QML and Qt Quick

I used 1024 segments because it was mend as stress test. But after I switched to 32-64 segments there was a significant difference.

See my post 'Why is drawcall batching (using my own QSGNodes) slower?'

I filed this issue too: https://qt-project.atlassian.net/browse/QTBUG-150742 - a suggestion to add support for unix sockets in the SatelliteSource object, which would mean no need to pipe gnss-share output. I would really like for someone to confirm if the sattlitesInView list is empty - I have not been able to fix that, and I consider filing an issue for that as well.

The "icon" is a text here, not SVG, right? https://github.com/qt-creator/qt-creator/blob/5f363dbc8782673fb3da53321f30070d1026eeca/share/qtcreator/qmldesigner/propertyEditorQmlSources/imports/HelperWidgets/IconLabel.qml#L10

@sierdzio There also seems to be some interaction with wrap mode of the text, also depends if one uses JS script: my text string, or not. Anyways, i ended up using ColumnLayout with a ListView that fills it and that ListView has delegate Item that has column embedded in it, which is anchors.horizontalCenter: parent.horizontalCenter . I tried to have just column as delegate, but that also wouldnt work, so i wrapped it in an item. Anyways it is not that important atm, i might return here once I have time to experiment more.

Consider the order to be undefined, and something you shouldn't rely on. To be honest, that's the same as if you were to use qmlRegisterSingletonType using the imperative API; there's no instantiation at the point of the registration, that will happen later when the engine actually needs the singleton (and "needs" is intentionally vague here). If you have an order-dependent construction, you should (in that order of preferability) a) consider if you can move away from that pattern, or b) use https://doc-snapshots.qt.io/qt6-dev/qqmlengine.html#setExternalSingletonInstance once 6.12 is released or c) keep using imperative registration.

Decouple Hydra and Qt for independent rendering, share the VkDevice in a synchronized manner, and connect them using VkImage and GPU synchronization (timeline semaphores) instead of blocking the GUI on every frame.

This is a nice mini writeup that will surely help people who encounter (and then google) the output: "This is probably intended to be a signal handler but no signal of the target matches the name"

Write a .pro file, import it into Qt VS Tools - QtQmlTypeRegistrar is valid in MSBuild - this is the only supported path,

@DSpUz said in How do those crazy Q Macros work?: there is no visible Object instance. There IS an object instance! The singleton is an instance. I do not quite understand how the so called "signal" can change value of a property A NOTIFY signal tells the QML engine to discard the old (cached) property value and read it again. When your Globals singleton (instance) emits the numberChanged signal, the QML engine re-reads Globals.number and updates the text.

I agree that for fixed sizes PNG is the better format. However, for mobile devices in a lot of cases the size is not fixed. Maybe I have assumed too much 😉. Even on desktop we tend to use SVG for icons because of display scaling (though as far as I know if you have a dedicated designer he should design PNGs for different resolutions instead).

I want to add, that changing hw.gpu.mode=hardware seems to be not the same as hw.gpu.mode=Hardware - GLES 2.0, changing it to hardware seemed to solve the issue for some time, but today as it resurfaced i first tried Software - GLES 2.0 and it (at least for now) solved the issue, so i switched to Hardware - GLES 2.0 for seemingly better responsiveness(might be placebo though).

@JKSH the QT_QML_OUTPUT_DIRECTORY is setting is not covered in the video tutorial itself, it is only in the github repository, one of the recent rating comments does hint at this: [image: db4c45f8-b684-4068-a7bf-c1ff17440729.png] I think if one includes it in the CMake file then it is enough (though i didn't test it), no need to use QML Language Server. Also your identifier tip solved the other warning, thanks.

@DSpUz my laptop was bad so i couldnt reply

thanks, Awesome Programmer, i somehow missed that line.

There is no built-in property for spacing between a label and a grid in Qt Charts - the only practical solution is to add a space/character at the beginning of each category text to visually push the label away from the grid.