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egui Integration

The lui-driver-egui crate lets you embed lui inside an egui or eframe application.

Basic Usage​

use lui_driver_egui::EguiRunner;

// Window must implement HasWindowHandle + HasDisplayHandle
let mut runner = EguiRunner::new(window, 800, 600);

// In your egui frame:
egui::CentralPanel::default().show(ctx, |ui| {
    let output = runner.show(ui, &mut tree, ui.available_size());
    if output.layout_available {
        // Submit output.display_list to your wgpu render pass
        // output.response contains the egui Response for interaction
    }
});

HtmlOutput​

pub struct HtmlOutput {
    pub response: Response,           // egui response (focus, interaction)
    pub display_list: DisplayList,    // draw command list for GPU
    pub layout_available: bool,       // false if tree is empty
    pub timings: PipelineTimings,     // cascade/layout/paint timing
}

Input Forwarding​

For proper keyboard and focus handling, forward egui input events:

// In each frame:
forward_input_events(&ui, &mut tree);

// Or manually:
forward_key(&mut tree, egui::Key::Enter, true, false); // key press

Pointer Translation​

use lui_driver_egui::pointer_button;

let mouse_button: MouseButton = pointer_button(egui::PointerButton::Primary);

Limitations​

  • The egui driver renders lui content into a texture that egui draws as an image widget. There's one extra texture copy compared to native winit rendering.
  • Focus management requires explicit forwarding since egui and lui have separate focus systems.
  • The egui driver does not handle OS-level clipboard directly; use the tree's clipboard events instead.