@base-ui/react/floating-ui-react/hooks/gridNavigation.mjs

Base UI is a library of headless ('unstyled') React components and low-level hooks. You gain complete control over your app's CSS and accessibility features.

import { getGridNavigatedIndex, isIndexOutOfListBounds } from "../utils/composite.mjs";

/**
 * Positional arguments are deliberate: property names of an options object
 * don't minify, and the signature is locked to the caller via `typeof` on the
 * `grid` option of `useListNavigation`.
 *
 * The injected grid navigator only ever operates on a uniform 1x1 grid (sizes are
 * always `1x1` and packing is never dense), so the cell-map machinery that supports
 * multi-cell items collapses to an identity transform over the item list. Calling
 * `getGridNavigatedIndex` directly keeps the cell-map helpers
 * (`createGridCellMap`/`getGridCellIndexOfCorner`/`getGridCellIndices`) out of
 * grid-combobox bundles.
 */
export function gridNavigation(event, prevIndex, listRef, orientation, loopFocus, rtl, disabledIndices, minIndex, maxIndex, cols = 2) {
  const nextIndex = getGridNavigatedIndex(listRef.current, {
    event,
    orientation,
    loopFocus,
    rtl,
    cols,
    disabledIndices,
    minIndex,
    maxIndex,
    // An out-of-range previous index falls back to the first enabled item.
    prevIndex: prevIndex > maxIndex ? minIndex : prevIndex,
    stopEvent: true
  });

  // `getGridNavigatedIndex` can return an out-of-bounds sentinel (e.g. `-1` when there is no
  // previous item to move from); surface that as `undefined` so the caller treats it as
  // "no navigation" rather than highlighting index `-1`.
  return isIndexOutOfListBounds(listRef.current, nextIndex) ? undefined : nextIndex;
}