Android fitsSystemWindows not working when replacing fragments

Question

I have SingleFramgnetActivity whose purpose is only to hold and replace fragments inside it.

layout looks like this:

Answer 1

Your FrameLayout is not aware of window inset sizes, because it's parent - LinearLayout hasn't dispatched him any. As a workaround, you can subclass LinearLayout and pass insets to children on your own:

@TargetApi(Build.VERSION_CODES.KITKAT_WATCH)
@Override
public WindowInsets onApplyWindowInsets(WindowInsets insets) {
    int childCount = getChildCount();
    for (int index = 0; index < childCount; index++)
        getChildAt(index).dispatchApplyWindowInsets(insets); // let children know about WindowInsets

    return insets;
}

You can have a look to my this answer, which will explain detailed how this works, and also how to use ViewCompat.setOnApplyWindowInsetsListener API.