repeatOnLifecycle<T> method

void repeatOnLifecycle<T>({ LifecycleState targetState = LifecycleState.started, bool runWithDelayed = false, bool ignoreBlockError = false, Cancellable? cancellable, required FutureOr<T> block(Cancellable cancellable), })

当高于某个状态时执行给定的block

• ignoreBlockError是否忽略错误 值为 false 时直接报错

Implementation

void repeatOnLifecycle<T>(
    {LifecycleState targetState = LifecycleState.started,
    bool runWithDelayed = false,
    bool ignoreBlockError = false,
    Cancellable? cancellable,
    required FutureOr<T> Function(Cancellable cancellable) block}) {
  if (cancellable?.isUnavailable == true) return;
  Cancellable? checkable;
  final observer = LifecycleObserver.stateChange((state) async {
    if (state >= targetState &&
        (checkable == null || checkable?.isUnavailable == true)) {
      final able = makeLiveCancellable(other: cancellable);
      checkable = able;
      try {
        if (runWithDelayed) {
          //转到下一个事件循环，可以过滤掉连续的状态变化
          await Future.delayed(Duration.zero);
        }
        if (able.isUnavailable) return;
        final result = block(able);
        if (result is Future<T>) {
          await Future.delayed(Duration.zero);
          if (able.isAvailable) await result;
        }
      } catch (exception, stack) {
        if (!ignoreBlockError) {
          FlutterError.reportError(FlutterErrorDetails(
            exception: exception,
            stack: stack,
            library: 'an_lifecycle_cancellable',
            context: ErrorDescription('repeatOnLifecycle run block error'),
          ));
        }
      }
    } else if (state < targetState && checkable?.isAvailable == true) {
      checkable?.cancel();
      checkable = null;
    }
  });
  addLifecycleObserver(observer, fullCycle: true);
  cancellable?.onCancel
      .then((value) => removeLifecycleObserver(observer, fullCycle: false));
}