Add a qDebug operator overload to handle registered enum

So if you stream enum type into qDebug, it will show the name
of the enum value instead of the int

Change-Id: Iec5e826623353560319890d3e7c4ab97d0645f4a
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

3 files changed, 32 insertions, 1 deletions

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index be6441933f..0a8369acbf 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -4105,6 +4105,20 @@ QDebug operator<<(QDebug dbg, const QObject *o)
     dbg << ')';
     return dbg;
 }
+
+QDebug qt_QMetaEnum_debugOperator(QDebug &dbg, int value, const QMetaObject *meta, const char *name)
+{
+    QDebugStateSaver saver(dbg);
+    QMetaEnum me = meta->enumerator(meta->indexOfEnumerator(name));
+    const char *key = me.valueToKey(value);
+    dbg.nospace() << meta->className() << "::" << name << '(';
+    if (key)
+        dbg << key;
+    else
+        dbg << value;
+    dbg << ')';
+    return dbg;
+}
 #endif
 
 /*!
diff --git a/src/corelib/kernel/qobject.h b/src/corelib/kernel/qobject.h
index 78f913acf8..20ff9981b1 100644
--- a/src/corelib/kernel/qobject.h
+++ b/src/corelib/kernel/qobject.h
@@ -547,6 +547,16 @@ template <class T> inline const char * qobject_interface_iid()
 
 #ifndef QT_NO_DEBUG_STREAM
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QObject *);
+Q_CORE_EXPORT QDebug qt_QMetaEnum_debugOperator(QDebug&, int value, const QMetaObject *meta, const char *name);
+
+template<typename T>
+typename QtPrivate::QEnableIf<QtPrivate::IsQEnumHelper<T>::Value , QDebug>::Type
+operator<<(QDebug &dbg, T value)
+{
+    const QMetaObject *obj = qt_getEnumMetaObject(value);
+    const char *name = qt_getEnumName(value);
+    return qt_QMetaEnum_debugOperator(dbg, typename QFlags<T>::Int(value), obj, name);
+}
 #endif
 
 class QSignalBlocker
diff --git a/tests/auto/corelib/kernel/qmetaobject/tst_qmetaobject.cpp b/tests/auto/corelib/kernel/qmetaobject/tst_qmetaobject.cpp
index 7614c52e66..1774782262 100644
--- a/tests/auto/corelib/kernel/qmetaobject/tst_qmetaobject.cpp
+++ b/tests/auto/corelib/kernel/qmetaobject/tst_qmetaobject.cpp
@@ -225,6 +225,7 @@ private slots:
     void signal();
     void signalIndex_data();
     void signalIndex();
+    void enumDebugStream();
 
 signals:
     void value6Changed();
@@ -1206,7 +1207,6 @@ void tst_QMetaObject::metaMethod()
     QCOMPARE(str, QString("foo"));
     QCOMPARE(ret, QString("bar"));
 
-
     QtTestObject obj;
     QString t1("1"); QString t2("2"); QString t3("3"); QString t4("4"); QString t5("5");
     QString t6("6"); QString t7("7"); QString t8("8"); QString t9("9"); QString t10("X");
@@ -1412,5 +1412,12 @@ void tst_QMetaObject::signalIndex()
              SignalTestHelper::signalIndex(mm));
 }
 
+void tst_QMetaObject::enumDebugStream()
+{
+    QTest::ignoreMessage(QtDebugMsg, "hello MyNamespace::MyClass::MyEnum(MyEnum2) world ");
+    MyNamespace::MyClass::MyEnum e = MyNamespace::MyClass::MyEnum2;
+    qDebug() << "hello" << e << "world";
+}
+
 QTEST_MAIN(tst_QMetaObject)
 #include "tst_qmetaobject.moc"