eframe: several windows in series

[emilk]

Part of #1918

This attempts to allow opening several eframe windows after each other (one at the time).

Try it out with cargo run -p serial_windows.

This works on Windows (thanks to @zu1k), but on Mac I get winit::event::Event::LoopDestroyed right away for the second window, and then the even loops closes.

[zu1k]

I add the following code to the start of GlowWinitApp.on_event() func, and found the second and third window receive some events which are not belong to them.

 if window_id != self.window().id() {
    println!("{event:?}");
    println!("window_id mismatch !");
    return EventResult::Wait;
}

# Running `target\debug\serial_windows.exe`
ModifiersChanged((empty))
window_id mismatch !
Focused(false)
window_id mismatch !
Destroyed
window_id mismatch !
ModifiersChanged((empty))
window_id mismatch !
Focused(false)
window_id mismatch !

[emilk]

Ignoring events to the wrong window seems like a good idea, so I added that. The extra call to run_return does nothing on my Mac.

Does it now work as expected on Windows?

[zu1k]

Does it now work as expected on Windows?

Yes, it works.

20220815_220324.mp4

[emilk]

Well, that's nice! On Mac I get winit::event::Event::LoopDestroyed right away, and then the event loop closes. Well, perhaps I can merge this as at least a step in the right direction.