Do not make request if there are no more items

app/src/main/java/it/danieleverducci/subitobeers/BeersRepository.kt

@@ -16,17 +16,27 @@ class BeersRepository {
     }
 
     var listener: Listener? = null
+    var page = 1
+    var filter = BeersFilter
+    private var more = true
 
-    fun getBeers(page: Int, filter: BeersFilter) {
+    /**
+     * Obtain a paginated list of beers from the server
+     * Use page property to set the page
+     */
+    fun getBeers() {
         // Obtain beers
         val call = RetrofitProvider.getClient.getBeers(page, filter.brewedBefore, filter.brewedAfter)
         call.enqueue(object: Callback<List<Beer>> {
             override fun onResponse(call: Call<List<Beer>>, response: Response<List<Beer>>) {
-                if (response.body() != null)
-                    listener?.onBeersObtained(response.body()!!)
-                else
+                if (response.body() != null) {
+                    if (response.body()!!.isEmpty())
+                        more = false
+                    listener?.onBeersObtained(response.body()!!, more)
+                } else {
                     listener?.onFailure()
                 }
+            }
 
             override fun onFailure(call: Call<List<Beer>>, t: Throwable) {
                 if (t.message != null)
@@ -36,8 +46,16 @@ class BeersRepository {
         })
     }
 
+    /**
+     * Discard page and restarts from first
+     */
+    fun reset() {
+        page = 1
+        more = true
+    }
+
     interface Listener {
-        fun onBeersObtained(beers: List<Beer>)
+        fun onBeersObtained(beers: List<Beer>, more: Boolean)
         fun onFailure()
     }
 }

app/src/main/java/it/danieleverducci/subitobeers/ui/BeerRecyclerAdapter.kt

@@ -15,7 +15,12 @@ import it.danieleverducci.subitobeers.entities.Beer
 
 class BeerRecyclerAdapter : RecyclerView.Adapter<BeerRecyclerAdapter.ViewHolder>() {
 
+    // The click event listener
     var listener: Listener? = null
+
+    // Whether there are more items in next page
+    private var more = true
+
     private val items: ArrayList<Beer> = ArrayList()
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
@@ -58,7 +63,7 @@ class BeerRecyclerAdapter : RecyclerView.Adapter<BeerRecyclerAdapter.ViewHolder>
             .into(holder.pic)
 
         // If we are drawing the last element, notify
-        if (position == items.size - 1) {
+        if (position == items.size - 1 && more) {
             holder.progress.visibility = View.VISIBLE
             listener?.OnLastItemScrolled()
         } else {
@@ -66,13 +71,23 @@ class BeerRecyclerAdapter : RecyclerView.Adapter<BeerRecyclerAdapter.ViewHolder>
         }
     }
 
-    fun addItems(ni: List<Beer>) {
+    /**
+     * Add items to the list and updates the view
+     * @param ni List of beers to be added
+     * @param more Whether there are more beers
+     */
+    fun addItems(ni: List<Beer>, more: Boolean) {
+        this.more = more
         items.addAll(ni)
         notifyDataSetChanged()
     }
 
+    /**
+     * Clears the list and updates the view
+     */
     fun clear() {
         items.clear()
+        more = true
         notifyDataSetChanged()
     }
 

app/src/main/java/it/danieleverducci/subitobeers/ui/BeersFragment.kt

@@ -26,8 +26,6 @@ class BeersFragment : Fragment(), BeersRepository.Listener, BeerRecyclerAdapter.
     private val rvAdapter = BeerRecyclerAdapter()
     private val repo = BeersRepository()
     lateinit var binding: FragmentBeersListBinding
-    private var page = 1
-    private var filter = BeersFilter
 
     override fun onCreateView(
         inflater: LayoutInflater, container: ViewGroup?,
@@ -75,8 +73,8 @@ class BeersFragment : Fragment(), BeersRepository.Listener, BeerRecyclerAdapter.
         return super.onOptionsItemSelected(item)
     }
 
-    override fun onBeersObtained(beers: List<Beer>) {
-        rvAdapter.addItems(beers)
+    override fun onBeersObtained(beers: List<Beer>, more: Boolean) {
+        rvAdapter.addItems(beers, more)
     }
 
     override fun onFailure() {
@@ -107,9 +105,9 @@ class BeersFragment : Fragment(), BeersRepository.Listener, BeerRecyclerAdapter.
             // On date chosen
             val formattedDate = "${String.format("%02d", month)}-${String.format("%04d", year)}"
             if (type == FILTERTYPE.SINCE)
-                filter.brewedAfter = formattedDate
+                repo.filter.brewedAfter = formattedDate
             else
-                filter.brewedBefore = formattedDate
+                repo.filter.brewedBefore = formattedDate
             // Update list
             loadBeers(true)
         })
@@ -121,7 +119,7 @@ class BeersFragment : Fragment(), BeersRepository.Listener, BeerRecyclerAdapter.
      * Used to fetch more elements
      */
     override fun OnLastItemScrolled() {
-        page++
+        repo.page++
         loadBeers(false)
     }
 
@@ -140,11 +138,11 @@ class BeersFragment : Fragment(), BeersRepository.Listener, BeerRecyclerAdapter.
     private fun loadBeers(clear: Boolean) {
         if (clear) {
             rvAdapter.clear()
-            page = 1
+            repo.reset()
         }
 
         // Load with filter
-        repo.getBeers(page, filter)
+        repo.getBeers()
     }
 
 }