Function on_entity 

pub fn on_entity<V, O, F>(
    entity: &Entity<V>,
    f: F,
) -> OnUi<impl Fn(&mut App) -> Result<O, ActionError> + Send + Sync + 'static>
where
    V: 'static,
    O: Into<Outcome> + Send + 'static,
    F: Fn(&mut V, &mut Context<'_, V>) -> Result<O, ActionError> + Send + Sync + 'static,

Build a parameterless action that mutates a gpui [Entity] on the main thread, exactly like a button’s cx.listener.

The returned value is what ActionBuilder::on accepts (it builds on on_ui(|cx|)).

win.actions().add("increment", "Increment").on(on_entity(&counter, |c, cx| {
    c.bump(1, cx);
    Ok::<_, ActionError>(Outcome::message(format!("count = {}", c.count)))
}));