dbustray: Handle StatusNotifierWatcher appearing and disappearing

If the StatusNotifierWatcher disappears and then appears again, we need
to register our tray icon again with it.

To do this, split the “register with watcher” part into a separate
method, and call it when m_dbusWatcher emits its serviceRegistered()
signal.

Change-Id: Id5fc8ac81b5038a61b678514dabd3eb9c8f1c106
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuconnection.cpp

@@ -119,13 +119,16 @@ bool QDBusMenuConnection::registerTrayIcon(QDBusTrayIcon *item)
     if (item->menu())
         registerTrayIconMenu(item);
 
+    return registerTrayIconWithWatcher(item);
+}
+
+bool QDBusMenuConnection::registerTrayIconWithWatcher(QDBusTrayIcon *item)
+{
     QDBusMessage registerMethod = QDBusMessage::createMethodCall(
                 StatusNotifierWatcherService, StatusNotifierWatcherPath, StatusNotifierWatcherService,
                 QLatin1String("RegisterStatusNotifierItem"));
     registerMethod.setArguments(QVariantList() << item->instanceId());
-    success = m_connection.callWithCallback(registerMethod, this, SIGNAL(trayIconRegistered()), SLOT(dbusError(QDBusError)));
-
-    return success;
+    return m_connection.callWithCallback(registerMethod, this, SIGNAL(trayIconRegistered()), SLOT(dbusError(QDBusError)));
 }
 
 bool QDBusMenuConnection::unregisterTrayIcon(QDBusTrayIcon *item)

src/platformsupport/themes/genericunix/dbusmenu/qdbusmenuconnection_p.h

@@ -69,11 +69,13 @@ class QDBusMenuConnection : public QObject
 public:
     QDBusMenuConnection(QObject *parent = 0, const QString &serviceName = QString());
     QDBusConnection connection() const { return m_connection; }
+    QDBusServiceWatcher *dbusWatcher() const { return m_dbusWatcher; }
     bool isStatusNotifierHostRegistered() const { return m_statusNotifierHostRegistered; }
 #ifndef QT_NO_SYSTEMTRAYICON
     bool registerTrayIconMenu(QDBusTrayIcon *item);
     void unregisterTrayIconMenu(QDBusTrayIcon *item);
     bool registerTrayIcon(QDBusTrayIcon *item);
+    bool registerTrayIconWithWatcher(QDBusTrayIcon *item);
     bool unregisterTrayIcon(QDBusTrayIcon *item);
 #endif // QT_NO_SYSTEMTRAYICON
 

src/platformsupport/themes/genericunix/dbustray/qdbustrayicon.cpp

@@ -116,6 +116,8 @@ void QDBusTrayIcon::init()
 {
     qCDebug(qLcTray) << "registering" << m_instanceId;
     m_registered = dBusConnection()->registerTrayIcon(this);
+    QObject::connect(dBusConnection()->dbusWatcher(), &QDBusServiceWatcher::serviceRegistered,
+                     this, &QDBusTrayIcon::watcherServiceRegistered);
 }
 
 void QDBusTrayIcon::cleanup()
@@ -130,6 +132,15 @@ void QDBusTrayIcon::cleanup()
     m_registered = false;
 }
 
+void QDBusTrayIcon::watcherServiceRegistered(const QString &serviceName)
+{
+    Q_UNUSED(serviceName);
+    // We have the icon registered, but the watcher has restarted or
+    // changed, so we need to tell it about our icon again
+    if (m_registered)
+        dBusConnection()->registerTrayIconWithWatcher(this);
+}
+
 void QDBusTrayIcon::attentionTimerExpired()
 {
     m_messageTitle = QString();

src/platformsupport/themes/genericunix/dbustray/qdbustrayicon_p.h

@@ -133,6 +133,7 @@ private Q_SLOTS:
     void attentionTimerExpired();
     void actionInvoked(uint id, const QString &action);
     void notificationClosed(uint id, uint reason);
+    void watcherServiceRegistered(const QString &serviceName);
 
 private:
     void setStatus(const QString &status);