Struct bevy::prelude::ChildBuilder

pub struct ChildBuilder<'a> { /* private fields */ }

Struct for building children entities and adding them to a parent entity.

Example

This example creates three entities, a parent and two children.

commands.spawn(MyBundle {}).with_children(|child_builder| {
    child_builder.spawn(MyChildBundle {});
    child_builder.spawn(MyChildBundle {});
});

Implementations

impl ChildBuilder<'_>

pub fn spawn(&mut self, bundle: impl Bundle) -> EntityCommands<'_>

Spawns an entity with the given bundle and inserts it into the parent entity’s Children. Also adds Parent component to the created entity.

Examples found in repository

examples/window/window_resizing.rs (lines 46-55)

fn setup_ui(mut cmd: Commands) {
    // Node that fills entire background
    cmd.spawn(NodeBundle {
        style: Style {
            width: Val::Percent(100.),
            ..default()
        },
        ..default()
    })
    .with_children(|root| {
        // Text where we display current resolution
        root.spawn((
            TextBundle::from_section(
                "Resolution",
                TextStyle {
                    font_size: 50.0,
                    ..default()
                },
            ),
            ResolutionText,
        ));
    });
}

examples/ui/font_atlas_debug.rs (lines 89-96)

fn setup(mut commands: Commands, asset_server: Res<AssetServer>, mut state: ResMut<State>) {
    let font_handle = asset_server.load("fonts/FiraSans-Bold.ttf");
    state.handle = font_handle.clone();
    commands.spawn(Camera2dBundle::default());
    commands
        .spawn(NodeBundle {
            background_color: Color::NONE.into(),
            style: Style {
                position_type: PositionType::Absolute,
                bottom: Val::ZERO,
                ..default()
            },
            ..default()
        })
        .with_children(|parent| {
            parent.spawn(TextBundle::from_section(
                "a",
                TextStyle {
                    font: font_handle,
                    font_size: 60.0,
                    color: Color::YELLOW,
                },
            ));
        });
}

examples/ui/ui_material.rs (lines 40-51)

fn setup(mut commands: Commands, mut ui_materials: ResMut<Assets<CustomUiMaterial>>) {
    // Camera so we can see UI
    commands.spawn(Camera2dBundle::default());

    commands
        .spawn(NodeBundle {
            style: Style {
                width: Val::Percent(100.0),
                height: Val::Percent(100.0),
                align_items: AlignItems::Center,
                justify_content: JustifyContent::Center,
                ..default()
            },
            ..default()
        })
        .with_children(|parent| {
            parent.spawn(MaterialNodeBundle {
                style: Style {
                    position_type: PositionType::Absolute,
                    width: Val::Px(250.0),
                    height: Val::Px(250.0),
                    ..default()
                },
                material: ui_materials.add(CustomUiMaterial {
                    color: Color::WHITE.rgba_to_vec4(),
                }),
                ..default()
            });
        });
}

examples/games/game_menu.rs (lines 91-99)

    fn splash_setup(mut commands: Commands, asset_server: Res<AssetServer>) {
        let icon = asset_server.load("branding/icon.png");
        // Display the logo
        commands
            .spawn((
                NodeBundle {
                    style: Style {
                        align_items: AlignItems::Center,
                        justify_content: JustifyContent::Center,
                        width: Val::Percent(100.0),
                        height: Val::Percent(100.0),
                        ..default()
                    },
                    ..default()
                },
                OnSplashScreen,
            ))
            .with_children(|parent| {
                parent.spawn(ImageBundle {
                    style: Style {
                        // This will set the logo to be 200px wide, and auto adjust its height
                        width: Val::Px(200.0),
                        ..default()
                    },
                    image: UiImage::new(icon),
                    ..default()
                });
            });
        // Insert the timer as a resource
        commands.insert_resource(SplashTimer(Timer::from_seconds(1.0, TimerMode::Once)));
    }

    // Tick the timer, and change state when finished
    fn countdown(
        mut game_state: ResMut<NextState<GameState>>,
        time: Res<Time>,
        mut timer: ResMut<SplashTimer>,
    ) {
        if timer.tick(time.delta()).finished() {
            game_state.set(GameState::Menu);
        }
    }
}

mod game {
    use bevy::prelude::*;

    use super::{despawn_screen, DisplayQuality, GameState, Volume, TEXT_COLOR};

    // This plugin will contain the game. In this case, it's just be a screen that will
    // display the current settings for 5 seconds before returning to the menu
    pub fn game_plugin(app: &mut App) {
        app.add_systems(OnEnter(GameState::Game), game_setup)
            .add_systems(Update, game.run_if(in_state(GameState::Game)))
            .add_systems(OnExit(GameState::Game), despawn_screen::<OnGameScreen>);
    }

    // Tag component used to tag entities added on the game screen
    #[derive(Component)]
    struct OnGameScreen;

    #[derive(Resource, Deref, DerefMut)]
    struct GameTimer(Timer);

    fn game_setup(
        mut commands: Commands,
        display_quality: Res<DisplayQuality>,
        volume: Res<Volume>,
    ) {
        commands
            .spawn((
                NodeBundle {
                    style: Style {
                        width: Val::Percent(100.0),
                        height: Val::Percent(100.0),
                        // center children
                        align_items: AlignItems::Center,
                        justify_content: JustifyContent::Center,
                        ..default()
                    },
                    ..default()
                },
                OnGameScreen,
            ))
            .with_children(|parent| {
                // First create a `NodeBundle` for centering what we want to display
                parent
                    .spawn(NodeBundle {
                        style: Style {
                            // This will display its children in a column, from top to bottom
                            flex_direction: FlexDirection::Column,
                            // `align_items` will align children on the cross axis. Here the main axis is
                            // vertical (column), so the cross axis is horizontal. This will center the
                            // children
                            align_items: AlignItems::Center,
                            ..default()
                        },
                        background_color: Color::BLACK.into(),
                        ..default()
                    })
                    .with_children(|parent| {
                        // Display two lines of text, the second one with the current settings
                        parent.spawn(
                            TextBundle::from_section(
                                "Will be back to the menu shortly...",
                                TextStyle {
                                    font_size: 80.0,
                                    color: TEXT_COLOR,
                                    ..default()
                                },
                            )
                            .with_style(Style {
                                margin: UiRect::all(Val::Px(50.0)),
                                ..default()
                            }),
                        );
                        parent.spawn(
                            TextBundle::from_sections([
                                TextSection::new(
                                    format!("quality: {:?}", *display_quality),
                                    TextStyle {
                                        font_size: 60.0,
                                        color: Color::BLUE,
                                        ..default()
                                    },
                                ),
                                TextSection::new(
                                    " - ",
                                    TextStyle {
                                        font_size: 60.0,
                                        color: TEXT_COLOR,
                                        ..default()
                                    },
                                ),
                                TextSection::new(
                                    format!("volume: {:?}", *volume),
                                    TextStyle {
                                        font_size: 60.0,
                                        color: Color::GREEN,
                                        ..default()
                                    },
                                ),
                            ])
                            .with_style(Style {
                                margin: UiRect::all(Val::Px(50.0)),
                                ..default()
                            }),
                        );
                    });
            });
        // Spawn a 5 seconds timer to trigger going back to the menu
        commands.insert_resource(GameTimer(Timer::from_seconds(5.0, TimerMode::Once)));
    }

    // Tick the timer, and change state when finished
    fn game(
        time: Res<Time>,
        mut game_state: ResMut<NextState<GameState>>,
        mut timer: ResMut<GameTimer>,
    ) {
        if timer.tick(time.delta()).finished() {
            game_state.set(GameState::Menu);
        }
    }
}

mod menu {
    use bevy::{app::AppExit, prelude::*};

    use super::{despawn_screen, DisplayQuality, GameState, Volume, TEXT_COLOR};

    // This plugin manages the menu, with 5 different screens:
    // - a main menu with "New Game", "Settings", "Quit"
    // - a settings menu with two submenus and a back button
    // - two settings screen with a setting that can be set and a back button
    pub fn menu_plugin(app: &mut App) {
        app
            // At start, the menu is not enabled. This will be changed in `menu_setup` when
            // entering the `GameState::Menu` state.
            // Current screen in the menu is handled by an independent state from `GameState`
            .init_state::<MenuState>()
            .add_systems(OnEnter(GameState::Menu), menu_setup)
            // Systems to handle the main menu screen
            .add_systems(OnEnter(MenuState::Main), main_menu_setup)
            .add_systems(OnExit(MenuState::Main), despawn_screen::<OnMainMenuScreen>)
            // Systems to handle the settings menu screen
            .add_systems(OnEnter(MenuState::Settings), settings_menu_setup)
            .add_systems(
                OnExit(MenuState::Settings),
                despawn_screen::<OnSettingsMenuScreen>,
            )
            // Systems to handle the display settings screen
            .add_systems(
                OnEnter(MenuState::SettingsDisplay),
                display_settings_menu_setup,
            )
            .add_systems(
                Update,
                (setting_button::<DisplayQuality>.run_if(in_state(MenuState::SettingsDisplay)),),
            )
            .add_systems(
                OnExit(MenuState::SettingsDisplay),
                despawn_screen::<OnDisplaySettingsMenuScreen>,
            )
            // Systems to handle the sound settings screen
            .add_systems(OnEnter(MenuState::SettingsSound), sound_settings_menu_setup)
            .add_systems(
                Update,
                setting_button::<Volume>.run_if(in_state(MenuState::SettingsSound)),
            )
            .add_systems(
                OnExit(MenuState::SettingsSound),
                despawn_screen::<OnSoundSettingsMenuScreen>,
            )
            // Common systems to all screens that handles buttons behavior
            .add_systems(
                Update,
                (menu_action, button_system).run_if(in_state(GameState::Menu)),
            );
    }

    // State used for the current menu screen
    #[derive(Clone, Copy, Default, Eq, PartialEq, Debug, Hash, States)]
    enum MenuState {
        Main,
        Settings,
        SettingsDisplay,
        SettingsSound,
        #[default]
        Disabled,
    }

    // Tag component used to tag entities added on the main menu screen
    #[derive(Component)]
    struct OnMainMenuScreen;

    // Tag component used to tag entities added on the settings menu screen
    #[derive(Component)]
    struct OnSettingsMenuScreen;

    // Tag component used to tag entities added on the display settings menu screen
    #[derive(Component)]
    struct OnDisplaySettingsMenuScreen;

    // Tag component used to tag entities added on the sound settings menu screen
    #[derive(Component)]
    struct OnSoundSettingsMenuScreen;

    const NORMAL_BUTTON: Color = Color::rgb(0.15, 0.15, 0.15);
    const HOVERED_BUTTON: Color = Color::rgb(0.25, 0.25, 0.25);
    const HOVERED_PRESSED_BUTTON: Color = Color::rgb(0.25, 0.65, 0.25);
    const PRESSED_BUTTON: Color = Color::rgb(0.35, 0.75, 0.35);

    // Tag component used to mark which setting is currently selected
    #[derive(Component)]
    struct SelectedOption;

    // All actions that can be triggered from a button click
    #[derive(Component)]
    enum MenuButtonAction {
        Play,
        Settings,
        SettingsDisplay,
        SettingsSound,
        BackToMainMenu,
        BackToSettings,
        Quit,
    }

    // This system handles changing all buttons color based on mouse interaction
    fn button_system(
        mut interaction_query: Query<
            (&Interaction, &mut BackgroundColor, Option<&SelectedOption>),
            (Changed<Interaction>, With<Button>),
        >,
    ) {
        for (interaction, mut color, selected) in &mut interaction_query {
            *color = match (*interaction, selected) {
                (Interaction::Pressed, _) | (Interaction::None, Some(_)) => PRESSED_BUTTON.into(),
                (Interaction::Hovered, Some(_)) => HOVERED_PRESSED_BUTTON.into(),
                (Interaction::Hovered, None) => HOVERED_BUTTON.into(),
                (Interaction::None, None) => NORMAL_BUTTON.into(),
            }
        }
    }

    // This system updates the settings when a new value for a setting is selected, and marks
    // the button as the one currently selected
    fn setting_button<T: Resource + Component + PartialEq + Copy>(
        interaction_query: Query<(&Interaction, &T, Entity), (Changed<Interaction>, With<Button>)>,
        mut selected_query: Query<(Entity, &mut BackgroundColor), With<SelectedOption>>,
        mut commands: Commands,
        mut setting: ResMut<T>,
    ) {
        for (interaction, button_setting, entity) in &interaction_query {
            if *interaction == Interaction::Pressed && *setting != *button_setting {
                let (previous_button, mut previous_color) = selected_query.single_mut();
                *previous_color = NORMAL_BUTTON.into();
                commands.entity(previous_button).remove::<SelectedOption>();
                commands.entity(entity).insert(SelectedOption);
                *setting = *button_setting;
            }
        }
    }

    fn menu_setup(mut menu_state: ResMut<NextState<MenuState>>) {
        menu_state.set(MenuState::Main);
    }

    fn main_menu_setup(mut commands: Commands, asset_server: Res<AssetServer>) {
        // Common style for all buttons on the screen
        let button_style = Style {
            width: Val::Px(250.0),
            height: Val::Px(65.0),
            margin: UiRect::all(Val::Px(20.0)),
            justify_content: JustifyContent::Center,
            align_items: AlignItems::Center,
            ..default()
        };
        let button_icon_style = Style {
            width: Val::Px(30.0),
            // This takes the icons out of the flexbox flow, to be positioned exactly
            position_type: PositionType::Absolute,
            // The icon will be close to the left border of the button
            left: Val::Px(10.0),
            ..default()
        };
        let button_text_style = TextStyle {
            font_size: 40.0,
            color: TEXT_COLOR,
            ..default()
        };

        commands
            .spawn((
                NodeBundle {
                    style: Style {
                        width: Val::Percent(100.0),
                        height: Val::Percent(100.0),
                        align_items: AlignItems::Center,
                        justify_content: JustifyContent::Center,
                        ..default()
                    },
                    ..default()
                },
                OnMainMenuScreen,
            ))
            .with_children(|parent| {
                parent
                    .spawn(NodeBundle {
                        style: Style {
                            flex_direction: FlexDirection::Column,
                            align_items: AlignItems::Center,
                            ..default()
                        },
                        background_color: Color::CRIMSON.into(),
                        ..default()
                    })
                    .with_children(|parent| {
                        // Display the game name
                        parent.spawn(
                            TextBundle::from_section(
                                "Bevy Game Menu UI",
                                TextStyle {
                                    font_size: 80.0,
                                    color: TEXT_COLOR,
                                    ..default()
                                },
                            )
                            .with_style(Style {
                                margin: UiRect::all(Val::Px(50.0)),
                                ..default()
                            }),
                        );

                        // Display three buttons for each action available from the main menu:
                        // - new game
                        // - settings
                        // - quit
                        parent
                            .spawn((
                                ButtonBundle {
                                    style: button_style.clone(),
                                    background_color: NORMAL_BUTTON.into(),
                                    ..default()
                                },
                                MenuButtonAction::Play,
                            ))
                            .with_children(|parent| {
                                let icon = asset_server.load("textures/Game Icons/right.png");
                                parent.spawn(ImageBundle {
                                    style: button_icon_style.clone(),
                                    image: UiImage::new(icon),
                                    ..default()
                                });
                                parent.spawn(TextBundle::from_section(
                                    "New Game",
                                    button_text_style.clone(),
                                ));
                            });
                        parent
                            .spawn((
                                ButtonBundle {
                                    style: button_style.clone(),
                                    background_color: NORMAL_BUTTON.into(),
                                    ..default()
                                },
                                MenuButtonAction::Settings,
                            ))
                            .with_children(|parent| {
                                let icon = asset_server.load("textures/Game Icons/wrench.png");
                                parent.spawn(ImageBundle {
                                    style: button_icon_style.clone(),
                                    image: UiImage::new(icon),
                                    ..default()
                                });
                                parent.spawn(TextBundle::from_section(
                                    "Settings",
                                    button_text_style.clone(),
                                ));
                            });
                        parent
                            .spawn((
                                ButtonBundle {
                                    style: button_style,
                                    background_color: NORMAL_BUTTON.into(),
                                    ..default()
                                },
                                MenuButtonAction::Quit,
                            ))
                            .with_children(|parent| {
                                let icon = asset_server.load("textures/Game Icons/exitRight.png");
                                parent.spawn(ImageBundle {
                                    style: button_icon_style,
                                    image: UiImage::new(icon),
                                    ..default()
                                });
                                parent.spawn(TextBundle::from_section("Quit", button_text_style));
                            });
                    });
            });
    }

    fn settings_menu_setup(mut commands: Commands) {
        let button_style = Style {
            width: Val::Px(200.0),
            height: Val::Px(65.0),
            margin: UiRect::all(Val::Px(20.0)),
            justify_content: JustifyContent::Center,
            align_items: AlignItems::Center,
            ..default()
        };

        let button_text_style = TextStyle {
            font_size: 40.0,
            color: TEXT_COLOR,
            ..default()
        };

        commands
            .spawn((
                NodeBundle {
                    style: Style {
                        width: Val::Percent(100.0),
                        height: Val::Percent(100.0),
                        align_items: AlignItems::Center,
                        justify_content: JustifyContent::Center,
                        ..default()
                    },
                    ..default()
                },
                OnSettingsMenuScreen,
            ))
            .with_children(|parent| {
                parent
                    .spawn(NodeBundle {
                        style: Style {
                            flex_direction: FlexDirection::Column,
                            align_items: AlignItems::Center,
                            ..default()
                        },
                        background_color: Color::CRIMSON.into(),
                        ..default()
                    })
                    .with_children(|parent| {
                        for (action, text) in [
                            (MenuButtonAction::SettingsDisplay, "Display"),
                            (MenuButtonAction::SettingsSound, "Sound"),
                            (MenuButtonAction::BackToMainMenu, "Back"),
                        ] {
                            parent
                                .spawn((
                                    ButtonBundle {
                                        style: button_style.clone(),
                                        background_color: NORMAL_BUTTON.into(),
                                        ..default()
                                    },
                                    action,
                                ))
                                .with_children(|parent| {
                                    parent.spawn(TextBundle::from_section(
                                        text,
                                        button_text_style.clone(),
                                    ));
                                });
                        }
                    });
            });
    }

    fn display_settings_menu_setup(mut commands: Commands, display_quality: Res<DisplayQuality>) {
        let button_style = Style {
            width: Val::Px(200.0),
            height: Val::Px(65.0),
            margin: UiRect::all(Val::Px(20.0)),
            justify_content: JustifyContent::Center,
            align_items: AlignItems::Center,
            ..default()
        };
        let button_text_style = TextStyle {
            font_size: 40.0,
            color: TEXT_COLOR,
            ..default()
        };

        commands
            .spawn((
                NodeBundle {
                    style: Style {
                        width: Val::Percent(100.0),
                        height: Val::Percent(100.0),
                        align_items: AlignItems::Center,
                        justify_content: JustifyContent::Center,
                        ..default()
                    },
                    ..default()
                },
                OnDisplaySettingsMenuScreen,
            ))
            .with_children(|parent| {
                parent
                    .spawn(NodeBundle {
                        style: Style {
                            flex_direction: FlexDirection::Column,
                            align_items: AlignItems::Center,
                            ..default()
                        },
                        background_color: Color::CRIMSON.into(),
                        ..default()
                    })
                    .with_children(|parent| {
                        // Create a new `NodeBundle`, this time not setting its `flex_direction`. It will
                        // use the default value, `FlexDirection::Row`, from left to right.
                        parent
                            .spawn(NodeBundle {
                                style: Style {
                                    align_items: AlignItems::Center,
                                    ..default()
                                },
                                background_color: Color::CRIMSON.into(),
                                ..default()
                            })
                            .with_children(|parent| {
                                // Display a label for the current setting
                                parent.spawn(TextBundle::from_section(
                                    "Display Quality",
                                    button_text_style.clone(),
                                ));
                                // Display a button for each possible value
                                for quality_setting in [
                                    DisplayQuality::Low,
                                    DisplayQuality::Medium,
                                    DisplayQuality::High,
                                ] {
                                    let mut entity = parent.spawn((
                                        ButtonBundle {
                                            style: Style {
                                                width: Val::Px(150.0),
                                                height: Val::Px(65.0),
                                                ..button_style.clone()
                                            },
                                            background_color: NORMAL_BUTTON.into(),
                                            ..default()
                                        },
                                        quality_setting,
                                    ));
                                    entity.with_children(|parent| {
                                        parent.spawn(TextBundle::from_section(
                                            format!("{quality_setting:?}"),
                                            button_text_style.clone(),
                                        ));
                                    });
                                    if *display_quality == quality_setting {
                                        entity.insert(SelectedOption);
                                    }
                                }
                            });
                        // Display the back button to return to the settings screen
                        parent
                            .spawn((
                                ButtonBundle {
                                    style: button_style,
                                    background_color: NORMAL_BUTTON.into(),
                                    ..default()
                                },
                                MenuButtonAction::BackToSettings,
                            ))
                            .with_children(|parent| {
                                parent.spawn(TextBundle::from_section("Back", button_text_style));
                            });
                    });
            });
    }

    fn sound_settings_menu_setup(mut commands: Commands, volume: Res<Volume>) {
        let button_style = Style {
            width: Val::Px(200.0),
            height: Val::Px(65.0),
            margin: UiRect::all(Val::Px(20.0)),
            justify_content: JustifyContent::Center,
            align_items: AlignItems::Center,
            ..default()
        };
        let button_text_style = TextStyle {
            font_size: 40.0,
            color: TEXT_COLOR,
            ..default()
        };

        commands
            .spawn((
                NodeBundle {
                    style: Style {
                        width: Val::Percent(100.0),
                        height: Val::Percent(100.0),
                        align_items: AlignItems::Center,
                        justify_content: JustifyContent::Center,
                        ..default()
                    },
                    ..default()
                },
                OnSoundSettingsMenuScreen,
            ))
            .with_children(|parent| {
                parent
                    .spawn(NodeBundle {
                        style: Style {
                            flex_direction: FlexDirection::Column,
                            align_items: AlignItems::Center,
                            ..default()
                        },
                        background_color: Color::CRIMSON.into(),
                        ..default()
                    })
                    .with_children(|parent| {
                        parent
                            .spawn(NodeBundle {
                                style: Style {
                                    align_items: AlignItems::Center,
                                    ..default()
                                },
                                background_color: Color::CRIMSON.into(),
                                ..default()
                            })
                            .with_children(|parent| {
                                parent.spawn(TextBundle::from_section(
                                    "Volume",
                                    button_text_style.clone(),
                                ));
                                for volume_setting in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] {
                                    let mut entity = parent.spawn((
                                        ButtonBundle {
                                            style: Style {
                                                width: Val::Px(30.0),
                                                height: Val::Px(65.0),
                                                ..button_style.clone()
                                            },
                                            background_color: NORMAL_BUTTON.into(),
                                            ..default()
                                        },
                                        Volume(volume_setting),
                                    ));
                                    if *volume == Volume(volume_setting) {
                                        entity.insert(SelectedOption);
                                    }
                                }
                            });
                        parent
                            .spawn((
                                ButtonBundle {
                                    style: button_style,
                                    background_color: NORMAL_BUTTON.into(),
                                    ..default()
                                },
                                MenuButtonAction::BackToSettings,
                            ))
                            .with_children(|parent| {
                                parent.spawn(TextBundle::from_section("Back", button_text_style));
                            });
                    });
            });
    }

examples/3d/parenting.rs (lines 50-55)

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    let cube_handle = meshes.add(Cuboid::new(2.0, 2.0, 2.0));
    let cube_material_handle = materials.add(StandardMaterial {
        base_color: Color::rgb(0.8, 0.7, 0.6),
        ..default()
    });

    // parent cube
    commands
        .spawn((
            PbrBundle {
                mesh: cube_handle.clone(),
                material: cube_material_handle.clone(),
                transform: Transform::from_xyz(0.0, 0.0, 1.0),
                ..default()
            },
            Rotator,
        ))
        .with_children(|parent| {
            // child cube
            parent.spawn(PbrBundle {
                mesh: cube_handle,
                material: cube_material_handle,
                transform: Transform::from_xyz(0.0, 0.0, 3.0),
                ..default()
            });
        });
    // light
    commands.spawn(PointLightBundle {
        transform: Transform::from_xyz(4.0, 5.0, -4.0),
        ..default()
    });
    // camera
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(5.0, 10.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
}

examples/stress_tests/many_glyphs.rs (lines 70-77)

fn setup(mut commands: Commands) {
    warn!(include_str!("warning_string.txt"));

    commands.spawn(Camera2dBundle::default());
    let mut text = Text {
        sections: vec![TextSection {
            value: "0123456789".repeat(10_000),
            style: TextStyle {
                font_size: 4.,
                ..default()
            },
        }],
        justify: JustifyText::Left,
        linebreak_behavior: BreakLineOn::AnyCharacter,
    };

    commands
        .spawn(NodeBundle {
            style: Style {
                width: Val::Percent(100.),
                align_items: AlignItems::Center,
                justify_content: JustifyContent::Center,
                ..default()
            },
            ..default()
        })
        .with_children(|commands| {
            commands.spawn(TextBundle {
                text: text.clone(),
                style: Style {
                    width: Val::Px(1000.),
                    ..Default::default()
                },
                ..Default::default()
            });
        });

    text.sections[0].style.color = Color::RED;

    commands.spawn(Text2dBundle {
        text,
        text_anchor: bevy::sprite::Anchor::Center,
        text_2d_bounds: Text2dBounds {
            size: Vec2::new(1000., f32::INFINITY),
        },
        ..Default::default()
    });
}

Additional examples can be found in:

• examples/window/scale_factor_override.rs
• examples/ecs/state.rs
• examples/ecs/hierarchy.rs
• examples/ui/button.rs
• examples/math/render_primitives.rs
• examples/ui/relative_cursor_position.rs
• examples/games/alien_cake_addict.rs
• examples/window/multiple_windows.rs
• examples/ui/ui_texture_atlas.rs
• examples/3d/spherical_area_lights.rs
• examples/ui/ui_scaling.rs
• examples/stress_tests/many_buttons.rs
• examples/audio/spatial_audio_2d.rs
• examples/ui/ui_texture_slice.rs
• examples/audio/spatial_audio_3d.rs
• examples/ui/overflow_debug.rs
• examples/ui/transparency_ui.rs
• examples/ui/size_constraints.rs
• examples/ui/viewport_debug.rs
• examples/ecs/iter_combinations.rs
• examples/time/virtual_time.rs
• examples/ui/render_ui_to_texture.rs
• examples/stress_tests/bevymark.rs
• examples/2d/sprite_slice.rs
• examples/3d/spotlight.rs
• examples/ui/flex_layout.rs
• examples/stress_tests/many_foxes.rs
• examples/ui/overflow.rs
• examples/ui/display_and_visibility.rs
• examples/2d/text2d.rs
• examples/ui/z_index.rs
• examples/3d/parallax_mapping.rs
• examples/3d/split_screen.rs
• examples/3d/shadow_biases.rs
• examples/animation/animated_transform.rs
• examples/ui/text_debug.rs
• examples/3d/blend_modes.rs
• examples/3d/lighting.rs
• examples/ui/grid.rs
• examples/ui/ui.rs

pub fn spawn_empty(&mut self) -> EntityCommands<'_>

Spawns an Entity with no components and inserts it into the parent entity’s Children. Also adds Parent component to the created entity.

pub fn parent_entity(&self) -> Entity

Returns the parent entity of this ChildBuilder.

pub fn add_command<C>(&mut self, command: C) -> &mut ChildBuilder<'_>

where C: Command,

Adds a command to be executed, like Commands::add.