Function createLoadingState

packages/core/src/widgets/tree.ts:396–417

(initial: readonly string[] = [])

 * @returns LoadingState object
 */
export function createLoadingState(initial: readonly string[] = []): LoadingState {
  const loading = new Set(initial);

  const state: LoadingState = Object.freeze({
    loading: loading as ReadonlySet<string>,
    startLoading: (key: string): LoadingState => {
      if (loading.has(key)) {
        return state;
      }
      return createLoadingState([...loading, key]);
    },
    finishLoading: (key: string): LoadingState => {
      if (!loading.has(key)) {
        return state;
      }
      return createLoadingState([...loading].filter((k) => k !== key));
    },
    isLoading: (key: string): boolean => loading.has(key),
  });

  return state;
}

/* ========== Expand/Collapse Indicators ========== */