Function section_expanded 

pub fn section_expanded(
    is_expanded: &BoundState<bool>,
    header: View,
    content: View,
) -> View

Section(isExpanded:) { … } header: { … } — a section that collapses.

The disclosure state is bound to Rust state rather than given as an initial value, so the section opens and closes by itself and whatever else reads that state sees it.

let open = BoundState::new(true);
let s = section_expanded(&open, text("Advanced"), text("the details"));