General and Desktop

QwtPlot::replot() is part of the Qwt library which I am using. For a spectrogram plot that eventually calls QwtPlotRasterItem::compose() which does: QVector< QFuture< void > > futures; futures.reserve( numThreads - 1 ); for ( uint i = 0; i < numThreads; i++ ) { QRect tile( 0, i * numRows, image.width(), numRows ); if ( i == numThreads - 1 ) { tile.setHeight( image.height() - i * numRows ); qwtToRgba( &image, &alphaImage, tile, m_data->alpha ); } else { futures += QtConcurrent::run( &qwtToRgba, &image, &alphaImage, tile, m_data->alpha ); } } for ( int i = 0; i < futures.size(); i++ ) futures[i].waitForFinished(); which completely blocks the Qt event loop until it finishes.

I would recommend StackView for any HMI with back and forth navigation. The Loader disadvantage is having one more Item in your hierarchy, less feature for your navigation and no transition animation out of the box. Note that you can use your custom manager in tandem with a StackView. Something like this should work: onCurrentScreenChanged: myStackView.replace(null, currentScreen). Having a StackView lets you keep some screens UI only, without making your ScreenManager aware. For example you could push a UI settings page (theme, font size) irrelevant to your business side.

After a lengthy tussle with QtConcurrent::run() (which is why the delay in responding), I managed to move the long running interpolation code off to another thread.

@Perdrix OK, for whatever reason (maybe misplaced) this appears in subsection https://doc.qt.io/qt-6/qtconcurrentrun.html#using-lambda-functions, for anyone reading this.

@dviktor I looked at your "minimal" repro. The queries are horrendously long and complex, and require many tables with many columns. If I were you and I wanted help/someone to look at it I would spend my time reducing to an absolute minimum, e.g. does it require a JOIN at all, does it show up with one JOIN, do I really need a calculated column, do I need MAX() or other "aggregate", does it matter whether a column is DATE versus DATETIME, does the WHERE clause matter, etc. I would hope to produce the absolute minimum code and database where I could say: "if you run this query it works fine but as soon as I make just this one little change it goes wrong". Up to you.

@Axel-Spoerl said in Does Qt (plan to) support Gnome Notifications?: Christian Buhtz, that should have rang me a bell. Heavy BIT user here. Your Qt UI is highly appreciated! Do let me know if there is anything I can help with. Does it not work to just spark your status updates on DBus? Hello Axel, thank you. Please be aware that I am only the 3rd generation maintainer of BIT. I am not the founder. And it wasn't even me who started this 3rd generation. It was someone else, I hopped on and we became a team of three. But now I am the only one left as active maintainer. But I have a fine community in the back supporting me with expertise and opinions. What do you mean by "spark your status updates on DBus"? This would result in that notification bubbles, right? That is not what I need. I also need a persistent systray icon that appears every time BIT is performing a backup or restore. Anyway, I do plan to rewrite the whole inter process communication part of BIT so we can have a full persistent systray that appears not only when BIT is performing a job. Everything is quit complex when it comes to BIT because of it old/smelly code base. ;) If you are interested in some insights of the projects: Maintenance status Strategy outline / Roadmap Best regards, Christian

Hi, I haven't used that module yet however did you check the C++ minimal example ?

As I said - the effect draws outside it's client area.

Clone: git clone https://github.com/open62541/open62541.git && cd open62541 && git checkout v1.4.5 Open ready-made solution: build\open62541.sln Select configuration Release-SECURE or Debug-SECURE Build → Build Solution Done. Full encryption (mbedTLS) enabled, works with KEPServerEX and all commercial servers. (Do not use CMake or MinGW if you want zero hassle with MSVC security.)

Glad to hear that you've made progress! Let's continue the security question at https://forum.qt.io/topic/163829/opc-ua-client-security

Are you setting them explicitly and assigning your widgets to them correctly ? Creating a UI in designer does not mean layouts are automatically used.

Full code linked below if it's helpful to anyone else. https://github.com/ZNohre/qt-cached-sql-tables

I was able to get it to work under windows now I need to get it to work in linux.

I just saw that QVncServer is part of the commercial offering. I would recommend checking with the Qt Company as that module's code does not seem to be available.

@Christian-Ehrlicher Tank you very much for your reply. This was indeed the problem

Hi @Chasing_Light, your thoughts are correct, this code tries to access private API. You should use the exactly same Qt version as the training course, then it should work. Regards

I figured out the issue. Buffer upload must be done before beginPass() is called.... in render function, this line resourceUpdates->updateDynamicBuffer(m_vbuf.get(), 0, sizeof(vertexData), vertexData); needs to be before this line cb->beginPass(renderTarget(), clearColor, { 1.0f, 0 }, resourceUpdates);