Class CellMeasurerCache

source/CellMeasurer/CellMeasurerCache.js:33–223

 * Caches measurements for a given cell.
 */
export default class CellMeasurerCache implements CellMeasureCache {
  _cellHeightCache: Cache = {};
  _cellWidthCache: Cache = {};
  _columnWidthCache: Cache = {};
  _rowHeightCache: Cache = {};
  _defaultHeight: number;
  _defaultWidth: number;
  _minHeight: number;
  _minWidth: number;
  _keyMapper: KeyMapper;
  _hasFixedHeight: boolean;
  _hasFixedWidth: boolean;
  _columnCount = 0;
  _rowCount = 0;

  constructor(params: CellMeasurerCacheParams = {}) {
    const {
      defaultHeight,
      defaultWidth,
      fixedHeight,
      fixedWidth,
      keyMapper,
      minHeight,
      minWidth,
    } = params;

    this._hasFixedHeight = fixedHeight === true;
    this._hasFixedWidth = fixedWidth === true;
    this._minHeight = minHeight || 0;
    this._minWidth = minWidth || 0;
    this._keyMapper = keyMapper || defaultKeyMapper;

    this._defaultHeight = Math.max(
      this._minHeight,
      typeof defaultHeight === 'number' ? defaultHeight : DEFAULT_HEIGHT,
    );
    this._defaultWidth = Math.max(
      this._minWidth,
      typeof defaultWidth === 'number' ? defaultWidth : DEFAULT_WIDTH,
    );

    if (process.env.NODE_ENV !== 'production') {
      if (this._hasFixedHeight === false && this._hasFixedWidth === false) {
        console.warn(
          "CellMeasurerCache should only measure a cell's width or height. " +
            'You have configured CellMeasurerCache to measure both. ' +
            'This will result in poor performance.',
        );
      }

      if (this._hasFixedHeight === false && this._defaultHeight === 0) {
        console.warn(
          'Fixed height CellMeasurerCache should specify a :defaultHeight greater than 0. ' +
            'Failing to do so will lead to unnecessary layout and poor performance.',
        );
      }

      if (this._hasFixedWidth === false && this._defaultWidth === 0) {