How to call qml signal handler synchronously from cpp code from another thread?
I know that normally you wouldn't do what I'm asking. I understand that these two layers should be separate and connect via signal/slot mechanism, which maybe asynchronous if we deal with threads.
Understanding this, I still need to call qml signal handler synchronously from SG thread. Qml objects live in GUI thread, thus emitting a signal from SG thread (particularly from updatePaintNode() method) results in asynchronous event.
I have read docs and I have no problem calling qml function from cpp. For example:
QMetaObject::invokeMethod(this, "myNiceQmlFunction", Qt::DirectConnection);
But imagine this:
signal void callQmlHandler();
// do something right now
I don't know how to call onCallQmlHandler synchronously via QMetaObject::invokeMethod.
I don't create qml object from code and at this point in cpp I don't have access to qml component to look for its children, find MyObject there by name and call its handler (if it is possible). Anyways, this is not a beautiful way to do so.
Does anyone know if I miss the right syntax to call signal handler via QMetaObject::invokeMethod or it is not possible at all? Any ideas?
Connect with a BlockingQueuedConnection.
bq. Connect with a BlockingQueuedConnection
AFAIK you can not connect to a signal handler manually. Connection is generated by qml, qml creates signal handler and I don't know a way to change that.