nrelm 0.1.0

An idiomatic GUI library inspired by Elm and based on gtk3-rs.

NeoRelm is a GTK3 port of Relm4 (the original Relm4 targets GTK4 and libadwaita, while this project backports the same API and design to GTK3). Why? Because gnome keeps deprecating everything in gtk4. Making apps with gtk4 without libadwaita might not be easy in future. And because I wanted to make apps for XFCE.

Documentation

• 📜 Rust documentation
• 🌐 The repository — including examples and the changelog

Dependencies

NeoRelm depends on GTK3

Ecosystem

• nrelm-macros - several macros for declarative UI definitions.
• nrelm-components - a collection of reusable components.
• nrelm-icons - icons for your application (maintained in its own repository).

Use this in your Cargo.toml:

# Core library
nrelm = "0.1"
# Optional: reusable components
nrelm-components = "0.1"
# Optional: icons (more info at https://gitlab.com/NeoRelm/NeoRelm-icons)
nrelm-icons = "0.1"

Features

The nrelm crate has two feature flags:

Examples

Several example applications are available at examples/.

📸 Screenshots from the example apps

A simple counter app

use gtk::prelude::*;
use nrelm::prelude::*;

struct AppModel {
    counter: u8,
}

#[derive(Debug)]
enum AppMsg {
    Increment,
    Decrement,
}

#[nrelm::component]
impl SimpleComponent for AppModel {
    type Init = u8;
    type Input = AppMsg;
    type Output = ();

    view! {
        gtk::Window {
            set_title: "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 => AppMsg::Increment,
                },

                gtk::Button {
                    set_label: "Decrement",
                    connect_clicked => AppMsg::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<Self>,
    ) -> ComponentParts<Self> {
        let model = AppModel { 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<Self>) {
        match msg {
            AppMsg::Increment => {
                self.counter = self.counter.wrapping_add(1);
            }
            AppMsg::Decrement => {
                self.counter = self.counter.wrapping_sub(1);
            }
        }
    }
}

fn main() {
    let app = RelmApp::new("nrelm.example.simple");
    app.run::<AppModel>(0);
}

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (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!