Cannot change icon dynamically on `macOS` and `Windows` using `ViewportCommand::Icon`

[dscso]

Using the master and running the following code does not change the Icon, whereas other commands like fullscreen(true) work just fine. Setting the icon via ViewportBuilder is also no problem. Am I doing any mistakes or is this a bug? Thank you very much for this great library btw :)!

use eframe::egui;
use eframe::egui::{IconData, ViewportCommand};
use std::sync::Arc;

fn main() -> Result<(), eframe::Error> {
    let options = eframe::NativeOptions {
        viewport: egui::ViewportBuilder::default().with_inner_size([320.0, 240.0]),
        ..Default::default()
    };
    eframe::run_native(
        "My egui App",
        options,
        Box::new(|cc| {
            // This gives us image support:
            egui_extras::install_image_loaders(&cc.egui_ctx);

            Box::<MyApp>::default()
        }),
    )
}

struct MyApp {}

impl Default for MyApp {
    fn default() -> Self {
        Self {}
    }
}

impl eframe::App for MyApp {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        egui::CentralPanel::default().show(ctx, |ui| {
            ui.heading("My egui Application");
            if ui.button("Add icon").clicked() {
                let icon =
                    include_bytes!("logo-mac.png");
                let image = image::load_from_memory(icon)
                    .expect("Image could not be loaded from memory")
                    .into_rgba8();
                let (width, height) = image.dimensions();
                let icon = Some(Arc::new(IconData {
                    rgba: image.into_raw(),
                    width,
                    height,
                }));
                println!("Icon added");
                ctx.send_viewport_cmd(ViewportCommand::Icon(icon));
            }
        });
    }
}

OS: MacOS 14.2

[emilk]

The API is not supported on winit on Mac:

https://docs.rs/winit/latest/winit/window/struct.Window.html#method.set_window_icon

You'll need to make a PR to winit to fix it!

[dscso]

I thought so as well, but the Icon can be set on GUI startup, but can not be changed later. Do you think this is a winit issue?

[emilk]

Well… it's both/either, I guess.

I would love it if winit supported icons on Mac and Windows, but since it doesn't, we have this in eframe:

https://github.com/emilk/egui/blob/4c8b95f365983582ccb7a97a29bafeecd7f4d6bc/crates/eframe/src/native/app_icon.rs

And yes, that only works for setting the icon on startup.