Add conversion between QVariantHash and QJsonObject

Adds automatic conversion from QVariants with a QVariantHash to
QJsonValue and explicit methods for conversion between QVariantHash
and QJsonObject.

[ChangeLog][QtCore][QJsonObject] Added conversion to and from QVariantHash

Change-Id: I140ef881463acabaab2648e28209487d8ad18e0d
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

src/corelib/json/qjsonobject.cpp

@@ -192,7 +192,7 @@ QJsonObject &QJsonObject::operator =(const QJsonObject &other)
     The keys in \a map will be used as the keys in the JSON object,
     and the QVariant values will be converted to JSON values.
 
-    \sa toVariantMap(), QJsonValue::fromVariant()
+    \sa fromVariantHash(), toVariantMap(), QJsonValue::fromVariant()
  */
 QJsonObject QJsonObject::fromVariantMap(const QVariantMap &map)
 {
@@ -208,6 +208,8 @@ QJsonObject QJsonObject::fromVariantMap(const QVariantMap &map)
     Converts this object to a QVariantMap.
 
     Returns the created map.
+
+    \sa toVariantHash()
  */
 QVariantMap QJsonObject::toVariantMap() const
 {
@@ -221,6 +223,45 @@ QVariantMap QJsonObject::toVariantMap() const
     return map;
 }
 
+/*!
+    Converts the variant hash \a hash to a QJsonObject.
+    \since 5.5
+
+    The keys in \a hash will be used as the keys in the JSON object,
+    and the QVariant values will be converted to JSON values.
+
+    \sa fromVariantMap(), toVariantHash(), QJsonValue::fromVariant()
+ */
+QJsonObject QJsonObject::fromVariantHash(const QVariantHash &hash)
+{
+    // ### this is implemented the trivial way, not the most efficient way
+
+    QJsonObject object;
+    for (QVariantHash::const_iterator it = hash.constBegin(); it != hash.constEnd(); ++it)
+        object.insert(it.key(), QJsonValue::fromVariant(it.value()));
+    return object;
+}
+
+/*!
+    Converts this object to a QVariantHash.
+    \since 5.5
+
+    Returns the created hash.
+
+    \sa toVariantMap()
+ */
+QVariantHash QJsonObject::toVariantHash() const
+{
+    QVariantHash hash;
+    if (o) {
+        for (uint i = 0; i < o->length; ++i) {
+            QJsonPrivate::Entry *e = o->entryAt(i);
+            hash.insert(e->key(), QJsonValue(d, o, e->value).toVariant());
+        }
+    }
+    return hash;
+}
+
 /*!
     Returns a list of all keys in this object.
  */

src/corelib/json/qjsonobject.h

@@ -46,6 +46,8 @@ QT_BEGIN_NAMESPACE
 class QDebug;
 template <class Key, class T> class QMap;
 typedef QMap<QString, QVariant> QVariantMap;
+template <class Key, class T> class QHash;
+typedef QHash<QString, QVariant> QVariantHash;
 
 class Q_CORE_EXPORT QJsonObject
 {
@@ -68,6 +70,8 @@ public:
 
     static QJsonObject fromVariantMap(const QVariantMap &map);
     QVariantMap toVariantMap() const;
+    static QJsonObject fromVariantHash(const QVariantHash &map);
+    QVariantHash toVariantHash() const;
 
     QStringList keys() const;
     int size() const;

src/corelib/json/qjsonvalue.cpp

@@ -373,6 +373,7 @@ QJsonValue &QJsonValue::operator =(const QJsonValue &other)
         \li
             \list
                 \li QMetaType::QVariantMap
+                \li QMetaType::QVariantHash
             \endlist
         \li QJsonValue::Object
     \endtable
@@ -402,6 +403,8 @@ QJsonValue QJsonValue::fromVariant(const QVariant &variant)
         return QJsonValue(QJsonArray::fromVariantList(variant.toList()));
     case QVariant::Map:
         return QJsonValue(QJsonObject::fromVariantMap(variant.toMap()));
+    case QVariant::Hash:
+        return QJsonValue(QJsonObject::fromVariantHash(variant.toHash()));
     default:
         break;
     }

tests/auto/corelib/json/tst_qtjson.cpp

@@ -90,7 +90,9 @@ private Q_SLOTS:
 
     void fromVariant();
     void fromVariantMap();
+    void fromVariantHash();
     void toVariantMap();
+    void toVariantHash();
     void toVariantList();
 
     void toJson();
@@ -1165,6 +1167,17 @@ void tst_QtJson::fromVariantMap()
     QCOMPARE(array.at(3).toString(), QLatin1String("foo"));
 }
 
+void tst_QtJson::fromVariantHash()
+{
+    QVariantHash map;
+    map.insert(QLatin1String("key1"), QLatin1String("value1"));
+    map.insert(QLatin1String("key2"), QLatin1String("value2"));
+    QJsonObject object = QJsonObject::fromVariantHash(map);
+    QCOMPARE(object.size(), 2);
+    QCOMPARE(object.value(QLatin1String("key1")), QJsonValue(QLatin1String("value1")));
+    QCOMPARE(object.value(QLatin1String("key2")), QJsonValue(QLatin1String("value2")));
+}
+
 void tst_QtJson::toVariantMap()
 {
     QCOMPARE(QMetaType::Type(QJsonValue(QJsonObject()).toVariant().type()), QMetaType::QVariantMap); // QTBUG-32524
@@ -1196,6 +1209,35 @@ void tst_QtJson::toVariantMap()
     QCOMPARE(list.at(3), QVariant());
 }
 
+void tst_QtJson::toVariantHash()
+{
+    QJsonObject object;
+    QVariantHash hash = object.toVariantHash();
+    QVERIFY(hash.isEmpty());
+
+    object.insert("Key", QString("Value"));
+    object.insert("null", QJsonValue());
+    QJsonArray array;
+    array.append(true);
+    array.append(999.);
+    array.append(QLatin1String("string"));
+    array.append(QJsonValue());
+    object.insert("Array", array);
+
+    hash = object.toVariantHash();
+
+    QCOMPARE(hash.size(), 3);
+    QCOMPARE(hash.value("Key"), QVariant(QString("Value")));
+    QCOMPARE(hash.value("null"), QVariant());
+    QCOMPARE(hash.value("Array").type(), QVariant::List);
+    QVariantList list = hash.value("Array").toList();
+    QCOMPARE(list.size(), 4);
+    QCOMPARE(list.at(0), QVariant(true));
+    QCOMPARE(list.at(1), QVariant(999.));
+    QCOMPARE(list.at(2), QVariant(QLatin1String("string")));
+    QCOMPARE(list.at(3), QVariant());
+}
+
 void tst_QtJson::toVariantList()
 {
     QCOMPARE(QMetaType::Type(QJsonValue(QJsonArray()).toVariant().type()), QMetaType::QVariantList); // QTBUG-32524