ctx.input(|i| i.focused) always gets false for the first few frames

[lopo12123]

description

I want my window to automatically close when it loses focus, but in the first few frames when the app starts, ctx.input(|i| i.focused) always gets false (which makes my app close on the first frame)

reproduce

fn main() {
    use eframe::epaint::Color32;
    use egui::{Frame, Key, ViewportBuilder, ViewportCommand};

    let option = eframe::NativeOptions {
        viewport: ViewportBuilder::default()
            .with_active(true)  // initially focused
            .with_position([100.0, 100.0])
            .with_inner_size([800.0, 600.0]),
        ..Default::default()
    };

    let mut count = 0;
    eframe::run_simple_native(
        "my-app",
        option,
        move |ctx, _frame| {
            egui::CentralPanel::default()
                .frame(Frame::none().fill(Color32::WHITE))
                .show(ctx, |ui| {
                    if ui.button("Close").clicked() {
                        ctx.send_viewport_cmd(ViewportCommand::Close);
                    }

                    // Here I print the first 10 frames. On my computer, the first 2 or 3 frames always show false, and then true.
                    if count < 10 {
                        println!("focused: {}", ctx.input(|i| i.focused));
                        count += 1;
                    }
                });
        },
    ).unwrap();
}

env

---

Now my solution is as follows, but it doesn't seem elegant.

fn main() {
    use eframe::epaint::Color32;
    use egui::{Frame, ViewportBuilder, ViewportCommand};

    let option = eframe::NativeOptions {
        viewport: ViewportBuilder::default()
            .with_active(true)  // initially focused
            .with_position([100.0, 100.0])
            .with_inner_size([800.0, 600.0]),
        ..Default::default()
    };

    let mut ready = false;

    eframe::run_simple_native(
        "my-app",
        option,
        move |ctx, _frame| {
            egui::CentralPanel::default()
                .frame(Frame::none().fill(Color32::WHITE))
                .show(ctx, |ui| {
                    if ui.button("Close").clicked() {
                        ctx.send_viewport_cmd(ViewportCommand::Close);
                    }

                    // the first time 'focused' becomes true, the app is ready
                    if !ready && ctx.input(|i| i.focused) {
                        ready = true;
                    }
                    // automatically close window when focus is lost (ignore frames that are not ready)
                    if ready && ctx.input(|i| !i.focused) {
                        ctx.send_viewport_cmd(ViewportCommand::Close);
                    }
                });
        },
    ).unwrap();
}