@atlaskit/editor-plugin-list/dist/es2019/pm-plugins/actions/move-selected-list-items.js

List plugin for @atlaskit/editor-core

import { computeSelectionOffsets, narrowReplacementRange, restoreSelection } from '@atlaskit/editor-common/lists';
import { MAX_NESTED_LIST_INDENTATION } from '../../types';
import { findFirstParentListNode, findRootParentListNode } from '../utils/find';
import { buildReplacementFragment, flattenList } from '../utils/list-indentation';

/**
 * Moves the selected list items n levels up (negative delta) or down (positive delta).
 */
export function moveSelectedListItems(tr, indentDelta) {
  const originalSelection = tr.selection;
  const rootListResolved = findRootParentListNode(originalSelection.$from);
  if (!rootListResolved) {
    return;
  }
  const rootList = findFirstParentListNode(rootListResolved);
  if (!rootList) {
    return;
  }
  const rootListStart = rootList.pos;
  const rootListEnd = rootListStart + rootList.node.nodeSize;
  const result = flattenList({
    doc: tr.doc,
    rootListStart,
    rootListEnd,
    selectionFrom: originalSelection.from,
    selectionTo: originalSelection.to,
    indentDelta,
    maxDepth: MAX_NESTED_LIST_INDENTATION
  });
  if (!result) {
    return;
  }
  const {
    items,
    startIndex,
    endIndex
  } = result;
  const {
    fragment,
    contentStartOffsets
  } = buildReplacementFragment(items, tr.doc.type.schema);
  if (fragment.size === 0) {
    return;
  }

  // Narrow the replacement to the minimal changed range for collab-friendly
  // cursor preservation on unaffected list items.
  const narrowed = narrowReplacementRange(tr.doc, rootListStart, rootListEnd, fragment, contentStartOffsets);
  tr.replaceWith(narrowed.start, narrowed.end, narrowed.fragment);
  const {
    from,
    to
  } = computeSelectionOffsets({
    items,
    startIndex,
    endIndex,
    originalFrom: originalSelection.from,
    originalTo: originalSelection.to,
    contentStartOffsets: narrowed.adjustedContentStartOffsets,
    rootListStart: narrowed.start,
    docSize: tr.doc.content.size
  });
  restoreSelection({
    tr,
    originalSelection,
    from,
    to
  });
}