OSX Tab change input field focus breaks rendering

[amatrelan]

When using tab to change focus to next input element it breaks rendering in OSX.
Normal clicking to elements don't break it.

Commit: c02452ddeebc527992e8f112f434f23ce24c934d

System info

• Macbook Pro 2019
• macOS: Ventura 13.2.1

Steps to Reproduce

• git clone https://github.com/linebender/druid
• cd druid/druid
• cargo run --example flex
• Go to either input field (I went to hello)
• Press tab

[matthewgapp]

This is reproducible by clicking between two input fields. The issue arises in 0.8.0. My issue is not reproducible in 0.7

See this video: https://github.com/linebender/druid/assets/61894094/a3edb4dc-c403-40e5-9414-d2658d6ee725

Repro code:

use std::sync::Arc;

use druid::{
    widget::{prelude::*, Flex, SizedBox, TextBox},
    AppLauncher, Color, Lens, LocalizedString, WidgetExt, WindowDesc,
};

fn launch<T: Data, W: Widget<T> + 'static>(make_ui: fn() -> W, data: T) {
    let main_window = WindowDesc::new(make_ui())
        .title(LocalizedString::new("learning the basics").with_placeholder("Hello world!"));

    AppLauncher::with_window(main_window).launch(data).unwrap();
}

#[derive(Clone, Data, Lens)]
struct AppState {
    name: Arc<String>,
    dog_name: Arc<String>,
}

fn main() {
    let ui = || {
        Flex::column()
            .with_child(
                TextBox::new()
                    .with_placeholder("What is your name?")
                    .fix_width(200.0)
                    .lens(AppState::name),
            )
            .with_child(SizedBox::empty().height(300.))
            .with_child(
                TextBox::new()
                    .with_placeholder("What is your dog's name?")
                    .fix_width(200.0)
                    .lens(AppState::dog_name),
            )
            .background(Color::GREEN)
    };

    launch(
        ui,
        AppState {
            name: Arc::new("".to_string()),
            dog_name: Arc::new("".to_string()),
        },
    );
}

[xStrom]

I managed to also reproduce it on my macOS Catalina 10.15, using the flex example and either clicking with the mouse or tabbing.

Definitely a bug that should be resolved.

[matthewgapp]

@xStrom would you mind reviewing my PR that fixes this issue? #2381

[xStrom]

Yes I will try to do that soon. Confirming the bug was the first step in that process. 👍