Function useTabListState

packages/react-stately/src/tabs/useTabListState.ts:56–107

(props: TabListStateOptions<T>)

 * which tab is currently selected and displays the content associated with that Tab in a TabPanel.
 */
export function useTabListState<T extends object>(props: TabListStateOptions<T>): TabListState<T> {
  let state = useSingleSelectListState<T>({
    ...props,
    onSelectionChange: props.onSelectionChange
      ? key => {
          if (key != null) {
            props.onSelectionChange?.(key);
          }
        }
      : undefined,
    suppressTextValueWarning: true,
    defaultSelectedKey:
      props.defaultSelectedKey ??
      findDefaultSelectedKey(
        props.collection,
        props.disabledKeys ? new Set(props.disabledKeys) : new Set()
      ) ??
      undefined
  });

  let {selectionManager, collection, selectedKey: currentSelectedKey} = state;

  let lastSelectedKey = useRef(currentSelectedKey);
  useEffect(() => {
    // Ensure a tab is always selected (in case no selected key was specified or if selected item was deleted from collection)
    let selectedKey = currentSelectedKey;
    if (
      props.selectedKey == null &&
      (selectionManager.isEmpty || selectedKey == null || !collection.getItem(selectedKey))
    ) {
      selectedKey = findDefaultSelectedKey(collection, state.disabledKeys);
      if (selectedKey != null) {
        // directly set selection because replace/toggle selection won't consider disabled keys
        selectionManager.setSelectedKeys([selectedKey]);
      }
    }

    // If the tablist doesn't have focus and the selected key changes or if there isn't a focused key yet, change focused key to the selected key if it exists.
    if (
      (selectedKey != null && selectionManager.focusedKey == null) ||
      (!selectionManager.isFocused && selectedKey !== lastSelectedKey.current)
    ) {
      selectionManager.setFocusedKey(selectedKey);
    }
    lastSelectedKey.current = selectedKey;
  });

  return {
    ...state,
    isDisabled: props.isDisabled || false
  };
}

function findDefaultSelectedKey<T>(
  collection: Collection<Node<T>> | undefined,