[piker]

Both approaches have their downsides and, in my view, retained mode and immediate mode tend to converge as the UI complexity increases. So far, no problems with implementing any UI I want in my experience with egui on a somewhat complicated application (Desktop word processor). Immediate mode is a breath of fresh air from React.

[Edit: although the standard accessibility criticisms apply to my application; although that's more of an issue with my implementation than an indictment of immediate mode generally.]

[ethin]

Accessibility problems are something both retained-mode and immediate-mode UIs have generally. I've found that you can kind-of hack it together but the best route is to incorporate the actual accessibility frameworks of the operating system(s) your targeting. Egui was doing this at one point I think but I'm pretty sure it's either broken now or just doesn't work all that well.

[miki123211]

The problem with immediate mode is that most a11y frameworks expect all UI elements to have a stable identity.

Imagine you have a to-do list of 100 items. What happens when a remote user drags and drops item 100 to lie between items 1 and 2? In retained mode, that's clearly communicated to the UI toolkit; the widget representing that todo is told to change its position in the list. In immediate mode, you can't just destroy and re-create the a11y tree on each render. You need some kind of tree diffing algorithm to figure out that it's one op (move item) instead of ~200 ops (change the name and checkbox state for all items between 2 and 100).

[apitman]

> In immediate mode, you can't just destroy and re-create the a11y tree on each render

You don't need to do it each render, just when something structural changes, right?

[spookie]

There are libs that function as a messenger between your "hack" and the OS on this.

You don't lose anything.

This is but my opinion, but toolkits tend to be opinionated piles of **. Talking directly with the GPU to paint stuff is often just saner to me.

[mhast]

From what I've seen immediate mode seems suitable for less fancy UI requirements. If you want to start having a framework solve things like animations and such then you'll probably end up with some form of retained mode.

Over my years making UIs I've found most of the bugs you get is due to incorrect state handling in applications. Having a framework you use which is opinionated and helps you solve that is pretty nice. (If your UI requirements are such that you need it.)

[the__alchemist]

I'm curious too. I currently have both a plasmid editor, and protein/molecule viewer using EGUI. Both have complex UIs, and I haven't hit roadblocks. I think the protein viewer might be more of a canonical immediate-mode case, because most of the window is a 3D render, but it still has a GUI above it.

[smj-edison]

Kind of off topic, but a protein viewer in Rust sounds really interesting! Is the source code available? I'd love to poke through it (understandable if not though).

[the__alchemist]

Yep - https://github.com/David-OConnor/daedalus/

[nopelynopington]

I'm also thinking of building a word processor so I'd be interested to see what you're working on if you fancy sharing?

[piker]

Sure, it's https://tritium.legal/preview