@atlaskit/editor-plugin-table/dist/es2019/pm-plugins/active-cell-highlight/plugin.js

Table plugin for the @atlaskit/editor

import { SafePlugin } from '@atlaskit/editor-common/safe-plugin';
import { PluginKey } from '@atlaskit/editor-prosemirror/state';
import { Decoration, DecorationSet } from '@atlaskit/editor-prosemirror/view';
import { CellSelection } from '@atlaskit/editor-tables/cell-selection';
import { findCellClosestToPos } from '@atlaskit/editor-tables/utils';
import { TableCssClassName as ClassName } from '../../types';
const EMPTY_STATE = {
  cellPos: -1,
  decorationSet: DecorationSet.empty
};
export const activeCellHighlightPluginKey = new PluginKey('tableActiveCellHighlight');

/**
 * Returns the position of the cell containing the cursor, or -1 if the cursor
 * is not in a table cell or the selection is a CellSelection.
 */
const getActiveCellPos = state => {
  if (state.selection instanceof CellSelection) {
    return -1;
  }
  try {
    const cell = findCellClosestToPos(state.selection.$from);
    return cell ? cell.pos : -1;
  } catch {
    return -1;
  }
};
const buildState = (cellPos, state) => {
  if (cellPos === -1) {
    return EMPTY_STATE;
  }
  try {
    const cell = state.doc.nodeAt(cellPos);
    if (!cell) {
      return EMPTY_STATE;
    }
    const decoration = Decoration.node(cellPos, cellPos + cell.nodeSize, {
      class: ClassName.ACTIVE_CURSOR_CELL
    });
    return {
      cellPos,
      decorationSet: DecorationSet.create(state.doc, [decoration])
    };
  } catch {
    return EMPTY_STATE;
  }
};
export const createPlugin = () => {
  return new SafePlugin({
    key: activeCellHighlightPluginKey,
    state: {
      init: (_, state) => {
        return buildState(getActiveCellPos(state), state);
      },
      apply: (tr, prev, _oldState, newState) => {
        if (tr.docChanged) {
          // Doc changed — always rebuild since positions may have shifted
          return buildState(getActiveCellPos(newState), newState);
        }
        if (!tr.selectionSet) {
          // Neither doc nor selection changed — nothing to do
          return prev;
        }

        // Selection changed — only rebuild if cursor moved to a different cell
        const nextCellPos = getActiveCellPos(newState);
        if (nextCellPos === prev.cellPos) {
          return prev;
        }
        return buildState(nextCellPos, newState);
      }
    },
    props: {
      decorations: state => {
        var _activeCellHighlightP, _activeCellHighlightP2;
        return (_activeCellHighlightP = (_activeCellHighlightP2 = activeCellHighlightPluginKey.getState(state)) === null || _activeCellHighlightP2 === void 0 ? void 0 : _activeCellHighlightP2.decorationSet) !== null && _activeCellHighlightP !== void 0 ? _activeCellHighlightP : DecorationSet.empty;
      }
    }
  });
};