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, 100 insertions, 0 deletions

diff --git a/src/opcua/client/qopcuamonitoringparameters_p.h b/src/opcua/client/qopcuamonitoringparameters_p.h
new file mode 100644
index 0000000..5b6e824
--- /dev/null
+++ b/src/opcua/client/qopcuamonitoringparameters_p.h
@@ -0,0 +1,100 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 basysKom GmbH, opensource@basyskom.com
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtOpcUa module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QOPCUAMONITORINGPARAMETERS_P_H
+#define QOPCUAMONITORINGPARAMETERS_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtOpcUa/qopcuamonitoringparameters.h>
+
+#include <QtCore/qshareddata.h>
+
+QT_BEGIN_NAMESPACE
+
+class Q_OPCUA_EXPORT QOpcUaMonitoringParametersPrivate : public QSharedData
+{
+public:
+
+    QOpcUaMonitoringParametersPrivate()
+        : samplingInterval(0)
+        , queueSize(0)
+        , discardOldest(true)
+        , monitoringMode(QOpcUaMonitoringParameters::MonitoringMode::Reporting)
+        , subscriptionId(0)
+        , publishingInterval(0)
+        , lifetimeCount(0)
+        , maxKeepAliveCount(0)
+        , maxNotificationsPerPublish(0)
+        , priority(0)
+        , publishingEnabled(true)
+        , statusCode(QOpcUa::UaStatusCode::BadAttributeIdInvalid)
+        , shared(QOpcUaMonitoringParameters::SubscriptionType::Shared)
+    {}
+
+    // MonitoredItem
+    double samplingInterval;
+    QVariant filter;
+    quint32 queueSize;
+    bool discardOldest;
+    QOpcUaMonitoringParameters::MonitoringMode monitoringMode;
+
+    // Subscription
+    quint32 subscriptionId;
+    double publishingInterval;
+    quint32 lifetimeCount;
+    quint32 maxKeepAliveCount;
+    quint32 maxNotificationsPerPublish;
+    quint8 priority;
+    bool publishingEnabled;
+
+    // QtOpcUa specific
+    QOpcUa::UaStatusCode statusCode;
+    QOpcUaMonitoringParameters::SubscriptionType shared;
+};
+
+QT_END_NAMESPACE
+
+#endif // QOPCUAMONITORINGPARAMETERS_P_H