Issue #15 Added IDataLink, an interface for registering observers and mutators,

and CDataLinkLocal, an implementation for sharing state within a single process

src/blackmisc/sharedstate/datalink.cpp

@@ -0,0 +1,44 @@
+/* Copyright (C) 2017
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution. No part of swift project, including this file, may be copied, modified, propagated,
+ * or distributed except according to the terms contained in the LICENSE file.
+ */
+
+//! \file
+
+#include "blackmisc/sharedstate/datalink.h"
+#include "blackmisc/promise.h"
+#include "blackmisc/variant.h"
+
+namespace BlackMisc
+{
+    namespace SharedState
+    {
+        void CDataLinkConnectionWatcher::setStatus(bool status)
+        {
+            if (status != m_connected)
+            {
+                m_connected = status;
+                if (m_connected) { emit connected(); }
+                else { emit disconnected(); }
+            }
+        }
+
+        IDataLink::~IDataLink() = default;
+
+        IDataLink::IDataLink()
+        {
+            qRegisterMetaType<CPromise<CVariant>>();
+        }
+
+        QString IDataLink::getChannelName(const QObject *object)
+        {
+            const QMetaObject *meta = object->parent()->metaObject();
+            const char *info = meta->classInfo(meta->indexOfClassInfo("SharedStateChannel")).value();
+            const QString name = object->parent()->objectName();
+            return name.isEmpty() ? QString(info) : (info % QLatin1Char(':') % name);
+        }
+    }
+}