tauri-plugin-egui

A simple way to render native egui UI in a Tauri-managed Window, either alongside or without a Webview.

Example Usage

// [1] import the necessary traits
use tauri_plugin_egui::{egui, EguiAppHandleExt, EguiPluginBuilder};

fn main() {
  tauri::Builder::default()
    .setup(|app| {
      // [2] register the plugin as a `wry_plugin`.
      app.wry_plugin(EguiPluginBuilder::new(app.handle().to_owned()));

      // [3] make or get a Tauri `WebviewWindow` / `Window`
      Window::builder(app, "main")
        .inner_size(600.0, 400.0)
        .title("tauri-plugin-egui demo")
        .build()?;

      // [4]
      // start egui for a window with its label
      // pass in a closure that receives the egui::Context
      app.handle().start_egui_for_window(
        "main",
        Box::new(|ctx| {
          egui::CentralPanel::default()
            .show(ctx, |ui| {
              ui.heading("Hello from Egui!");
            });
        }),
      )?;

      Ok(())
    })
    .run(tauri::generate_context!())
    .expect("error while running tauri application");
}

Development Guide

This plugin tracks all the windows marked for egui in a thread-safe HashMap. Tauri maintains control over the windowing system, egui is only used to draw within them. For each "egui-marked" Tauri window, we create an egui context, a GPU surface and graphics renderer (wgpu). And tauri's wry_plugin mechanism is used to hook into the event loop and drive all the inputs, etc. that egui needs, like RequestRedraw.

Notes:

1. You can have multiple egui-powered windows in the same Tauri app.
2. We use wgpu as graphics backend, but can also consider adding glow eventually.
3. Our approach minimizes needing "soft forks", which was a big pitfall of tauri-egui
4. TEMP: a custom tauri fork is needed atm. Effort is being made to merge these changes upstream. ✅ merged in Tauri v2.7.0

# to check and verify everything
cargo check

# to run example app (needs bun)
cd examples/vanilla
bun tauri dev

Goals

I have a Tauri app that needs to render UI without the webview-overhead for some cases. egui seemed like it can work well for this. There was a previous attempt at this by the Tauri team, detailed here but it has since been de-prioritized due to a large maintainance surface-area. My approach tries to minimize "fork maintainance" as much as possible.

See also

Perhaps we can eventually have this supported as an official Tauri plugin from their plugins workspace, but for now, this is a standalone plugin.

References

• egui + it's subcrates
• official tauri plugins
• tauri-egui integration (now unmaintained)