how do I make eventing extensible without cluttering this file with standalone functions

src/event_system.rs

@@ -0,0 +1,64 @@
+use std::sync::Arc;
+
+use specs::{Component, Entities, Join, System, VecStorage, Write, WriteStorage};
+use vulkano::swapchain::Surface;
+use winit::window::Window;
+
+use crate::canvas::canvas_frame::CanvasFrame;
+use crate::canvas::compu_frame::CompuFrame;
+use crate::PersistentState;
+use crate::render_system::Position;
+use crate::util::tr_event::{TrEvent, TrEventExtension, TrWindowEvent};
+use crate::vkprocessor::VkProcessor;
+use winit::event::ElementState;
+
+#[derive(Debug, Clone)]
+pub struct Evented {
+    pub subscribed: fn(event: TrEvent<TrEventExtension>) -> bool,
+}
+
+impl Component for Evented {
+    type Storage = VecStorage<Self>;
+}
+
+pub struct EventSystem;
+
+impl<'a> System<'a> for EventSystem {
+    type SystemData = (
+        Entities<'a>,
+        WriteStorage<'a, Position>,
+        WriteStorage<'a, Evented>,
+        Write<'a, PersistentState>,
+        Write<'a, VkProcessor>,
+        Write<'a, Vec<TrEvent<TrEventExtension>>>
+    );
+
+    fn run(&mut self, (
+        entity,
+        mut position_list,
+        mut evented_list,
+        mut state,
+        mut vk_processor,
+        event_stack
+    ): Self::SystemData) {
+
+        for (position, evented) in (&mut position_list, &evented_list).join() {
+            for event in &*event_stack {
+                match event {
+                    TrEvent::WindowEvent { window_id, event } => {
+                        match event {
+                            TrWindowEvent::MouseInput { device_id, state, button, modifiers } => {
+                                if *state == ElementState::Pressed {
+                                    position.x += 100.0;
+                                }
+                            },
+                            _ => {}
+                        }
+                    }
+                    _ => {}
+                }
+            }
+        }
+        for (entity, evented) in (&*entity, &mut evented_list).join() {}
+    }
+}