public class ClippingActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new ClippingView(this));
    }
}

class ClippingView extends View {

    Rect r = new Rect();

    public ClippingView(Context context) {
        super(context);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.getClipBounds(r);
        Log.d("ClippingView","onDraw: " + r);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        invalidate(0,0,400,400);
        return true;
    }
}