WIP implementing infinte scroll

app/build.gradle

@@ -46,6 +46,7 @@ dependencies {
     implementation 'com.squareup.retrofit2:converter-gson:2.4.0'
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
     implementation 'androidx.recyclerview:recyclerview:1.2.1'
+    implementation 'com.squareup.picasso:picasso:2.8'
     testImplementation 'junit:junit:4.+'
     androidTestImplementation 'androidx.test.ext:junit:1.1.3'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'

app/src/main/AndroidManifest.xml

@@ -11,7 +11,8 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.SubitoBeers">
-        <activity android:name=".MainActivity">
+        <activity android:name=".MainActivity"
+            android:configChanges="orientation|screenSize|screenLayout|keyboardHidden">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

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

@@ -2,19 +2,23 @@ package it.danieleverducci.subitobeers
 
 import androidx.recyclerview.widget.RecyclerView
 import android.view.LayoutInflater
+import android.view.View
 import android.view.ViewGroup
+import android.widget.ImageView
 import android.widget.TextView
+import com.squareup.picasso.Picasso
 
 import it.danieleverducci.subitobeers.databinding.FragmentBeersListitemBinding
 import it.danieleverducci.subitobeers.entities.Beer
 
 class BeerRecyclerAdapter : RecyclerView.Adapter<BeerRecyclerAdapter.ViewHolder>() {
 
+    var listener: Listener? = null
     private val items: ArrayList<Beer> = ArrayList()
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
-
+        // Create viewholder
-        return ViewHolder(
+        val vh = ViewHolder(
             FragmentBeersListitemBinding.inflate(
                 LayoutInflater.from(parent.context),
                 parent,
@@ -22,12 +26,37 @@ class BeerRecyclerAdapter : RecyclerView.Adapter<BeerRecyclerAdapter.ViewHolder>
             )
         )
 
+        // Register click listener
+        vh.root.setOnClickListener(object: View.OnClickListener{
+            override fun onClick(v: View?) {
+                if (v != null) {
+                    listener?.OnItemClicked(v.getTag() as Beer)
+                }
+            }
+        })
+
+        return vh
+
     }
 
     override fun onBindViewHolder(holder: ViewHolder, position: Int) {
         val item = items[position]
+
+        // Attach item to view to retrieve in case of click
+        holder.root.setTag(item)
+
+        // Fill layout with data
         holder.name.text = item.name
         holder.descr.text = item.tagline
+        Picasso.get()
+            .load(item.imageUrl)
+            .placeholder(R.drawable.ic_launcher_foreground)
+            .error(R.drawable.ic_launcher_foreground)
+            .into(holder.pic)
+
+        // If we are drawing the last element, notify
+        if (position == items.size - 1)
+            listener?.OnLastItemScrolled()
     }
 
     fun addItems(ni: List<Beer>) {
@@ -38,8 +67,15 @@ class BeerRecyclerAdapter : RecyclerView.Adapter<BeerRecyclerAdapter.ViewHolder>
     override fun getItemCount(): Int = items.size
 
     inner class ViewHolder(binding: FragmentBeersListitemBinding) : RecyclerView.ViewHolder(binding.root) {
+        val root: View = binding.root
         val name: TextView = binding.beerItemName
         val descr: TextView = binding.beerItemDescr
+        val pic: ImageView = binding.beerItemPic
+    }
+
+    interface Listener {
+        fun OnItemClicked(item: Beer)
+        fun OnLastItemScrolled()
     }
 
 }

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

@@ -13,9 +13,11 @@ import it.danieleverducci.subitobeers.entities.Beer
 /**
  * A fragment representing a list of Items.
  */
-class BeersFragment : Fragment(), BeersRepository.Listener {
+class BeersFragment : Fragment(), BeersRepository.Listener, BeerRecyclerAdapter.Listener {
 
     private val rvAdapter = BeerRecyclerAdapter()
+    private val repo = BeersRepository()
+    private var page = 1
 
     override fun onCreateView(
         inflater: LayoutInflater, container: ViewGroup?,
@@ -30,6 +32,10 @@ class BeersFragment : Fragment(), BeersRepository.Listener {
                 adapter = rvAdapter
             }
         }
+
+        // Register for recyclerview adapter events
+        rvAdapter.listener = this
+
         return view
     }
 
@@ -37,9 +43,11 @@ class BeersFragment : Fragment(), BeersRepository.Listener {
         super.onStart()
 
         // Load beers from network
-        val repo = BeersRepository()
         repo.listener = this
-        repo.getBeers(1)
+
+        // TODO: evitare che ogni volta ricarichi gli stessi elementi
+        page = 1
+        repo.getBeers(page)
     }
 
     override fun onBeersObtained(beers: List<Beer>) {
@@ -50,4 +58,20 @@ class BeersFragment : Fragment(), BeersRepository.Listener {
         Toast.makeText(context, R.string.network_error, Toast.LENGTH_SHORT).show()
     }
 
+    /**
+     * Called when an item is clicked in the list
+     */
+    override fun OnItemClicked(item: Beer) {
+        TODO("Not yet implemented")
+    }
+
+    /**
+     * Called when last list item is displayed.
+     * Used to fetch more elements
+     */
+    override fun OnLastItemScrolled() {
+        page++;
+        repo.getBeers(page)
+    }
+
 }

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

@@ -29,7 +29,7 @@ class BeersRepository {
 
             override fun onFailure(call: Call<List<Beer>>, t: Throwable) {
                 if (t.message != null)
-                    Log.e(TAG, "Unable to obtain beers: ${t.message!!}")
+                    Log.e(TAG, "Unable to obtain beers: ${t}")
                 listener?.onFailure()
             }
         })

app/src/main/java/it/danieleverducci/subitobeers/entities/Beer.kt

@@ -1,27 +1,21 @@
 package it.danieleverducci.subitobeers.entities
 
+import com.google.gson.annotations.SerializedName
 import org.json.JSONException
 import org.json.JSONObject
 import java.time.LocalDate
 import java.time.format.DateTimeFormatter
 import java.util.*
 
-class Beer {
+class Beer// Parse date
-    val id: Int
+@Throws(JSONException::class) constructor() {
-    val name: String
+    val id: Int = 0
-    val tagline: String
+    val name: String = ""
-    val description: String
+    val tagline: String = ""
-    val firstBrewed: LocalDate
+    val description: String = ""
+    @SerializedName("image_url")
+    val imageUrl: String = ""
+//    @SerializedName("first_brewed")
+//    val firstBrewed: Date? = null
 
-    @Throws(JSONException::class)
-    constructor(jo: JSONObject) {
-        this.id = jo.getInt("id")
-        this.name = jo.getString("name")
-        this.tagline = jo.getString("tagline")
-        this.description = jo.getString("description")
-
-        // Parse date
-        val formatter = DateTimeFormatter.ofPattern("mm/yyyy", Locale.ENGLISH)
-        this.firstBrewed = LocalDate.parse(jo.getString("first_brewed"), formatter)
-    }
 }

app/src/main/java/it/danieleverducci/subitobeers/networking/RetrofitProvider.kt

@@ -1,5 +1,6 @@
 package it.danieleverducci.subitobeers.networking
 
+import com.google.gson.FieldNamingPolicy
 import com.google.gson.GsonBuilder
 import it.danieleverducci.subitobeers.Config
 import okhttp3.OkHttpClient

app/src/main/res/layout/fragment_beers_listitem.xml

@@ -7,9 +7,8 @@
 
     <ImageView
         android:id="@+id/beer_item_pic"
-        android:layout_width="wrap_content"
+        android:layout_width="60dp"
-        android:layout_height="wrap_content"
+        android:layout_height="100dp"
-        android:layout_marginStart="10dp"
         android:layout_marginTop="10dp"
         android:layout_marginBottom="10dp"
         android:src="@mipmap/ic_launcher"
@@ -23,13 +22,15 @@
         android:id="@+id/beer_item_name"
         style="@style/Widget.AppCompat.TextView"
         android:layout_width="0dp"
-        android:layout_height="19dp"
+        android:layout_height="wrap_content"
         android:layout_marginStart="20dp"
+        android:layout_marginTop="16dp"
         android:layout_marginEnd="10dp"
         android:ellipsize="end"
         android:lines="1"
         android:maxLines="1"
         android:text="Beer name"
+        android:textSize="20sp"
         android:textStyle="bold"
         app:layout_constraintBottom_toTopOf="@+id/beer_item_descr"
         app:layout_constraintEnd_toEndOf="parent"
@@ -39,12 +40,12 @@
     <TextView
         android:id="@+id/beer_item_descr"
         android:layout_width="0dp"
-        android:layout_height="21dp"
+        android:layout_height="wrap_content"
         android:layout_marginStart="20dp"
         android:layout_marginEnd="10dp"
+        android:layout_marginBottom="16dp"
         android:ellipsize="end"
-        android:lines="1"
+        android:maxLines="3"
-        android:maxLines="1"
         android:text="Beer description lorem ipsum dolor sit amet"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"