Res<ButtonInput<MouseButton>> is cleared when hovering a bevy_ui interactable.

[rparrett]

Version

0.16

Operating system & version

Macos

What you did

Have an app with InputManagerPlugin and a normal bevy_ui button.

Hover over the button, left click, and release.

Expand Code

use bevy::prelude::*;
use leafwing_input_manager::prelude::*;

#[derive(Actionlike, PartialEq, Eq, Clone, Copy, Hash, Debug, Reflect)]
enum Action {
    Run,
    Jump,
}

const NORMAL_BUTTON: Color = Color::srgb(0.15, 0.15, 0.15);

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, setup)
        .add_systems(Update, (button_system, button_input_system))
        .add_plugins(InputManagerPlugin::<Action>::default())
        .run();
}

fn button_system(
    mut interaction_query: Query<(&Interaction, &Children), (Changed<Interaction>, With<Button>)>,
    mut text_query: Query<&mut Text>,
) {
    for (interaction, children) in &mut interaction_query {
        let mut text = text_query.get_mut(children[0]).unwrap();
        match *interaction {
            Interaction::Pressed => {
                **text = "Press".to_string();
            }
            Interaction::Hovered => {
                **text = "Hover".to_string();
            }
            Interaction::None => {
                **text = "Button".to_string();
            }
        }
    }
}

fn button_input_system(input: Res<ButtonInput<MouseButton>>) {
    if input.is_changed() {
        info!("{:?}", input);
    }
}

fn setup(mut commands: Commands) {
    commands.spawn(Camera2d);

    commands
        .spawn(Node {
            width: Val::Percent(100.0),
            height: Val::Percent(100.0),
            align_items: AlignItems::Center,
            justify_content: JustifyContent::Center,
            ..default()
        })
        .with_children(|parent| {
            parent
                .spawn((
                    Button,
                    Node {
                        width: Val::Px(150.0),
                        height: Val::Px(65.0),
                        border: UiRect::all(Val::Px(5.0)),
                        justify_content: JustifyContent::Center,
                        align_items: AlignItems::Center,
                        ..default()
                    },
                    BackgroundColor(NORMAL_BUTTON),
                ))
                .with_child(Text::new("Button"));
        });
}

What you expected to happen

Res(ButtonInput { pressed: {}, just_pressed: {}, just_released: {} })
Res(ButtonInput { pressed: {Left}, just_pressed: {Left}, just_released: {} })
Res(ButtonInput { pressed: {}, just_pressed: {}, just_released: {Left} })

(This is the output when the button is not hovered)

What actually happened

1. There is a debug print every frame, because LWIM is triggering Res<ButtonInput<MouseButton>>'s change detection.
2. just_released and just_released are never Left at any point.
3. LWIM is seemingly clearing ButtonInput on purpose, yet pressed occasionally does have a value.

Res(ButtonInput { pressed: {}, just_pressed: {}, just_released: {} }) // lots of these
Res(ButtonInput { pressed: {}, just_pressed: {}, just_released: {} })
Res(ButtonInput { pressed: {}, just_pressed: {}, just_released: {} })
Res(ButtonInput { pressed: {Left}, just_pressed: {}, just_released: {} })
Res(ButtonInput { pressed: {Left}, just_pressed: {}, just_released: {} })
Res(ButtonInput { pressed: {Left}, just_pressed: {}, just_released: {} })
Res(ButtonInput { pressed: {}, just_pressed: {}, just_released: {} }) // IMPORTANT: just_released is empty
Res(ButtonInput { pressed: {}, just_pressed: {}, just_released: {} })
Res(ButtonInput { pressed: {}, just_pressed: {}, just_released: {} })

Additional information

I got here while debugging an app that uses both leafwing-input-manager and bevy-alt-ui-navigation-lite. bevy-alt-ui-navigation-lite uses some convoluted logic and Res<ButtonInput<MouseButton>> to determine whether a nav or focus event should be sent when either hovering or clicking. After upgrading to LWIM / Bevy 0.15, this no longer works.

I think that in my case, I can just disable leafwing-input-manager's ui feature. But I'm opening this because at the very least, the change detection thing seems like a potential LWIM bug.

[alice-i-cecile]

Hmm; I think we should be able to just kill the ui feature entirely at this point.