bevy-playground/src/main_menu.rs

use bevy::prelude::*;

#[derive(Component, Debug)]
pub struct MainMenu;

pub fn startup(mut commands: Commands) {
    commands
        .spawn((
            MainMenu,
            NodeBundle {
                style: Style {
                    width: Val::Percent(100.0),
                    height: Val::Percent(100.0),
                    justify_content: JustifyContent::SpaceBetween,
                    ..default()
                },
                ..default()
            },
        ))
        .with_children(|parent| {
            // text
            parent.spawn((
                TextBundle::from_section(
                    "Text Example\nPress ENTER to play",
                    TextStyle {
                        font_size: 100.0,
                        ..default()
                    },
                )
                .with_style(Style {
                    margin: UiRect::all(Val::Px(12.)),
                    ..default()
                }),
                // Because this is a distinct label widget and
                // not button/list item text, this is necessary
                // for accessibility to treat the text accordingly.
                Label,
            ));

            parent.spawn(NodeBundle {
                style: Style {
                    width: Val::Px(200.0),
                    height: Val::Px(200.0),
                    position_type: PositionType::Absolute,
                    left: Val::Px(210.),
                    bottom: Val::Px(10.),
                    border: UiRect::all(Val::Px(20.)),
                    ..default()
                },
                border_color: Color::srgb(0., 1., 0.).into(),
                background_color: Color::srgb(0.4, 0.4, 1.).into(),
                ..default()
            });
        });
}

pub fn exit(mut commands: Commands, q: Query<Entity, With<MainMenu>>) {
    for id in q.iter() {
        commands.entity(id).despawn_recursive();
    }
}

pub fn update() {}