qt: Add support for stringValueList in CryptoConf

* lang/qt/src/Makefile.am (qgpgme_sources): Add cryptoconfig.cpp
* lang/qt/src/cryptoconfig.cpp: New.
* lang/qt/src/cryptoconfig.h (CryptoConfigEntry::stringValueList):
New.
* lang/qt/src/qgpgmenewcryptoconfig.cpp
(QGpgMENewCryptoConfigEntry::stringValueList): New.
* lang/qt/src/qgpgmenewcryptoconfig.h: Update accordingly.

--
This is a pardigm change in cryptoconfig.h to avoid ABI breaks
with each new config value we support it now has an implementation
that is directly related to qgpgmenewcryptoconfig, which is now
the only one.

NEWS

@@ -11,6 +11,7 @@ Noteworthy changes in version 1.8.1 (unreleased)
  cpp: Context::startAddUid(const Key&, const char*) NEW.
  cpp: Key::UserID::revoke()                         NEW.
  cpp: Key::addUid()                                 NEW.
+ qt: CryptoConfig::stringValueList()                NEW.
 
 
 Noteworthy changes in version 1.8.0 (2016-11-16)

lang/qt/src/Makefile.am

@@ -37,7 +37,7 @@ qgpgme_sources = \
     qgpgmekeyformailboxjob.cpp gpgme_backend_debug.cpp \
     qgpgmetofupolicyjob.cpp \
     defaultkeygenerationjob.cpp qgpgmewkspublishjob.cpp \
-    dn.cpp
+    dn.cpp cryptoconfig.cpp
 
 # If you add one here make sure that you also add one in camelcase
 qgpgme_headers= \

lang/qt/src/cryptoconfig.cpp

@@ -0,0 +1,44 @@
+/*
+    cryptoconfig.cpp
+
+    This file is part of qgpgme, the Qt API binding for gpgme
+    Copyright (c) 2017 Intevation GmbH
+
+    QGpgME is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    QGpgME 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
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+#include "cryptoconfig.h"
+#include "qgpgmenewcryptoconfig.h"
+
+using namespace QGpgME;
+
+QStringList CryptoConfigEntry::stringValueList() const
+{
+    const QGpgMENewCryptoConfigEntry *entry = dynamic_cast <const QGpgMENewCryptoConfigEntry*> (this);
+    if (!entry) {
+        return QStringList();
+    }
+    return entry->stringValueList();
+}

lang/qt/src/cryptoconfig.h

@@ -248,6 +248,15 @@ public:
      * @return true if the value was changed
      */
     virtual bool isDirty() const = 0;
+
+    // Design change from here on we are closely bound to one implementation
+    // of cryptoconfig. To avoid ABI breaks with every new function we
+    // add real functions from now on.
+
+    /**
+     * @return a stringValueList.
+     */
+    QStringList stringValueList() const;
 };
 
 /**

lang/qt/src/qgpgmenewcryptoconfig.cpp

@@ -546,6 +546,18 @@ std::vector<unsigned int> QGpgMENewCryptoConfigEntry::uintValueList() const
     return m_option.currentValue().uintValues();
 }
 
+QStringList QGpgMENewCryptoConfigEntry::stringValueList() const
+{
+    Q_ASSERT(isList());
+    const Argument arg = m_option.currentValue();
+    const std::vector<const char *> values = arg.stringValues();
+    QStringList ret;
+    for(const char *value: values) {
+        ret << QString::fromUtf8(value);
+    }
+    return ret;
+}
+
 QList<QUrl> QGpgMENewCryptoConfigEntry::urlValueList() const
 {
     const Type type = m_option.type();

lang/qt/src/qgpgmenewcryptoconfig.h

@@ -93,6 +93,8 @@ public:
     void setURLValueList(const QList<QUrl> &) Q_DECL_OVERRIDE;
     bool isDirty() const Q_DECL_OVERRIDE;
 
+    QStringList stringValueList() const;
+
 #if 0
     void setDirty(bool b);
     QString outputString() const;