General and Desktop

@byrAlpha Hi, You can try this. https://stackoverflow.com/questions/68769475/how-to-set-the-color-of-caret-blinking-cursor-in-qlineedit

@JonB THAKN YOU! You save me !

I have gotten a new sample from the library vendor, and it does use paintGL. We were working off a sample from 12 years ago as our base and apparently they have updated a lot since then. I am trying to fit their new implementation in and see how it works. Thanks for the feedback

@AliQT FWIW I included a CMakeLists.txt which should work (again, inside it a couple of lines for ActiveX need uncommenting) as an alternative to .pro/qmake. Most people use cmake with Qt6, but .pro/qmake is still supported if you prefer. Just check the other code does not require Qt5, else you won't be able to use the Q_MOC_INCLUDE() it now relies on.

Thank you for the tip; I'm using Python, so I rewrote like this, and it works: class VerticalScrollArea(QtWidgets.QScrollArea): def __init__(self): super().__init__() self.setWidgetResizable(True) self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff) self.setVerticalScrollBarPolicy(Qt.ScrollBarAsNeeded) def eventFilter(self, object, event): # This works because QScrollArea::setWidget installs an eventFilter on the widget if object is not None and object == self and event.type() == QEvent.Resize: self.setMinimumWidth(self.minimumSizeHint().width() + self.verticalScrollBar.width()) return super().eventFilter(object, event)

Hi @Ben-Campbell-Wallis, sorry for the delayed response. If you use vcpkg protobuf installation please make sure that the vcpkg tripplet binary directory is in PATH when you build your project. I expect that it should be something like "C:/Projects/_clientserverpoc/smappoc-gl-client-grpc/build/Desktop_Qt_6_9_1_MSVC2022_64bit-FromSrc-Debug/vcpkg_installed/x64-windows/bin" in your layout. It should help, but we probably need to think about setting it automatically. Qt delivers packages where protoc plugins are build statically, so you don't face missing dependency issues.

for (int i = 0; i < count(); ++i) { QWidget *viewport = widget(i)->parentWidget();//viewport qDebug() << viewport->metaObject()->className(); QScrollArea *scrollArea = qobject_cast<QScrollArea*>(viewport->parentWidget()); qDebug() << scrollArea->metaObject()->className(); Q_CHECK_PTR (scrollArea); scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarPolicy::ScrollBarAlwaysOff); scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarPolicy::ScrollBarAlwaysOff); }

This is for sure no compiler issue. More an access problem due to a virus scanner or tests running simultaneously.

@JonB Oh, right. I just did and it worked. I was tried to change CalibrationMaterial::updateTextures(QRhi *rhi, QRhiResourceUpdateBatch *resourceUpdates) to void CalibrationMaterial::updateTextures(QRhi &rhi, QRhiResourceUpdateBatch *resourceUpdates) so many other issues occured and I tried to fix them. But wit just *rhi, it solved.

It seems like some .dll files was missing. I ran the debug log and it said the libwinpthread-1.dll was missing. So I copied it to the mingw64/bin/ folder and then it worked. It didn't say missing that .dll file when I run it normally but only when run by debug log

@nicker-player said in when using the qml occured the errors.couldnt find the wrong code line.: so how to find the wrong place.any good ideas? Do you use QPainter somewhere? You seem to make screen-shots - I would start there. You can also remove functionality step by step until it does not crash anymore then you know where it happens. Also, debugger is the usual tool to investigate problems...

Well, this would be a possible workaround, but it neither explains nor solves the underlying problem …

Correct. You cannot simulate that level of fidelity in realtime using win/linux/Qt. You would need to drastically lower your iterative frequency and maybe interpolate intermediate values. Otherwise, Do as I mention and use a synthetic timer that has no ties to realtime. As a safety margin on generic desktop systems don't do timers or trigger timed events at periods less than about 50ms (or 20hz). That broadly covers lower HZ values and "usually" handles scheduler noise. Remember that the Qt timers are more for UI responsiveness than tracking high precision events.

@hskoglund I think this may be the only way to go, especially if the result of the thread interaction requires any sort of GUI (posting error messages, etc.). It does seem that aboutToQuit() is too late in the sequence. Evidence, after some exploration: My problem was caused by a change in Qt 6.5.0 (link) that moved the signaling point from QCoreApplication::execCleanup() (which explicitly turns off the quitNow flag) to exit() (which doesn't). That flag is what prevents a local QEventLoop in my slot handler from spinning up. It's not clear if they meant to do that, but... That change refers to a bug report (link). A comment by the maintainer says, "The docs for aboutToQuit specify 'Note that no user interaction is possible in this state.'" And indeed they do (link).

@TolleTafel You need to set one or both of QApplication::setWindowIcon() and QWindow::setIcon(). See also https://doc.qt.io/qt-6/appicon.html. If by any chance you mean change the icon for every Python script, nothing to do with Qt or your applications, that would be by changing the icon for python.exe.

Sooooo, QMediaMetaData tmp = m_mp->metaData(); m_singers = tmp.value(QMediaMetaData::ContributingArtist).toString(); m_title = tmp.value(QMediaMetaData::Title).toString(); m_album = tmp.value(QMediaMetaData::AlbumTitle).toString(); m_duration = tmp.value(QMediaMetaData::Duration).toULongLong(); qDebug() << "Path:" << m_path; qDebug() << "Singers:" << m_singers; qDebug() << "Title:" << m_title; qDebug() << "Album:" << m_album; Works Fine !

@DmitryTS said in UB or not: a constant reference extend the life of this temporary object or not? I already answered it...

@kehr_I You have my sympathies. QtCharts was a bit "dodgy" at times. Whether we like it or not it is going away, to be replaced by QtGraphs. I too have zero desire to use anything QML in my code (widgets). I believe it is "supposed" to be callable from widgets app --- presumably all QML/QtQuick stuff to support it will now have to be bundled with widgets app for deployment --- but I have a feeling there was a recent post saying the API "is not available"(?) from widgets, as of the present time at least. It might have said it works for 3D but not 2D. Ah, have a read of https://forum.qt.io/topic/159224/qt-graphs-building-2d-plot-using-c-only