供 React Native 等环境使用的 Scheduler

让调度程序在 React Native 运行更稳定。

一、兼容性支持

兼容性导出

declare const nativeRuntimeScheduler: void | NativeSchedulerType;

export const unstable_UserBlockingPriority: PriorityLevels['UserBlockingPriority'] =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_UserBlockingPriority
    : Scheduler.unstable_UserBlockingPriority;

export const unstable_NormalPriority: PriorityLevels['NormalPriority'] =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_NormalPriority
    : Scheduler.unstable_NormalPriority;

export const unstable_IdlePriority: PriorityLevels['IdlePriority'] =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_IdlePriority
    : Scheduler.unstable_IdlePriority;

export const unstable_LowPriority: PriorityLevels['LowPriority'] =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_LowPriority
    : Scheduler.unstable_LowPriority;

export const unstable_ImmediatePriority: PriorityLevels['ImmediatePriority'] =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_ImmediatePriority
    : Scheduler.unstable_ImmediatePriority;

export const unstable_scheduleCallback: (
  priorityLevel: PriorityLevel,
  callback: Callback,
) => Task =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_scheduleCallback
    : Scheduler.unstable_scheduleCallback;

export const unstable_cancelCallback: (task: Task) => void =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_cancelCallback
    : Scheduler.unstable_cancelCallback;

export const unstable_getCurrentPriorityLevel: () => PriorityLevel =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_getCurrentPriorityLevel
    : Scheduler.unstable_getCurrentPriorityLevel;

export const unstable_shouldYield: () => boolean =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_shouldYield
    : Scheduler.unstable_shouldYield;

export const unstable_requestPaint: () => void =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_requestPaint
    : Scheduler.unstable_requestPaint;

export const unstable_now: () => number | DOMHighResTimeStamp =
  typeof nativeRuntimeScheduler !== 'undefined'
    ? nativeRuntimeScheduler.unstable_now
    : Scheduler.unstable_now;

二、不支持功能将抛出错误

// These were never implemented on the native scheduler because React never calls them.
// 这些从未在本地调度器上实现过，因为 React 从未调用它们。
// For consistency, let's disable them altogether and make them throw.
// 为了一致性，我们完全禁用它们，并使其抛出异常。
export const unstable_next: any = throwNotImplemented;
export const unstable_runWithPriority: any = throwNotImplemented;
export const unstable_wrapCallback: any = throwNotImplemented;
export const unstable_forceFrameRate: any = throwNotImplemented;
export const unstable_Profiling: any = null;

function throwNotImplemented() {
  throw Error('Not implemented.');
}