I love control flow

src/bin/test/app.rs

@@ -0,0 +1,37 @@
+use winit::{
+    application::ApplicationHandler,
+    event::WindowEvent,
+    event_loop::{ActiveEventLoop, EventLoop},
+    window::{Window, WindowId},
+};
+
+use super::Client;
+
+#[derive(Default)]
+pub struct App {
+    client: Option<Client>,
+}
+
+impl App {
+    pub fn run() {
+        let event_loop = EventLoop::new().unwrap();
+        event_loop.run_app(&mut App::default()).unwrap();
+    }
+}
+
+impl ApplicationHandler for App {
+    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+        if self.client.is_none() {
+            let window = event_loop
+                .create_window(Window::default_attributes())
+                .unwrap();
+            let client = Client::new(window.into());
+            self.client = Some(client);
+        }
+    }
+
+    fn window_event(&mut self, event_loop: &ActiveEventLoop, _id: WindowId, event: WindowEvent) {
+        let client = self.client.as_mut().unwrap();
+        client.event(event, event_loop);
+    }
+}