Accordion

ui.Accordion creates sections, one above the other in a bordered box, that ui.AccordionItem builds: a header showing a title, which a click opens and closes, as do Enter and Space, and below it what its function builds while its *bool is true. Each opens and closes on its own; Up and Down move the focus between their headers, as do Home and End. An item's Changed reports a click.

ui.Accordion(c, func() {
	ui.AccordionItem(c, "General", &app.general, func() { app.generalSettings(c) })
	ui.AccordionItem(c, "Privacy", &app.privacy, func() { app.privacySettings(c) })
	ui.AccordionItem(c, "Advanced", &app.advanced, func() { app.advancedSettings(c) })
})

For one section open at a time, close the others as one opens:

for i, s := range sections {
	open := app.section == i
	if ui.AccordionItem(c, s.Title, &open, s.Build).Changed() {
		app.section = -1
		if open {
			app.section = i
		}
	}
}

Tab goes from a header into the content of its section while it is open.

Accessibility

Assistive technology sees each header as a disclosure, expanded or collapsed, before the content of its section.