When i set a paint stroke size to say 15, it fits one screen while in another it is too large or small, how can i know the screen density to let it set the stroke width to fit the screen density?
i am trying to use it for a live wallpaper, a service, not an application, so i can't use get windows manager...
This article might help you:
http://developer.android.com/guide/practices/screens_support.html
Ultimately, you are going to have to develop for different screen densities.