QState: Added template PointerToMemberFunction

Added the function pointer to addTransition to take
advantage of the new connect syntax.

[ChangeLog][QtCore][State Machine] Added an addTransition() overload that
takes a pointer-to-member for the signal triggering the transition.

Change-Id: Ic97f7983839217ca0c8484b269d38221cbe804e3
Task-number: QTBUG-40293
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/statemachine/qstate.cpp

@@ -338,6 +338,17 @@ void QState::addTransition(QAbstractTransition *transition)
         QStateMachinePrivate::get(mach)->maybeRegisterTransition(transition);
 }
 
+/*!
+  \fn QState::addTransition(const QObject *sender, PointerToMemberFunction signal,
+                       QAbstractState *target);
+  \since 5.5
+  \overload
+
+  Adds a transition associated with the given \a signal of the given \a sender
+  object, and returns the new QSignalTransition object. The transition has
+  this state as the source, and the given \a target as the target state.
+*/
+
 /*!
   Adds a transition associated with the given \a signal of the given \a sender
   object, and returns the new QSignalTransition object. The transition has

src/corelib/statemachine/qstate.h

@@ -35,8 +35,8 @@
 #define QSTATE_H
 
 #include <QtCore/qabstractstate.h>
-
 #include <QtCore/qlist.h>
+#include <QtCore/qmetaobject.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -74,6 +74,18 @@ public:
 
     void addTransition(QAbstractTransition *transition);
     QSignalTransition *addTransition(const QObject *sender, const char *signal, QAbstractState *target);
+#ifdef Q_QDOC
+    QSignalTransition *addTransition(const QObject *sender, PointerToMemberFunction signal,
+                       QAbstractState *target);
+#else
+    template <typename Func>
+    QSignalTransition *addTransition(const typename QtPrivate::FunctionPointer<Func>::Object *obj,
+                      Func signal, QAbstractState *target)
+    {
+        const QMetaMethod signalMetaMethod = QMetaMethod::fromSignal(signal);
+        return addTransition(obj, signalMetaMethod.methodSignature().constData(), target);
+    }
+#endif // Q_QDOC
     QAbstractTransition *addTransition(QAbstractState *target);
     void removeTransition(QAbstractTransition *transition);
     QList<QAbstractTransition*> transitions() const;

tests/auto/corelib/statemachine/qstate/tst_qstate.cpp

@@ -205,12 +205,16 @@ void tst_QState::transitions()
     QVERIFY(s1.transitions().isEmpty());
 
     QAbstractTransition *t1 = s1.addTransition(this, SIGNAL(destroyed()), &s2);
+    QAbstractTransition *t1_1 = s1.addTransition(this, &tst_QState::destroyed, &s2);
     QVERIFY(t1 != 0);
-    QCOMPARE(s1.transitions().count(), 1);
+    QVERIFY(t1_1 != 0);
+    QCOMPARE(s1.transitions().count(), 2);
     QCOMPARE(s1.transitions().first(), t1);
+    QCOMPARE(s1.transitions().last(), t1_1);
     QVERIFY(s2.transitions().isEmpty());
 
     s1.removeTransition(t1);
+    s1.removeTransition(t1_1);
     QVERIFY(s1.transitions().isEmpty());
 
     s1.addTransition(t1);