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

5 files changed, 166 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index 830d206e..96520552 100644
--- a/NEWS
+++ b/NEWS
@@ -20,6 +20,8 @@ Noteworthy changes in version 1.14.1 (unreleased)
  cpp: EngineInfo::Version::operator<=       NEW.
  cpp: EngineInfo::Version::operator>=       NEW.
  cpp: EngineInfo::Version::operator!=       NEW.
+ cpp: StatusConsumer                        NEW.
+ cpp: StatusConsumerAssuanTransaction       NEW.
  qt: operator<<(QDebug debug, const GpgME::Error &err) NEW.
 
 
diff --git a/lang/cpp/src/Makefile.am b/lang/cpp/src/Makefile.am
index 1b1de327..32e3045c 100644
--- a/lang/cpp/src/Makefile.am
+++ b/lang/cpp/src/Makefile.am
@@ -35,6 +35,7 @@ main_sources = \
     gpgadduserideditinteractor.cpp gpggencardkeyinteractor.cpp \
     defaultassuantransaction.cpp \
     scdgetinfoassuantransaction.cpp gpgagentgetinfoassuantransaction.cpp \
+    statusconsumerassuantransaction.cpp \
     vfsmountresult.cpp configuration.cpp tofuinfo.cpp swdbresult.cpp
 
 gpgmepp_headers = \
@@ -47,6 +48,7 @@ gpgmepp_headers = \
     gpggencardkeyinteractor.h \
     importresult.h keygenerationresult.h key.h keylistresult.h \
     notation.h result.h scdgetinfoassuantransaction.h signingresult.h \
+    statusconsumerassuantransaction.h \
     trustitem.h verificationresult.h vfsmountresult.h gpgmepp_export.h \
     tofuinfo.h swdbresult.h
 
@@ -55,7 +57,8 @@ private_gpgmepp_headers = \
 
 interface_headers= \
     interfaces/assuantransaction.h interfaces/dataprovider.h \
-    interfaces/passphraseprovider.h interfaces/progressprovider.h
+    interfaces/passphraseprovider.h interfaces/progressprovider.h \
+    interfaces/statusconsumer.h
 
 gpgmeppincludedir = $(includedir)/gpgme++
 gpgmeppinclude_HEADERS = $(gpgmepp_headers)
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__
diff --git a/lang/cpp/src/statusconsumerassuantransaction.cpp b/lang/cpp/src/statusconsumerassuantransaction.cpp
new file mode 100644
index 00000000..7adfac03
--- /dev/null
+++ b/lang/cpp/src/statusconsumerassuantransaction.cpp
@@ -0,0 +1,67 @@
+/*
+  statusconsumerassuantransaction.cpp
+  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.
+*/
+
+#ifdef HAVE_CONFIG_H
+ #include "config.h"
+#endif
+
+#include "statusconsumerassuantransaction.h"
+
+#include "data.h"
+#include "error.h"
+
+#include "interfaces/statusconsumer.h"
+
+using namespace GpgME;
+
+StatusConsumerAssuanTransaction::StatusConsumerAssuanTransaction(StatusConsumer *statusConsumer)
+    : AssuanTransaction()
+    , m_consumer(statusConsumer)
+{
+}
+
+StatusConsumerAssuanTransaction::~StatusConsumerAssuanTransaction()
+{
+}
+
+Error StatusConsumerAssuanTransaction::data(const char *data, size_t datalen)
+{
+    (void) data;
+    (void) datalen;
+    return Error();
+}
+
+Data StatusConsumerAssuanTransaction::inquire(const char *name, const char *args, Error &err)
+{
+    (void)name;
+    (void)args;
+    (void)err;
+    return Data::null;
+}
+
+Error StatusConsumerAssuanTransaction::status(const char *status, const char *args)
+{
+    m_consumer->status(status, args);
+
+    return Error();
+}
diff --git a/lang/cpp/src/statusconsumerassuantransaction.h b/lang/cpp/src/statusconsumerassuantransaction.h
new file mode 100644
index 00000000..9501b0ee
--- /dev/null
+++ b/lang/cpp/src/statusconsumerassuantransaction.h
@@ -0,0 +1,51 @@
+/*
+  statusconsumerassuantransaction.h - Assuan transaction that forwards status lines to a consumer
+  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_STATUSCONSUMERASSUANTRANSACTION_H__
+#define __GPGMEPP_STATUSCONSUMERASSUANTRANSACTION_H__
+
+#include <interfaces/assuantransaction.h>
+
+namespace GpgME
+{
+
+class StatusConsumer;
+
+class GPGMEPP_EXPORT StatusConsumerAssuanTransaction: public AssuanTransaction
+{
+public:
+    explicit StatusConsumerAssuanTransaction(StatusConsumer *statusConsumer);
+    ~StatusConsumerAssuanTransaction();
+
+private:
+    Error data(const char *data, size_t datalen) override;
+    Data inquire(const char *name, const char *args, Error &err) override;
+    Error status(const char *status, const char *args) override;
+
+private:
+    StatusConsumer *m_consumer;
+};
+
+} // namespace GpgME
+
+#endif // __GPGMEPP_STATUSCONSUMERASSUANTRANSACTION_H__