Also worth noting that many creation-centric applications for the desktop (graphics, audio, video etc. etc.) don't look "native" even when they actually are. In one case (Logic Pro, from Apple), the "platform leading app from the platform creator" doesn't even look native!
Qt also supports rendering directly on the GPU (or with software rendering on the framebuffer) without any windowing system such as X11 or Wayland - that's likely how it is most commonly used in the wild, as that's one of the main way to use it on embedded devices.
You're seriously suggesting that the common use of Qt on Linux systems is direct rendering without the windowing system?
Arguably it's use in embedded contexts is much larger than desktop. It's quite popular for in-car computers, defense systems, etc.
For desktop linux, yes, it uses the windowing system.
I know how Qt works at that level. I did a bunch of work in the mid-naughts on the equivalent stuff in GTK.
That's true of QtWidgets, but not QML / Qt Quick (the newer tool), correct? (I found this hard to determine online).
But :
- QML can be used with other graphics stack - for instance Qt Widgets like with https://www.kdab.com/declarative-widgets/ or alternatives to the official Qt Quick controls with https://github.com/uwerat/qskinny or with completely custom rendering like here with NanoVG : https://github.com/QUItCoding/qnanopainter
- QtQuick Controls can be made to use the same style hints than the desktop with https://github.com/KDE/qqc2-desktop-style
Put a <button/> in an HTML page and you get a platform-provided UI widget.
I did a small bit of research into this, and found plenty of "anecdotal" evidence, but nothing confirming for sure. I'm looking and interacting with the controls and they seem pretty native - if they're a recreation than that's pretty impressive :)
Implementing the look is simple, adding behaviour quite harder and utilizing the service the endgame. WebUI usually does nothing from those or some parts, it all depends on the constellation. But usually there is a obvious difference at some point where you realize whether something is native or just made an attempt.