up

Author: hoc081098

app/src/main/java/com/hoc/pagination_mvi/ui/main/MainAdapter.kt

@@ -1,5 +1,6 @@
 package com.hoc.pagination_mvi.ui.main
 
+import android.graphics.Rect
 import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
@@ -15,6 +16,7 @@ import com.hoc.pagination_mvi.R
 import com.hoc.pagination_mvi.asObservable
 import com.hoc.pagination_mvi.ui.main.MainContract.Item
 import com.hoc.pagination_mvi.ui.main.MainContract.PlaceholderState
+import com.jakewharton.rxbinding3.recyclerview.scrollEvents
 import com.jakewharton.rxbinding3.view.clicks
 import com.jakewharton.rxbinding3.view.detaches
 import io.reactivex.disposables.CompositeDisposable
@@ -53,12 +55,15 @@ class MainAdapter(private val compositeDisposable: CompositeDisposable) :
   private val retryS = PublishSubject.create<Unit>()
   val retryObservable get() = retryS.asObservable()
 
+  private val loadNextPageHorizontalS = PublishSubject.create<Unit>()
+  val loadNextPageHorizontalObservable get() = loadNextPageHorizontalS.asObservable()
+
   override fun onCreateViewHolder(parent: ViewGroup, @LayoutRes viewType: Int): VH {
     val itemView = LayoutInflater.from(parent.context).inflate(viewType, parent, false)
     return when (viewType) {
       R.layout.recycler_item_photo -> PhotoVH(itemView)
       R.layout.recycler_item_placeholder -> PlaceHolderVH(itemView, parent)
-      R.layout.recycler_item_horizontal_list -> HorizontalListVH(itemView)
+      R.layout.recycler_item_horizontal_list -> HorizontalListVH(itemView, parent)
       else -> error("Unknown viewType=$viewType")
     }
   }
@@ -151,19 +156,41 @@ class MainAdapter(private val compositeDisposable: CompositeDisposable) :
     }
   }
 
-  private class HorizontalListVH(itemView: View) : VH(itemView) {
+  private inner class HorizontalListVH(itemView: View, parent: ViewGroup) : VH(itemView) {
     private val recycler = itemView.recycler_horizontal!!
     private val progressBar = itemView.progress_bar_horizontal!!
     private val textError = itemView.text_error_horizontal!!
     private val buttonRetry = itemView.button_retry_horizontal!!
     private val adapter = HorizontalAdapter()
+    private val visibleThreshold get() = 2
 
     init {
       recycler.run {
         setHasFixedSize(true)
         adapter = this@HorizontalListVH.adapter
         layoutManager = LinearLayoutManager(context, RecyclerView.HORIZONTAL, false)
+        addItemDecoration(object : RecyclerView.ItemDecoration() {
+          override fun getItemOffsets(
+            outRect: Rect,
+            view: View,
+            parent: RecyclerView,
+            state: RecyclerView.State
+          ) {
+            outRect.left =
+              if (parent.getChildAdapterPosition(view) == parent.adapter!!.itemCount - 1) 0 else 8
+          }
+        })
       }
+
+      recycler
+        .scrollEvents()
+        .takeUntil(parent.detaches())
+        .filter { (_, dx, _) ->
+          val layoutManager = recycler.layoutManager as LinearLayoutManager
+          dx > 0 && layoutManager.findLastVisibleItemPosition() + visibleThreshold >= layoutManager.itemCount
+        }
+        .subscribeBy { loadNextPageHorizontalS.onNext(Unit) }
+        .addTo(compositeDisposable)
     }
 
     override fun bind(item: Item) {

app/src/main/java/com/hoc/pagination_mvi/ui/main/MainContract.kt

@@ -109,6 +109,9 @@ interface MainContract {
     object Initial : ViewIntent()
     object LoadNextPage : ViewIntent()
     object RetryLoadPage : ViewIntent()
+
+    object LoadNextPageHorizontal: ViewIntent()
+    object RetryLoadPageHorizontal: ViewIntent()
   }
 
   sealed class PartialStateChange {

app/src/main/java/com/hoc/pagination_mvi/ui/main/MainFragment.kt

@@ -124,7 +124,10 @@ class MainFragment : Fragment() {
         adapter
           .retryObservable
           .throttleFirst(500, TimeUnit.MILLISECONDS)
-          .map { ViewIntent.RetryLoadPage }
+          .map { ViewIntent.RetryLoadPage },
+        adapter
+          .loadNextPageHorizontalObservable
+          .map { ViewIntent.LoadNextPageHorizontal }
       )
     ).addTo(compositeDisposable)
   }

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

@@ -3,6 +3,7 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
+    android:background="#fafafa"
     android:layout_height="200dp">
 
     <androidx.recyclerview.widget.RecyclerView