useFocusWithin

Track focus within a keyed DOM subtree.

useFocusWithin reports whether the target itself or any descendant currently owns document focus.

Signature

bool? useFocusWithin(
  GlobalNodeKey<web.Element> target, {
  bool enabled = true,
});

final region = useNodeKey<web.HTMLDivElement>();
final focused = useFocusWithin(region);
return div(key: region, [input(), button([.text('Save')])]);

Interactive useFocusWithin demo

Focus within: waiting

The hook listens to bubbling focus transitions and cleans up automatically.

The result is null during SSR and before post-frame attachment.

Do not confuse focus-within with hover. Disabling the hook resets its value to null.

Use useFocus to request focus and useActiveElement to inspect the focused node.