Add QAbstractDeclarativeData::isSignalConnected hook

Similar to QAbstractDeclarative::receivers. This hook will allow
QObject::isSignalConnected(QMetaMethod) to return true when there are
QML-managed connections.

It's important that the hook is called from
QObjectPrivate::isSignalConnected(uint), since QML calls that
function.

Change-Id: I9c5e42f2b3e7f985af02905985a3a47101cdee05
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Michael Brasser <michael.brasser@nokia.com>

2 files changed, 10 insertions, 6 deletions

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index d00f8cf761..b0213efa19 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -174,6 +174,7 @@ void (*QAbstractDeclarativeData::destroyed)(QAbstractDeclarativeData *, QObject
 void (*QAbstractDeclarativeData::parentChanged)(QAbstractDeclarativeData *, QObject *, QObject *) = 0;
 void (*QAbstractDeclarativeData::signalEmitted)(QAbstractDeclarativeData *, QObject *, int, void **) = 0;
 int  (*QAbstractDeclarativeData::receivers)(QAbstractDeclarativeData *, const QObject *, int) = 0;
+bool (*QAbstractDeclarativeData::isSignalConnected)(QAbstractDeclarativeData *, const QObject *, int) = 0;
 
 QObjectData::~QObjectData() {}
 
@@ -2182,14 +2183,14 @@ int QObject::receivers(const char *signal) const
             return 0;
         }
 
+        if (!d->isSignalConnected(signal_index))
+            return receivers;
+
         if (d->declarativeData && QAbstractDeclarativeData::receivers) {
             receivers += QAbstractDeclarativeData::receivers(d->declarativeData, this,
                                                              signal_index);
         }
 
-        if (!d->isSignalConnected(signal_index))
-            return receivers;
-
         QMutexLocker locker(signalSlotLock(this));
         if (d->connectionLists) {
             if (signal_index < d->connectionLists->count()) {
@@ -3285,13 +3286,13 @@ void QMetaObject::activate(QObject *sender, int signalOffset, int local_signal_i
 {
     int signal_index = signalOffset + local_signal_index;
 
+    if (!sender->d_func()->isSignalConnected(signal_index))
+        return; // nothing connected to these signals, and no spy
+
     if (sender->d_func()->declarativeData && QAbstractDeclarativeData::signalEmitted)
         QAbstractDeclarativeData::signalEmitted(sender->d_func()->declarativeData, sender, 
                                                 signal_index, argv);
 
-    if (!sender->d_func()->isSignalConnected(signal_index))
-        return; // nothing connected to these signals, and no spy
-
     if (sender->d_func()->blockSig)
         return;
 
diff --git a/src/corelib/kernel/qobject_p.h b/src/corelib/kernel/qobject_p.h
index 02c9ac61a7..0d491a2b87 100644
--- a/src/corelib/kernel/qobject_p.h
+++ b/src/corelib/kernel/qobject_p.h
@@ -92,6 +92,7 @@ public:
     static void (*parentChanged)(QAbstractDeclarativeData *, QObject *, QObject *);
     static void (*signalEmitted)(QAbstractDeclarativeData *, QObject *, int, void **);
     static int  (*receivers)(QAbstractDeclarativeData *, const QObject *, int);
+    static bool (*isSignalConnected)(QAbstractDeclarativeData *, const QObject *, int);
 };
 
 class Q_CORE_EXPORT QObjectPrivate : public QObjectData
@@ -224,6 +225,8 @@ inline bool QObjectPrivate::isSignalConnected(uint signal_index) const
 {
     return signal_index >= sizeof(connectedSignals) * 8
         || (connectedSignals[signal_index >> 5] & (1 << (signal_index & 0x1f))
+        || (declarativeData && QAbstractDeclarativeData::isSignalConnected
+            && QAbstractDeclarativeData::isSignalConnected(declarativeData, q_func(), signal_index))
         || qt_signal_spy_callback_set.signal_begin_callback
         || qt_signal_spy_callback_set.signal_end_callback);
 }