java android code script animation

Hello, We are trying to make a animation scroll and need help with this. JAVA ANDROID SCRIPT ONLY. It should work as follows: When you hit a button it should start spinning horizontal and after 3 seconds it should decrease speed until it finally stops. All this should happen within a 5 second range. PLEASE SEE THIS VIDEO ON HOW IT SHOULD BE THE ANIMATION: [login to view URL] Please note: i only need script animation. We already have the button, and items thats in the animation etc, but we struggle with getting this animation to spin and then slow down until it stops.