How to use bindings to access BottomAppBar in Activity from Fragment?

Question

I'm moved from kotlin-extention to binding usage as the extention was deprecated so i'm rebuilding the whole app by using the bindings.

I have an issue with the accessing the BottomAppBar from fragment which is situated in my Activity.

Before bindings i was using the code like:

class CorpoFragment : Fragment() {
    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        (activity as LetturaActivity).bottomAppBar.navigationIcon = ContextCompat.getDrawable(
            requireContext(),
            R.drawable.ic_baseline_menu_24
        )
     }
}

But now i've set the binding in that fragment like:

class CorpoFragment : Fragment() {

    private var fragmentCorpoBinding: FragmentCorpoBinding? = null
    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        val binding = FragmentCorpoBinding.inflate(inflater, container, false)
        fragmentCorpoBinding = binding
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        // how can i access the bottomAppBar from the activity at this point?
    }

After removing the kotlin-extention i get the Unresolved reference: bottomAppBar on the first block of code..

Answer 1

The variables are accessible via the binding class.

private lateinit var binding: FragmentCorpoBinding

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
    binding = FragmentCorpoBinding.inflate(inflater, container, false)
    return binding.root
}

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    binding.bottomAppBar
}

I recommend you, not accessing the view elements from the Fragment to the Activity because every activity/fragment should have its self-independent view (separation of concern). If you really need it, just add something like this in your Activity:

class LetturaActivity {

 fun updateBottomMenu() {
  binding.bottomAppBar.navigationIcon = ContextCompat.getDrawable(
            requireContext(),
            R.drawable.ic_baseline_menu_24
        )
 }

}