fix(android): resolve Scrapped or attached views may not be recycled crash

Author: MrRefactor

android/src/main/java/com/reactnativepagerview/PagerViewViewManager.kt

@@ -2,6 +2,7 @@ package com.reactnativepagerview
 
 import android.view.View
 import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView
 import androidx.viewpager2.widget.ViewPager2
 import androidx.viewpager2.widget.ViewPager2.OnPageChangeCallback
 import com.facebook.infer.annotation.Assertions
@@ -88,6 +89,18 @@ class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>(), RNCViewPa
         return host
     }
 
+    private fun stopScrollIfNeeded(host: NestedScrollableHost) {
+        val recyclerView = (host.getChildAt(0) as? ViewPager2)?.getChildAt(0) as? RecyclerView
+        recyclerView?.stopScroll()
+    }
+
+    override fun onDropViewInstance(view: NestedScrollableHost) {
+        stopScrollIfNeeded(view)
+        val recyclerView = (view.getChildAt(0) as? ViewPager2)?.getChildAt(0) as? RecyclerView
+        recyclerView?.swapAdapter(null, false)
+        super.onDropViewInstance(view)
+    }
+
     override fun addView(host: NestedScrollableHost, child: View, index: Int) {
         PagerViewViewManagerImpl.addView(host, child, index)
     }
@@ -99,14 +112,17 @@ class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>(), RNCViewPa
     }
 
     override fun removeView(parent: NestedScrollableHost, view: View) {
+        stopScrollIfNeeded(parent)
         PagerViewViewManagerImpl.removeView(parent, view)
     }
 
     override fun removeAllViews(parent: NestedScrollableHost) {
+        stopScrollIfNeeded(parent)
         PagerViewViewManagerImpl.removeAllViews(parent)
     }
 
     override fun removeViewAt(parent: NestedScrollableHost, index: Int) {
+        stopScrollIfNeeded(parent)
         PagerViewViewManagerImpl.removeViewAt(parent, index)
     }
 
@@ -206,4 +222,4 @@ class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>(), RNCViewPa
                 PageScrollStateChangedEvent.EVENT_NAME, MapBuilder.of("registrationName", "onPageScrollStateChanged"),
                 PageSelectedEvent.EVENT_NAME, MapBuilder.of("registrationName", "onPageSelected"))
     }
-}
+}

android/src/main/java/com/reactnativepagerview/PagerViewViewManagerImpl.kt

@@ -74,16 +74,7 @@ object PagerViewViewManagerImpl {
 
     fun removeViewAt(parent: NestedScrollableHost, index: Int) {
         val pager = getViewPager(parent)
-        val adapter = pager.adapter as ViewPagerAdapter?
-
-        val child = adapter?.getChildAt(index)
-
-        if (child != null && child.parent != null) {
-            (child.parent as? ViewGroup)?.removeView(child)
-        }
-
-        adapter?.removeChildAt(index)
-
+        (pager.adapter as? ViewPagerAdapter)?.removeChildAt(index)
         debouncedRefreshViewChildrenLayout(pager)
     }
 

android/src/main/java/com/reactnativepagerview/ViewPagerAdapter.kt

@@ -6,6 +6,9 @@ import android.widget.FrameLayout
 import androidx.recyclerview.widget.RecyclerView.Adapter
 import java.util.*
 
+private fun View.detachFromParent() {
+  (parent as? ViewGroup)?.removeView(this)
+}
 
 class ViewPagerAdapter() : Adapter<ViewPagerViewHolder>() {
   private val childrenViews: ArrayList<View> = ArrayList()
@@ -17,19 +20,26 @@ class ViewPagerAdapter() : Adapter<ViewPagerViewHolder>() {
   override fun onBindViewHolder(holder: ViewPagerViewHolder, index: Int) {
     val container: FrameLayout = holder.container
     val child = getChildAt(index)
-    holder.setIsRecyclable(false)
 
     if (container.childCount > 0) {
       container.removeAllViews()
     }
 
-    if (child.parent != null) {
-      (child.parent as FrameLayout).removeView(child)
-    }
+    child.detachFromParent()
 
     container.addView(child)
   }
 
+  override fun onViewRecycled(holder: ViewPagerViewHolder) {
+    super.onViewRecycled(holder)
+    holder.container.removeAllViews()
+  }
+
+  override fun onFailedToRecycleView(holder: ViewPagerViewHolder): Boolean {
+    holder.container.removeAllViews()
+    return true
+  }
+
   override fun getItemCount(): Int {
     return childrenViews.size
   }
@@ -45,26 +55,24 @@ class ViewPagerAdapter() : Adapter<ViewPagerViewHolder>() {
 
   fun removeChild(child: View) {
     val index = childrenViews.indexOf(child)
-    
-    if(index > -1) {
+
+    if (index > -1) {
       removeChildAt(index)
     }
   }
 
   fun removeAll() {
-    for (index in 1..childrenViews.size) {
-      val child = childrenViews[index-1]
-      if (child.parent?.parent != null) {
-        (child.parent.parent as ViewGroup).removeView(child.parent as View)
-      }
+    for (child in childrenViews) {
+      child.detachFromParent()
     }
     val removedChildrenCount = childrenViews.size
     childrenViews.clear()
     notifyItemRangeRemoved(0, removedChildrenCount)
   }
 
   fun removeChildAt(index: Int) {
-    if (index >= 0 && index < childrenViews.size) { 
+    if (index >= 0 && index < childrenViews.size) {
+      childrenViews[index].detachFromParent()
       childrenViews.removeAt(index)
       notifyItemRemoved(index)
     }