When rearranging rows in a tableview, the user feedback should just go between rows (the whole-row highlighting is confusing). In the drop validation method only let things through forNSTableViewDropAbove
- (NSDragOperation) tableView: (NSTableView*) tableView validateDrop: (id) info proposedRow: (int) row proposedDropOperation: (NSTableViewDropOperation) op { int result = NSDragOperationNone; if (op == NSTableViewDropAbove) { result = NSDragOperationMove; } return (result); } // validateDrop