Blender_bevy_components_workflow/examples/advanced/state.rs

use bevy::prelude::*;
use bevy::app::AppExit;

#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash, Default, States)]
pub enum AppState{
    #[default]
    CoreLoading,
    MenuRunning,
    AppLoading,
    AppRunning,
    AppEnding,

    // FIXME: not sure
    LoadingGame
}

#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash, Default, States)]
pub enum GameState {
    #[default]
    None,
    
    InMenu,
    InGame,

    InGameOver,

    InSaving,
    InLoading
}

// tag components for all entities within a certain state (for despawning them if needed) , FIXME: seems kinda hack-ish
#[derive(Component)]
pub struct InCoreLoading;
#[derive(Component, Default)]
pub struct InMenuRunning;
#[derive(Component)]
pub struct InAppLoading;
#[derive(Component)]
pub struct InAppRunning;

// components for tagging in game vs in game menu stuff
#[derive(Component, Default)]
pub struct InMainMenu;
#[derive(Component, Default)]
pub struct InMenu;
#[derive(Component, Default)]
pub struct InGame;


pub struct StatePlugin;
impl Plugin for StatePlugin {
  fn build(&self, app: &mut App) {
      app
        .add_state::<AppState>()
        .add_state::<GameState>()
    ;
  }
}