Is ViewGroup with id android.R.id.content always FrameLayout?

Question

In my activity I get a root view by code:

ViewGroup root = findViewById(android.R.id.content);

Debugger shows me that root variable is instance of FrameLayout. My Question is: "Android guarantees to me that root always will be a Framelayout on all devices and on all api versions?"

Answer 1

i would rely that android.R.id.content will be of type ViewGroup but not FrameLayout or any other specific. i checked on AppCompatActivity and on simple Activity and they return different types of ViewGroup.