feat(ecs): add component added event

1 files changed, 29 insertions, 6 deletions

diff --git a/ecs/src/event.rs b/ecs/src/event.rs
index 93d4545..0caa56f 100644
--- a/ecs/src/event.rs
+++ b/ecs/src/event.rs
@@ -1,10 +1,21 @@
 use std::any::TypeId;
 use std::fmt::Debug;
-use std::hash::Hash;
+use std::hash::{DefaultHasher, Hash, Hasher};
 
 use seq_macro::seq;
 
-pub trait Event: Debug + 'static {}
+pub mod component;
+
+pub trait Event: Debug + 'static
+{
+    /// Returns the ID of this event.
+    fn id() -> Id
+    where
+        Self: Sized,
+    {
+        Id::new::<Self, ()>(None)
+    }
+}
 
 pub mod start;
 
@@ -13,15 +24,27 @@ pub mod start;
 pub struct Id
 {
     inner: TypeId,
+    extra: Option<u64>,
 }
 
 impl Id
 {
-    /// Returns the id of a [`Event`];
     #[must_use]
-    pub fn of<EventT: Event>() -> Self
+    pub fn new<EventT, Extra>(extra: Option<Extra>) -> Self
+    where
+        EventT: Event,
+        Extra: Hash,
     {
-        Self { inner: TypeId::of::<EventT>() }
+        Self {
+            inner: TypeId::of::<EventT>(),
+            extra: extra.map(|extra| {
+                let mut hasher = DefaultHasher::new();
+
+                extra.hash(&mut hasher);
+
+                hasher.finish()
+            }),
+        }
     }
 }
 
@@ -59,7 +82,7 @@ macro_rules! impl_sequence {
 
                 fn ids() -> Self::Ids {
                     [#(
-                        Id::of::<Event~I>(),
+                        Event~I::id(),
                     )*]
                 }
             }