Whether the semantics node is considered hidden.
Hidden elements are currently not visible on screen. They may be covered by other elements or positioned outside of the visible area of a viewport.
Hidden elements cannot gain accessibility focus though regular touch. The only way they can be focused is by moving the focus to them via linear navigation.
Platforms are free to completely ignore hidden elements and new platforms are encouraged to do so.
Instead of marking an element as hidden it should usually be excluded from the semantics tree altogether. Hidden elements are only included in the semantics tree to work around platform limitations and they are mainly used to implement accessibility scrolling on iOS.
static const SemanticsFlag isHidden = SemanticsFlag._(_kIsHiddenIndex);