Add Assuan transaction that forwards status lines to another object

* lang/cpp/src/Makefile.am: Add new files.
* lang/cpp/src/interfaces/statusconsumer.h,
lang/cpp/src/statusconsumerassuantransaction.cpp,
lang/cpp/src/statusconsumerassuantransaction.h: New.
* NEWS: Mention new API.
--

This Assuan transaction is useful for long running Assuan commands.
Classes implementing the StatusConsumer interface can process received
status lines while the Assuan command is still running.

GnuPG-bug-id: 5066

1 files changed, 42 insertions, 0 deletions

diff --git a/lang/cpp/src/interfaces/statusconsumer.h b/lang/cpp/src/interfaces/statusconsumer.h
new file mode 100644
index 00000000..a819fccf
--- /dev/null
+++ b/lang/cpp/src/interfaces/statusconsumer.h
@@ -0,0 +1,42 @@
+/*
+  statusconsumer.h - Interface for status callbacks
+  Copyright (c) 2020 g10 Code GmbH
+  Software engineering by Ingo Klöcker <[email protected]>
+
+  This file is part of GPGME++.
+
+  GPGME++ is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Library General Public
+  License as published by the Free Software Foundation; either
+  version 2 of the License, or (at your option) any later version.
+
+  GPGME++ is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU Library General Public License for more details.
+
+  You should have received a copy of the GNU Library General Public License
+  along with GPGME++; see the file COPYING.LIB.  If not, write to the
+  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+  Boston, MA 02110-1301, USA.
+*/
+
+#ifndef __GPGMEPP_INTERFACES_STATUSCONSUMER_H__
+#define __GPGMEPP_INTERFACES_STATUSCONSUMER_H__
+
+#include "gpgmepp_export.h"
+
+namespace GpgME
+{
+
+class GPGMEPP_EXPORT StatusConsumer
+{
+public:
+    virtual ~StatusConsumer() {}
+
+    virtual void status(const char *status, const char *details) = 0;
+};
+
+} // namespace GpgME
+
+#endif // __GPGMEPP_INTERFACES_STATUSCONSUMER_H__