How many pull ups can gymnasts do?

I want to find out what you call those pull ups that gymnasts do, that let them go over the bar.Kind of like a pull up and then a dip. Any techniques to it, because I can't seem to do it. Also how can you perform that move where you hold yourself in the air in push ups position. I've seen break dancers do it as well. Any hints/slash specific workouts are welcome. I think I'm up for it, I can do 20 pullups and 50 pushups in good form. Thanks to everyone.