Add async API for data change subscriptions

Subscriptions and monitored items are now handled entirely in the backend,
no objects are passed to the user.

Monitoring of attributes is activated using enableMonitoring() on the node.
Different attributes of the node can be monitored with different intervals.
Subscriptions are shared by default. Parameters allow requesting the creation
of an exclusive subscription or to assign monitored items for attributes to
an existing subscription. disableMonitoring() removes a monitored item.

The enableMonitoringFinished and disableMonitoringFinished signals inform
the user about the success of adding and removing monitored items.

Data changes are reported by the attributeUpdated signal, this also updates
the attribute cache.

Monitoring parameters can be modified using modifyMonitoring(). Changed
settings are reported by the monitoringStatusChanged signal, the value can be
checked by calling monitoringStatus() for an attribute.

Modifying monitoring parameters is currently not supported in freeopcua.
Open62541 allows modifying subscription settings, monitored items can't be
modified.

Change-Id: I3ba5b3f03bd9f0413c98feefa9ad9571f82e8f0d
Reviewed-by: Frank Meerkoetter <frank.meerkoetter@basyskom.com>

1 files changed, 0 insertions, 3 deletions

diff --git a/src/opcua/client/qopcuaclient.h b/src/opcua/client/qopcuaclient.h
index 604c5f4..15c9ee2 100644
--- a/src/opcua/client/qopcuaclient.h
+++ b/src/opcua/client/qopcuaclient.h
@@ -39,7 +39,6 @@
 
 #include <QtOpcUa/qopcuaglobal.h>
 #include <QtOpcUa/qopcuanode.h>
-#include <QtOpcUa/qopcuasubscription.h>
 
 #include <QtCore/qobject.h>
 #include <QtCore/qurl.h>
@@ -82,8 +81,6 @@ public:
     Q_INVOKABLE void disconnectFromEndpoint();
     QOpcUaNode *node(const QString &nodeId);
 
-    QOpcUaSubscription *createSubscription(quint32 interval);
-
     QUrl url() const;
 
     ClientState state() const;