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Lts/Services/AudioVideoManagement/list_response_collector.h

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+/**
+  * @RDE_HEADER@
+  * ListResponseCollector
+  * $Id$
+  * $HeadURL$
+  * $Author$
+  * Created by Christian Fröbel, NLE, 2018-12-18
+  */
+
+#pragma once
+
+#include "iava_comm.h"
+#include "ava_types.h"
+#include "avm_export.h"
+#include <QVector>
+#include <QList>
+#include <QObject>
+#include <functional>
+
+class QString;
+class QByteArray;
+
+namespace AudioVideoManagement
+{
+
+class StreamNameMapping;
+
+/**
+ * Internal helper class for ListResponseCollector.
+ *
+ * @author Christian Fröbel
+ */
+template<class ResultContainer, class ElementFactory>
+class ListResponseCollectorHelper
+{
+public:
+  using DoneCallback  = std::function<void(ResultContainer &&)>;
+  using AliveCallback = std::function<void()>;
+
+  ListResponseCollectorHelper(IAvaComm *comm, const DoneCallback &doneCallback, const ElementFactory &elementFactory = {});
+
+  /**
+   * @param aliveCallback may be empty, i.e. no callback given.
+   */
+  ListResponseCollectorHelper(IAvaComm *comm, const DoneCallback &doneCallback, const AliveCallback &aliveCallback, const ElementFactory &elementFactory = {});
+
+  /**
+   * Connect to the signals and start collecting; stop after the list was collected.
+   * May be called again when the doneCallback was called.
+   */
+  void start();
+  void reset();
+
+private:
+  void onListValueReceived(const QVector<QByteArray> &parts);
+  void onEndOfListReceived();
+
+  QObject           m_hint; //!< used to control the lifetime of the signal-to-lambda connections
+  IAvaComm         *m_comm;
+  DoneCallback      m_doneCallback;
+  AliveCallback     m_aliveCallback;
+  ElementFactory    m_elementFactory;
+  bool              m_started{false};
+  ResultContainer   m_elements;
+  unsigned          m_elementCount{0};
+};
+
+
+/**
+ * Template class for collecting the list responses on the RCP_AVA interface to AVS_Workstation.
+ *
+ * It works ontop of IAvaComm. It connects to the following three signals:
+ * - a list-specific signal that marks the begin of the list, e.g. IAvaComm::invalidNameListBeginReceived()
+ * - IAvaComm::listValueReceived(const QVector<QString> &parts)
+ * - IAvaComm::endOfListReceived()
+ * The first list-specific signal must be specified as 2nd template parameter.
+ * The 3rd template parameter is a factory functor that creates an element of type T
+ * from the parts as signalled by IAvaComm::listValueReceived().
+ * As a result a QVector<T> is built where T is the 1st template parameter.
+ * When the list response is finished the DoneCallback given to the constructor will be called.
+ *
+ * The user does not need to specify the template parameters himself.
+ * There are predefined type aliases for the different types of list responses.
+ *
+ * For the list response of QueryTimeline there exists a separate collector-class: TimelineListCollector
+ *
+ * @see StreamListCollector
+ * @see InvalidNameListCollector
+ * @see ElokaListCollector
+ * @see QueryElokaListCollector
+ * @see TimelineListCollector
+ *
+ * @author Christian Fröbel
+ */
+template<class T, void (IAvaComm::*listBeginSignal)(), class ElementFactory>
+class ListResponseCollector
+{
+private:
+  using Helper = ListResponseCollectorHelper<QVector<T>, ElementFactory>;
+
+public:
+  using DoneCallback = typename Helper::DoneCallback;
+
+  ListResponseCollector(IAvaComm *comm, const DoneCallback &doneCallback, const ElementFactory &elementFactory = ElementFactory{});
+
+  /**
+   * Connect to the signals and start collecting; stop after the list was collected.
+   * May be called again when the doneCallback was called.
+   */
+  void start();
+
+  /**
+   * Reset the collector.
+   * Can be useful in case the connection to AVS breaks in the middle of receiving a list.
+   */
+  void reset();
+
+private:
+  void onBeginOfListReceived();
+  void onDone(QVector<T> &&result);
+
+  QObject        m_hint;
+  IAvaComm      *m_comm;
+  DoneCallback   m_doneCallback;
+  bool           m_started{false};
+  Helper         m_helper;
+};
+
+
+struct AVM_COMMON_EXPORT TimelineListElementFactory
+{
+  AvaTimelinePart operator()(const QVector<QByteArray> &parts) const;
+};
+
+
+/**
+ * A special collector-implementation for the list-reponse of QueryTimeline.
+ * The reason for this is that the list-begin-signal takes a parameter (IAvaComm::timelineListBegin(const QString&))
+ * and thus we cannot use the generalized ListCollector.
+ *
+ * The result as passed to the DoneCallback is an AvaTimeline.
+ *
+ * @author Christian Fröbel
+ */
+class AVM_COMMON_EXPORT TimelineListCollector
+{
+private:
+  using Helper = ListResponseCollectorHelper<AvaTimeline, TimelineListElementFactory>;
+
+public:
+  using DoneCallback  = typename Helper::DoneCallback;
+  using AliveCallback = typename Helper::AliveCallback;
+
+  /**
+   * @param aliveCallback may be empty, i.e. no callback given.
+   */
+  TimelineListCollector(IAvaComm *comm, const QString &streamName, const DoneCallback &doneCallback, const AliveCallback &aliveCallback);
+
+  /**
+   * Connect to the signals and start collecting; stop after the list was collected.
+   * May be called again when the doneCallback was called.
+   */
+  void start();
+
+private:
+  void onBeginOfListReceived(const QString &streamName);
+  void onDone(AvaTimeline &&timeline);
+
+  QObject         m_hint;
+  IAvaComm       *m_comm;
+  const QString   m_streamName;
+  DoneCallback    m_doneCallback;
+  bool            m_started{false};
+  Helper          m_helper;
+};
+
+
+class StreamListElementFactory
+{
+public:
+  StreamListElementFactory(AvaStreamType streamType, AvaStreamSource streamSource, StreamNameMapping *streamNameMapping);
+
+  AvaStream operator()(const QVector<QByteArray> &parts) const;
+
+private:
+  const AvaStreamType        m_streamType;
+  const AvaStreamSource      m_streamSource;
+  StreamNameMapping         *m_streamNameMapping;
+};
+
+
+struct InvalidNameListElementFactory
+{
+  QString operator()(const QVector<QByteArray> &parts) const;
+};
+
+
+using ElokaListElementFactory = InvalidNameListElementFactory;
+
+
+struct QueryElokaListElementFactory
+{
+  AvaEloka operator()(const QVector<QByteArray> &parts) const;
+};
+
+
+/** @name Concrete collector types. */
+///@{
+using StreamListCollector      = ListResponseCollector<AvaStream, &IAvaComm::streamListBeginReceived, StreamListElementFactory>;
+using InvalidNameListCollector = ListResponseCollector<QString, &IAvaComm::invalidNameListBeginReceived, InvalidNameListElementFactory>;
+using ElokaListCollector       = ListResponseCollector<QString, &IAvaComm::elokaListBeginReceived, ElokaListElementFactory>;
+using QueryElokaListCollector  = ListResponseCollector<AvaEloka, &IAvaComm::queryElokaListBeginReceived, QueryElokaListElementFactory>;
+///@}
+
+} // namespace AudioVideoManagement