Working D-Bus desktop notifications (#361)

* Working D-Bus desktop notifications

* Remove return type on constructor

* Fix the Windows placeholder class

* Fix wrong variable name

* Fix windows and macOS versions of notificationsmanager

include/notifications/Manager.h

@@ -1,12 +1,55 @@
 #pragma once
 
 #include <QImage>
+#include <QObject>
 #include <QString>
 
-class NotificationsManager
+#if defined(Q_OS_LINUX)
+#include <QtDBus/QDBusArgument>
+#include <QtDBus/QDBusInterface>
+#endif
+
+struct roomEventId
 {
-public:
-        static void postNotification(const QString &room,
-                                     const QString &user,
-                                     const QString &message);
+        QString roomId;
+        QString eventId;
 };
+
+class NotificationsManager : public QObject
+{
+        Q_OBJECT
+public:
+        NotificationsManager(QObject *parent = nullptr);
+
+        void postNotification(const QString &roomId,
+                              const QString &eventId,
+                              const QString &roomName,
+                              const QString &senderName,
+                              const QString &text,
+                              const QImage &icon);
+
+signals:
+        void notificationClicked(const QString roomId, const QString eventId);
+
+#if defined(Q_OS_LINUX)
+private:
+        QDBusInterface dbus;
+        uint showNotification(const QString summary, const QString text, const QImage image);
+
+        // notification ID to (room ID, event ID)
+        QMap<uint, roomEventId> notificationIds;
+#endif
+
+        // these slots are platform specific (D-Bus only)
+        // but Qt slot declarations can not be inside an ifdef!
+private slots:
+        void actionInvoked(uint id, QString action);
+        void notificationClosed(uint id, uint reason);
+};
+
+#if defined(Q_OS_LINUX)
+QDBusArgument &
+operator<<(QDBusArgument &arg, const QImage &image);
+const QDBusArgument &
+operator>>(const QDBusArgument &arg, QImage &);
+#endif