Auto-fill (Fill Handle)

Auto-fill exposes Excel’s familiar fill handle — a small square at the bottom-right of the active selection. Drag it down, up, left, or right to extend the selection with values inferred from the source cells.

Detected patterns:

Undo restores prior values, including cells that previously held different data.

Enabling and disabling

Auto-fill is enabled by default.

import { createReogrid } from '@reogrid/lite'

// Disable at construction
const { worksheet } = createReogrid({
  workspace: '#grid',
  autoFill: false,
})

// Toggle at runtime
worksheet.setAutoFillEnabled(true)
worksheet.setAutoFillEnabled(false)

In React / Vue, pass options={{ autoFill: false }} to the <Reogrid> component if you want to ship without the fill handle.

Programmatic fill

For tooling and tests, the value-inference logic is exposed as a pure function so you can compute the same series the UI would produce.

import { computeAutoFillValues, type AutoFillSourceCell } from '@reogrid/pro'

const source: AutoFillSourceCell[][] = [
  [{ input: '1' }],
  [{ input: '2' }],
]

const result = computeAutoFillValues({ source, direction: 'down', steps: 5 })
// result -> [[{ input: '3' }], [{ input: '4' }], [{ input: '5' }], [{ input: '6' }], [{ input: '7' }]]

Combine with AutoFillAction if you need to drive the fill through the standard undo/redo pipeline:

import { AutoFillAction } from '@reogrid/pro'

// Fill A1:A2 down through A7 (the target range contains the source)
const action = new AutoFillAction(
  { topRow: 0, leftColumn: 0, bottomRow: 1, rightColumn: 0 },
  { topRow: 0, leftColumn: 0, bottomRow: 6, rightColumn: 0 },
)
grid.actionManager.execute(action)

Notes

• The fill handle is drawn as part of the selection chrome, so it follows the active selection automatically.
• Custom series like weekday names (Mon, Tue, ...) or month names are not detected in this release — they tile-copy instead.
• Double-clicking the fill handle to auto-extend downward is not yet supported.