relm4 0.1.0

An idiomatic GUI library inspired by Elm and based on gtk4-rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150

<h1>
  <img src="assets/Relm_logo_with_text.svg" height="65" alt="Relm4">
</h1>

[![CI](https://github.com/AaronErhardt/relm4/actions/workflows/rust.yml/badge.svg)](https://github.com/AaronErhardt/relm4/actions/workflows/rust.yml)
[![Matrix](https://img.shields.io/matrix/relm4:matrix.org?label=matrix%20chat)](https://matrix.to/#/#relm4:matrix.org)
[![Relm4 on crates.io](https://img.shields.io/crates/v/relm4.svg)](https://crates.io/crates/relm4)
[![Relm4 docs](https://img.shields.io/badge/rust-documentation-blue)](https://aaronerhardt.github.io/docs/relm4/relm4/)
[![Relm4 book](https://img.shields.io/badge/rust-book-fc0060)](https://aaronerhardt.github.io/relm4-book/book/)
![Minimum Rust version 1.53](https://img.shields.io/badge/rustc-1.53+-06a096.svg)

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).

## Goals

+ ⏱️ **Productivity:** Writing Relm4 applications should be intuitive and efficient
+ ⚡ **Flexibility:** Anything that’s possible in GTK4 should work well in Relm4, too
+ ✨ **Simplicity:** Writing applications should be as easy and straightforward as possible
+ 🔧 **Maintainability**: The Elm programming model used by Relm4 provides a simple and clear structure for app development

## Documentation

+ 📖 **[Book](https://aaronerhardt.github.io/relm4-book/book/)**
+ **[Rust documentation](https://aaronerhardt.github.io/docs/relm4/relm4/)**

## Dependencies

Relm4 only depends on GTK4: [How to install GTK4](https://www.gtk.org/docs/installations/)

## Ecosystem

Relm4 has two crates that extend the core functionality:

+ [relm4-macros](https://crates.io/crates/relm4-macros) provides a `widget` macro that simplifies UI creation
+ [relm4-components](https://crates.io/crates/relm4-components) is a collections of reusable components you can easily integrate into your application

Add this to your `Cargo.toml`:

```toml
gtk = { version = "0.2", package = "gtk4" }
relm4 = "0.1.0"
relm4-macros = "0.1.0"
relm4-components = "0.1.0"
```

### Features

The relm4 crate has two feature flags:

+ tokio-rt: Adds the `AsyncWorker` type that uses an async update function
+ libadwaita: Improved support for [libadwaita](https://gitlab.gnome.org/World/Rust/libadwaita-rs)

## Examples

Several example applications are available at [relm4-examples/](relm4-examples/).

### A simple counter app

```rust
use gtk::prelude::{BoxExt, ButtonExt, GtkWindowExt, OrientableExt};
use relm4::{send, AppUpdate, Model, RelmApp, Sender, WidgetPlus, Widgets};

#[derive(Default)]
struct AppModel {
    counter: u8,
}

enum AppMsg {
    Increment,
    Decrement,
}

impl Model for AppModel {
    type Msg = AppMsg;
    type Widgets = AppWidgets;
    type Components = ();
}

impl AppUpdate for AppModel {
    fn update(&mut self, msg: AppMsg, _components: &(), _sender: Sender<AppMsg>) -> bool {
        match msg {
            AppMsg::Increment => {
                self.counter = self.counter.wrapping_add(1);
            }
            AppMsg::Decrement => {
                self.counter = self.counter.wrapping_sub(1);
            }
        }
        true
    }
}

#[relm4_macros::widget]
impl Widgets<AppModel, ()> for AppWidgets {
    view! {
        gtk::ApplicationWindow {
            set_title: Some("Simple app"),
            set_default_width: 300,
            set_default_height: 100,
            set_child = Some(&gtk::Box) {
                set_orientation: gtk::Orientation::Vertical,
                set_margin_all: 5,
                set_spacing: 5,

                append = &gtk::Button {
                    set_label: "Increment",
                    connect_clicked(sender) => move |_| {
                        send!(sender, AppMsg::Increment);
                    },
                },
                append = &gtk::Button {
                    set_label: "Decrement",
                    connect_clicked(sender) => move |_| {
                        send!(sender, AppMsg::Decrement);
                    },
                },
                append = &gtk::Label {
                    set_margin_all: 5,
                    set_label: watch! { &format!("Counter: {}", model.counter) },
                }
            },
        }
    }
}

fn main() {
    let model = AppModel::default();
    let app = RelmApp::new(model);
    app.run();
}

```

## 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!**