VisibilityDetector constructor
const
VisibilityDetector({
- required Key key,
- required Widget child,
- required VisibilityChangedCallback? onVisibilityChanged,
Constructor.
key
is required to properly identify this widget; it must be unique
among all VisibilityDetector and SliverVisibilityDetector widgets.
onVisibilityChanged
may be null
to disable this VisibilityDetector.
Implementation
const VisibilityDetector({
required Key key,
required Widget child,
required this.onVisibilityChanged,
}) : assert(key != null),
assert(child != null),
super(key: key, child: child);