[pen2l]

Something being highlighted about Flutter is that it ultimately compiles to native code so unlike RN which transpiles to native widgets, its UI animations should technically be buttery smooth.

But in watching the flutter announcement video https://youtu.be/Nu5m1FiS5X4?t=60 (timestamped link) on the screen as menus are opening and the mouse cursor is shown selecting different items, there is... a very perceptible stutter and lag. What is that due to?

[munificent]

There are a lot of levels of indirection here:

* A video on YouTube...

* Of a livestream...

* Of a video made by a separate video production team...

* Based a slideshow (probably Google Sheets)...

* Containing a pre-rendered video...

* Of a screen recording...

* Of a Flutter desktop app.

Any and all of those can introduce latency or lag in the video. It's a great form for showing users features, but probably not a great way to evaluate UI performance, unfortunately.

[pen2l]

On the one hand, ok... sure... on the other:

this just makes me think of the fact that this sort of thing would absolutely never fly at Apple. And I really, really want to say that is shouldn't fly at Google either. They're spending what, 400k on the median developer annually? Have standards, make them have some sense of responsibility and respect for their craft so they don't do this. I mean, like come on, one of the main value propositions for someone considering Flutter as opposed to RN is the fact that it isn't transpiled, there is thus an expectation for widget performance to be basically be similar to that of native code -- well, this is exactly where you proudly and loudly showcase this -- in an announcement video. Widget performance should be absolutely flawless in the presentations.

But all that said, no I don't think that's what's going on here. The things shown right thereafter are stutter free. I think this is a quirk with Flutter. While for mobile/desktop it compiles to native code, for web it does transpile to JS and I think that's perhaps what is being shown there. Though I would think if they wrap it in some sort of wasm the lag wouldn't be perceptible.

It just really grates me that in this day and age this is the reality of UI. If you'd told me 10 years ago that a simple menu shown in a major UI toolkit announcement by the main web player would have these kinds of problems I'd have assumed you were just bad at telling jokes. It also makes me sad because I want Flutter to succeed but seeing these kinds of missteps gives me a pause.

edit: I see now that you're a googler, I'd have phrased it differently if I'd known. Cheers.