Apps Zooming

[fargospanner]

Hi, I am new to this OS, coming over from iPhone.

I have the start of my app running on Android but cannot see how to invoke any form of zoom control.

I see on some screens the zoom controls appear when the screen is touched.

Is there a specific view type that allows this?

I currently have all my controls in a scrollview which allows scrolling up vertically which is what I require, but I also need to be able to zoom the screen.

Any pointers please?

Thanks