Spinner

ui.Spinner creates an indicator of work of unknown length, as AppKit's spinning progress indicator: spokes turning, in the theme's muted text color, a little higher than the theme's font size.

ui.Row(c).Gap(8).Children(func() {
	ui.Spinner(c).Label("Loading")
	ui.Text(c, "Loading messages…")
})

Size makes it larger, as Size(32, 32) in an empty view. It goes on turning when the desktop asks for less motion, as the system's spinners do: it shows that something is going on.

It turns only while it is in view, and costs only its painting: its spokes move twelve times a turn, and each time the window paints the last frame again without running the view.

Accessibility

Assistive technology sees a progress indicator of unknown length, named by its Label.