Struct bevy::hierarchy::ChildBuilder
pub struct ChildBuilder<'a> { /* private fields */ }
Expand description
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<'_>
impl ChildBuilder<'_>
pub fn spawn(&mut self, bundle: impl Bundle) -> EntityCommands<'_>
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/app/log_layers_ecs.rs (lines 145-148)
136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151
fn print_logs(
mut events: EventReader<LogEvent>,
mut commands: Commands,
log_viewer_root: Query<Entity, With<LogViewerRoot>>,
) {
let root_entity = log_viewer_root.single();
commands.entity(root_entity).with_children(|child| {
for event in events.read() {
child.spawn(TextBundle::from_section(
&event.message,
TextStyle::default(),
));
}
});
}
More examples
examples/window/window_resizing.rs (lines 46-55)
35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
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/dev_tools/fps_overlay.rs (lines 47-56)
30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58
fn setup(mut commands: Commands) {
// We need to spawn a camera (2d or 3d) to see the overlay
commands.spawn(Camera2dBundle::default());
// Instruction text
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(|c| {
c.spawn(TextBundle::from_section(
concat!(
"Press 1 to change color of the overlay.\n",
"Press 2 to change size of the overlay."
),
TextStyle {
font_size: 25.0,
..default()
},
));
});
}
examples/games/loading_screen.rs (lines 95-98)
71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306
fn setup(mut commands: Commands) {
let level_data = LevelData {
unload_level_id: commands.register_one_shot_system(unload_current_level),
level_1_id: commands.register_one_shot_system(load_level_1),
level_2_id: commands.register_one_shot_system(load_level_2),
};
commands.insert_resource(level_data);
// Spawns the UI that will show the user prompts.
let text_style = TextStyle {
font_size: 50.0,
..default()
};
commands
.spawn(NodeBundle {
background_color: BackgroundColor(Color::NONE),
style: Style {
justify_self: JustifySelf::Center,
align_self: AlignSelf::FlexEnd,
..default()
},
..default()
})
.with_children(|parent| {
parent.spawn(TextBundle::from_section(
"Press 1 or 2 to load a new scene.",
text_style,
));
});
}
// Selects the level you want to load.
fn level_selection(
mut commands: Commands,
keyboard: Res<ButtonInput<KeyCode>>,
level_data: Res<LevelData>,
loading_state: Res<LoadingState>,
) {
// Only trigger a load if the current level is fully loaded.
if let LoadingState::LevelReady = loading_state.as_ref() {
if keyboard.just_pressed(KeyCode::Digit1) {
commands.run_system(level_data.unload_level_id);
commands.run_system(level_data.level_1_id);
} else if keyboard.just_pressed(KeyCode::Digit2) {
commands.run_system(level_data.unload_level_id);
commands.run_system(level_data.level_2_id);
}
}
}
// Marker component for easier deletion of entities.
#[derive(Component)]
struct LevelComponents;
// Removes all currently loaded level assets from the game World.
fn unload_current_level(
mut commands: Commands,
mut loading_state: ResMut<LoadingState>,
entities: Query<Entity, With<LevelComponents>>,
) {
*loading_state = LoadingState::LevelLoading;
for entity in entities.iter() {
commands.entity(entity).despawn_recursive();
}
}
fn load_level_1(
mut commands: Commands,
mut loading_data: ResMut<LoadingData>,
asset_server: Res<AssetServer>,
) {
// Spawn the camera.
commands.spawn((
Camera3dBundle {
transform: Transform::from_xyz(155.0, 155.0, 155.0)
.looking_at(Vec3::new(0.0, 40.0, 0.0), Vec3::Y),
..default()
},
LevelComponents,
));
// Save the asset into the `loading_assets` vector.
let fox = asset_server.load("models/animated/Fox.glb#Scene0");
loading_data.loading_assets.push(fox.clone().into());
// Spawn the fox.
commands.spawn((
SceneBundle {
scene: fox.clone(),
transform: Transform::from_xyz(0.0, 0.0, 0.0),
..default()
},
LevelComponents,
));
// Spawn the light.
commands.spawn((
DirectionalLightBundle {
transform: Transform::from_xyz(3.0, 3.0, 2.0).looking_at(Vec3::ZERO, Vec3::Y),
directional_light: DirectionalLight {
shadows_enabled: true,
..default()
},
..default()
},
LevelComponents,
));
}
fn load_level_2(
mut commands: Commands,
mut loading_data: ResMut<LoadingData>,
asset_server: Res<AssetServer>,
) {
// Spawn the camera.
commands.spawn((
Camera3dBundle {
transform: Transform::from_xyz(1.0, 1.0, 1.0)
.looking_at(Vec3::new(0.0, 0.2, 0.0), Vec3::Y),
..default()
},
LevelComponents,
));
// Spawn the helmet.
let helmet_scene = asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0");
loading_data
.loading_assets
.push(helmet_scene.clone().into());
commands.spawn((
SceneBundle {
scene: helmet_scene.clone(),
..default()
},
LevelComponents,
));
// Spawn the light.
commands.spawn((
DirectionalLightBundle {
transform: Transform::from_xyz(3.0, 3.0, 2.0).looking_at(Vec3::ZERO, Vec3::Y),
directional_light: DirectionalLight {
shadows_enabled: true,
..default()
},
..default()
},
LevelComponents,
));
}
// Monitors current loading status of assets.
fn update_loading_data(
mut loading_data: ResMut<LoadingData>,
mut loading_state: ResMut<LoadingState>,
asset_server: Res<AssetServer>,
pipelines_ready: Res<PipelinesReady>,
) {
if !loading_data.loading_assets.is_empty() || !pipelines_ready.0 {
// If we are still loading assets / pipelines are not fully compiled,
// we reset the confirmation frame count.
loading_data.confirmation_frames_count = 0;
// Go through each asset and verify their load states.
// Any assets that are loaded are then added to the pop list for later removal.
let mut pop_list: Vec<usize> = Vec::new();
for (index, asset) in loading_data.loading_assets.iter().enumerate() {
if let Some(state) = asset_server.get_load_states(asset) {
if let bevy::asset::RecursiveDependencyLoadState::Loaded = state.2 {
pop_list.push(index);
}
}
}
// Remove all loaded assets from the loading_assets list.
for i in pop_list.iter() {
loading_data.loading_assets.remove(*i);
}
// If there are no more assets being monitored, and pipelines
// are compiled, then start counting confirmation frames.
// Once enough confirmations have passed, everything will be
// considered to be fully loaded.
} else {
loading_data.confirmation_frames_count += 1;
if loading_data.confirmation_frames_count == loading_data.confirmation_frames_target {
*loading_state = LoadingState::LevelReady;
}
}
}
// Marker tag for loading screen components.
#[derive(Component)]
struct LoadingScreen;
// Spawns the necessary components for the loading screen.
fn load_loading_screen(mut commands: Commands) {
let text_style = TextStyle {
font_size: 80.0,
..default()
};
// Spawn the UI and Loading screen camera.
commands.spawn((
Camera2dBundle {
camera: Camera {
order: 1,
..default()
},
..default()
},
LoadingScreen,
));
// Spawn the UI that will make up the loading screen.
commands
.spawn((
NodeBundle {
background_color: BackgroundColor(Color::BLACK),
style: Style {
height: Val::Percent(100.0),
width: Val::Percent(100.0),
justify_content: JustifyContent::Center,
align_items: AlignItems::Center,
..default()
},
..default()
},
LoadingScreen,
))
.with_children(|parent| {
parent.spawn(TextBundle::from_sections([TextSection::new(
"Loading...",
text_style.clone(),
)]));
});
}
examples/ui/ui_material.rs (lines 40-51)
24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
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: LinearRgba::WHITE.to_f32_array().into(),
}),
..default()
});
});
}
examples/ui/font_atlas_debug.rs (lines 99-106)
84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111
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: YELLOW.into(),
},
));
});
// We're seeding the PRNG here to make this example deterministic for testing purposes.
// This isn't strictly required in practical use unless you need your app to be deterministic.
commands.insert_resource(SeededRng(ChaCha8Rng::seed_from_u64(19878367467713)));
}
Additional examples can be found in:
- examples/games/game_menu.rs
- examples/3d/parenting.rs
- examples/3d/color_grading.rs
- examples/stress_tests/many_glyphs.rs
- examples/window/scale_factor_override.rs
- examples/ecs/state.rs
- examples/ecs/hierarchy.rs
- examples/math/render_primitives.rs
- examples/ecs/sub_states.rs
- examples/ui/button.rs
- examples/ui/relative_cursor_position.rs
- examples/games/alien_cake_addict.rs
- examples/window/multiple_windows.rs
- examples/3d/spherical_area_lights.rs
- examples/ui/ui_scaling.rs
- examples/ui/ui_texture_atlas.rs
- examples/stress_tests/many_buttons.rs
- examples/audio/spatial_audio_2d.rs
- examples/ui/overflow_debug.rs
- examples/ui/ui_texture_slice.rs
- examples/audio/spatial_audio_3d.rs
- examples/3d/motion_blur.rs
- examples/ui/transparency_ui.rs
- examples/ui/size_constraints.rs
- examples/ui/ui_texture_atlas_slice.rs
- examples/ui/viewport_debug.rs
- examples/time/virtual_time.rs
- examples/ui/render_ui_to_texture.rs
- examples/ecs/iter_combinations.rs
- examples/2d/sprite_slice.rs
- examples/stress_tests/bevymark.rs
- examples/ecs/computed_states.rs
- examples/tools/gamepad_viewer.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/games/desk_toy.rs
- examples/3d/parallax_mapping.rs
- examples/3d/split_screen.rs
- examples/3d/shadow_biases.rs
- examples/ui/text_debug.rs
- examples/animation/animated_transform.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<'_>
pub fn spawn_empty(&mut self) -> EntityCommands<'_>
pub fn parent_entity(&self) -> 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,
pub fn add_command<C>(&mut self, command: C) -> &mut ChildBuilder<'_>where
C: Command,
Adds a command to be executed, like Commands::add
.
Auto Trait Implementations§
impl<'a> Freeze for ChildBuilder<'a>
impl<'a> RefUnwindSafe for ChildBuilder<'a>
impl<'a> Send for ChildBuilder<'a>
impl<'a> Sync for ChildBuilder<'a>
impl<'a> Unpin for ChildBuilder<'a>
impl<'a> !UnwindSafe for ChildBuilder<'a>
Blanket Implementations§
§impl<T, U> AsBindGroupShaderType<U> for T
impl<T, U> AsBindGroupShaderType<U> for T
§fn as_bind_group_shader_type(&self, _images: &RenderAssets<GpuImage>) -> U
fn as_bind_group_shader_type(&self, _images: &RenderAssets<GpuImage>) -> U
Return the
T
ShaderType
for self
. When used in AsBindGroup
derives, it is safe to assume that all images in self
exist.source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
§fn into_any(self: Box<T>) -> Box<dyn Any>
fn into_any(self: Box<T>) -> Box<dyn Any>
Convert
Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
.§fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
Convert
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
.§fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Convert
&Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s.§fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
Convert
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s.§impl<T> DowncastSync for T
impl<T> DowncastSync for T
§impl<S> FromSample<S> for S
impl<S> FromSample<S> for S
fn from_sample_(s: S) -> S
§impl<T> Instrument for T
impl<T> Instrument for T
§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
§fn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
Converts
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
Converts
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more