ibus: de-virtualize QIBusSerializable hierarchy

These types don't inherit to be reused, they inherit to reuse.
Consequently, change the inheritance to private, remove the
virtual ~QIBusSerializable and rewrite the streaming operators
as member functions.

Remove the now-unused QIBusSerializable streaming operators and
meta-type registration.

Change-Id: Icf7a89174592ba62b39f73f0f016c8296cab5993
Reviewed-by: Takao Fujiwara <takao.fujiwara1@gmail.com>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

3 files changed, 114 insertions, 106 deletions

diff --git a/src/plugins/platforminputcontexts/ibus/main.cpp b/src/plugins/platforminputcontexts/ibus/main.cpp
index b47c0b40de..2846f52c8c 100644
--- a/src/plugins/platforminputcontexts/ibus/main.cpp
+++ b/src/plugins/platforminputcontexts/ibus/main.cpp
@@ -59,7 +59,6 @@ QIBusPlatformInputContext *QIbusPlatformInputContextPlugin::create(const QString
     Q_UNUSED(paramList);
 
     if (system.compare(system, QLatin1String("ibus"), Qt::CaseInsensitive) == 0) {
-        qDBusRegisterMetaType<QIBusSerializable>();
         qDBusRegisterMetaType<QIBusAttribute>();
         qDBusRegisterMetaType<QIBusAttributeList>();
         qDBusRegisterMetaType<QIBusText>();
diff --git a/src/plugins/platforminputcontexts/ibus/qibustypes.cpp b/src/plugins/platforminputcontexts/ibus/qibustypes.cpp
index a168836a06..9d219ff8c1 100644
--- a/src/plugins/platforminputcontexts/ibus/qibustypes.cpp
+++ b/src/plugins/platforminputcontexts/ibus/qibustypes.cpp
@@ -54,9 +54,9 @@ QIBusSerializable::~QIBusSerializable()
 {
 }
 
-const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusSerializable &object)
+void QIBusSerializable::deserializeFrom(const QDBusArgument &argument)
 {
-    argument >> object.name;
+    argument >> name;
 
     argument.beginMap();
     while (!argument.atEnd()) {
@@ -66,19 +66,18 @@ const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusSerializable
         argument >> key;
         argument >> value;
         argument.endMapEntry();
-        object.attachments[key] = value.variant().value<QDBusArgument>();
+        attachments[key] = value.variant().value<QDBusArgument>();
     }
     argument.endMap();
-    return argument;
 }
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusSerializable &object)
+void QIBusSerializable::serializeTo(QDBusArgument &argument) const
 {
-    argument << object.name;
+    argument << name;
 
     argument.beginMap(qMetaTypeId<QString>(), qMetaTypeId<QDBusVariant>());
 
-    QHashIterator<QString, QDBusArgument> i(object.attachments);
+    QHashIterator<QString, QDBusArgument> i(attachments);
     while (i.hasNext()) {
         i.next();
 
@@ -91,7 +90,6 @@ QDBusArgument &operator<<(QDBusArgument &argument, const QIBusSerializable &obje
         argument.endMapEntry();
     }
     argument.endMap();
-    return argument;
 }
 
 QIBusAttribute::QIBusAttribute()
@@ -107,39 +105,35 @@ QIBusAttribute::~QIBusAttribute()
 {
 }
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusAttribute &attribute)
+void QIBusAttribute::serializeTo(QDBusArgument &argument) const
 {
     argument.beginStructure();
 
-    argument << static_cast<const QIBusSerializable &>(attribute);
+    QIBusSerializable::serializeTo(argument);
 
-    quint32 t = (quint32) attribute.type;
+    quint32 t = (quint32) type;
     argument << t;
-    argument << attribute.value;
-    argument << attribute.start;
-    argument << attribute.end;
+    argument << value;
+    argument << start;
+    argument << end;
 
     argument.endStructure();
-
-    return argument;
 }
 
-const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusAttribute &attribute)
+void QIBusAttribute::deserializeFrom(const QDBusArgument &argument)
 {
     argument.beginStructure();
 
-    argument >> static_cast<QIBusSerializable &>(attribute);
+    QIBusSerializable::deserializeFrom(argument);
 
     quint32 t;
     argument >> t;
-    attribute.type = (QIBusAttribute::Type) t;
-    argument >> attribute.value;
-    argument >> attribute.start;
-    argument >> attribute.end;
+    type = (QIBusAttribute::Type) t;
+    argument >> value;
+    argument >> start;
+    argument >> end;
 
     argument.endStructure();
-
-    return argument;
 }
 
 QTextCharFormat QIBusAttribute::format() const
@@ -191,30 +185,30 @@ QIBusAttributeList::~QIBusAttributeList()
 {
 }
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusAttributeList &attrList)
+void QIBusAttributeList::serializeTo(QDBusArgument &argument) const
 {
     argument.beginStructure();
 
-    argument << static_cast<const QIBusSerializable &>(attrList);
+    QIBusSerializable::serializeTo(argument);
 
     argument.beginArray(qMetaTypeId<QDBusVariant>());
-    for (int i = 0; i < attrList.attributes.size(); ++i) {
+    for (int i = 0; i < attributes.size(); ++i) {
         QVariant variant;
-        variant.setValue(attrList.attributes.at(i));
+        variant.setValue(attributes.at(i));
         argument << QDBusVariant (variant);
     }
     argument.endArray();
 
     argument.endStructure();
-    return argument;
 }
 
-const QDBusArgument &operator>>(const QDBusArgument &arg, QIBusAttributeList &attrList)
+void QIBusAttributeList::deserializeFrom(const QDBusArgument &arg)
 {
     qCDebug(qtQpaInputMethodsSerialize) << "QIBusAttributeList::fromDBusArgument()" << arg.currentSignature();
+
     arg.beginStructure();
 
-    arg >> static_cast<QIBusSerializable &>(attrList);
+    QIBusSerializable::deserializeFrom(arg);
 
     arg.beginArray();
     while (!arg.atEnd()) {
@@ -223,12 +217,11 @@ const QDBusArgument &operator>>(const QDBusArgument &arg, QIBusAttributeList &at
 
         QIBusAttribute attr;
         var.variant().value<QDBusArgument>() >> attr;
-        attrList.attributes.append(attr);
+        attributes.append(attr);
     }
     arg.endArray();
 
     arg.endStructure();
-    return arg;
 }
 
 QList<QInputMethodEvent::Attribute> QIBusAttributeList::imAttributes() const
@@ -273,31 +266,30 @@ QIBusText::~QIBusText()
 {
 }
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusText &text)
+void QIBusText::serializeTo(QDBusArgument &argument) const
 {
     argument.beginStructure();
 
-    argument << static_cast<const QIBusSerializable &>(text);
+    QIBusSerializable::serializeTo(argument);
 
-    argument << text.text << text.attributes;
+    argument << text << attributes;
     argument.endStructure();
-    return argument;
 }
 
-const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusText &text)
+void QIBusText::deserializeFrom(const QDBusArgument &argument)
 {
     qCDebug(qtQpaInputMethodsSerialize) << "QIBusText::fromDBusArgument()" << argument.currentSignature();
+
     argument.beginStructure();
 
-    argument >> static_cast<QIBusSerializable &>(text);
+    QIBusSerializable::deserializeFrom(argument);
 
-    argument >> text.text;
+    argument >> text;
     QDBusVariant variant;
     argument >> variant;
-    variant.variant().value<QDBusArgument>() >> text.attributes;
+    variant.variant().value<QDBusArgument>() >> attributes;
 
     argument.endStructure();
-    return argument;
 }
 
 QIBusEngineDesc::QIBusEngineDesc()
@@ -326,81 +318,79 @@ QIBusEngineDesc::~QIBusEngineDesc()
 {
 }
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusEngineDesc &desc)
+void QIBusEngineDesc::serializeTo(QDBusArgument &argument) const
 {
     argument.beginStructure();
 
-    argument << static_cast<const QIBusSerializable &>(desc);
-
-    argument << desc.engine_name;
-    argument << desc.longname;
-    argument << desc.description;
-    argument << desc.language;
-    argument << desc.license;
-    argument << desc.author;
-    argument << desc.icon;
-    argument << desc.layout;
-    argument << desc.rank;
-    argument << desc.hotkeys;
-    argument << desc.symbol;
-    argument << desc.setup;
-    argument << desc.layout_variant;
-    argument << desc.layout_option;
-    argument << desc.version;
-    argument << desc.textdomain;
-    argument << desc.iconpropkey;
+    QIBusSerializable::serializeTo(argument);
+
+    argument << engine_name;
+    argument << longname;
+    argument << description;
+    argument << language;
+    argument << license;
+    argument << author;
+    argument << icon;
+    argument << layout;
+    argument << rank;
+    argument << hotkeys;
+    argument << symbol;
+    argument << setup;
+    argument << layout_variant;
+    argument << layout_option;
+    argument << version;
+    argument << textdomain;
+    argument << iconpropkey;
 
     argument.endStructure();
-    return argument;
 }
 
-const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusEngineDesc &desc)
+void QIBusEngineDesc::deserializeFrom(const QDBusArgument &argument)
 {
     qCDebug(qtQpaInputMethodsSerialize) << "QIBusEngineDesc::fromDBusArgument()" << argument.currentSignature();
     argument.beginStructure();
 
-    argument >> static_cast<QIBusSerializable &>(desc);
-
-    argument >> desc.engine_name;
-    argument >> desc.longname;
-    argument >> desc.description;
-    argument >> desc.language;
-    argument >> desc.license;
-    argument >> desc.author;
-    argument >> desc.icon;
-    argument >> desc.layout;
-    argument >> desc.rank;
-    argument >> desc.hotkeys;
-    argument >> desc.symbol;
-    argument >> desc.setup;
+    QIBusSerializable::deserializeFrom(argument);
+
+    argument >> engine_name;
+    argument >> longname;
+    argument >> description;
+    argument >> language;
+    argument >> license;
+    argument >> author;
+    argument >> icon;
+    argument >> layout;
+    argument >> rank;
+    argument >> hotkeys;
+    argument >> symbol;
+    argument >> setup;
     // Previous IBusEngineDesc supports the arguments between engine_name
     // and setup.
     if (argument.currentSignature() == "") {
         argument.endStructure();
-        return argument;
+        return;
     }
-    argument >> desc.layout_variant;
-    argument >> desc.layout_option;
+    argument >> layout_variant;
+    argument >> layout_option;
     // Previous IBusEngineDesc supports the arguments between engine_name
     // and layout_option.
     if (argument.currentSignature() == "") {
         argument.endStructure();
-        return argument;
+        return;
     }
-    argument >> desc.version;
+    argument >> version;
     if (argument.currentSignature() == "") {
         argument.endStructure();
-        return argument;
+        return;
     }
-    argument >> desc.textdomain;
+    argument >> textdomain;
     if (argument.currentSignature() == "") {
         argument.endStructure();
-        return argument;
+        return;
     }
-    argument >> desc.iconpropkey;
+    argument >> iconpropkey;
 
     argument.endStructure();
-    return argument;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforminputcontexts/ibus/qibustypes.h b/src/plugins/platforminputcontexts/ibus/qibustypes.h
index 9dca7e3903..9f2b0eb41f 100644
--- a/src/plugins/platforminputcontexts/ibus/qibustypes.h
+++ b/src/plugins/platforminputcontexts/ibus/qibustypes.h
@@ -54,13 +54,16 @@ class QIBusSerializable
 {
 public:
     QIBusSerializable();
-    virtual ~QIBusSerializable();
+    ~QIBusSerializable();
+
+    void serializeTo(QDBusArgument &argument) const;
+    void deserializeFrom(const QDBusArgument &argument);
 
     QString name;
     QHash<QString, QDBusArgument>  attachments;
 };
 
-class QIBusAttribute : public QIBusSerializable
+class QIBusAttribute : private QIBusSerializable
 {
 public:
     enum Type {
@@ -83,13 +86,16 @@ public:
 
     QTextCharFormat format() const;
 
+    void serializeTo(QDBusArgument &argument) const;
+    void deserializeFrom(const QDBusArgument &argument);
+
     Type type;
     quint32 value;
     quint32 start;
     quint32 end;
 };
 
-class QIBusAttributeList : public QIBusSerializable
+class QIBusAttributeList : private QIBusSerializable
 {
 public:
     QIBusAttributeList();
@@ -97,25 +103,34 @@ public:
 
     QList<QInputMethodEvent::Attribute> imAttributes() const;
 
+    void serializeTo(QDBusArgument &argument) const;
+    void deserializeFrom(const QDBusArgument &argument);
+
     QVector<QIBusAttribute> attributes;
 };
 
-class QIBusText : public QIBusSerializable
+class QIBusText : private QIBusSerializable
 {
 public:
     QIBusText();
     ~QIBusText();
 
+    void serializeTo(QDBusArgument &argument) const;
+    void deserializeFrom(const QDBusArgument &argument);
+
     QString text;
     QIBusAttributeList attributes;
 };
 
-class QIBusEngineDesc : public QIBusSerializable
+class QIBusEngineDesc : private QIBusSerializable
 {
 public:
     QIBusEngineDesc();
     ~QIBusEngineDesc();
 
+    void serializeTo(QDBusArgument &argument) const;
+    void deserializeFrom(const QDBusArgument &argument);
+
     QString engine_name;
     QString longname;
     QString description;
@@ -135,24 +150,28 @@ public:
     QString iconpropkey;
 };
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusSerializable &object);
-const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusSerializable &object);
-
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusAttribute &attribute);
-const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusAttribute &attribute);
+inline QDBusArgument &operator<<(QDBusArgument &argument, const QIBusAttribute &attribute)
+{ attribute.serializeTo(argument); return argument; }
+inline const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusAttribute &attribute)
+{ attribute.deserializeFrom(argument); return argument; }
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusAttributeList &attributeList);
-const QDBusArgument &operator>>(const QDBusArgument &arg, QIBusAttributeList &attrList);
+inline QDBusArgument &operator<<(QDBusArgument &argument, const QIBusAttributeList &attributeList)
+{ attributeList.serializeTo(argument); return argument; }
+inline const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusAttributeList &attributeList)
+{ attributeList.deserializeFrom(argument); return argument; }
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusText &text);
-const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusText &text);
+inline QDBusArgument &operator<<(QDBusArgument &argument, const QIBusText &text)
+{ text.serializeTo(argument); return argument; }
+inline const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusText &text)
+{ text.deserializeFrom(argument); return argument; }
 
-QDBusArgument &operator<<(QDBusArgument &argument, const QIBusEngineDesc &desc);
-const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusEngineDesc &desc);
+inline QDBusArgument &operator<<(QDBusArgument &argument, const QIBusEngineDesc &desc)
+{ desc.serializeTo(argument); return argument; }
+inline const QDBusArgument &operator>>(const QDBusArgument &argument, QIBusEngineDesc &desc)
+{ desc.deserializeFrom(argument); return argument; }
 
 QT_END_NAMESPACE
 
-Q_DECLARE_METATYPE(QIBusSerializable)
 Q_DECLARE_METATYPE(QIBusAttribute)
 Q_DECLARE_METATYPE(QIBusAttributeList)
 Q_DECLARE_METATYPE(QIBusText)