Freya 🦀

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Freya is a cross-platform, native, declarative GUI library for Rust 🦀.

⚠️ I recently rewrote a huge percentage of Freya in #1351, so the main branch differs a lot from the latest stable release.

Components & State

Freya’s component model lets you create reusable UI elements that automatically re-render when the state they depend on changes. Components can hold their own internal state or subscribe to shared state, and they produce UI as their output. Any type that implements the Component trait can be a component, while the root (app) component can simply be a function. Built-in examples include components like Button and Switch.

fn app() -> impl IntoElement { let mut count = use_state(|| 4); let counter = rect() .width(Size::fill()) .height(Size::percent(50.)) .center() .color((255, 255, 255)) .background((15, 163, 242)) .font_weight(FontWeight::BOLD) .font_size(75.) .shadow((0., 4., 20., 4., (0, 0, 0, 80))) .child(count.read().to_string()); let actions = rect() .horizontal() .width(Size::fill()) .height(Size::percent(50.)) .center() .spacing(8.0) .child( Button::new() .on_press(move |_| { *count.write() += 1; }) .child("Increase"), ) .child( Button::new() .on_press(move |_| { *count.write() -= 1; }) .child("Decrease"), ); rect().child(counter).child(actions) }

Out of the box components

Freya comes with a set of components out of the box, from simple like Button, Switch, Slider to more complex like VirtualScrollView, Calendar, ColorPicker, etc.

You can check all the examples that start with component_ in the examples folder.

Example of component_input.rs:

Smooth Animations

Create transitions for colors, sizes, positions, and other visual properties. The animation API gives you full control over timing, easing functions, and animation sequences.

Code

use freya::prelude::*;

fn app() -> impl IntoElement {
    let mut animation = use_animation(|_| AnimColor::new((246, 240, 240), (205, 86, 86)).time(400));

    rect()
        .background(&*animation.read())
        .expanded()
        .center()
        .spacing(8.0)
        .child(
            Button::new()
                .on_press(move |_| {
                    animation.start();
                })
                .child("Start"),
        )
        .child(
            Button::new()
                .on_press(move |_| {
                    animation.reverse();
                })
                .child("Reverse"),
        )
}

Portal example

Kooha-2026-01-28-21-56-13.compressed.mp4

Rich Text Editing

Freya provides text editing capabilities that go beyond simple input fields. You can create rich text editors with cursor management, text selection, keyboard shortcuts, custom formatting, virtulization and more.

Code

use freya::prelude::*;

fn app() -> impl IntoElement {
    let holder = use_state(ParagraphHolder::default);
    let mut editable = use_editable(|| "Hello, World!".to_string(), EditableConfig::new);
    let focus = use_focus();

    paragraph()
        .a11y_id(focus.a11y_id())
        .cursor_index(editable.editor().read().cursor_pos())
        .highlights(
            editable
                .editor()
                .read()
                .get_selection()
                .map(|selection| vec![selection])
                .unwrap_or_default(),
        )
        .on_mouse_down(move |e: Event<MouseEventData>| {
            focus.request_focus();
            editable.process_event(EditableEvent::Down {
                location: e.element_location,
                editor_line: EditorLine::SingleParagraph,
                holder: &holder.read(),
            });
        })
        .on_mouse_move(move |e: Event<MouseEventData>| {
            editable.process_event(EditableEvent::Move {
                location: e.element_location,
                editor_line: EditorLine::SingleParagraph,
                holder: &holder.read(),
            });
        })
        .on_global_mouse_up(move |_| editable.process_event(EditableEvent::Release))
        .on_key_down(move |e: Event<KeyboardEventData>| {
            editable.process_event(EditableEvent::KeyDown {
                key: &e.key,
                modifiers: e.modifiers,
            });
        })
        .on_key_up(move |e: Event<KeyboardEventData>| {
            editable.process_event(EditableEvent::KeyUp { key: &e.key });
        })
        .span(editable.editor().read().to_string())
        .holder(holder.read().clone())
}

Routing & Navigation

Define routes, manage navigation state, and transition between different views. Enable with the router feature.

Code

use freya::prelude::*;
use freya::router::prelude::*;

#[derive(Routable, Clone, PartialEq)]
#[rustfmt::skip]
pub enum Route {
    #[layout(AppBottomBar)]
        #[route("/")]
        Home,
        #[route("/settings")]
        Settings,
}

fn app() -> impl IntoElement {
    router::<Route>(|| RouterConfig::default().with_initial_path(Route::Settings))
}


#[derive(PartialEq)]
struct AppBottomBar;
impl Component for AppBottomBar {
    fn render(&self) -> impl IntoElement {
        NativeRouter::new().child(
            rect()
                .content(Content::flex())
                .child(
                    rect()
                        .width(Size::fill())
                        .height(Size::flex(1.))
                        .center()
                        .child(outlet::<Route>()),
                )
                .child(
                    rect()
                        .horizontal()
                        .width(Size::fill())
                        .main_align(Alignment::center())
                        .padding(8.)
                        .spacing(8.)
                        .child(
                            Link::new(Route::Home)
                                .child(FloatingTab::new().child("Home"))
                                .activable_route(Route::Home)
                                .exact(true),
                        )
                        .child(
                            Link::new(Route::Settings)
                                .child(FloatingTab::new().child("Settings"))
                                .activable_route(Route::Settings)
                                .exact(true),
                        ),
                ),
        )
    }
}

#[derive(PartialEq)]
struct Home {}
impl Component for Home {
    fn render(&self) -> impl IntoElement {
        Button::new()
            .on_press(|_| {
                RouterContext::get().replace(Route::Settings);
            })
            .child("Go Settings")
    }
}

#[derive(PartialEq)]
struct Settings {}
impl Component for Settings {
    fn render(&self) -> impl IntoElement {
        Button::new()
            .on_press(|_| {
                RouterContext::get().replace(Route::Home);
            })
            .child("Go Home")
    }
}

Global State Management

Freya's freya-radio state management system provides efficient global state management through a channels system. Components subscribe to specific "channels" and only receive updates when data is mutated and notified through their channel. Enable with the radio feature.

Code

use freya::prelude::*;
use freya::radio::*;

#[derive(Default)]
struct Data {
    pub lists: Vec<Vec<String>>,
}

#[derive(PartialEq, Eq, Clone, Debug, Copy, Hash)]
pub enum DataChannel {
    ListCreation,
    SpecificListItemUpdate(usize),
}

impl RadioChannel<Data> for DataChannel {}

fn app() -> impl IntoElement {
    use_init_radio_station::<Data, DataChannel>(Data::default);
    let mut radio = use_radio::<Data, DataChannel>(DataChannel::ListCreation);

    let on_press = move |_| {
        radio.write().lists.push(Vec::default());
    };

    rect()
        .horizontal()
        .child(Button::new().on_press(on_press).child("Add new list"))
        .children(
            radio
                .read()
                .lists
                .iter()
                .enumerate()
                .map(|(list_n, _)| ListComp(list_n).into()),
        )
}


#[derive(PartialEq)]
struct ListComp(usize);
impl Component for ListComp {
    fn render(&self) -> impl IntoElement {
        let list_n = self.0;
        let mut radio = use_radio::<Data, DataChannel>(DataChannel::SpecificListItemUpdate(list_n));

        println!("Running DataChannel::SpecificListItemUpdate({list_n})");

        rect()
            .child(
                Button::new()
                    .on_press(move |_| radio.write().lists[list_n].push("Hello, World".to_string()))
                    .child("New Item"),
            )
            .children(
                radio.read().lists[list_n]
                    .iter()
                    .enumerate()
                    .map(move |(i, item)| label().key(i).text(item.clone()).into()),
            )
    }
}

Icon Library

Easily integrate icons into your applications, only supports Lucide at the moment.

Code

use freya::prelude::*;
use freya::icons;

fn app() -> impl IntoElement {
    svg(icons::lucide::antenna())
        .color((120, 50, 255))
        .expanded()
}

Headless Testing

Using freya-testing you can test your Freya components in a no-window (headless) environment. You can decide to render the app at any moment to a file though. freya-testing is actually used by Freya itself to test all the out of the box components and other APIs.

Code

use freya::prelude::*;
use freya_testing::prelude::*;

fn app() -> impl IntoElement {
    let mut state = use_consume::<State<i32>>();
    rect()
        .expanded()
        .center()
        .background((240, 240, 240))
        .on_mouse_up(move |_| *state.write() += 1)
        .child(format!("Clicked: {}", state.read()))
}

fn main() {
    // Create headless testing runner
    let (mut test, state) = TestingRunner::new(
        app,
        (300., 300.).into(),
        |runner| runner.provide_root_context(|| State::create(0)),
        1.,
    );

    test.sync_and_update();
    assert_eq!(*state.peek(), 0);

    // Simulate user interactions
    test.click_cursor((15., 15.));
    assert_eq!(*state.peek(), 1);

    // Render the current ui state to a file
    test.render_to_file("./demo-1.png");
}

Advanced Plotting & Charts

Using the Plotters library, you can create charts, graphs, and data visualizations directly within your application. Enable with the ploters feature.

Code

use freya::prelude::*;
use freya::plot::*;
use freya::plot::plotters::*;

fn on_render(ctx: &mut RenderContext, (cursor_x, cursor_y): (f64, f64)) {
    let backend = PlotSkiaBackend::new(
        ctx.canvas,
        ctx.font_collection,
        ctx.layout_node.area.size.to_i32().to_tuple(),
    ).into_drawing_area();

    backend.fill(&WHITE).unwrap();

    let pitch = std::f64::consts::PI * (0.5 - cursor_y / ctx.layout_node.area.height() as f64);
    let yaw = std::f64::consts::PI * 2.0 * (cursor_x / ctx.layout_node.area.width() as f64 - 0.5);
    let scale = 0.4 + 0.6 * (1.0 - cursor_y / ctx.layout_node.area.height() as f64);

    let x_axis = (-3.0..3.0).step(0.1);
    let z_axis = (-3.0..3.0).step(0.1);

    let mut chart = ChartBuilder::on(&backend)
        .caption("3D Surface Plot", ("sans", 20))
        .build_cartesian_3d(x_axis.clone(), -3.0..3.0, z_axis.clone())
        .unwrap();

    chart.with_projection(|mut pb| {
        pb.pitch = pitch;
        pb.yaw = yaw;
        pb.scale = scale;
        pb.into_matrix()
    });

    chart
        .draw_series(
            SurfaceSeries::xoz(
                (-30..30).map(|f| f as f64 / 10.0),
                (-30..30).map(|f| f as f64 / 10.0),
                |x, z| (x * x + z * z).cos(),
            )
            .style(BLUE.mix(0.2).filled()),
        )
        .unwrap()
        .label("Interactive Surface")
        .legend(|(x, y)| Rectangle::new([(x + 5, y - 5), (x + 15, y + 5)], BLUE.mix(0.5).filled()));
}

fn app() -> impl IntoElement {
    let mut cursor_position = use_state(CursorPoint::default);

    plot(RenderCallback::new(move |context| {
        on_render(context, cursor_position().to_tuple());
    }))
    .expanded()
}

Kooha-2026-01-25-20-10-58.webm

Internationalization (i18n)

Freya supports internationalization with built-in support for the Fluent localization system. Easily manage translations, pluralization, and locale-specific formatting. Enable with the i18n feature.

Code

use freya::prelude::*;
use freya::i18n::*;

fn app() -> impl IntoElement {
    let mut i18n = use_init_i18n(|| {
        I18nConfig::new(langid!("en-US"))
            .with_locale((langid!("en-US"), include_str!("./i18n/en-US.ftl")))
            .with_locale((langid!("es-ES"), PathBuf::from("./examples/i18n/es-ES.ftl")))
    });

    let change_to_english = move |_| i18n.set_language(langid!("en-US"));
    let change_to_spanish = move |_| i18n.set_language(langid!("es-ES"));

    rect()
        .expanded()
        .center()
        .child(
            rect()
                .horizontal()
                .child(Button::new().on_press(change_to_english).child("English"))
                .child(Button::new().on_press(change_to_spanish).child("Spanish")),
        )
        .child(t!("hello_world"))
        .child(t!("hello", name: "Freya!"))
}

Material Design Components

Freya provides Material Design-inspired style modifiers. Enable with the material-design feature.

Code

use freya::prelude::*;
use freya::material_design::*;

fn app() -> impl IntoElement {
    rect().center().expanded().child(
        Button::new()
            .on_press(|_| println!("Material button pressed"))
            .ripple()  // Adds Material Design ripple effect
            .child("Material Button"),
    )
}

WebView Integration

Integrate web content into your native applications with Freya's WebView support. Embed web applications, or simply display web-based content alongside your native UI components. Enable with the webview feature.

Code

use freya::prelude::*;
use freya::webview::*;

fn app() -> impl IntoElement {
    // Multi-tab webview implementation
    let mut tabs = use_state(|| vec![Tab {
        id: WebViewId::new(),
        title: "Tab 1".to_string(),
        url: "https://duckduckgo.com".to_string(),
    }]);
    let mut active_tab = use_state(|| tabs.read()[0].id);

    rect()
        .expanded()
        .height(Size::fill())
        .background((35, 35, 35))
        .child(
            rect()
                .width(Size::fill())
                .height(Size::px(45.))
                .padding(4.)
                .background((50, 50, 50))
                .horizontal()
                .cross_align(Alignment::Center)
                .spacing(4.)
                .children(tabs.read().iter().map(|tab| {
                    // Tab implementation...
                }))
        )
        .child(WebView::new("https://duckduckgo.com").expanded())
}

Terminal Emulation

Freya includes terminal emulation capabilities with full PTY (pseudo-terminal) support. Create integrated terminal applications, SSH clients, or development tools. Enable with the terminal feature.

Code

use freya::prelude::*;
use freya::terminal::*;

fn app() -> impl IntoElement {
    let mut handle = use_state(|| {
        let mut cmd = CommandBuilder::new("bash");
        cmd.env("TERM", "xterm-256color");
        cmd.env("COLORTERM", "truecolor");
        TerminalHandle::new(cmd).ok()
    });

    rect()
        .expanded()
        .center()
        .background((30, 30, 30))
        .color((245, 245, 245))
        .child(if let Some(handle) = handle.read().clone() {
            rect()
                .child(Terminal::new(handle.clone()))
                .expanded()
                .background((10, 10, 10))
                .padding(6.)
                .a11y_id(focus.a11y_id())
                .on_key_down(move |e: Event<KeyboardEventData>| {
                    if e.modifiers.contains(Modifiers::CONTROL)
                        && matches!(&e.key, Key::Character(ch) if ch.len() == 1)
                    {
                        if let Key::Character(ch) = &e.key {
                            let _ = handle.write(&[ch.as_bytes()[0] & 0x1f]);
                        }
                    } else if let Some(ch) = e.try_as_str() {
                        let _ = handle.write(ch.as_bytes());
                    } else {
                        let _ = handle.write(match &e.key {
                            Key::Named(NamedKey::Enter) => b"\r",
                            Key::Named(NamedKey::Backspace) => &[0x7f],
                            Key::Named(NamedKey::Delete) => b"\x1b[3~",
                            Key::Named(NamedKey::Tab) => b"\t",
                            Key::Named(NamedKey::Escape) => &[0x1b],
                            Key::Named(NamedKey::ArrowUp) => b"\x1b[A",
                            Key::Named(NamedKey::ArrowDown) => b"\x1b[B",
                            Key::Named(NamedKey::ArrowLeft) => b"\x1b[D",
                            Key::Named(NamedKey::ArrowRight) => b"\x1b[C",
                            _ => return,
                        });
                    };
                })
        } else {
            "Terminal exited".into_element()
        })
}

Developer Tools

Examine the component tree in real-time.

Enable the devtools feature in freya and then run the devtools app.

Code

use freya::prelude::*;

fn app() -> impl IntoElement {
    rect()
        .expanded()
        .center()
        .child("Hello, World!")
}

Trying it out

Make sure to have Development Setup ready.

⚠️ If you happen to be on Windows using windows-gnu and get compile errors, maybe go check this issue.

Clone this repo and run:

Note: After cloning, make sure to initialize and update the git submodules: git submodule update --init --recursive

cargo run --example counter

Usage 📜

main branch:

freya = { git = "https://github.com/marc2332/freya", branch = "main" }

Release candidates:

freya = "0.4.0-rc.7"

Contributing 🧙‍♂️

If you are interested in contributing please make sure to have read the Contributing guide first!

Contact

You may contact me for questions, collaboration or anything that comes to your mind at [email protected].

Support 🤗

If you are interested in supporting the development of this project feel free to donate to my Github Sponsor page.

Thanks to my sponsors for supporting this project! 😄

Special thanks 💪

• Jonathan Kelley and Evan Almloff for making Dioxus and all their help, specially when I was still creating Freya.
• Armin for making rust-skia and all his help and making the favor of hosting prebuilt binaries of skia for the combo of features use by Freya.
• geom3trik for helping me figure out how to add incremental rendering.
• Tropical for this contributions to improving accessibility and rendering.
• Aiving for having made heavy contributions to rust-skia for better SVG support, and helped optimizing images rendering in Freya.
• RobertasJ for having added nested parenthesis to the calc() function and also pushed for improvements in the animation APIs.
• And to the rest of contributors and anybody who gave me any kind of feedback!

History with Dioxus

Freya 0.1, 0.2 and 0.3 were based on the core crates of Dioxus. Starting 0.4 Freya does no longer use Dioxus, instead it uses its own reactive core, partially inspired by Dioxus but yet with lots of differences.

License

MIT License