Add event handler methods to the engine structure

engine/src/engine.rs

@@ -56,6 +56,18 @@ impl EngineTrait for Engine {
         }
     }
 
+    fn handle_event(&mut self, platform_context: PlatformContext) {
+        let mut ctx = SystemContext {
+            scene: self.scene_manager.current_mut(),
+            platform_context,
+            debug_ui_buffer: self.debug_ui_buffer.clone(),
+        };
+
+        for system in self.system_manager.systems.values_mut() {
+            system.handle_event(&mut ctx);
+        }
+    }
+
     // pub fn build_system_context(&mut self) -> SystemContext {
     //     SystemContext {
     //         scene: self.scene_manager.current_mut(),

engine/src/system.rs

@@ -18,6 +18,7 @@ pub trait System {
     fn initialize(&mut self) {}
     /// Spawn the first entities of the world.
     fn load_world(&mut self, _ctx: &mut SystemContext) {}
+    fn handle_event(&mut self, _ctx: &mut SystemContext) {}
     fn update(&mut self, _ctx: &mut SystemContext) {}
 }
 
@@ -40,4 +41,4 @@ impl SystemManager {
     pub fn remove<S: 'static>(&mut self) {
         self.systems.shift_remove(&TypeId::of::<S>());
     }
-}
+}