service/notifications: make notifications Retainable

src/services/notifications/notification.cpp

@@ -39,6 +39,11 @@ QString NotificationAction::identifier() const { return this->mIdentifier; }
 QString NotificationAction::text() const { return this->mText; }
 
 void NotificationAction::invoke() {
+	if (this->notification->isRetained()) {
+		qCritical() << "Cannot invoke destroyed notification" << this;
+		return;
+	}
+
 	NotificationServer::instance()->ActionInvoked(this->notification->id(), this->mIdentifier);
 
 	if (!this->notification->isResident()) {
@@ -57,6 +62,11 @@ void Notification::expire() { this->close(NotificationCloseReason::Expired); }
 void Notification::dismiss() { this->close(NotificationCloseReason::Dismissed); }
 
 void Notification::close(NotificationCloseReason::Enum reason) {
+	if (this->isRetained()) {
+		qCritical() << "Cannot close destroyed notification" << this;
+		return;
+	}
+
 	this->mCloseReason = reason;
 
 	if (reason != 0) {

src/services/notifications/notification.hpp

@@ -8,6 +8,8 @@
 #include <qqmlintegration.h>
 #include <qtmetamacros.h>
 
+#include "../../core/retainable.hpp"
+
 namespace qs::service::notifications {
 
 class NotificationImage;
@@ -50,7 +52,12 @@ public:
 class NotificationAction;
 
 ///! A notification emitted by a NotificationServer.
-class Notification: public QObject {
+/// A notification emitted by a NotificationServer.
+/// > [!INFO] This type is [Retainable](/docs/types/quickshell/retainable). It
+/// > can be retained after destruction if necessary.
+class Notification
+    : public QObject
+    , public Retainable {
 	Q_OBJECT;
 	/// Id of the notification as given to the client.
 	Q_PROPERTY(quint32 id READ id CONSTANT);

src/services/notifications/server.cpp

@@ -105,7 +105,7 @@ void NotificationServer::deleteNotification(
 	this->idMap.remove(notification->id());
 
 	emit this->NotificationClosed(notification->id(), reason);
-	delete notification;
+	notification->retainedDestroy();
 }
 
 void NotificationServer::tryRegister() {