Struct hecs_hierarchy::TreeBuilder

pub struct TreeBuilder<T> { /* private fields */ }

Ergonomically construct trees without knowledge of world.

This struct builds the world using EntityBuilder

Example

use hecs_hierarchy::*;
use hecs::*;

struct Tree;
let mut world = World::default();
let mut builder = TreeBuilder::<Tree>::from(("root",));
builder.attach(("child 1",));
builder.attach({
    let mut builder = TreeBuilder::new();
    builder.add("child 2");
    builder
});
let root = builder.spawn(&mut world);
assert_eq!(*world.get::<&'static str>(root).unwrap(), "root");
for (a, b) in world
    .descendants_depth_first::<Tree>(root)
    .zip(["child 1", "child 2"])
{
    assert_eq!(*world.get::<&str>(a).unwrap(), b)
}

Implementations

impl<T: Component> TreeBuilder<T>

pub fn new() -> Self

Construct a new empty tree

pub fn reserve(&self, world: &impl GenericWorld) -> Entity

Reserve the entity which this node will spawn

pub fn spawn(&mut self, world: &mut World) -> Entity

Spawn the whole tree into the world

pub fn spawn_deferred(
    &mut self,
    world: &impl GenericWorld,
    cmd: &mut CommandBuffer
) -> Entity

Spawn the whole tree into a commandbuffer. The world is required for reserving entities.

pub fn add(&mut self, component: impl Component) -> &mut Self

Add a component to the root

pub fn add_bundle(&mut self, bundle: impl DynamicBundle) -> &mut Self

Add a bundle to the root

pub fn attach_tree(&mut self, child: Self) -> &mut Self

Atttach a new subtree

pub fn attach(&mut self, child: impl Into<Self>) -> &mut Self

Attach a new leaf as a bundle

pub fn attach_move(self, child: impl Into<Self>) -> Self

Consuming variant of Self::attach.

This is useful for nesting to alleviate the need to save an intermediate builder

pub fn attach_tree_move(self, child: impl Into<Self>) -> Self

Consuming variant of Self::attach_tree. This is useful for nesting to alleviate the need to save an intermediate builder

pub fn children(&self) -> &[Self]

Get a reference to the deferred tree builder’s children.

pub fn root(&self) -> &EntityBuilder

Get a reference to the deferred tree builder’s root.

pub fn root_mut(&mut self) -> &mut EntityBuilder

Get a mutable reference to the deferred tree builder’s root.

Trait Implementations

impl<B: DynamicBundle, T: Component> From<B> for TreeBuilder<T>

fn from(bundle: B) -> Self

Performs the conversion.

impl<T: Component> From<TreeBuilderClone<T>> for TreeBuilder<T>

fn from(tree: TreeBuilderClone<T>) -> Self

Performs the conversion.