Android Gridview with a external scrollbar

I have a gridview with some objects inside it and I have an alphabetic list that is compose by a lof of textviews.

I want to 开发者_如何学Goclick on "A" and the gridview is going down until the letter "A" and the same with the other letters.

Maybe that won't be a problem but the big problem is when I scrolling the gridview, I want to know which items are display and try to get the first item to decide which letter is it.

That look like the iphone contact

There's a very similar situation addressed here:

How to implement scrollbar with thumb for fast scrolling

I'm pretty sure that's exactly what you want.