cdmunoz

class CryptocurrencyRepository @Inject constructor(val apiInterface: ApiInterface,
    val cryptocurrenciesDao: CryptocurrenciesDao, val utils: Utils) {

  fun getCryptocurrencies(limit: Int, offset: Int): Observable<List<Cryptocurrency>> {
    val hasConnection = utils.isConnectedToInternet()
    var observableFromApi: Observable<List<Cryptocurrency>>? = null
    if (hasConnection){
      observableFromApi = getCryptocurrenciesFromApi()
    }
    val observableFromDb = getCryptocurrenciesFromDb(limit, offset)

cdmunoz

class Utils @Inject constructor(private val context: Context) {

  fun isConnectedToInternet(): Boolean {
    val connectivity = context.getSystemService(
        Context.CONNECTIVITY_SERVICE) as ConnectivityManager
    if (connectivity != null) {
      val info = connectivity.allNetworkInfo
      if (info != null)
        for (i in info.indices)
          if (info[i].state == NetworkInfo.State.CONNECTED) {

cdmunoz

@Module
class AppModule(val app: Application) {

  //...rest of the code

  @Provides
  @Singleton
  fun provideUtils(): Utils = Utils(app)
}

cdmunoz

<?xml version="1.0" encoding="utf-8"?>

<android.support.v7.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/cryptocurrency_card"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="@dimen/default_4dp"
    app:cardElevation="@dimen/cardview_default_elevation"

cdmunoz

class CryptocurrenciesAdapter(
    cryptocurrencies: List<Cryptocurrency>?) : RecyclerView.Adapter<CryptocurrencieViewHolder>() {

  private var cryptocurrenciesList = ArrayList<Cryptocurrency>()

  init {
    this.cryptocurrenciesList = cryptocurrencies as ArrayList<Cryptocurrency>
  }

  override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): CryptocurrencieViewHolder {

cdmunoz

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="8dp"
    tools:context="co.cdmunoz.cryptocurrencyapp.ui.list.CryptocurrenciesActivity"
    >

cdmunoz

class InfiniteScrollListener(
    val func: () -> Unit,
    val layoutManager: LinearLayoutManager) : RecyclerView.OnScrollListener() {

  private var previousTotal = 0
  private var loading = true
  private var visibleThreshold = 2
  private var firstVisibleItem = 0
  private var visibleItemCount = 0
  private var totalItemCount = 0

cdmunoz

class InfiniteScrollListener(
    val func: () -> Unit,
    val layoutManager: LinearLayoutManager) : RecyclerView.OnScrollListener() {

  private var previousTotal = 0
  private var loading = true
  private var visibleThreshold = 2
  private var firstVisibleItem = 0
  private var visibleItemCount = 0
  private var totalItemCount = 0

cdmunoz

class CryptocurrenciesActivity : AppCompatActivity() {

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(layout.activity_cryptocurrencies)

    initializeRecycler()

    progressBar.visibility = View.VISIBLE
    loadData()

cdmunoz

class Constants {
  companion object {
    const val OFFSET = 12
    const val LIMIT = 12
    const val START_ZERO_VALUE = "0"
    const val DATABASE_NAME = "cryptocurrencies_db"
    const val LIST_SCROLLING = 12
  }
}