Crate eframe

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eframe - the egui framework crate

If you are planning to write an app for web or native, and want to use egui for everything, then eframe is for you!

To get started, see the examples. To learn how to set up eframe for web and native, go to https://github.com/emilk/eframe_template/ and follow the instructions there!

In short, you implement App (especially App::update) and then call crate::run_native from your main.rs, and/or call eframe::start_web from your lib.rs.

Usage, native:

use eframe::egui;

fn main() {
    let native_options = eframe::NativeOptions::default();
    eframe::run_native("My egui App", native_options, Box::new(|cc| Box::new(MyEguiApp::new(cc))));
}

#[derive(Default)]
struct MyEguiApp {}

impl MyEguiApp {
    fn new(cc: &eframe::CreationContext<'_>) -> Self {
        // Customize egui here with cc.egui_ctx.set_fonts and cc.egui_ctx.set_visuals.
        // Restore app state using cc.storage (requires the "persistence" feature).
        // Use the cc.gl (a glow::Context) to create graphics shaders and buffers that you can use
        // for e.g. egui::PaintCallback.
        Self::default()
    }
}

impl eframe::App for MyEguiApp {
   fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
       egui::CentralPanel::default().show(ctx, |ui| {
           ui.heading("Hello World!");
       });
   }
}

Usage, web:

use wasm_bindgen::prelude::*;

/// Your handle to the web app from JavaScript.
#[derive(Clone)]
#[wasm_bindgen]
pub struct WebHandle {
    runner: WebRunner,
}

#[wasm_bindgen]
impl WebHandle {
    /// Installs a panic hook, then returns.
    #[allow(clippy::new_without_default)]
    #[wasm_bindgen(constructor)]
    pub fn new() -> Self {
        // Redirect [`log`] message to `console.log` and friends:
        eframe::WebLogger::init(log::LevelFilter::Debug).ok();

        Self {
            runner: WebRunner::new(),
        }
    }

    /// Call this once from JavaScript to start your app.
    #[wasm_bindgen]
    pub async fn start(&self, canvas_id: &str) -> Result<(), wasm_bindgen::JsValue> {
        self.runner
            .start(
                canvas_id,
                eframe::WebOptions::default(),
                Box::new(|cc| Box::new(MyEguiApp::new(cc))),
            )
            .await
    }

    // The following are optional:

    #[wasm_bindgen]
    pub fn destroy(&self) {
        self.runner.destroy();
    }

    /// Example on how to call into your app from JavaScript.
    #[wasm_bindgen]
    pub fn example(&self) {
        if let Some(app) = self.runner.app_mut::<MyEguiApp>() {
            app.example();
        }
    }

    /// The JavaScript can check whether or not your app has crashed:
    #[wasm_bindgen]
    pub fn has_panicked(&self) -> bool {
        self.runner.has_panicked()
    }

    #[wasm_bindgen]
    pub fn panic_message(&self) -> Option<String> {
        self.runner.panic_summary().map(|s| s.message())
    }

    #[wasm_bindgen]
    pub fn panic_callstack(&self) -> Option<String> {
        self.runner.panic_summary().map(|s| s.callstack())
    }
}

Simplified usage

If your app is only for native, and you don’t need advanced features like state persistence, then you can use the simpler function run_simple_native.

Feature flags

  • accesskit (enabled by default) — Enable platform accessibility API implementations through AccessKit.

  • default_fonts (enabled by default) — If set, egui will use include_bytes! to bundle some fonts. If you plan on specifying your own fonts you may disable this feature.

  • glow (enabled by default) — Use glow for painting, via egui_glow.

  • wayland — Enables wayland support and fixes clipboard issue.

  • persistence — Enable saving app state to disk.

  • puffin — Enable profiling with the puffin crate.

    Only enabled on native, because of the low resolution (1ms) of time keeping in browsers. eframe will call puffin::GlobalProfiler::lock().new_frame() for you

  • web_screen_reader — Enable screen reader support (requires ctx.options_mut(|o| o.screen_reader = true);) on web.

    For other platforms, use the “accesskit” feature instead.

  • __screenshot — If set, eframe will look for the env-var EFRAME_SCREENSHOT_TO and write a screenshot to that location, and then quit. This is used to generate images for the examples.

  • wgpu — Use wgpu for painting (via egui-wgpu). This overrides the glow feature.

  • android-native-activity — Enable the native-activity backend via egui-winit on Android

  • android-game-activity — Enable the game-activity backend via egui-winit on Android

Optional dependencies

  • document-features — Enable this when generating docs.

Re-exports

Structs

  • CreationContext
    Data that is passed to AppCreator that can be used to setup and initialize your app.
  • EventLoopBuilder
    Object that allows building the event loop.
  • Frame
    Represents the surroundings of your app.
  • IconData
    Image data for an application icon.
  • IntegrationInfo
    Information about the integration passed to the use app each frame.
  • NativeOptions
    Options controlling the behavior of a native window.
  • WindowInfo
    Information about the application’s main window, if available.

Enums

Constants

Traits

  • App
    Implement this trait to write apps that can be compiled for both web/wasm and desktop/native using eframe.
  • Storage
    A place where you can store custom data in a way that persists when you restart the app.

Functions

  • get_value
    Get and deserialize the RON stored at the given key.
  • run_native
    This is how you start a native (desktop) app.
  • run_simple_native
    The simplest way to get started when writing a native app.
  • set_value
    Serialize the given value as RON and store with the given key.

Type Definitions