QJsonObject: use QJsonValueConstRef

Change-Id: I5e52dc5b093c43a3b678fffd16b608f32f8eb4b4
Reviewed-by: Sona Kurazyan <sona.kurazyan@qt.io>

3 files changed, 26 insertions, 77 deletions

diff --git a/src/corelib/serialization/qjsonobject.cpp b/src/corelib/serialization/qjsonobject.cpp
index a06af5d02d..502d64d854 100644
--- a/src/corelib/serialization/qjsonobject.cpp
+++ b/src/corelib/serialization/qjsonobject.cpp
@@ -1003,11 +1003,16 @@ QJsonObject::const_iterator QJsonObject::constFindImpl(T key) const
     \sa key()
 */
 
-/*! \fn QJsonValueRef *QJsonObject::iterator::operator->() const
+/*! \fn QJsonValueRef *QJsonObject::iterator::operator->()
 
     Returns a pointer to a modifiable reference to the current item.
 */
 
+/*! \fn const QJsonValueConstRef *QJsonObject::iterator::operator->() const
+
+    Returns a pointer to a constant reference to the current item.
+*/
+
 /*! \fn const QJsonValueRef QJsonObject::iterator::operator[](qsizetype j)
 
     Returns a modifiable reference to the item at offset \a j from the
@@ -1238,14 +1243,14 @@ QJsonObject::const_iterator QJsonObject::constFindImpl(T key) const
     \sa value()
 */
 
-/*! \fn QJsonValueRef QJsonObject::const_iterator::value() const
+/*! \fn QJsonValueConstRef QJsonObject::const_iterator::value() const
 
     Returns the current item's value.
 
     \sa key(), operator*()
 */
 
-/*! \fn const QJsonValueRef QJsonObject::const_iterator::operator*() const
+/*! \fn const QJsonValueConstRef QJsonObject::const_iterator::operator*() const
 
     Returns the current item's value.
 
@@ -1254,12 +1259,12 @@ QJsonObject::const_iterator QJsonObject::constFindImpl(T key) const
     \sa key()
 */
 
-/*! \fn const QJsonValueRef *QJsonObject::const_iterator::operator->() const
+/*! \fn const QJsonValueConstRef *QJsonObject::const_iterator::operator->() const
 
     Returns a pointer to the current item.
 */
 
-/*! \fn const QJsonValue QJsonObject::const_iterator::operator[](qsizetype j)
+/*! \fn const QJsonValueConstRef QJsonObject::const_iterator::operator[](qsizetype j)
 
     Returns the item at offset \a j from the item pointed to by this iterator (the item at
     position \c{*this + j}).
diff --git a/src/corelib/serialization/qjsonobject.h b/src/corelib/serialization/qjsonobject.h
index 5c0cc1f5dc..e569d85192 100644
--- a/src/corelib/serialization/qjsonobject.h
+++ b/src/corelib/serialization/qjsonobject.h
@@ -121,7 +121,7 @@ public:
     {
         friend class const_iterator;
         friend class QJsonObject;
-        mutable QJsonValueRef item;
+        QJsonValueRef item;
 
     public:
         typedef std::random_access_iterator_tag iterator_category;
@@ -144,7 +144,8 @@ public:
         inline QString key() const { return item.o->keyAt(item.index); }
         inline QJsonValueRef value() const { return item; }
         inline QJsonValueRef operator*() const { return item; }
-        inline QJsonValueRef *operator->() const { return &item; }
+        inline const QJsonValueConstRef *operator->() const { return &item; }
+        inline QJsonValueRef *operator->() { return &item; }
         const QJsonValueRef operator[](qsizetype j) { return { item.o, qsizetype(item.index) + j }; }
 
         inline bool operator==(const iterator &other) const
@@ -184,14 +185,14 @@ public:
     class const_iterator
     {
         friend class iterator;
-        QJsonValueRef item;
+        QJsonValueConstRef item;
 
     public:
         typedef std::random_access_iterator_tag iterator_category;
         typedef qsizetype difference_type;
         typedef QJsonValue value_type;
-        typedef const QJsonValueRef reference;
-        typedef const QJsonValueRef *pointer;
+        typedef const QJsonValueConstRef reference;
+        typedef const QJsonValueConstRef *pointer;
 
         inline const_iterator() : item(static_cast<QJsonObject*>(nullptr), 0) { }
         inline const_iterator(const QJsonObject *obj, qsizetype index)
@@ -208,10 +209,10 @@ public:
         }
 
         inline QString key() const { return item.o->keyAt(item.index); }
-        inline QJsonValueRef value() const { return item; }
-        inline const QJsonValueRef operator*() const { return item; }
-        inline const QJsonValueRef *operator->() const { return &item; }
-        const QJsonValueRef operator[](qsizetype j) { return { item.o, qsizetype(item.index) + j }; }
+        inline QJsonValueConstRef value() const { return item; }
+        inline const QJsonValueConstRef operator*() const { return item; }
+        inline const QJsonValueConstRef *operator->() const { return &item; }
+        const QJsonValueConstRef operator[](qsizetype j) { return { item.o, qsizetype(item.index) + j }; }
 
         inline bool operator==(const const_iterator &other) const
         { return item.o == other.item.o && item.index == other.item.index; }
diff --git a/tests/auto/gui/kernel/qhighdpi/tst_qhighdpi.cpp b/tests/auto/gui/kernel/qhighdpi/tst_qhighdpi.cpp
index cd721f249b..98c045aeaf 100644
--- a/tests/auto/gui/kernel/qhighdpi/tst_qhighdpi.cpp
+++ b/tests/auto/gui/kernel/qhighdpi/tst_qhighdpi.cpp
@@ -205,65 +205,6 @@ QJsonObject tst_QHighDpi::offscreenConfiguration()
     return getConfiguration(platformNativeInterface);
 }
 
-// JsonValueRef implements support for mutating nested JSON structures, e.g.
-//
-//   JsonValueRef::get(&config)["screens"][0]["logicalDpi"] = 192
-//
-class JsonValueRef {
-public:
-    static JsonValueRef get(QJsonValue *value) {
-        return JsonValueRef(value);
-    }
-
-    JsonValueRef(QJsonValue *value)
-        : m_value(value) { }
-
-    JsonValueRef(QJsonValue *value, JsonValueRef *parent, QString key)
-        : m_value(value), m_parent(parent), m_key(key) { }
-
-    JsonValueRef(QJsonValue *value, JsonValueRef *parent, int index)
-        : m_value(value), m_parent(parent), m_index(index) { }
-
-    ~JsonValueRef() {
-        if (m_parent) {
-            if (!m_key.isNull()) {
-                QJsonObject parentObject = m_parent->m_value->toObject();
-                parentObject[m_key] = *m_value;
-                *m_parent->m_value = parentObject;
-            } else if (m_index > -1) {
-                QJsonArray parentArray = m_parent->m_value->toArray();
-                parentArray[m_index] = *m_value;
-                *m_parent->m_value = parentArray;
-            }
-            delete m_value; // owned if we have a parent, see operator[]
-        }
-    }
-
-    JsonValueRef operator[](const char *str) {
-        QString key = QString::fromUtf8(str);
-        return JsonValueRef(new QJsonValue((*m_value)[key]), this, key);
-    }
-
-    JsonValueRef operator[](int index) {
-        return JsonValueRef(new QJsonValue((*m_value)[index]), this, index);
-    }
-
-    void operator=(int value) {
-        *m_value = QJsonValue(value);
-    }
-
-    void operator=(const char *str) {
-        *m_value = QJsonValue(QString(str));
-    }
-
-private:
-    Q_DISABLE_COPY(JsonValueRef);
-    QJsonValue *m_value = nullptr;
-    JsonValueRef *m_parent = nullptr;
-    QString m_key;
-    int m_index = -1;
-};
-
 void tst_QHighDpi::cleanup()
 {
     // Some test functions set environment variables. Unset them here,
@@ -329,10 +270,12 @@ void tst_QHighDpi::screenDpiChange()
     // Set new DPI
     int newDpi = 192;
     QJsonValue config = offscreenConfiguration();
-    JsonValueRef::get(&config)["screens"][0]["logicalDpi"] = newDpi;
-    JsonValueRef::get(&config)["screens"][1]["logicalDpi"] = newDpi;
-    JsonValueRef::get(&config)["screens"][2]["logicalDpi"] = newDpi;
-    setOffscreenConfiguration(config.toObject());
+    // API defect until Qt 7, so go indirectly via CBOR
+    QCborMap map = QCborMap::fromJsonObject(config.toObject());
+    map[QLatin1String("screens")][0][QLatin1String("logicalDpi")] = newDpi;
+    map[QLatin1String("screens")][1][QLatin1String("logicalDpi")] = newDpi;
+    map[QLatin1String("screens")][2][QLatin1String("logicalDpi")] = newDpi;
+    setOffscreenConfiguration(map.toJsonObject());
 
     // TODO check events