Remove EventData trait and drop the requirement. Components can now a…

…lways be events.

flecs_ecs/examples/observer_custom_event.rs

@@ -5,8 +5,6 @@ use common::*;
 #[derive(Default, Clone, Component)]
 struct MyEvent;
 
-impl EventData for MyEvent {}
-
 fn main() {
     let world = World::new();
 

flecs_ecs/examples/observer_entity_event.rs

@@ -22,9 +22,6 @@ struct Resize {
     height: f32,
 }
 
-impl EventData for Click {}
-impl EventData for Resize {}
-
 fn main() {
     let world = World::new();
 

flecs_ecs/src/core/entity.rs

@@ -258,8 +258,15 @@ impl Entity {
     ///
     /// * C++ API: `entity::null`
     #[doc(alias = "entity::null")]
-    pub fn new_null() -> Entity {
-        Entity::default()
+    pub const fn new_null() -> Entity {
+        Entity {
+            entity_view: EntityView {
+                id: super::Id {
+                    raw_id: 0,
+                    world: std::ptr::null_mut(),
+                },
+            },
+        }
     }
 
     /// Add an id to an entity.
@@ -1526,7 +1533,8 @@ impl Entity {
     ///
     /// * C++ API: `entity::get_mut`
     #[doc(alias = "entity::get_mut")]
-    pub fn get_mut<T: ComponentId>(&mut self) -> &mut T::UnderlyingType {
+    #[allow(clippy::mut_from_ref)]
+    pub fn get_mut<T: ComponentId>(&self) -> &mut T::UnderlyingType {
         // This branch will be removed in release mode since this can be determined at compile time.
         if !T::IS_ENUM {
             let component_id = T::get_id(self.world);

flecs_ecs/src/core/entity_view.rs

@@ -38,7 +38,7 @@ use super::{
     table::{Table, TableRange},
     try_register_component,
     world::World,
-    CachedEnumData, EmptyComponent, EventBuilderImpl, EventData, IntoComponentId, IntoEntityId,
+    CachedEnumData, EmptyComponent, EventBuilderImpl, IntoComponentId, IntoEntityId,
     IntoEntityIdExt, IntoWorld, IterT, NotEmptyComponent, ObserverEntityBindingCtx, ECS_ANY,
     ECS_CHILD_OF, ECS_WILDCARD,
 };
@@ -1769,7 +1769,7 @@ impl EntityView {
     ///
     /// * C++ API: `entity_view::emit`
     #[doc(alias = "entity_view::emit")]
-    pub fn emit<T: EventData + EmptyComponent + ComponentId>(&self) {
+    pub fn emit<T: EmptyComponent + ComponentId>(&self) {
         self.emit_id(T::get_id(self.world));
     }
 
@@ -1783,7 +1783,7 @@ impl EntityView {
     ///
     /// * C++ API: `entity_view::emit`
     #[doc(alias = "entity_view::emit")]
-    pub fn emit_payload<T: EventData + NotEmptyComponent + ComponentId>(&self, payload: &mut T) {
+    pub fn emit_payload<T: NotEmptyComponent + ComponentId>(&self, payload: &mut T) {
         self.get_world()
             .event::<T>()
             .set_entity_to_emit(self.to_entity())
@@ -1818,7 +1818,7 @@ impl EntityView {
     ///
     /// * C++ API: `entity_view::enqueue`
     #[doc(alias = "entity_view::enqueue")]
-    pub fn enqueue<T: EventData + EmptyComponent + ComponentId>(&self) {
+    pub fn enqueue<T: EmptyComponent + ComponentId>(&self) {
         self.enqueue_id(T::get_id(self.world));
     }
 
@@ -1832,7 +1832,7 @@ impl EntityView {
     ///
     /// * C++ API: `entity_view::enqueue`
     #[doc(alias = "entity_view::enqueue")]
-    pub fn enqueue_payload<T: EventData + NotEmptyComponent + ComponentId>(&self, payload: &mut T) {
+    pub fn enqueue_payload<T: NotEmptyComponent + ComponentId>(&self, payload: &mut T) {
         self.get_world()
             .event::<T>()
             .set_entity_to_emit(self.to_entity())
@@ -1859,15 +1859,15 @@ impl EntityView {
     #[doc(alias = "entity_builder::observe")]
     pub fn observe<C>(&self, func: impl FnMut()) -> &Self
     where
-        C: EventData + ComponentId + EmptyComponent,
+        C: ComponentId + EmptyComponent,
     {
         self.observe_impl::<C, _>(func)
     }
 
     fn observe_impl<C, Func>(&self, func: Func) -> &Self
     where
         Func: FnMut(),
-        C: EventData + ComponentId,
+        C: ComponentId,
     {
         let new_binding_ctx = Box::<super::ObserverEntityBindingCtx>::default();
         let binding_ctx = Box::leak(new_binding_ctx);
@@ -1904,15 +1904,15 @@ impl EntityView {
     #[doc(alias = "entity_builder::observe")]
     pub fn observe_entity<C>(&self, func: impl FnMut(&mut Entity)) -> &Self
     where
-        C: EventData + ComponentId + EmptyComponent,
+        C: ComponentId + EmptyComponent,
     {
         self.observe_entity_impl::<C, _>(func)
     }
 
     fn observe_entity_impl<C, Func>(&self, func: Func) -> &Self
     where
         Func: FnMut(&mut Entity),
-        C: EventData + ComponentId,
+        C: ComponentId,
     {
         let new_binding_ctx = Box::<super::ObserverEntityBindingCtx>::default();
         let binding_ctx = Box::leak(new_binding_ctx);
@@ -1949,15 +1949,15 @@ impl EntityView {
     #[doc(alias = "entity_builder::observe")]
     pub fn observe_payload<C>(&self, func: impl FnMut(&mut C)) -> &Self
     where
-        C: EventData + ComponentId + NotEmptyComponent,
+        C: ComponentId + NotEmptyComponent,
     {
         self.observe_payload_impl::<C, _>(func)
     }
 
     fn observe_payload_impl<C, Func>(&self, func: Func) -> &Self
     where
         Func: FnMut(&mut C),
-        C: EventData + ComponentId,
+        C: ComponentId,
     {
         let new_binding_ctx = Box::<super::ObserverEntityBindingCtx>::default();
         let binding_ctx = Box::leak(new_binding_ctx);
@@ -1994,15 +1994,15 @@ impl EntityView {
     #[doc(alias = "entity_builder::observe")]
     pub fn observe_payload_entity<C>(&self, func: impl FnMut(&mut Entity, &mut C)) -> &Self
     where
-        C: EventData + ComponentId + NotEmptyComponent,
+        C: ComponentId + NotEmptyComponent,
     {
         self.observe_payload_entity_impl::<C, _>(func)
     }
 
     fn observe_payload_entity_impl<C, Func>(&self, func: Func) -> &Self
     where
         Func: FnMut(&mut Entity, &mut C),
-        C: EventData + ComponentId,
+        C: ComponentId,
     {
         let new_binding_ctx = Box::<super::ObserverEntityBindingCtx>::default();
         let binding_ctx = Box::leak(new_binding_ctx);

flecs_ecs/src/core/event.rs

@@ -6,11 +6,6 @@ use super::{
     ecs_pair, ComponentId, EventBuilder, IntoComponentId, IntoEntityId, IntoEntityIdExt, IntoTable,
 };
 
-/// Trait to mark component structs as `EventData` to be used in `EventBuilderTyped`.
-/// This is used to set the event data for the event to be emitted
-/// this is to ensure that the event data is of the correct type and the component is meant to be used with `EventBuilderTyped`
-pub trait EventData {}
-
 /// Event builder trait to implement '`set_event_data`' for untyped and typed `EventBuilder`
 pub trait EventBuilderImpl {
     type BuiltType;

flecs_ecs/src/core/event_builder.rs

@@ -8,7 +8,7 @@ use crate::sys::{ecs_event_desc_t, FLECS_EVENT_DESC_MAX};
 use super::{
     c_types::{IdT, TypeT},
     component_registration::ComponentId,
-    event::{EventBuilderImpl, EventData},
+    event::EventBuilderImpl,
     world::World,
     IntoEntityId,
 };
@@ -93,12 +93,12 @@ impl EventBuilderImpl for EventBuilder {
 /// Ensures the use of appropriate data types for events, enhancing type safety and data integrity.
 /// This design aims to prevent the utilization of incompatible components as event data,
 /// thereby ensuring greater explicitness and correctness in event handling.
-pub struct EventBuilderTyped<'a, T: EventData + ComponentId> {
+pub struct EventBuilderTyped<'a, T: ComponentId> {
     pub(crate) builder: EventBuilder,
     _phantom: std::marker::PhantomData<&'a T>,
 }
 
-impl<'a, T: EventData + ComponentId> EventBuilderTyped<'a, T> {
+impl<'a, T: ComponentId> EventBuilderTyped<'a, T> {
     /// Create a new typed `EventBuilder`
     ///
     /// # Arguments
@@ -121,7 +121,7 @@ impl<'a, T: EventData + ComponentId> EventBuilderTyped<'a, T> {
 /// The `Deref` trait is implemented to allow `EventBuilderTyped` instances to be treated as
 /// references to `EventBuilder`. This enables the use of `EventBuilder` methods directly on
 /// `EventBuilderTyped` instances.
-impl<'a, T: EventData + ComponentId> Deref for EventBuilderTyped<'a, T> {
+impl<'a, T: ComponentId> Deref for EventBuilderTyped<'a, T> {
     type Target = EventBuilder;
 
     fn deref(&self) -> &Self::Target {
@@ -130,15 +130,15 @@ impl<'a, T: EventData + ComponentId> Deref for EventBuilderTyped<'a, T> {
 }
 
 /// See `Deref` trait for more information.
-impl<'a, T: EventData + ComponentId> DerefMut for EventBuilderTyped<'a, T> {
+impl<'a, T: ComponentId> DerefMut for EventBuilderTyped<'a, T> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         &mut self.builder
     }
 }
 
-impl<'a, T: EventData + ComponentId> EventBuilderImpl for EventBuilderTyped<'a, T>
+impl<'a, T: ComponentId> EventBuilderImpl for EventBuilderTyped<'a, T>
 where
-    T: EventData + ComponentId,
+    T: ComponentId,
 {
     type BuiltType = &'a mut T;
     type ConstBuiltType = &'a T;

flecs_ecs/src/core/world.rs

@@ -46,7 +46,6 @@ use super::{EmptyComponent, NotEmptyComponent};
 use super::{
     ecs_pair,
     entity::Entity,
-    event::EventData,
     event_builder::{EventBuilder, EventBuilderTyped},
     id::Id,
     iterable::Iterable,
@@ -3055,7 +3054,7 @@ impl World {
     ///
     /// * C++ API: `world::event`
     #[doc(alias = "world::event")]
-    pub fn event<T: EventData + ComponentId>(&self) -> EventBuilderTyped<T> {
+    pub fn event<T: ComponentId>(&self) -> EventBuilderTyped<T> {
         EventBuilderTyped::<T>::new(self, T::get_id(self.raw_world))
     }
 }