react-native-big-list-fixed/dist/commonjs/utils.js

A big and fast list implementation for react-native with a recycler API focused on performance and ram usage while processing thousand items on the list.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.processBlock = exports.mergeViewStyle = exports.isNumeric = exports.createElement = exports.autobind = void 0;
var _react = _interopRequireDefault(require("react"));
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
/**
 * Is numeric.
 * @param {any} num
 * @returns {boolean}
 */
const isNumeric = num => {
  return !isNaN(parseFloat(num)) && isFinite(num);
};

/**
 * Process block.
 * @param {number} containerHeight
 * @param {number} scrollTop
 * @param {number|null|undefined} batchSizeThreshold
 * @returns {{blockStart: number, batchSize: number, blockEnd: number}}
 */
exports.isNumeric = isNumeric;
const processBlock = ({
  containerHeight,
  scrollTop,
  batchSizeThreshold = 1
}) => {
  if (containerHeight === 0) {
    return {
      batchSize: 0,
      blockStart: 0,
      blockEnd: 0
    };
  }
  const batchSize = Math.ceil(containerHeight * Math.max(0.5, batchSizeThreshold));
  const blockNumber = Math.ceil(scrollTop / batchSize);
  const blockStart = batchSize * blockNumber;
  const blockEnd = blockStart + batchSize;
  return {
    batchSize,
    blockStart,
    blockEnd
  };
};

/**
 * Autobind context to class methods.
 * @param {object} self
 * @returns {{}}
 */
exports.processBlock = processBlock;
const autobind = (self = {}) => {
  const exclude = ["componentWillMount", /UNSAFE_.*/, "render", "getSnapshotBeforeUpdate", "componentDidMount", "componentWillReceiveProps", "shouldComponentUpdate", "componentWillUpdate", "componentDidUpdate", "componentWillUnmount", "componentDidCatch", "setState", "forceUpdate"];
  const filter = key => {
    const match = pattern => typeof pattern === "string" ? key === pattern : pattern.test(key);
    if (exclude) {
      return !exclude.some(match);
    }
    return true;
  };
  const getAllProperties = object => {
    const properties = new Set();
    do {
      for (const key of Object.getOwnPropertyNames(object).concat(Object.getOwnPropertySymbols(object))) {
        properties.add([object, key]);
      }
    } while ((object = Object.getPrototypeOf(object)) && object !== Object.prototype);
    return properties;
  };
  for (const [object, key] of getAllProperties(self.constructor.prototype)) {
    if (key === "constructor" || !filter(key)) {
      continue;
    }
    const descriptor = Object.getOwnPropertyDescriptor(object, key);
    if (descriptor && typeof descriptor.value === "function") {
      self[key] = self[key].bind(self);
    }
  }
  return self;
};

/**
 * Merge styles
 * @param {array|object|null|undefined} style
 * @param {array|object} defaultStyle
 * @returns {Object}
 */
exports.autobind = autobind;
const mergeViewStyle = (style, defaultStyle = {}) => {
  let mergedStyle = style;
  if (mergedStyle == null) {
    mergedStyle = defaultStyle;
  } else if (Array.isArray(style) && Array.isArray(defaultStyle)) {
    const mergedDefaultStyle = [...defaultStyle];
    mergedDefaultStyle.concat(style);
    mergedStyle = mergedDefaultStyle;
  } else if (Array.isArray(defaultStyle)) {
    const mergedDefaultStyle = [...defaultStyle];
    mergedDefaultStyle.push(style);
    mergedStyle = mergedDefaultStyle;
  } else if (Array.isArray(style)) {
    mergedStyle = [...style];
    mergedStyle.unshift(defaultStyle);
  } else {
    mergedStyle = [defaultStyle, style];
  }
  return mergedStyle;
};

/**
 * Get element from component.
 * @param {React.node} Component
 * @param props
 * @returns {JSX.Element|[]|*}
 */
exports.mergeViewStyle = mergeViewStyle;
const createElement = (Component, props = {}) => {
  return Component != null ? /*#__PURE__*/_react.default.isValidElement(Component) ? (/*#__PURE__*/_react.default.cloneElement(Component, props)) : /*#__PURE__*/_react.default.createElement(Component, props) : null;
};
exports.createElement = createElement;
//# sourceMappingURL=utils.js.map