react-virtualized/dist/commonjs/Grid/utils/calculateSizeAndPositionDataAndUpdateScrollOffset.js

React components for efficiently rendering large, scrollable lists and tabular data

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = calculateSizeAndPositionDataAndUpdateScrollOffset;
/**
 * Helper method that determines when to recalculate row or column metadata.
 *
 * @param cellCount Number of rows or columns in the current axis
 * @param cellsSize Width or height of cells for the current axis
 * @param computeMetadataCallback Method to invoke if cell metadata should be recalculated
 * @param computeMetadataCallbackProps Parameters to pass to :computeMetadataCallback
 * @param nextCellsCount Newly updated number of rows or columns in the current axis
 * @param nextCellsSize Newly updated width or height of cells for the current axis
 * @param nextScrollToIndex Newly updated scroll-to-index
 * @param scrollToIndex Scroll-to-index
 * @param updateScrollOffsetForScrollToIndex Callback to invoke if the scroll position should be recalculated
 */
function calculateSizeAndPositionDataAndUpdateScrollOffset(_ref) {
  var cellCount = _ref.cellCount;
  var cellSize = _ref.cellSize;
  var computeMetadataCallback = _ref.computeMetadataCallback;
  var computeMetadataCallbackProps = _ref.computeMetadataCallbackProps;
  var nextCellsCount = _ref.nextCellsCount;
  var nextCellSize = _ref.nextCellSize;
  var nextScrollToIndex = _ref.nextScrollToIndex;
  var scrollToIndex = _ref.scrollToIndex;
  var updateScrollOffsetForScrollToIndex = _ref.updateScrollOffsetForScrollToIndex;

  // Don't compare cell sizes if they are functions because inline functions would cause infinite loops.
  // In that event users should use the manual recompute methods to inform of changes.
  if (cellCount !== nextCellsCount || (typeof cellSize === 'number' || typeof nextCellSize === 'number') && cellSize !== nextCellSize) {
    computeMetadataCallback(computeMetadataCallbackProps);

    // Updated cell metadata may have hidden the previous scrolled-to item.
    // In this case we should also update the scrollTop to ensure it stays visible.
    if (scrollToIndex >= 0 && scrollToIndex === nextScrollToIndex) {
      updateScrollOffsetForScrollToIndex();
    }
  }
}