use-visibility/throttle.js

React hook to check component visibility

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;

function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }

var nativeMax = Math.max;
var nativeMin = Math.min;

function debounce(func, wait, options) {
  var lastArgs,
      lastThis,
      maxWait,
      result,
      timerId,
      lastCallTime,
      lastInvokeTime = 0,
      leading = false,
      maxing = false,
      trailing = true;

  if (typeof func !== 'function') {
    throw new TypeError(FUNC_ERROR_TEXT);
  }

  wait = Number(wait) || 0;

  if (_typeof(options) === 'object') {
    leading = !!options.leading;
    maxing = 'maxWait' in options;
    maxWait = maxing ? nativeMax(Number(options.maxWait) || 0, wait) : maxWait;
    trailing = 'trailing' in options ? !!options.trailing : trailing;
  }

  function invokeFunc(time) {
    var args = lastArgs,
        thisArg = lastThis;
    lastArgs = lastThis = undefined;
    lastInvokeTime = time;
    result = func.apply(thisArg, args);
    return result;
  }

  function leadingEdge(time) {
    // Reset any `maxWait` timer.
    lastInvokeTime = time; // Start the timer for the trailing edge.

    timerId = setTimeout(timerExpired, wait); // Invoke the leading edge.

    return leading ? invokeFunc(time) : result;
  }

  function remainingWait(time) {
    var timeSinceLastCall = time - lastCallTime,
        timeSinceLastInvoke = time - lastInvokeTime,
        result = wait - timeSinceLastCall;
    console.log('remainingWait');
    return maxing ? nativeMin(result, maxWait - timeSinceLastInvoke) : result;
  }

  function shouldInvoke(time) {
    var timeSinceLastCall = time - lastCallTime,
        timeSinceLastInvoke = time - lastInvokeTime; // Either this is the first call, activity has stopped and we're at the trailing
    // edge, the system time has gone backwards and we're treating it as the
    // trailing edge, or we've hit the `maxWait` limit.

    return lastCallTime === undefined || timeSinceLastCall >= wait || timeSinceLastCall < 0 || maxing && timeSinceLastInvoke >= maxWait;
  }

  function timerExpired() {
    var time = Date.now();

    if (shouldInvoke(time)) {
      return trailingEdge(time);
    } // Restart the timer.


    timerId = setTimeout(timerExpired, remainingWait(time));
  }

  function trailingEdge(time) {
    timerId = undefined; // Only invoke if we have `lastArgs` which means `func` has been debounced at
    // least once.

    if (trailing && lastArgs) {
      return invokeFunc(time);
    }

    lastArgs = lastThis = undefined;
    return result;
  }

  function cancel() {
    if (timerId !== undefined) {
      clearTimeout(timerId);
    }

    lastInvokeTime = 0;
    lastArgs = lastCallTime = lastThis = timerId = undefined;
  }

  function flush() {
    return timerId === undefined ? result : trailingEdge(Date.now());
  }

  function debounced() {
    var time = Date.now(),
        isInvoking = shouldInvoke(time);
    lastArgs = arguments;
    lastThis = this;
    lastCallTime = time;

    if (isInvoking) {
      if (timerId === undefined) {
        return leadingEdge(lastCallTime);
      }

      if (maxing) {
        // Handle invocations in a tight loop.
        timerId = setTimeout(timerExpired, wait);
        return invokeFunc(lastCallTime);
      }
    }

    if (timerId === undefined) {
      timerId = setTimeout(timerExpired, wait);
    }

    return result;
  }

  debounced.cancel = cancel;
  debounced.flush = flush;
  return debounced;
}

function throttle(func, wait, options) {
  var leading = true,
      trailing = true;

  if (typeof func !== 'function') {
    throw new TypeError(FUNC_ERROR_TEXT);
  }

  if (_typeof(options) === 'object') {
    leading = 'leading' in options ? !!options.leading : leading;
    trailing = 'trailing' in options ? !!options.trailing : trailing;
  }

  return debounce(func, wait, {
    leading: leading,
    maxWait: wait,
    trailing: trailing
  });
}

var _default = throttle;
exports["default"] = _default;