qt: Allow retrieving the default value of a config entry

* lang/qt/src/cryptoconfig.cpp, lang/qt/src/cryptoconfig.h
(CryptoConfigEntry::defaultValue): New.
* lang/qt/src/qgpgmenewcryptoconfig.cpp,
lang/qt/src/qgpgmenewcryptoconfig.h
(QGpgMENewCryptoConfigEntry::defaultValue): New.
* lang/qt/tests/t-config.cpp (CryptoConfigTest::testDefault()):
Add test of CryptoConfigEntry::defaultValue(). Port away from deprecated
CryptoConfig::entry overload.
--

GnuPG-bug-id: 5515

lang/qt/src/cryptoconfig.cpp

@@ -44,6 +44,15 @@ QStringList CryptoConfigEntry::stringValueList() const
     return entry->stringValueList();
 }
 
+QVariant CryptoConfigEntry::defaultValue() const
+{
+    const QGpgMENewCryptoConfigEntry *entry = dynamic_cast <const QGpgMENewCryptoConfigEntry*>(this);
+    if (!entry) {
+        return {};
+    }
+    return entry->defaultValue();
+}
+
 QGpgME::CryptoConfigEntry *CryptoConfig::entry(const QString &componentName, const QString &entryName) const
 {
     const CryptoConfigComponent *comp = component(componentName);

lang/qt/src/cryptoconfig.h

@@ -44,6 +44,8 @@
 
 #include <vector>
 
+class QVariant;
+
 /* Start reading this file from the bottom up :) */
 
 namespace QGpgME
@@ -258,6 +260,11 @@ public:
      * @return a stringValueList.
      */
     QStringList stringValueList() const;
+
+    /**
+     * Return the default value as a variant (available for all argtypes).
+     */
+    QVariant defaultValue() const;
 };
 
 /**

lang/qt/src/qgpgmenewcryptoconfig.cpp

@@ -43,6 +43,7 @@
 
 #include <QFile>
 #include <QDir>
+#include <QList>
 
 #include "global.h"
 #include "error.h"
@@ -710,6 +711,57 @@ bool QGpgMENewCryptoConfigEntry::isDirty() const
     return m_option.dirty();
 }
 
+QVariant QGpgMENewCryptoConfigEntry::defaultValue() const
+{
+    const auto defaultValue = m_option.defaultValue();
+    if (defaultValue.isNull() || defaultValue.numElements() == 0) {
+        return {};
+    }
+    if (defaultValue.numElements() == 1) {
+        switch (m_option.alternateType()) {
+        case NoType:
+            return QVariant{defaultValue.boolValue()};
+        case StringType:
+            return QVariant{QString::fromUtf8(defaultValue.stringValue())};
+        case IntegerType:
+            return QVariant{defaultValue.intValue()};
+        case UnsignedIntegerType:
+            return QVariant{defaultValue.uintValue()};
+        default:
+            // alternateType should always be one of the above four types
+            qCWarning(QGPGME_LOG) << __func__ << ": unsupported alternateType" << m_option.alternateType();
+        }
+    } else {
+        QList<QVariant> list;
+        switch (m_option.alternateType()) {
+        case StringType: {
+            const auto values = defaultValue.stringValues();
+            std::transform(std::begin(values), std::end(values), std::back_inserter(list),
+                          [] (const char *value) { return QVariant{QString::fromUtf8(value)}; });
+            break;
+        }
+        case IntegerType: {
+            const auto values = defaultValue.intValues();
+            std::transform(std::begin(values), std::end(values), std::back_inserter(list),
+                          [] (int value) { return QVariant{value}; });
+            break;
+        }
+        case UnsignedIntegerType: {
+            const auto values = defaultValue.uintValues();
+            std::transform(std::begin(values), std::end(values), std::back_inserter(list),
+                          [] (unsigned int value) { return QVariant{value}; });
+            break;
+        }
+        default:
+            // alternateType should always be one of the above four types
+            qCWarning(QGPGME_LOG) << __func__ << ": unsupported alternateType" << m_option.alternateType() << "for list";
+        }
+        return QVariant{list};
+    }
+
+    return {};
+}
+
 #if 0
 QString QGpgMENewCryptoConfigEntry::toString(bool escape) const
 {

lang/qt/src/qgpgmenewcryptoconfig.h

@@ -95,6 +95,7 @@ public:
     bool isDirty() const Q_DECL_OVERRIDE;
 
     QStringList stringValueList() const;
+    QVariant defaultValue() const;
 
 #if 0
     void setDirty(bool b);

lang/qt/tests/t-config.cpp

@@ -57,27 +57,24 @@ private Q_SLOTS:
             // be unsupported in older versions.
             return;
         }
-        // First set compliance to de-vs
         auto conf = cryptoConfig();
         QVERIFY(conf);
-        auto entry = conf->entry(QStringLiteral("gpg"),
-                QStringLiteral("Configuration"),
-                QStringLiteral("compliance"));
+        auto entry = conf->entry(QStringLiteral("gpg"), QStringLiteral("compliance"));
         QVERIFY(entry);
+        const auto defaultValue = entry->defaultValue().toString();
+        QCOMPARE(defaultValue, QStringLiteral("gnupg"));
+
         entry->setStringValue("de-vs");
         conf->sync(true);
         conf->clear();
-        entry = conf->entry(QStringLiteral("gpg"),
-                QStringLiteral("Configuration"),
-                QStringLiteral("compliance"));
+        entry = conf->entry(QStringLiteral("gpg"), QStringLiteral("compliance"));
         QCOMPARE(entry->stringValue(), QStringLiteral("de-vs"));
+
         entry->resetToDefault();
         conf->sync(true);
         conf->clear();
-        entry = conf->entry(QStringLiteral("gpg"),
-                QStringLiteral("Configuration"),
-                QStringLiteral("compliance"));
-        QCOMPARE(entry->stringValue(), QStringLiteral("gnupg"));
+        entry = conf->entry(QStringLiteral("gpg"), QStringLiteral("compliance"));
+        QCOMPARE(entry->stringValue(), defaultValue);
     }
 
     void initTestCase()