add this method as a category or subclass method of NSOutlineView

• (NSArray *)selectedItems { NSIndexSet *selectedRowsIndexSet = [self selectedRowIndexes]; int i;

  NSMutableArray *itemsArray = [NSMutableArray array]; while ((i = [selectedRowsIndexSet indexGreaterThanIndex:i]) != NSNotFound) { [itemsArray addObject:[self itemAtRow:i]]; }

  return itemsArray; }