Core/kernel: Make some signals private.

There are more opportunities in QtCore and the rest of Qt to make signals
private instead of public. This is a test-dart to see if there is any
reason not to do this.

It would be nice to make QObject::destroyed private, but as it has a
default argument it would be source incompatible to anyone connecting
to the SIGNAL(destroyed()) instead of SIGNAL(destroyed(QObject*)).

Currently the function-pointer-based connect syntax does not accept
a functor (or lambda) with a different number of arguments than the
signal. Olivier says a fix for that might come in 5.1, but for now
the qfiledialog2 test is changed to not use that anymore.

Also, the function pointer for a private signal can not be assigned to
a local variable, so the qmetamethod test is changed to not do so
anymore.

Change-Id: Iaf776b822f9ba364f2c184df0c6b23811da56e44
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

src/corelib/kernel/qcoreapplication.cpp

@@ -1003,7 +1003,7 @@ int QCoreApplication::exec()
     if (self) {
         self->d_func()->in_exec = false;
         if (!self->d_func()->aboutToQuitEmitted)
-            emit self->aboutToQuit();
+            emit self->aboutToQuit(QPrivateSignal());
         self->d_func()->aboutToQuitEmitted = true;
         sendPostedEvents(0, QEvent::DeferredDelete);
     }

src/corelib/kernel/qcoreapplication.h

@@ -166,8 +166,16 @@ public Q_SLOTS:
     static void quit();
 
 Q_SIGNALS:
-    void aboutToQuit();
+    void aboutToQuit(
-    void unixSignal(int);
+#if !defined(qdoc)
+    QPrivateSignal
+#endif
+    );
+    void unixSignal(int
+#if !defined(qdoc)
+    , QPrivateSignal
+#endif
+    );
 
 protected:
     bool event(QEvent *);

src/corelib/kernel/qeventdispatcher_unix.cpp

@@ -191,7 +191,7 @@ int QEventDispatcherUNIXPrivate::doSelect(QEventLoop::ProcessEventsFlags flags,
                 for (int i = 0; i < NSIG; ++i) {
                     if (signals_fired[i]) {
                         signals_fired[i] = 0;
-                        emit QCoreApplication::instance()->unixSignal(i);
+                        emit QCoreApplication::instance()->unixSignal(i, QCoreApplication::QPrivateSignal());
                     }
                 }
             }

src/corelib/kernel/qobject.cpp

@@ -1004,7 +1004,7 @@ void QObject::setObjectName(const QString &name)
 
     if (d->extraData->objectName != name) {
         d->extraData->objectName = name;
-        emit objectNameChanged(d->extraData->objectName);
+        emit objectNameChanged(d->extraData->objectName, QPrivateSignal());
     }
 }
 

src/corelib/kernel/qobject.h

@@ -348,7 +348,11 @@ public:
 
 Q_SIGNALS:
     void destroyed(QObject * = 0);
-    void objectNameChanged(const QString &objectName);
+    void objectNameChanged(const QString &objectName
+#if !defined(qdoc)
+    , QPrivateSignal
+#endif
+    );
 
 public:
     inline QObject *parent() const { return d_ptr->parent; }

src/corelib/kernel/qsocketnotifier.cpp

@@ -298,7 +298,7 @@ bool QSocketNotifier::event(QEvent *e)
     }
     QObject::event(e);                        // will activate filters
     if ((e->type() == QEvent::SockAct) || (e->type() == QEvent::SockClose)) {
-        emit activated(d->sockfd);
+        emit activated(d->sockfd, QPrivateSignal());
         return true;
     }
     return false;

src/corelib/kernel/qsocketnotifier.h

@@ -69,7 +69,11 @@ public Q_SLOTS:
     void setEnabled(bool);
 
 Q_SIGNALS:
-    void activated(int socket);
+    void activated(int socket
+#if !defined(qdoc)
+    , QPrivateSignal
+#endif
+    );
 
 protected:
     bool event(QEvent *);

src/corelib/kernel/qtimer.cpp

@@ -247,7 +247,7 @@ void QTimer::timerEvent(QTimerEvent *e)
     if (e->timerId() == id) {
         if (single)
             stop();
-        emit timeout();
+        emit timeout(QPrivateSignal());
     }
 }
 

src/corelib/kernel/qtimer.h

@@ -88,7 +88,11 @@ public Q_SLOTS:
     void stop();
 
 Q_SIGNALS:
-    void timeout();
+    void timeout(
+#if !defined(qdoc)
+      QPrivateSignal
+#endif
+    );
 
 protected:
     void timerEvent(QTimerEvent *);

src/corelib/kernel/qwineventnotifier.cpp

@@ -234,7 +234,7 @@ bool QWinEventNotifier::event(QEvent * e)
     }
     QObject::event(e);                        // will activate filters
     if (e->type() == QEvent::WinEventAct) {
-        emit activated(d->handleToEvent);
+        emit activated(d->handleToEvent, QPrivateSignal());
         return true;
     }
     return false;

src/corelib/kernel/qwineventnotifier.h

@@ -74,7 +74,11 @@ public Q_SLOTS:
     void setEnabled(bool enable);
 
 Q_SIGNALS:
-    void activated(HANDLE hEvent);
+    void activated(HANDLE hEvent
+#if !defined(qdoc)
+    , QPrivateSignal
+#endif
+    );
 
 protected:
     bool event(QEvent * e);

tests/auto/corelib/kernel/qmetamethod/tst_qmetamethod.cpp

@@ -714,9 +714,8 @@ void tst_QMetaMethod::comparisonOperators()
 void tst_QMetaMethod::fromSignal()
 {
 #define FROMSIGNAL_HELPER(ObjectType, Name, Arguments)  { \
-        void (ObjectType::*signal)Arguments = &ObjectType::Name; \
         const QMetaObject *signalMeta = &ObjectType::staticMetaObject; \
-        QCOMPARE(QMetaMethod::fromSignal(signal), \
+        QCOMPARE(QMetaMethod::fromSignal(&ObjectType::Name), \
             signalMeta->method(signalMeta->indexOfSignal(QMetaObject::normalizedSignature(#Name #Arguments)))); \
     }
 

tests/auto/widgets/dialogs/qfiledialog2/tst_qfiledialog2.cpp

@@ -319,10 +319,11 @@ void tst_QFileDialog2::emptyUncPath()
 }
 
 #if !defined(QT_NO_CONTEXTMENU) && !defined(QT_NO_MENU)
-struct MenuCloser {
+struct MenuCloser : public QObject {
     QWidget *w;
     explicit MenuCloser(QWidget *w) : w(w) {}
-    void operator()() const
+
+    void close()
     {
         QMenu *menu = qFindChild<QMenu*>(w);
         if (!menu) {
@@ -342,7 +343,8 @@ static bool openContextMenu(QFileDialog &fd)
     QTimer timer;
     timer.setInterval(300);
     timer.setSingleShot(true);
-    QObject::connect(&timer, &QTimer::timeout, MenuCloser(&fd));
+    MenuCloser closer(&fd);
+    QObject::connect(&timer, &QTimer::timeout, &closer, &MenuCloser::close);
     timer.start();
     QContextMenuEvent cme(QContextMenuEvent::Mouse, QPoint(10, 10));
     qApp->sendEvent(list->viewport(), &cme); // blocks until menu is closed again.