title: How to rotate an ViewGroup
body: <p>I have an FrameLayout and I use WindowManager.addView to show this FrameLayout as a float window. In this FrameLayout there are many subviews such as ImageView and SeekBar. Then I need rotate this FrameLayout through View.setRotate. After this method called, the FrameLayout seems rotated but when I want to interact it by some subviews in it, I found all subviews still in the origin place before it rotated. So how do I rotate an ViewGroup with all its subview?</p>