WidgetKit

language: English, Russian

WidgetKit is a modular Rust library for building desktop widgets.

It currently focuses on a simple but structured native path:

Widget + Canvas + WindowsHost + WidgetApp
software 2D rendering on Windows
demand-driven redraw
a clearer render pipeline under the public Canvas API

If you want the detailed list of what changed in v0.2, see CHANGELOG.md.

What It Feels Like

WidgetKit is still intentionally small, but it already has a usable shape:

Canvas is the main public drawing API
rendering goes through RenderFrame and RenderCommand
the runtime owns widget lifecycle, scheduler, tasks, and redraw invalidation
the Windows host can run decorated or frameless windows

Quick Start

use widgetkit::prelude::*;

fn main() -> widgetkit::Result<()> {
    WidgetApp::new()
        .widget("clock", ClockWidget)
        .host(
            WindowsHost::new()
                .with_size(Size::new(360.0, 135.0))
                .with_standard_top_bar(true),
        )
        .renderer(SoftwareRenderer::new())
        .run()
}

Example Widget

use widgetkit::prelude::*;

struct MyWidget;

impl Widget for MyWidget {
    type State = ();
    type Message = ();

    fn mount(&mut self, _ctx: &mut MountCtx<Self>) -> Self::State {}

    fn render(&self, _state: &Self::State, canvas: &mut Canvas, _ctx: &RenderCtx<Self>) {
        canvas.clear(Color::rgb(14, 17, 22));
        canvas.save();
        canvas.clip_rect(Rect::xywh(12.0, 12.0, 220.0, 72.0));
        canvas.round_rect(
            Rect::xywh(12.0, 12.0, 220.0, 72.0),
            16.0,
            Color::rgb(30, 36, 48),
        );
        canvas.text(
            Point::new(24.0, 28.0),
            "Hello",
            TextStyle::new().size(16.0),
            Color::rgb(127, 160, 255),
        );
        canvas.circle(Point::new(206.0, 28.0), 6.0, Color::rgb(127, 160, 255));
        canvas.restore();
    }
}

Examples

The workspace includes:

clock
pulse

Run them with:

cargo run --example clock --features "windows canvas"

cargo run --example pulse --features "windows canvas"

With the optional Tokio-backed task runtime:

cargo run --example clock --features "windows canvas runtime-tokio"

Features

Top-level features:

canvas
windows
runtime-tokio

Example dependency setup:

[dependencies]

widgetkit = { version = "0.2.0", default-features = false, features = ["windows", "canvas"] }

Workspace Layout

widgetkit/
  crates/
    widgetkit
    widgetkit-core
    widgetkit-runtime
    widgetkit-render
    widgetkit-host-windows

widgetkit: top-level facade crate
widgetkit-core: geometry, colors, ids, errors, host events
widgetkit-runtime: lifecycle, scheduler, tasks, redraw coordination
widgetkit-render: Canvas, render commands, text styles, software renderer
widgetkit-host-windows: Windows host based on winit and softbuffer

Direction

Planned later:

stable low-level raw rendering API
richer image and text pipelines
declarative UI and layout
broader input model
GPU renderer backend
hybrid or web-backed integration paths

License

MIT

widgetkit-core 0.2.0