The method is not called if there is no change in the first navigation fragment, so if the user does not perform any action that changes the first of the initial fragments, the method is not called, for example not executing the scrolling action until top if necessary.
The method is not called if there is no change in the first navigation fragment, so if the user does not perform any action that changes the first of the initial fragments, the method is not called, for example not executing the scrolling action until top if necessary.