xilem

f that you can find a few egui examples in the rust-android-examples repo. Alright, so after I've got the basic examples running, I wanted to combine them with iced. Iced is a crossplatform gui library focusing on desktop and web. The mobile support is explicitly a non-goal, as far as I can tell at the moment of writing. Yet, there's an issue where some people posted their experiments. That's how I knew it was possible: https://github.com/iced-rs/iced/issues/302 There's a way to integrate iced in wgpu applications, so called integration example: https://github.com/iced-rs/iced/tree/0.14.0/examples/integra... Above I mentioned that using winit and wgpu in combination with android-activity is enough to build the app. Putting together 1 + 1 I got 2: let's use iced integration example with android-activity. It was quite easy to compile with almost no errors. First issue I encountered is that there was no text rendered. I solved this by loading fonts the way it was shown here: https://github.com/pop-os/cosmic-text/issues/243#issue-21899... Then I patched a few widgets to add touch support. And that's it. My role here was to take all the prior work and combine it together in a way that there's a working example. Some other ways of building Android apps using Rust: - xilem has an explicit goal to support mobile https://github.com/linebender/xilem - egui supports mobile https://github.com/emilk/egui - game engines such as Fyrox and Bevy support mobile: - https://github.com/FyroxEngine/Fyrox - https://github.com/bevyengine/bevy - pretty much anything built on top of winit and wgpu All of the above is related to building native apps using either NativeActivity or GameActivity. I'm leaving webview out of scope of current post. What about iOS? As far as I know it should be similar or maybe simpler compared to Android. I haven't built it yet, but the next time I have a sizeable amount of free time, I'll try to make it work. The plan is the same: pick winit, wgpu, iced integration example, mix it together until it works. It'll require the same trick to load fonts, and maybe something else, but no visible blockers as of now. Once again, thanks to all the people who made it possible and I wish you have a great time building mobile apps with Rust!

ering switching to Impeller (a new 2D rendering engine in Flutter) because of performance issues in Skia with shaders compiling. Slint [6], was founded by 3 guys who's been working for a long time in Qt Group. It is written in Rust but uses DSL to develop GUI. As I understand, they try to solve the main fundamental issues in Qt. MAUI, as I understand it, was Xamarin.Forms and now Microsoft tries to develop it. Another interesting thing. There is a part of each GUI framework, a system to automatically place widgets on the screen - layouting, something like a grid, table, and so on. Several years ago, Apple had a big boom in the implementation and use of the Cassowary algorithm [7] in their GUI frameworks. It was a promising, strong math-based academia-proof algorithm, but in real life, as I understood, it can not work reliably in many edge cases [8], so Apple quietly removed it and implemented Flexbox [9]. More approaches: to use game engines as GUI frameworks: Unity, Unreal, Godot, etc. Fun fact: Blender has its own GUI library, which is implemented on top of OpenGL. PS If you find anything interesting, I would appreciate it if you share. PPS As a way to find more, I can recommend using search in HN, Reddit, and GitHub. Try to find projects that people develop to solve something and look at what ideas they use. [1] https://raphlinus.github.io/ [2] https://linebender.org/ [3] https://github.com/linebender/xilem [4] WebGPU implementation in Rust, used in Firefox and many other projects, can be used as a separate library, cross-platform, meta-API over Vulkan, DirectX, Metal etc [5] https://www.jetbrains.com/compose-multiplatform/ [6] https://github.com/slint-ui/slint [7] https://en.wikipedia.org/wiki/Cassowary_(software) [8] https://news.ycombinator.com/item?id=13935264 [9] https://en.wikipedia.org/wiki/CSS_Flexible_Box_Layout

h other to achieve what should be doable in one or two. And our highly-lightweight JS which calls into Rust (Wasm) lets it keep the slow logic out of slow JS. And we are using Svelte to move most of the frontend DOM management logic from runtime to compile time. This architecture really helps us keep performance levels as close as possible to feeling native despite using the web for its GUI rendering; and I believe it has succeeded at feeling responsive by comparison to most other web apps you use (even Slack, for example, which shouldn't be nearly as complex). Web lets us build fast, deploy the latest version to users fast, leverage prevalent developer experience with HTML/CSS for creating GUIs, and avoid getting stuck in a box with Rust's currently-immature GUI ecosystem. That's the tradeoff we had to make early on, and it was a good decision. But we will eventually move towards a fully native version... In the short term, we plan to use [Tauri](https://tauri.app/) which is sort of a hybrid between Electron and a native application. It uses the OS's webview to shrink the shipped binary to only a few megabytes and reuse shared memory resources with other webviews at runtime. It also runs all our Rust code natively instead of through WebAssembly so all the business logic in Graphite runs natively and only the thin UI layer becomes dependent on web tech for the GUI display. In the long term, we plan to rewrite the entire GUI in [Xilem](https://github.com/linebender/xilem) which is the up-and-coming Rust GUI that I believe will finally get everything right, including performance (which is something many desktop GUI frameworks are actually bad it, and sometimes even worse than web). We'll still deploy a web version but at that point, it will become native-first. Hopefully that roadmap and explanation of the architectural decisions clears up any worries about the short and long term state of our GUI.

) - 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)