events: implement a first attempt at an eventing system

src/animations.rs

@@ -2,6 +2,7 @@ use palette::Hsv;
 
 use rgb::RGB8;
 
+use crate::events::{Event, EventBus};
 use crate::time::Periodically;
 use crate::geometry::*;
 use crate::render::{Shader, Surface, Surfaces};
@@ -75,7 +76,7 @@ impl<T: Surface> Task for IdleTask<T> {
         self.shimmer.set_opacity(64);
     }
 
-    fn tick(&mut self) {}
+    fn tick(&mut self, event: &Event, bus: &mut EventBus) {}
 
     fn stop(&mut self) {
         self.solid.clear_shader();
@@ -172,7 +173,7 @@ impl<T: Surface> Task for TestPattern<T> {
         self.surface.set_shader(Box::new(self.pattern.clone()));
     }
 
-    fn tick(&mut self) {
+    fn tick(&mut self, event: &Event, bus: &mut EventBus) {
         self.updater.run(|| {
             self.pattern = self.pattern.next();
             log::info!("Test pattern: {:?}", self.pattern);