Collects the members of one radio group under root into out, in scene
order, and returns it.
A radio joins when its RadioButton.group matches, it is not disabled,
and it is not disposed; the walk prunes at any node that is visible = false
or enabled = false, so a hidden branch contributes nobody. Scene order —
not tabIndex order — because this is the order arrow keys move in and the
order a group reads in; a group whose keyboard order disagreed with its
visual order would be a worse bug than one that ignores an author's
tabIndex.
Zero-alloc when out is supplied: it is overwritten and truncated.
Collects the members of one radio group under
rootintoout, in scene order, and returns it.A radio joins when its RadioButton.group matches, it is not disabled, and it is not disposed; the walk prunes at any node that is
visible = falseorenabled = false, so a hidden branch contributes nobody. Scene order — nottabIndexorder — because this is the order arrow keys move in and the order a group reads in; a group whose keyboard order disagreed with its visual order would be a worse bug than one that ignores an author'stabIndex.Zero-alloc when
outis supplied: it is overwritten and truncated.