message: example: Refactor event loop handling for continuous redraw
  Switch to continuous redrawing using `Poll` and `MainEventsCleared`.
  Fixes hangs in case of non-Mailbox present modes.
diff: @@ -184,9 +184,9 @@ impl ExampleBase {
  self.event_loop
  .borrow_mut()
  .run_return(|event, _, control_flow| {
  - *control_flow = ControlFlow::Wait;
  - f();
  - if let Event::WindowEvent {
  + *control_flow = ControlFlow::Poll;
  + match event {
  + Event::WindowEvent {
  event:
  WindowEvent::CloseRequested
  | WindowEvent::KeyboardInput {
  @@ -199,9 +199,9 @@ impl ExampleBase {
  ..
  },
  ..
  - } = event
  - {
  - *control_flow = ControlFlow::Exit
  + } => *control_flow = ControlFlow::Exit,
  + Event::MainEventsCleared => f(),
  + _ => (),
  }
  });
  }
  