QML and Qt Quick

@JKSH said in What is best way to implement controls that render very fast?: QQuickPaintedItem I already tried the QML-only and QQuickPaintedItem options. Both are to slow for me. So I now choosed for QQuickItem + QSGGeometryNode. Not to complicated and hopefully fast enough.

@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.

For multiple reasons, calling setData in this case is the only viable option. This is what I have in my head: ListView { model: /* ... */ delegate: SomeWidget { onEdit: { model.setData(model.index(row, column), someDataToMutate) } } } Column is always 0 in this case, but how is one supposed to get the current row in a QML model-view?

Its working now. Thanks! @Nils-Sjoberg

Hi and welcome to devnet, Can you test this with a more recent version of Qt ?

Hi and welcome to devnet, Please show a minimal code sample that reproduces your situation. Also: Which version of Qt ? On which OS ?

Try this. Maybe that's what you want. Rectangle { width: 300 height: 100 anchors.centerIn: parent color: "#f0f0f0" Flickable { anchors.fill: parent contentWidth: width contentHeight: editor.contentHeight ScrollBar.vertical: ScrollBar {} TextEdit { id: editor width: parent.width wrapMode: TextEdit.Wrap text: "Linha 1\nLinha 2\nLinha 3\nLinha 4\nLinha 5\nLinha 6\nLinha 7\nLinha 8\nLinha 9\nLinha 10" } } }

@JonB Hey, I've figured out the cause. It's being caused by the thumbnail rendering. I commented out the line ui->thumbnailView->setModel(pdfDocument->pageModel()); and the PDF is loaded instantly. Maybe loading the thumbnails on a different thread won't freeze the UI? (setModel isn't thread safe it seems). The setModel probably causing problems since the pdfDocument->pageModel() is huge. Can you please help me out with how I could fix this? The thumbnailView is a QListView btw. EDIT: I've set setUniformItemSizes to true and the loading is much faster now (almost instantaneous). ui->thumbnailView->setUniformItemSizes(true); I think this was the key to making the view load its items faster. But the scrolling in the thumbnailView widget is pretty laggy.

@JKSH said in Qt 6 QML TextArea C++ header. Where located?: QQuickPlainText Got messed with QPlainTextEdit. Three weeks of non-stop coding. :-))))

@GrecKo Thank you! I checked and it is really there. Going to use them further since we have no proper methods even in 2026. About this: @Markkyboy said in IconImage and ColorImage current state: layer.effect: MultiEffect I believe it is much more expensive in terms of performance just like Qt5's GraphicalEffects was.