service/tray: report misbehaving tray hosts

I've debugged broken tray items that just end up being a bad host far
too many times.

src/dbus/properties.cpp

@@ -268,14 +268,15 @@ void DBusPropertyGroup::updateAllViaGetAll() {
 			qCWarning(logDbusProperties).noquote()
 			    << "Error updating properties of" << this->toString() << "via GetAll";
 			qCWarning(logDbusProperties) << reply.error();
+			emit this->getAllFailed(reply.error());
 		} else {
 			qCDebug(logDbusProperties).noquote()
 			    << "Received GetAll property set for" << this->toString();
 			this->updatePropertySet(reply.value(), true);
+			emit this->getAllFinished();
 		}
 
 		delete call;
-		emit this->getAllFinished();
 	};
 
 	QObject::connect(call, &QDBusPendingCallWatcher::finished, this, responseCallback);

src/dbus/properties.hpp

@@ -135,6 +135,7 @@ public:
 
 signals:
 	void getAllFinished();
+	void getAllFailed(QDBusError error);
 
 private slots:
 	void onPropertiesChanged(

src/services/status_notifier/item.cpp

@@ -26,6 +26,7 @@
 #include "dbus_item.h"
 #include "dbus_item_types.hpp"
 #include "host.hpp"
+#include "watcher.hpp"
 
 using namespace qs::dbus;
 using namespace qs::dbus::dbusmenu;
@@ -76,6 +77,7 @@ StatusNotifierItem::StatusNotifierItem(const QString& address, QObject* parent)
 	QObject::connect(&this->overlayIconPixmaps, &AbstractDBusProperty::changed, this, &StatusNotifierItem::updateIcon);
 
 	QObject::connect(&this->properties, &DBusPropertyGroup::getAllFinished, this, &StatusNotifierItem::onGetAllFinished);
+	QObject::connect(&this->properties, &DBusPropertyGroup::getAllFailed, this, &StatusNotifierItem::onGetAllFailed);
 	QObject::connect(&this->menuPath, &AbstractDBusProperty::changed, this, &StatusNotifierItem::onMenuPathChanged);
 	// clang-format on
 
@@ -246,6 +248,19 @@ void StatusNotifierItem::onGetAllFinished() {
 	emit this->ready();
 }
 
+void StatusNotifierItem::onGetAllFailed() {
+	// Not changing the item to ready, as it is almost definitely broken.
+	if (!this->mReady) {
+		qWarning(logStatusNotifierItem) << "Failed to load tray item" << this->properties.toString();
+
+		if (!StatusNotifierWatcher::instance()->isRegistered()) {
+			qWarning(logStatusNotifierItem)
+			    << "Another StatusNotifier host seems to be running. Please disable it and check that "
+			       "the problem persists before reporting an issue.";
+		}
+	}
+}
+
 TrayImageHandle::TrayImageHandle(StatusNotifierItem* item)
     : QsImageHandle(QQmlImageProviderBase::Pixmap, item)
     , item(item) {}
@@ -257,6 +272,7 @@ TrayImageHandle::requestPixmap(const QString& /*unused*/, QSize* size, const QSi
 
 	auto pixmap = this->item->createPixmap(targetSize);
 	if (pixmap.isNull()) {
+		qCWarning(logStatusNotifierItem) << "Unable to create pixmap for tray icon" << this->item;
 		pixmap = IconImageProvider::missingPixmap(targetSize);
 	}
 

src/services/status_notifier/item.hpp

@@ -75,6 +75,7 @@ signals:
 private slots:
 	void updateIcon();
 	void onGetAllFinished();
+	void onGetAllFailed();
 	void onMenuPathChanged();
 
 private:

src/services/status_notifier/watcher.cpp

@@ -47,12 +47,15 @@ StatusNotifierWatcher::StatusNotifierWatcher(QObject* parent): QObject(parent) {
 	this->tryRegister();
 }
 
+bool StatusNotifierWatcher::isRegistered() const { return this->registered; }
+
 void StatusNotifierWatcher::tryRegister() { // NOLINT
 	auto bus = QDBusConnection::sessionBus();
 	auto success = bus.registerService("org.kde.StatusNotifierWatcher");
 
 	if (success) {
 		qCDebug(logStatusNotifierWatcher) << "Registered watcher at org.kde.StatusNotifierWatcher";
+		this->registered = true;
 	} else {
 		qCDebug(logStatusNotifierWatcher)
 		    << "Could not register watcher at org.kde.StatusNotifierWatcher, presumably because one is "
@@ -68,7 +71,6 @@ void StatusNotifierWatcher::onServiceUnregistered(const QString& service) {
 		    << "Active StatusNotifierWatcher unregistered, attempting registration";
 		this->tryRegister();
 		return;
-		;
 	} else {
 		QString qualifiedItem;
 		this->items.removeIf([&](const QString& item) {

src/services/status_notifier/watcher.hpp

@@ -29,6 +29,7 @@ public:
 	[[nodiscard]] qint32 protocolVersion() const { return 0; } // NOLINT
 	[[nodiscard]] bool isHostRegistered() const;
 	[[nodiscard]] QList<QString> registeredItems() const;
+	[[nodiscard]] bool isRegistered() const;
 
 	// NOLINTBEGIN
 	void RegisterStatusNotifierHost(const QString& host);
@@ -54,6 +55,7 @@ private:
 	QDBusServiceWatcher serviceWatcher;
 	QList<QString> hosts;
 	QList<QString> items;
+	bool registered = false;
 };
 
 } // namespace qs::service::sni