[](https://github.com/Relm4/Relm4/actions/workflows/rust.yml) [](https://matrix.to/#/#relm4:matrix.org) [](https://crates.io/crates/relm4) [](https://docs.rs/relm4/) [](https://relm4.org/book/stable/)  [](https://deps.rs/repo/github/Relm4/Relm4) An idiomatic GUI library inspired by [Elm](https://elm-lang.org/) and based on [gtk4-rs](https://crates.io/crates/gtk4). Relm4 is a new version of [relm](https://github.com/antoyo/relm) that's built from scratch and is compatible with [GTK4](https://www.gtk.org/) and [libadwaita](https://gitlab.gnome.org/GNOME/libadwaita). ## Why Relm4 We believe that GUI development should be easy, productive and delightful. The [gtk4-rs](https://crates.io/crates/gtk4) crate already provides everything you need to write modern, beautiful and cross-platform applications. Built on top of this foundation, Relm4 makes developing more idiomatic, simpler and faster and enables you to become productive in just a few hours. ## Our goals + ⏱️ **Productivity** + ✨ **Simplicity** + 📎 **Outstanding documentation** + 🔧 **Maintainability** ## Documentation + 📖 **[The Relm4 book](https://relm4.org/book/stable/)** + 📜 **[Rust documentation](https://docs.rs/relm4/)** ## Dependencies Relm4 depends on GTK4: [How to install GTK4 and Rust](https://gtk-rs.org/gtk4-rs/git/book/installation.html) ## Ecosystem + [relm4-macros](https://crates.io/crates/relm4-macros) - several macros for declarative UI definitions. + [relm4-components](https://crates.io/crates/relm4-components) - a collections of reusable components. + [relm4-icons](https://crates.io/crates/relm4-icons) - icons for your application. + [relm4-template](https://github.com/Relm4/relm4-template) - a starter template for creating Relm4 applications in the Flatpak package format. + [relm4-snippets](https://github.com/Relm4/vscode-relm4-snippets) - code snippets to speed up your development. Use this in to your `Cargo.toml`: ```toml # Core library relm4 = "0.9" # Optional: reusable components relm4-components = "0.9" # Optional: icons (more info at https://github.com/Relm4/icons) relm4-icons = "0.9.0" ``` ### Features The `relm4` crate has four feature flags: | Flag | Purpose | Default | | :--- | :------ | :-----: | | `macros` | Enable macros by re-exporting [`relm4-macros`](https://crates.io/crates/relm4-macros) | ✅ | | `libadwaita` | Improved support for [libadwaita](https://gitlab.gnome.org/World/Rust/libadwaita-rs) | - | | `libpanel` | Improved support for [libpanel](https://gitlab.gnome.org/World/Rust/libpanel-rs) | - | | `gnome_46` | Enable all version feature flags of all dependencies to match the GNOME 46 SDK | - | | `gnome_45` | Enable all version feature flags of all dependencies to match the GNOME 45 SDK | - | | `gnome_44` | Enable all version feature flags of all dependencies to match the GNOME 44 SDK | - | | `gnome_43` | Enable all version feature flags of all dependencies to match the GNOME 43 SDK | - | | `gnome_42` | Enable all version feature flags of all dependencies to match the GNOME 42 SDK | ✅ | The `macros` feature is a default feature. ## Examples Several example applications are available at [examples/](examples/). #### [📸 Screenshots from the example apps](assets/screenshots) ### A simple counter app   ```rust use gtk::prelude::*; use relm4::prelude::*; struct App { counter: u8, } #[derive(Debug)] enum Msg { Increment, Decrement, } #[relm4::component] impl SimpleComponent for App { type Init = u8; type Input = Msg; type Output = (); view! { gtk::Window { set_title: Some("Simple app"), set_default_size: (300, 100), gtk::Box { set_orientation: gtk::Orientation::Vertical, set_spacing: 5, set_margin_all: 5, gtk::Button { set_label: "Increment", connect_clicked => Msg::Increment, }, gtk::Button { set_label: "Decrement", connect_clicked => Msg::Decrement, }, gtk::Label { #[watch] set_label: &format!("Counter: {}", model.counter), set_margin_all: 5, } } } } // Initialize the component. fn init( counter: Self::Init, root: Self::Root, sender: ComponentSender, ) -> ComponentParts { let model = App { counter }; // Insert the code generation of the view! macro here let widgets = view_output!(); ComponentParts { model, widgets } } fn update(&mut self, msg: Self::Input, _sender: ComponentSender) { match msg { Msg::Increment => { self.counter = self.counter.wrapping_add(1); } Msg::Decrement => { self.counter = self.counter.wrapping_sub(1); } } } } fn main() { let app = RelmApp::new("relm4.example.simple"); app.run::(0); } ``` ## Projects using Relm4 - [fm](https://github.com/euclio/fm) — A small, general-purpose file manager. - [Done](https://github.com/edfloreshz/done) - A simple and versatile to do app. - [Reovim](https://github.com/songww/reovim) - GUI frontend for neovim. - [NixOS Configuration Editor](https://github.com/vlinkz/nixos-conf-editor) - A graphical configuration editor for [NixOS](https://nixos.org). - [Rhino Setup](https://github.com/rhino-linux/rhino-setup) - Setup wizard for [Rolling Rhino](https://rhinolinux.org/) - [Lemoa](https://github.com/lemmy-gtk/lemoa) - Desktop client for Lemmy - [Score Tracker](https://github.com/weclaw1/score-tracker) - App for tracking player scores in card and board games - [Spidey](https://github.com/kdwk/Spidey) - A seamless and distraction-free work and play environment on the web - [Toolbox Tuner](https://github.com/13hannes11/toolbox-tuner) - An application to manage Toolbx containers - [BitRitter](https://codeberg.org/Chfkch/bitritter) - A bitwarden/vaultwarden client with mobile devices in mind - [Space Acres](https://github.com/autonomys/space-acres) - An opinionated GUI application for farming on Autonomys Network ## License Licensed under either of * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) at your option. ### Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. **Feedback and contributions are highly appreciated!**