Function onFocus

packages/react-aria/src/grid/useGridCell.ts:257–279

  // Grid cells can have focusable elements inside them. In this case, focus should
  // be marshalled to that element rather than focusing the cell itself.
  let onFocus = e => {
    keyWhenFocused.current = node.key;
    if (getEventTarget(e) !== ref.current) {
      // useSelectableItem only handles setting the focused key when
      // the focused element is the gridcell itself. We also want to
      // set the focused key when a child element receives focus.
      // If focus is currently visible (e.g. the user is navigating with the keyboard),
      // then skip this. We want to restore focus to the previously focused row/cell
      // in that case since the table should act like a single tab stop.
      if (!isFocusVisible()) {
        state.selectionManager.setFocusedKey(node.key);
      }
      return;
    }

    // If the cell itself is focused, wait a frame so that focus finishes propagatating
    // up to the tree, and move focus to a focusable child if possible.
    requestAnimationFrame(() => {
      if (focusMode === 'child' && getActiveElement() === ref.current) {
        focus();
      }
    });
  };

  let gridCellProps: DOMAttributes = mergeProps(itemProps, {
    role: 'gridcell',