Accessibility

Assistive technology, such as VoiceOver on macOS, Orca on Linux and Narrator or NVDA on Windows, reads a window's native UI as it reads other apps: the widgets with their roles, names, values and states, the texts, and the elements that take the focus, as the content changes. It acts on them as the keyboard and the pointer would: it presses buttons, checks boxes, moves sliders, edits text inputs and moves the focus.

Names

Widgets describe themselves, and the text inside an element names it, as a button's does. Elements without text need a Label, which also finds them in tests:

ui.Slider(c, &app.volume, 0, 100).Label("Volume")
ui.TextInput(c, &app.query).Placeholder("Search").Label("Search")
ui.Box(c).Size(24, 24).Draw(drawIcon).Label("Unread messages")

A field names its control with its label.

Roles

Other elements get a role from what they do: one that is clickable and takes the focus is a button, a scroll container a scroll area, and one with a Label, or that takes the focus, a group. Role sets it for an element drawn as a widget it is not built from, and ui.RoleNone leaves an element out but not its children:

toggle := ui.Box(c).Size(36, 20).Focusable().Role(ui.RoleSwitch).Label("Wi-Fi")

Descriptions and errors

Description tells more than the name, as help text read after it, as a tooltip does, and Error marks a value as invalid, for a message read with it; a field gives its control the texts below it.

Lists and tables

A list's rows are list items, and a table's rows, named by the text inside them, and each says which of all the rows it is, "5 of 10,000", although the list builds only those in view. A list choosing its rows gives assistive technology the focus on the row chosen: Up and Down are read as they move the choice, and focusing a row chooses it. A screen reader moving out of view asks the list to scroll there, which builds the rows it reaches. Label names a list or a table.

Announcements

News that does not move the focus, as a search done or a file saved, reaches screen readers with c.Announce(text), which they read once, after what they are reading: VoiceOver's and Orca's announcements, and a live region that Narrator and NVDA read on Windows. Toasts announce their text, and a router the title of a page shown while the focus stays outside it.

if ui.Button(c, "Search").Clicked() {
	app.results = search(app.query)
	c.Announce(fmt.Sprintf("%d results", len(app.results)))
}

MyGo describes frames only once assistive technology asked, so apps pay nothing for it otherwise.

Each component's page says what assistive technology sees of it.