Where are android sdk's 9-patch drawables?

I am looking for android sdk's built-in 9-patch drawables, in particular the ones for EditText and for Button.

I need them because I wa开发者_如何转开发nt to change them a bit and get custom controls that take less space on the screen. I don't want to draw everything from scratch because I want my controls to look like the standard ones.

I guess it's already on my hard drive, since I have installed the sdk, but where ?

Look in <android install directory>/platforms/android-<platform version>/data/res/drawable-mdpi