refun/node/map-throttled-handler.js

A collection of React Hook-enabled functions that compose harmoniously with each other. Similar to `recompose`, but:

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.mapThrottledHandlerAnimationFrame = exports.mapThrottledHandlerTimeout = exports.mapThrottledHandlerFactory = void 0;

var _react = require("react");

var _tsfn = require("tsfn");

const mapThrottledHandlerFactory = (setFn, clearFn) => (handlerName, ...setFnArgs) => props => {
  const timerId = (0, _react.useRef)(null);
  const throttledHandlerRef = (0, _react.useRef)();
  const onUnmountRef = (0, _react.useRef)();
  const currentPropsHandlerRef = (0, _react.useRef)();
  const handlerArgsRef = (0, _react.useRef)(_tsfn.EMPTY_ARRAY);
  currentPropsHandlerRef.current = props[handlerName];

  if (throttledHandlerRef.current === _tsfn.UNDEFINED) {
    const timeoutCallback = () => {
      timerId.current = null;

      if ((0, _tsfn.isFunction)(currentPropsHandlerRef.current)) {
        currentPropsHandlerRef.current(...handlerArgsRef.current);
      }
    };

    throttledHandlerRef.current = (...args) => {
      handlerArgsRef.current = args;

      if (timerId.current === null && (0, _tsfn.isFunction)(currentPropsHandlerRef.current)) {
        timerId.current = setFn(timeoutCallback, ...setFnArgs);
      }
    };

    onUnmountRef.current = () => () => {
      if (timerId.current !== null) {
        clearFn(timerId.current);
        timerId.current = null;
      }
    };
  }

  (0, _react.useEffect)(onUnmountRef.current, _tsfn.EMPTY_ARRAY);
  return { ...props,
    [handlerName]: throttledHandlerRef.current
  };
};

exports.mapThrottledHandlerFactory = mapThrottledHandlerFactory;
const mapThrottledHandlerTimeout = mapThrottledHandlerFactory(setTimeout, clearTimeout);
exports.mapThrottledHandlerTimeout = mapThrottledHandlerTimeout;
const mapThrottledHandlerAnimationFrame = mapThrottledHandlerFactory(_tsfn.requestAnimationFrame, _tsfn.cancelAnimationFrame);
exports.mapThrottledHandlerAnimationFrame = mapThrottledHandlerAnimationFrame;