Challenge: Polishing Your App Some More

Android Programming (4th Edition) 26. SearchView and SharedPreferences
1

First, I declare a lateinit var to hold a reference to ProgressDialog

private lateinit var progressDialog:ProgressDialog

And I instantiate in onCreate

override fun onCreate(savedInstanceState: Bundle?) {
    progressDialog = ProgressDialog(requireContext())
    progressDialog.setTitle("Downloading photos")
    progressDialog.setMessage("It might take a few seconds..")
    progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);

I used clearFocus to hide the keyboard, I also make the dialog visible. Then I also listen to focus change to collapse the searchview

    searchView.apply {
        setOnQueryTextListener(object : SearchView.OnQueryTextListener{
            override fun onQueryTextSubmit(queryText: String): Boolean {
                Log.d(TAG, "QueryTextSubmit: $queryText")
                progressDialog.show()
                photoGalleryViewModel.fetchPhotos(queryText)
                clearFocus()
                return true
            }
            override fun onQueryTextChange(queryText: String): Boolean {
                Log.d(TAG, "QueryTextChange: $queryText")
                return false
            }
        })
        setOnFocusChangeListener { v, hasFocus ->
            if (!hasFocus) {
                searchItem.collapseActionView()
            }

Finally, onViewCreated, we dimiss the dialog after downloading the json

 override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        photoGalleryViewModel.galleryItemLiveData.observe(viewLifecycleOwner,
        Observer {galleryItems ->
            Log.d(TAG, "Have gallery items from ViewModel $galleryItems")
            progressDialog.dismiss()
            photoRecyclerView?.adapter = PhotoAdapter(galleryItems)
        })
    }