Function useKeyboardResize

src/hooks/useKeyboardResize.ts:39–216

(options: UseKeyboardResizeOptions)

 * @returns Handler for keyboard events
 */
export function useKeyboardResize(options: UseKeyboardResizeOptions) {
  const {
    direction,
    sizes,
    minSizes,
    maxSizes,
    step = DEFAULT_STEP,
    largeStep = DEFAULT_LARGE_STEP,
    onResize,
    onResizeEnd,
  } = options;

  // Track sizes at start of keyboard interaction for Escape to restore
  const initialSizesRef = useRef<number[] | null>(null);

  const handleKeyDown = useCallback(
    (dividerIndex: number) => (e: React.KeyboardEvent) => {
      const isHorizontal = direction === 'horizontal';
      const moveKeys = isHorizontal
        ? ['ArrowLeft', 'ArrowRight']
        : ['ArrowUp', 'ArrowDown'];

      if (
        !moveKeys.includes(e.key) &&
        e.key !== 'Home' &&
        e.key !== 'End' &&
        e.key !== 'Escape'
      ) {
        return;
      }

      e.preventDefault();

      // Handle Escape - restore to initial sizes
      if (e.key === 'Escape') {
        if (initialSizesRef.current) {
          const restoredSizes = initialSizesRef.current;
          initialSizesRef.current = null;

          if (onResize) {
            onResize(restoredSizes, {
              sizes: restoredSizes,
              source: 'keyboard',
              originalEvent: e.nativeEvent,
            });
          }

          if (onResizeEnd) {
            onResizeEnd(restoredSizes, {
              sizes: restoredSizes,
              source: 'keyboard',
              originalEvent: e.nativeEvent,
            });
          }

          announce('Pane sizes restored');
        }
        return;