General and Desktop

@jsulm @jsulm void MainWindow::on_openCamera_clicked() { try { static QTimer qTimer ; if ( bContinue ) { qTimer.stop(); QObject::disconnect(&qTimer, SIGNAL(timeout()),this, SLOT(showPicture())) ; ui->openCamera->setText("open"); ui->status_label->setText("Trạng thái máy ảnh: Tắt"); } else { QObject::connect(&qTimer, SIGNAL(timeout()),this, SLOT(showPicture())) ; qTimer.start(100); ui->openCamera->setText("close"); ui->status_label->setText("Trạng thái máy ảnh: Bật"); } bContinue = !bContinue ; } catch( exception const &e ){ ui->status_label->setText("ERROR"); } }

@Hyperspider-Software Resizing and moving the window will cause updates, renders and repaints. If everything is done and nothing changes, it doesn't have to get updated at such high rate as it would, when you grab the window and move it around and change dimensions of the content. Just a guess. Maybe it might be helpful if you show some code, how the window is rendered. Is it just one window or does everything behave like this?

@ChrisW67 Ahh, ok good info thanks, I'll take a look at that library; thank you.

@Roberrt Read characteristics are undefined if you don't guarantee exclusive access, or at least use data types that are guaranteed to be atomic. Generally the read of a native word sized int is atomic across architectures because the CPU microcode likes to deal with a whole word at a time, and preemption wont occur in the middle of a machine code instruction. But it is safer to lock for reads as well.

@Paul-Colby Thanks for the reply. Just for sake of discussion - what would be the benefit of adding EXTRA file to EACH suboproject ? Besides it does not meet the post " specification" to " add single place to control preprocessor" to main .pro. Cheers

@DatGK https://codebrowser.dev/qt5/qtbase/src/widgets/widgets/qprogressbar.cpp.html#424 QFontMetrics fm = fontMetrics(); QStyleOptionProgressBar opt; initStyleOption(&opt); int cw = style()->pixelMetric(QStyle::PM_ProgressBarChunkWidth, &opt, this); QSize size = QSize(qMax(9, cw) * 7 + fm.horizontalAdvance(QLatin1Char('0')) * 4, fm.height() + 8); if (opt.orientation == Qt::Vertical) size = size.transposed(); So qMax(9, cw) * 7 + fm.horizontalAdvance(QLatin1Char('0')) * 4. I think the gist is 63+-odd for the chunks (7 chunks) + 4 character 0s. Then in your case this is applied for the height instead of the width. May be quite close to 95-odd pixels.

@SGaist You are right.. I missed that completely. m_client = new QMqttClient(this); m_client->setHostname(ui->lineEditHost->text()); m_client->setPort(ui->spinBoxPort->value()); m_client->setProtocolVersion(QMqttClient::MQTT_5_0); Thank you very much for quick help

@Queen Something like this should work: Rectangle { width: 100 height: 400 Image { id: img1 source: "YourImage.png" // path to image or qrc resource path } }

Then use QVariant::value<long>(). But since sizeof(long long) = sizeof(long) on all 64 bit platforms - why do you need it?

@orsini29 Found it.. super simple and knew I'd kick myself over it. For anyone in the future, you need to use series->setLabelsFormat("@value enter text here"); Documentation: https://doc.qt.io/qt-6/qabstractbarseries.html#labelsFormat-prop

@Ylvy said in Qt DllMain doesn't get called: what you mean mix debug and release build? I mean that if your application is built in debug mode you can't load DLLs built in release mode

In the end I refactored mediator QtObject from QML into a C++ QObject. However, I am surprised sender() returns NULL. Maybe it is so because I connect slots in QML with Connections on mediator instance set as a context property. Perhaps if I were to use QObject::connect() in C++ instead, sender() might have worked as expected.

@kshegunov I have ~80 classes, each with 5-10 different properties (enums, POD, custom types, containers). The problem are all implicit (in a loop) conversions of these properties.

@johnco3 I'm afraid I know nothing about std::variant, but a couple of observations. Your setData() is void. QStandardItemModel's is bool. Have you checked the return result when you call that, you never know if it might be barfing? Your setData() defaults to Qt::UserRole + 1. How does your item->data().value<PortVariant>() pass that role to fetch? setData() copies its argument. I assume the equivalent code to test would be something like: PortVariant portVariant = port; QVariant v = QVariant::fromStdVariant(portVariant); QVariant v2 = v1; const auto& portVariant = v2.value<PortVariant>(); How does that come out? You might also call QVariant::canConvert<>() to check, including on your item->data(). I assume all the various component types in your structs are serializable to QVariant without further registration.

@Chris-Kawa Thanks for the quick reply! It might be helpful, I will think whether I can use it to my advantage.

Update to the DeprecationWarning: Using QLibraryInfo.path(QLibraryInfo.LibraryPath.TranslationsPath) the warning is gone.