Crate lumen_core 

Lumen UI framework core crate.

• Owns the tick loop, command queue, ECS components, and the two ECS worlds (main + render). See render_world for the cross-world flow.
• Backend roles are traits in traits; concrete backends implement them and register systems via app::Plugin.
• Hierarchy uses bevy_ecs::hierarchy::ChildOf and bevy_ecs::hierarchy::Children, re-exported from prelude.

Modules

app

App builder and Plugin trait. Wraps [bevy_ecs::World] and Schedule directly without depending on bevy_app.

app_paths

Process-global app location: the directory an app was loaded from, and the per-user directory it keeps saved data in.

backends

The registry every backend kind shares.

command

Bounded command queue for off-main-thread mutations of ECS state.

components

ECS component primitives.

i18n

Process-wide translation and formatting hooks - the surfaces a script host reaches an app’s locale through.

input

Pointer, keyboard, drag, IME, and file-drop event types plus shared input resources.

introspect

Typed, whitelisted component-introspection registry for the dynamic DOM n.components() / n.component("LayoutBox") reads (design 4.7).

layout_backend

The layout engines a binary carries, how a launch installs one, and the system set that marks where layout is solved.

native

Native paint seam - the way a plugin draws its own pixels inside the retained scene.

nav

File-based-pages navigation primitive - the ONE surface every embedding reaches through.

net_capture

Process-wide, opt-in HTTP capture sink for dev tooling.

node

Node handles and the per-tick DOM index for the dynamic query API.

node_ir

Retained Node IR - typed scene-graph tree produced from the flat Extracted* bag.

output

Saying things without staking the process on being heard.

palette

Design-token / named-color Palette.

plugin_events

Cross-thread event bus for plugins, modules and add-ons.

prelude

Crate prelude re-exporting the common types. Glob-import with use lumen_core::prelude::*;.

property_store

Typed reactive property store with notify-on-write semantics.

render_backend

The render backends a binary carries, how a launch picks one, and the render-world system that drives a renderer drawing offscreen.

render_world

Render world definitions and the extract pipeline.

request

The request a document is being produced for.

signals

Reactive named-value store backing bind-text="..." markup attributes and <for each="..."> iteration.

style_overrides

The values runtime systems hold on an element over what its styles say.

task

The async seam: Spawn for running work off the main thread, Timer for waiting without blocking it, and the two service resources that carry the selected backend through the world.

text_events

W3.2: text-editing message bus.

text_model

W3.1: rope-backed text model components.

tick

Main-world tick stages and the Tick resource.

time

Clock types for the tick loop, animation primitives, and script timers.

traits

The backend roles, plus the Bindable trait declaring a component as a property-bus participant.

window

Backend-neutral description of the app’s window and its native menu bar.

window_backend

The window backends a binary carries, and the window-free state every window backend shares with the app.

window_state

Process-global window-state mirror for the window script namespace.

Macros

say_line

Tell the person running this something. Reads like println!, and cannot end the process.

warn_line

Warn the person running this about something. Reads like eprintln!, and cannot end the process.