Make add_container public again

[vladbat00]

I was using add_container as follows:

let continue_response =
    flex.add_container(egui_flex::item().grow(1.0), Box::new(|ui, container| {
        ui.add_enabled_ui(is_enabled, |ui| {
            container.content_widget(ui, egui::Button::new("[C] Restart"))
        })
        .inner
    }));

as a work-around for item growth not applying recursively to inner UI elements.

If I try to use the following code:

let continue_response = flex.add_ui(egui_flex::item().grow(1.0), |ui| {
    let is_enabled = time.elapsed() - *last_requested_respawn_at
        > Duration::from_secs_f32(RESPAWN_REQUEST_COOLDOWN_SECS);
    ui.add_enabled(is_enabled, egui::Button::new("[C] Restart"))
});

my UI looks like this (note the Restart button not occupying all the available width):

Probably there's a better solution for this particular problem, I'd appreciate it as well, but at this point maybe we could just make add_container public again.

[lucasmerlin]

Hmm, I'd really like to keep it private, since it is an implementaion detail at this point and I might want to remove it in a future version.
The reason you need this is that you'd like to disable the button you add, right?
How about adding a .disabled() or a .enabled(bool) function to the FlexItem?