feat(ecs): re-implement component added & removed eventsHEADmaster

1 files changed, 39 insertions, 0 deletions

diff --git a/ecs/examples/component_removed_event.rs b/ecs/examples/component_removed_event.rs
new file mode 100644
index 0000000..ffa37f4
--- /dev/null
+++ b/ecs/examples/component_removed_event.rs
@@ -0,0 +1,39 @@
+use ecs::actions::Actions;
+use ecs::component::Component;
+use ecs::event::component::Removed;
+use ecs::pair::Pair;
+use ecs::phase::UPDATE;
+use ecs::system::observer::Observe;
+use ecs::{Component, Query, World};
+
+#[derive(Debug, Component)]
+struct Cheese;
+
+fn eat_cheese(query: Query<(&Cheese,)>, mut actions: Actions)
+{
+    for (cheese_ent_id, (_,)) in query.iter_with_euids() {
+        println!("Eating cheese!");
+
+        actions.remove_components(cheese_ent_id, [Cheese::id()]);
+    }
+}
+
+fn on_cheese_removed(observe: Observe<Pair<Removed, Cheese>>)
+{
+    for cheese_ent in &observe {
+        println!("Cheese entity {} was eaten", cheese_ent.uid());
+    }
+}
+
+fn main()
+{
+    let mut world = World::new();
+
+    world.register_system(*UPDATE, eat_cheese);
+    world.register_observer(on_cheese_removed);
+
+    world.create_entity((Cheese,));
+
+    world.step();
+    world.step();
+}