Re: [Interest] sharing singleton instance between C++ and QML

which works fine. Then I wanted to clean the code up a little more, and removed the "public:", given that the above is a `struct`, so everything in it is public anyhow. And that's where it stopped working ! The Q_GADGET macro contains a "private:", just like the Q_OBJECT macro: #define Q_GADGE

Re: [Interest] sharing singleton instance between C++ and QML

Oh wow, that's rude ! Thanks ! On Sat, Oct 28, 2023, 09:58 Constantin Makshin wrote: > Hi Ulf. > > MOC is fine, it's the Q_GADGET macro: > #define Q_GADGET_EXPORT(...) \ > public: \ > static __VA_ARGS__ const QMetaObject staticMetaObject; \ > void qt_check_for_QGADGET_macro(); \ >

Re: [Interest] sharing singleton instance between C++ and QML

Hi Ulf. MOC is fine, it's the Q_GADGET macro: #define Q_GADGET_EXPORT(...) \ public: \ static __VA_ARGS__ const QMetaObject staticMetaObject; \ void qt_check_for_QGADGET_macro(); \ typedef void QtGadgetHelper; \ private: \ QT_WARNING_PUSH \ Q_OBJECT_NO_ATTRIBUTES_WARNING \

Re: [Interest] sharing singleton instance between C++ and QML

Hi Uli, thank you for sharing that document, that's indeed very helpful. Following its examples, I was able to set up my singleton such that both runtimes (C++, QML) would share the same instance. Doing that I bumped into what I would consider a bug, probably in the MOC infrastructure: The example

Re: [Interest] sharing singleton instance between C++ and QML

Dear Stefan, I don't want to patronize you, but I know the person who has to handle your bug reports if things go south with whatever architecture you come up with. Such things have happened before. So, sorry if that came across in the wrong way. Wrapping your C++ singleton into another obje

Re: [Interest] sharing singleton instance between C++ and QML

On Thu, Oct 26, 2023 at 2:53 AM Ulf Hermann via Interest < interest@qt-project.org> wrote: > The very common misconception I keep reading over and over is that C++ > singletons should be the same as QML singletons. They generally aren't. > You can shoehorn a C++ singleton into a QML one, but if yo

Re: [Interest] sharing singleton instance between C++ and QML

__ From: Ulf Hermann Sent: Thursday, October 26, 2023 7:53:17 PM To: Mike Trahearn ; interest@qt-project.org Subject: Re: [Interest] sharing singleton instance between C++ and QML > For the record it is actually possible (I proved it) to create multiple > instances of the same singleton

Re: [Interest] sharing singleton instance between C++ and QML

For the record it is actually possible (I proved it) to create multiple instances of the same singleton with only one engine using a singleton published from C++ if you concoct your C++ side, um,  poorly. But that's another matter for people stuck before C++11... I've fixed QTBUG-116432 if tha

Re: [Interest] sharing singleton instance between C++ and QML

: interest@qt-project.org Subject: Re: [Interest] sharing singleton instance between C++ and QML The very common misconception I keep reading over and over is that C++ singletons should be the same as QML singletons. They generally aren't. You can shoehorn a C++ singleton into a QML one, but

Re: [Interest] sharing singleton instance between C++ and QML

The very common misconception I keep reading over and over is that C++ singletons should be the same as QML singletons. They generally aren't. You can shoehorn a C++ singleton into a QML one, but if you can avoid that exercise, you should avoid it. The usual way to declare a QML singleton is j

[Interest] sharing singleton instance between C++ and QML

Hello, I'm trying to "modernize" a large code base that just migrated from Qt5 to Qt6. Our code is using a few singleton objects that used to be exported into the QML runtime via `qmlRegisterSingletonInstance()`. But as it is now recommended to move away from `qmlRegisterType()` (in favour of lett