[Interest] Guide me through the Qt offerings for GUIs

[Volker Hilsheimer]

> On 15 Apr 2021, at 12:25, Rui Oliveira <ruilvo at hotmail.com> wrote:
> 
> Hey,
> As per the title implies, I would like some comments on the GUI offerings Qt currently has. 
> 
> I'll share my own assessments and needs, and I'd like very much to hear your comments.
> 
> So:
> 
> I want to write a desktop application. This desktop application would not involve displaying lists of things, which seems to be what all tutorials/guides/courses are about, especially on the QML side. This application would involve some "custom graphics", namely a FFT display, and a "waterfall" display. You can google for "GQRX" and you'll know what I want.
> 
> 
> 
> And then I looked at Qt, and:
> 
> First thing I have looked at were QWidgets. I feel comfortable staying in the C++ domain. To implement said custom widgets I gave a shot to a class inheriting from QOpenGLWidget. And honestly, the experience wasn't bad at all! 
> 
> But, I feel very hesitant to start a project on QWidgets. It feels like starting a project on dead tech. Although, I did watch Giuseppe D’Angelo's talk in Qt Desktop Days 2020 (slides [1]), and looking at slide 19, there seem to be prospects of evolution. My attention goes especially to "Accelerate widget rendering & compositing through RHI". Will QWidgets really have a RHI backend? And a QRhiWidget option? Or maybe just QWidget and everything HW accelerated? I can dream...
> 
> I know QWidgets are no longer "interesting". Even KDE moved on from them... And I understand that's not where the money is for now... Still, I'd like some comments.
> 
> Now, QML.
> 
> Slide 25 of the same talk mentions native desktop styling for QQC2. I can't find documentations on this. Are they already available yet? Also, in the previous slide, "Planned in Qt 6.x: C++ API for Qt Quick elements". Does this mean Qt Quick *without* QML? 
> 
> Also, in QML it seems to be very hard to have anything native-looking. I looked at Qt Labs Platform [2] and things like the right click menu aren't available on Windows, for example. Are there plans to expand this? 
> 
> 
> 
> Either way, I'm quite divided. I'd like to hear your thoughts and recommendations. 
> 
> In summary, it would seem that my options for the desktop with Qt are two self-competing technologies: one "half-dead", one "3/4-baked"... I'd really love to be wrong.
> 
> 
> 
> Thank you for your time,
> Rui


Hi Rui,

Richard and I had a talk about our plans in that respect at last year’s "Qt Goes Virt:Desktop” event. The recording is available here, if you are ok with providing your digits to The Qt Company:

https://resources.qt.io/qt-goes-virt-2020/desktop-applications-with-qt-native-styling-and-the-future-3

This outlines the general direction, and the work on this will keep us busy for several years to come.

TL;DR: Qt Widgets will be with us for a long time, and we’ll continue to maintain them and make sure that they continue to work and look great on future versions of the various operating systems as well. There’ll probably always be applications for which the widget concepts are a perfect fit.

For an increasing amount of applications and environments however, Qt Quick provides the better architecture, and we see a growing number of Qt Quick based desktop applications already today, also outside of the KDE environment. But yes, making Qt Quick a first class toolkit for desktop use cases is work in progress and there’s a lot of catching up to do. Native look’n’feel on Windows and macOS was introduced with Qt 6.


Cheers,
Volker