If someone is rude and inattentive, they're unchivalrous. It's most common to describe men as unchivalrous, particularly when they behave impolitely toward women.
This adjective, like its opposite, chivalrous, is a bit old-fashioned, but it's still used to describe men who don't act gallantly — or the ungallant act itself. Both words come from chivalry, the medieval code that knights lived by. If a guy doesn't act the way a gallant knight would, letting the door slam in your face, he's unchivalrous.