by rubymamis | 2026-01-06 16:15:51+00:00
> How much experience do you have writing mobile apps in Kotlin or Swift, as a comparison?

No, in the mobile space I've only used React Native and QML with C++.

> This almost certainly does not matter for a mobile app, and definitely not for the UI part.

I disagree. For example, I expect block editors to handle large texts efficiency - both in terms of power draw and performance. Writing in a non-compiled language already puts you in a disadvantage in both aspects. But this is just the standard I set to myself - the entire industry clearly has different priorities.

> I didn't mean that it is complicated. I can totally write C++. What I meant is that it is more complicated to get it right than modern languages. If users complain about a segmentation fault, it's often pretty tricky to debug. In Java/Kotlin, you will get an exception that tells you exactly which line crashed.

Yep, I generally agree, tho with good debugging tools and LLMs I have found this to not be a problem anymore.

> On top of that, C++ is slower to write. Again I have been able to compare teams working on the same app both in C++ and in Java/Kotlin/Swift (Java is not exactly a modern language, but still it's a lot faster to develop with).

I write in TypeScript at my day job and C++ for my side projects and I don't feel like I'm slower in C++. Again, I'm using the subset I'm conformable with.

> And after all those disadvantages of using C++ for a mobile app, you end up with a UI that doesn't feel native to the platform.

That has certainly been the case, and what I'm trying to fix - because I've proven that it is fixable by caring about UI/UX. QML is great for UI, it's just that Qt developers (both the developers of Qt and those using it) don't care much about those things. But it's definitely posiible to get good results. For example, I'm working on SwipeStackView like other iOS apps have in QML, and I'm liking what I've made so far: https://rubymamistvalove.com/notes-mobile-swipe-stack-view.M...

> Even for writing a Desktop app, I don't understand why people use Qt instead of e.g. Java. Kotlin/Compose seem to be coming on Desktop too, which makes a lot of sense to me. And maybe even Flutter.

Again, I can't stretch how FUN, easy, and overall a great experience to develop with QML and C++ together, it's just HOW GUI should always been. I'm thinking of creating some Youtube tutorials that will try to present this feeling.

> Finally, I don't understand writing a cross-platform UI for Desktop and mobile. On mobile, I have a big finger and a small touch screen. On Desktop, I have a big screen, a mouse and a keyboard. Those require different UIs. Sharing the logic is fine, but the UI needs to be written for the platform.

100%. Completely in agreement. The fact that you can develop both Desktop and mobile apps in QML doesn't mean you must make them share the same code (at least, not fully). I think Kirigami have gone the wrong way with their 'adaptable' UI (I've also thought about doing that until I realized it's the wrong approach). One should always start with the UX that the end result should be - never start from tech considerations.

[1] https://develop.kde.org/frameworks/kirigami//