@itwin/itwinui-react/esm/core/Table/hooks/useStickyColumns.js

A react component library for iTwinUI

import { actions } from 'react-table';
actions.setScrolledLeft = 'setScrolledLeft';
actions.setScrolledRight = 'setScrolledRight';
export const useStickyColumns = (hooks) => {
  hooks.stateReducers.push(reducer);
  hooks.useInstance.push(useInstance);
};
let reducer = (newState, action) => {
  if (action.type === actions.init)
    return {
      ...newState,
      sticky: {},
    };
  if (
    action.type === actions.setScrolledLeft &&
    newState.sticky?.isScrolledToLeft !== action.value
  )
    return {
      ...newState,
      sticky: {
        ...newState.sticky,
        isScrolledToLeft: action.value,
      },
    };
  if (
    action.type === actions.setScrolledRight &&
    newState.sticky?.isScrolledToRight !== action.value
  )
    return {
      ...newState,
      sticky: {
        ...newState.sticky,
        isScrolledToRight: action.value,
      },
    };
  return newState;
};
let useInstance = (instance) => {
  let { flatHeaders } = instance;
  flatHeaders.forEach((header) => {
    if (!header.originalSticky) header.originalSticky = header.sticky ?? 'none';
    header.sticky =
      'none' === header.originalSticky ? void 0 : header.originalSticky;
  });
  let hasLeftStickyColumn = false;
  [...flatHeaders].reverse().forEach((header) => {
    if ('left' === header.sticky) hasLeftStickyColumn = true;
    if (hasLeftStickyColumn) header.sticky = 'left';
  });
  let hasRightStickyColumn = false;
  flatHeaders.forEach((header) => {
    if ('right' === header.sticky) hasRightStickyColumn = true;
    if (hasRightStickyColumn) header.sticky = 'right';
  });
};