Cameron 01649f13e2 Refactor App and SubApp internals for better separation (#9202) ... # Objective This is a necessary precursor to #9122 (this was split from that PR to reduce the amount of code to review all at once). Moving `!Send` resource ownership to `App` will make it unambiguously `!Send`. `SubApp` must be `Send`, so it can't wrap `App`. ## Solution Refactor `App` and `SubApp` to not have a recursive relationship. Since `SubApp` no longer wraps `App`, once `!Send` resources are moved out of `World` and into `App`, `SubApp` will become unambiguously `Send`. There could be less code duplication between `App` and `SubApp`, but that would break `App` method chaining. ## Changelog - `SubApp` no longer wraps `App`. - `App` fields are no longer publicly accessible. - `App` can no longer be converted into a `SubApp`. - Various methods now return references to a `SubApp` instead of an `App`. ## Migration Guide - To construct a sub-app, use `SubApp::new()`. `App` can no longer convert into `SubApp`. - If you implemented a trait for `App`, you may want to implement it for `SubApp` as well. - If you're accessing `app.world` directly, you now have to use `app.world()` and `app.world_mut()`. - `App::sub_app` now returns `&SubApp`. - `App::sub_app_mut` now returns `&mut SubApp`. - `App::get_sub_app` now returns `Option<&SubApp>.` - `App::get_sub_app_mut` now returns `Option<&mut SubApp>.`		2024-03-31 03:16:10 +00:00
..
3d	Deferred Renderer (#9258)	2023-10-12 22:10:38 +00:00
window	Migrate from LegacyColor to bevy_color::Color (#12163)	2024-02-29 19:35:12 +00:00
how_to_test_systems.rs	Refactor App and SubApp internals for better separation (#9202)	2024-03-31 03:16:10 +00:00