accesskit VS QMetaObject crate for Rust

If you were to implement this yourself, i'd look into either swash or cosmic-text for the text rendering stack (this is one of the things you really don't want to write from the ground up). For accessibility, AccessKit has quickly become the standard for communicating with crossplatform accessibility APIs in rust GUI. lightningcss (or its lower level counterpart cssparser) are both decent options for CSS parsing. Taffy handles some of what browsers offer for a layout engine, but is still being worked on.

> Fleet relies on the Java AWT/Swing framework to get a window from an operating system, but it doesn’t use the Java platform for managing its GUI components besides one JFrame and JPanel on top of it.

This is a terrible decision that is going to bite them in the long run. Doing things this way makes it far, far more difficult to implement accessibility, and regulations on this are only going to get stricter.

Implementing accessibility for a framework like that would involve three separate implementations for three separate platforms and the need to interface with D-Bus, COM and Objective C, from Java. I imagine that the latter two would be particularly difficult, considering how bad Java's FFI support is. It's not just calling methods either, you'd actually need to implement your own classes that conform to the relevant COM interfaces / Objective C protocols. There are libraries that can help with this[1], but I don't think they would work particularly well for something as complex as a code editor.

[1] https://github.com/AccessKit/accesskit

fltk-accesskit is an accesskit integration crate for fltk-rs, the gui crate. It's implemented as an external crate to allow for more experimentation before stabilizing the api, especially since fltk is at version 1.4.

Libraries for a lot of this stuff exist (albeit in many cases not very mature yet):

- https://github.com/pop-os/cosmic-text does text layout (which Taffy explicitly considers out of scope)

- https://github.com/AccessKit/accesskit does accessibility

- https://github.com/servo/rust-cssparser does value-agnostic CSS parsing (it will parse the general syntax but leaves value parsing up to the user, meaning you can easily add support for whatever properties you what). Libraries like https://github.com/parcel-bundler/lightningcss implement parsing for the standard css properties.

- There are crates like https://github.com/BurntSushi/bstr and https://docs.rs/wtf8/latest/wtf8/ for working with non-unicode text

We are planning to add a C API to Taffy, but tbh I feel like C is not very good for this kind of modularised approach. You really want to be able to expose complex APIs with enforced type safety and this isn't possible with C.

There are a number of up-and-coming Rust-based frameworks in this niche:

- https://github.com/iced-rs/iced (probably the most usable today)

- https://github.com/vizia/vizia

- https://github.com/marc2332/freya

- https://github.com/linebender/xilem (currently very incomplete but exciting because it's from a team with a strong track record)

What is also exciting to me is that the Rust GUI ecosystem is in many cases building itself up with modular libraries. So while we have umpteen competing frameworks they are to a large degree all building and collaborating on the same foundations. For example, we have:

- https://github.com/rust-windowing/winit (cross-platform window creation)

- https://github.com/gfx-rs/wgpu (abstraction on top of vulkan/metal/dx12)

- https://github.com/linebender/vello (a canvas like imperative drawing API on top of wgpu)

- https://github.com/DioxusLabs/taffy (UI layout algorithms)

- https://github.com/pop-os/cosmic-text (text rendering and editing)

- https://github.com/AccessKit/accesskit (cross-platform accessibility APIs)

In many cases there a see https://blessed.rs/crates#section-graphics-subsection-gui for a more complete list of frameworks and foundational libraries)

Using HarfBuzz makes sense. But if you're looking for a pure-Rust alternative, I hear cosmic-text (made by Pop!_OS) is good. There's also AccessKit for accessibility.

There are efforts to support a cross platform accessibility library:

https://github.com/AccessKit/accesskit

egui is an easy-to-use immediate mode GUI for Rust, and I just released 0.20. It's a big release!

There is now support for AccessKit (https://github.com/AccessKit/accesskit) which brings accessibility to egui (a first for an immediate mode GUI?).

There is also better table support, nicer keyboard shortcut handling, better looking text in light mode (still not great, but better).

See more in the changelog: https://github.com/emilk/egui/blob/master/CHANGELOG.md

Try it out at www.egui.rs

You can use Rust with QML[1].

QML is actually pretty amazing. I've been building my block editor[2] view entirely in QML while the model is in C++. This separation of logic and presentation works great. And yes, there are some crashes sometimes (that I find quite easy to debug thanks to the built-in debugger), but take for example a similar app that's built with Rust and Dart[3], in my testing there were still memory leaks that caused my computer to hang. It's better to know you have a bug than for it to be hidden from you.

I agree with parent commenter, saying these cross-platform frameworks will end up supporting the least common denominator set of features. But I found with external open source libraries, the community is catching up very fast. For example, you want the awesome translucency macOS apps have for your Qt app? Here you go[4]. Many such cases. It's also pretty straightforward to add your own custom OS-dependent code, especially so, if someone already open sourced his approach. I recently wanted to move the traffic light buttons on macOS for my app, but couldn't figure the Objective-C code for that. I ended up looking at either Tauri or Electron source code and found my answer.

[1] https://github.com/woboq/qmetaobject-rs

[2] https://www.get-plume.com/

[3] https://www.appflowy.io/

[4] https://github.com/stdware/qwindowkit

I just used qmetaobject-rs and my experience with Qt/QML. There's the QML book from Qt if you're just starting, which is pretty nice https://www.qt.io/product/qt6/qml-book

qmetaobject is probably the most mature Qt Rust binding at the moment. It uses the cpp crate to embed C++ inline in Rust to create its bindings. There are some people using it and it does get some maintenance, but it's not under active development since the original author is now working on Slint.

The bindings currently use the git version of qttypes since I had to merge some upstream changes that are needed for these bindings. So they are not ready for prime time just yet.

There are a bunch of bindings with different language, but even the ones that are officially supported like PySide will still be second class citizen and awkward to use.

Automated binding generation will never give you idiomatic API in whatever language. And if you want an idiomatic library that wraps Qt, it's going to take a huge amount of work.

Which is why I think restricting to QML makes sense because that's a much smaller API surface. That was the ambition behind my previous crate that exposes QML to rust: https://github.com/woboq/qmetaobject-rs/

But now I've moved on to another GUI project: Slint https://github.com/slint-ui/slint

Whisperfish does this with Qt: https://github.com/woboq/qmetaobject-rs/issues/102

What do you want to know? It's pretty easy thanks to the amazing work of guys behind qmetaobject-rs.

This is probably the portion that I found the most difficult. The README of qmetaobject-rs gives us a basic idea of the build script, so I started with that. Here is my starting script