refun/node/on-layout.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.onLayout = void 0;

var _react = require("react");

var _tsfn = require("tsfn");

var _utils = require("./utils");

const onLayout = (onLayoutHandler, watchKeys) => props => {
  const propsRef = (0, _react.useRef)(_tsfn.EMPTY_OBJECT);
  const useEffectFnRef = (0, _react.useRef)(_tsfn.NOOP);
  const watchValuesRef = (0, _react.useRef)(_tsfn.EMPTY_ARRAY);

  if (watchValuesRef.current === _tsfn.EMPTY_ARRAY || !(0, _utils.shallowEqualByKeys)(propsRef.current, props, watchKeys)) {
    watchValuesRef.current = watchKeys.map(k => props[k]);
  }

  propsRef.current = props;

  if (useEffectFnRef.current === _tsfn.NOOP) {
    useEffectFnRef.current = () => {
      return onLayoutHandler(propsRef.current);
    };
  }

  (0, _react.useLayoutEffect)(useEffectFnRef.current, watchValuesRef.current);
  return props;
};

exports.onLayout = onLayout;