message: Propagate `Button` events to contents
diff: @@ -161,9 +161,20 @@ where
  layout: Layout<'_>,
  cursor_position: Point,
  messages: &mut Vec<Message>,
  - _renderer: &Renderer,
  - _clipboard: Option<&dyn Clipboard>,
  + renderer: &Renderer,
  + clipboard: Option<&dyn Clipboard>,
  ) -> event::Status {
  + if let event::Status::Captured = self.content.on_event(
  + event.clone(),
  + layout.children().next().unwrap(),
  + cursor_position,
  + messages,
  + renderer,
  + clipboard,
  + ) {
  + return event::Status::Captured;
  + }
  +
  match event {
  Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
  | Event::Touch(touch::Event::FingerPressed { .. }) => {
  