Structure

Structural operations — rows, columns, merges, groups, nested headers, freeze panes, visibility — all produce undoable operations and keep formulas and selection consistent.

Rows & columns

sheet.insertRows(2, 3);     // insert 3 rows at index 2
sheet.deleteRows(2, 3);
sheet.insertColumns(1, 2);
sheet.deleteColumns(1, 2);

Structural changes:

• Emit rows.insert / rows.delete / columns.insert / columns.delete operations
• Transform undo/redo history so entries survive the shift
• Translate relative formula references (absolute refs stay put; off-sheet refs become #REF!)
• Clamp selection ranges and merges

Resizing rows and columns

In the editor, select cells and open the Layout tab. The Rows and Columns ribbon groups show the affected selection without requiring numeric indexes or a sidebar. Click a row number or column letter to select its entire band; Shift-click another header to extend the selection. Disconnected selections must be replaced with one continuous range before using layout actions. Hover over an icon to see its action name.

Insert above/below and Insert left/right insert as many rows or columns as selected. Delete and Hide apply to the selection. The Show hidden rows/columns ribbon menus list hidden ranges and a Show all action. Layout actions keep at least one row/column and at least one visible band. Each completed action is one undo step.

Enter Row height (px) or Column width (px) in the ribbon and choose Apply row height or Apply column width for exact dimensions. Differing selected dimensions show Mixed. The editor accepts 16–2000px row heights and 24–2000px column widths. Auto-fit measures formatted cell values, font styles, line breaks and wrapping, excluding merged cells; empty bands return to their default size. Dimensions are worksheet pixels and do not change with zoom.

Drag the right edge of a column header or the bottom edge of a row header to resize it. Cells follow the pointer immediately, including when scrolled or zoomed. Release to save one undoable change, or press Escape to cancel. Dragging affects only that row or column, with a minimum column width of 24px and row height of 16px before zoom.

Set exact dimensions through the Worksheet API:

const sheet = editor.workbook.activeWorksheet;
sheet.setColumnWidth(0, 180);
sheet.setRowHeight(0, 40);

Indexes are zero-based and dimensions are unscaled pixels. Both methods update the grid automatically and support undo/redo. A drag preview is not saved until release; changing sheets, changing zoom, or losing window focus cancels it.

Merged cells

sheet.merge('A1:B2');         // undoable, rejects overlaps and degenerate rects
sheet.unmerge('A1:B2');
sheet.merges.findAt(0, 0);    // MergeRect | undefined
sheet.merges.isCovered(0, 1); // true — covered by the anchor

Merges render with the anchor cell spanning the region; covered cells are recycled by the virtualizer. Sorting refuses ranges containing merges.

Row & column groups

sheet.groupRows(1, 4);        // group rows 2-5
sheet.ungroupRows(1);
sheet.collapseGroup(1);       // hides grouped rows
sheet.expandGroup(1);
sheet.getGroups();

Nested headers

In the Layout ribbon's Grouped headers group, add a header level, then edit the selected group's label and first/last column letters. Use the level/group selectors to switch between entries, and the action icons to add, remove or reorder them. New groups use the selected columns when possible, otherwise the first available column. Groups on the same level cannot overlap; different levels are independent. Blank labels are allowed for spacing.

Preview grouped headers opens a live preview beneath the ribbon, showing eight columns at a time with Previous/Next controls. Save headers commits the draft as one undo step. Cancel header changes, Escape in the header controls, changing tabs or changing sheets discards it. Escape inside the preview closes the preview. Remove every level and save to clear grouped headers. These labels appear above A/B/C and do not replace values in worksheet cells.

Inserting or deleting columns through the Layout ribbon moves grouped headers with their columns. Insertion inside a group expands it; deletion shrinks it or removes it when all its columns are deleted. One undo restores both the columns and headers. Programmatic structural APIs retain their existing behavior.

Multi-level column headers with spans:

sheet.setNestedHeaders([
  [{ title: 'Revenue', span: 2 }, { title: 'Costs', span: 2 }],
  ['Q1', 'Q2', 'Q1', 'Q2'],
]);
sheet.nestedHeaders;

Strings are single-span titles; { title, span } merges that many columns.

Freeze panes

Set the frozen row/column counts directly on the worksheet:

sheet.freezeRows = 1;    // header row stays visible
sheet.freezeColumns = 2;

Frozen rows/columns render in dedicated overlay layers and remain visible while scrolling.

Visibility

sheet.hideRows(4, 2);        // hide rows 5-6
sheet.hideColumns(1);
sheet.showRows(4, 2);
sheet.isRowHidden(4);
sheet.hiddenRows;            // Set<number>

Pagination (renderer view)

The renderer can present rows in pages without touching the model:

const renderer = editor.renderer;
renderer.enablePagination(50);  // 50 rows per page
renderer.setPage(3);
renderer.pageCount;
renderer.disablePagination();

Zoom

renderer.setZoom(1.25);
renderer.getZoom();

Formula translation

Reference rewriting is token-based (never regex over raw text). During structural changes, transformFormulaRefs(formula, shift, options) shifts relative references; deleting referenced rows/cols turns them into #REF!. renameSheetRefs(formula, from, to) handles sheet renames.