How can i enable pinching and stretching on my app's UI

I've a table layout with a textview in it. As 开发者_如何学Gothe texts within every row are small enough to fit into the screen, I want my users to be able to pinch and stretch the screen so that they can zoom in. But, currently that feature is not working by default. How can i enable pinching and stretching the screen, then?

Thanks

You can implement it yourself. Start by reading this multipart tutorial: http://www.zdnet.com/blog/burnette/how-to-use-multi-touch-in-android-2/1747 (part 6 is devoted to pinch and zoom) and this other post in the devs blog: http://android-developers.blogspot.com/2010/06/making-sense-of-multitouch.html

There's also a library that looks promising (although I did not try it): http://code.google.com/p/android-pinch/