Adding children to UI Text makes it disappear

[eero-lehtinen]

Bevy version

main (1c765c9)

What you did

When you add a Node as a child of a Text, the text is not rendered at all.

use bevy::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, setup)
        .run();
}

fn setup(mut commands: Commands) {
    commands.spawn(Camera2d);
    commands
        .spawn((
            Text::new("hello\nbevy!"),
            TextFont {
                font_size: 67.0,
                ..default()
            },
            Node {
                left: Val::Px(20.),
                ..default()
            },
        ))
        // Adding this makes the above text disappear
        .with_child((
            Node {
                width: Val::Px(40.),
                height: Val::Px(40.),
                ..default()
            },
            BackgroundColor(Color::WHITE.with_alpha(0.5)),
        ));
}

What went wrong

I would expect the text to remain visible.

The entity with Text still seems to contribute to the layout, but it doesn't show up. It seems that Text is somehow hardcoded to only allow TextSpan children and breaks with anything else.

I ran into this while trying to make pseudo outlines by drawing multiple texts on top of each other in the hierarchy, but the parent text just doesn't show up.

[ickshonpe]

Text should always be leaf nodes imo.

It's easier to implement pseudo-outlines using an extraction system. Should be straightforward to repurpose the changes from #17559.

[eero-lehtinen]

I think it would be convenient to sometimes have extra nodes that are positioned relative to text, e.g. a poison icon attached to a poison number.

Is there any reason this needs to work like this? Why not just display non-leaf text?

But yeah you can work around this by having another parent node for the text and add the secondary text as a sibling with absolute positioning.

It's easier to implement pseudo-outlines using an extraction system. Should be straightforward to repurpose the changes from #17559.

Thanks. I'll look into that. Extraction doesn't seem very approachable for user code but good to know. Also I'm using another font for the outline so that code won't work directly.