-			this->bActiveWorkspace = this->ipc->findWorkspaceByName(activeWorkspaceName);
+			activeWorkspace = this->ipc->findWorkspaceByName(activeWorkspaceName);
 		}
 	};
 
+	this->setActiveWorkspace(activeWorkspace);
+
 	Qt::endPropertyUpdateGroup();
 }
 
 void I3Monitor::updateInitial(const QString& name) { this->bName = name; }
 
-void I3Monitor::setFocusedWorkspace(I3Workspace* workspace) { this->bActiveWorkspace = workspace; };
+void I3Monitor::setActiveWorkspace(I3Workspace* workspace) {
+	auto* oldWorkspace = this->bActiveWorkspace.value();
+	if (oldWorkspace == workspace) return;
+
+	if (oldWorkspace) {
+		QObject::disconnect(oldWorkspace, nullptr, this, nullptr);
+	}
+
+	if (workspace) {
+		QObject::connect(workspace, &QObject::destroyed, this, &I3Monitor::onActiveWorkspaceDestroyed);
+	}
+
+	this->bActiveWorkspace = workspace;
+}
+
+void I3Monitor::onActiveWorkspaceDestroyed() { this->bActiveWorkspace = nullptr; }
 
 } // namespace qs::i3::ipc

src/x11/i3/ipc/monitor.hpp

@@ -55,7 +55,7 @@ public:
 	[[nodiscard]] QBindable<qreal> bindableScale() { return &this->bScale; }
 	[[nodiscard]] QBindable<bool> bindableFocused() { return &this->bFocused; }
 
-	[[nodiscard]] QBindable<I3Workspace*> bindableActiveWorkspace() {
+	[[nodiscard]] QBindable<I3Workspace*> bindableActiveWorkspace() const {
 		return &this->bActiveWorkspace;
 	}
 
@@ -64,7 +64,7 @@ public:
 	void updateFromObject(const QVariantMap& obj);
 	void updateInitial(const QString& name);
 
-	void setFocusedWorkspace(I3Workspace* workspace);
+	void setActiveWorkspace(I3Workspace* workspace);
 
 signals:
 	void idChanged();
@@ -79,6 +79,9 @@ signals:
 	void lastIpcObjectChanged();
 	void focusedChanged();
 
+private slots:
+	void onActiveWorkspaceDestroyed();
+
 private:
 	I3IpcController* ipc;
 

src/x11/i3/ipc/workspace.cpp

@@ -43,14 +43,17 @@ void I3Workspace::updateFromObject(const QVariantMap& obj) {
 
 	auto monitorName = obj.value("output").value<QString>();
 
-	if (!this->bMonitor || monitorName != this->bMonitor->bindableName().value()) {
+	auto* monitor = this->bMonitor.value();
+	if (!monitor || monitorName != monitor->bindableName().value()) {
 		if (monitorName.isEmpty()) {
-			this->bMonitor = nullptr;
+			monitor = nullptr;
 		} else {
-			this->bMonitor = this->ipc->findMonitorByName(monitorName, true);
+			monitor = this->ipc->findMonitorByName(monitorName, true);
 		}
 	}
 
+	this->setMonitor(monitor);
+
 	Qt::endPropertyUpdateGroup();
 }
 
@@ -58,4 +61,21 @@ void I3Workspace::activate() {
 	this->ipc->dispatch(QString("workspace number %1").arg(this->bNumber.value()));
 }
 
+void I3Workspace::setMonitor(I3Monitor* monitor) {
+	auto* oldMonitor = this->bMonitor.value();
+	if (oldMonitor == monitor) return;
+
+	if (oldMonitor) {
+		QObject::disconnect(oldMonitor, nullptr, this, nullptr);
+	}
+
+	if (monitor) {
+		QObject::connect(monitor, &QObject::destroyed, this, &I3Workspace::onMonitorDestroyed);
+	}
+
+	this->bMonitor = monitor;
+}
+
+void I3Workspace::onMonitorDestroyed() { this->bMonitor = nullptr; }
+
 } // namespace qs::i3::ipc

src/x11/i3/ipc/workspace.hpp

@@ -57,11 +57,13 @@ public:
 	[[nodiscard]] QBindable<bool> bindableActive() { return &this->bActive; }
 	[[nodiscard]] QBindable<bool> bindableFocused() { return &this->bFocused; }
 	[[nodiscard]] QBindable<bool> bindableUrgent() { return &this->bUrgent; }
-	[[nodiscard]] QBindable<I3Monitor*> bindableMonitor() { return &this->bMonitor; }
+	[[nodiscard]] QBindable<I3Monitor*> bindableMonitor() const { return &this->bMonitor; }
 	[[nodiscard]] QVariantMap lastIpcObject() const;
 
 	void updateFromObject(const QVariantMap& obj);
 
+	void setMonitor(I3Monitor* monitor);
+
 signals:
 	void idChanged();
 	void nameChanged();
@@ -72,6 +74,9 @@ signals:
 	void monitorChanged();
 	void lastIpcObjectChanged();
 
+private slots:
+	void onMonitorDestroyed();
+
 private:
 	I3IpcController* ipc;