Fix: scrapped views crash

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

@@ -2,10 +2,10 @@ 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
-import com.facebook.react.bridge.ReactContext
 import com.facebook.react.bridge.ReadableArray
 import com.facebook.react.common.MapBuilder
 import com.facebook.react.module.annotations.ReactModule
@@ -18,9 +18,10 @@ import com.reactnativepagerview.event.PageScrollEvent
 import com.reactnativepagerview.event.PageScrollStateChangedEvent
 import com.reactnativepagerview.event.PageSelectedEvent
 
-
 @ReactModule(name = PagerViewViewManagerImpl.NAME)
-class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>(), RNCViewPagerManagerInterface<NestedScrollableHost> {
+class PagerViewViewManager :
+        ViewGroupManager<NestedScrollableHost>(),
+        RNCViewPagerManagerInterface<NestedScrollableHost> {
     companion object {
         init {
             if (BuildConfig.CODEGEN_MODULE_REGISTRATION != null) {
@@ -29,84 +30,199 @@ class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>(), RNCViewPa
         }
     }
 
-    private val mDelegate: ViewManagerDelegate<NestedScrollableHost> = RNCViewPagerManagerDelegate(this)
+    private val mDelegate: ViewManagerDelegate<NestedScrollableHost> =
+            RNCViewPagerManagerDelegate(this)
 
     override fun getDelegate() = mDelegate
 
     override fun getName(): String {
         return PagerViewViewManagerImpl.NAME
     }
 
-    override fun receiveCommand(root: NestedScrollableHost, commandId: String, args: ReadableArray?) {
+    override fun receiveCommand(
+            root: NestedScrollableHost,
+            commandId: String,
+            args: ReadableArray?
+    ) {
         mDelegate.receiveCommand(root, commandId, args)
     }
 
     public override fun createViewInstance(reactContext: ThemedReactContext): NestedScrollableHost {
         val host = NestedScrollableHost(reactContext)
         host.id = View.generateViewId()
-        host.layoutParams = ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT)
+        host.layoutParams =
+                ViewGroup.LayoutParams(
+                        ViewGroup.LayoutParams.MATCH_PARENT,
+                        ViewGroup.LayoutParams.MATCH_PARENT
+                )
         host.isSaveEnabled = false
         val vp = ViewPager2(reactContext)
+
+        // Access private mRecyclerView field using reflection to disable animations
+        val recyclerViewField = ViewPager2::class.java.getDeclaredField("mRecyclerView")
+        recyclerViewField.isAccessible = true
+        val recyclerView = recyclerViewField.get(vp) as RecyclerView
+
+        // Disable all animations to prevent layout change issues
+        recyclerView.itemAnimator = null
+        recyclerView.layoutTransition = null
+
         vp.adapter = ViewPagerAdapter()
-        //https://github.com/callstack/react-native-viewpager/issues/183
+        // https://github.com/callstack/react-native-viewpager/issues/183
         vp.isSaveEnabled = false
 
         vp.post {
-            vp.registerOnPageChangeCallback(object : OnPageChangeCallback() {
-                override fun onPageScrolled(position: Int, positionOffset: Float, positionOffsetPixels: Int) {
-                    super.onPageScrolled(position, positionOffset, positionOffsetPixels)
-                    UIManagerHelper.getEventDispatcherForReactTag(reactContext, host.id)?.dispatchEvent(
-                            PageScrollEvent(host.id, position, positionOffset)
-                    )
-                }
-
-                override fun onPageSelected(position: Int) {
-                    super.onPageSelected(position)
-                    UIManagerHelper.getEventDispatcherForReactTag(reactContext, host.id)?.dispatchEvent(
-                            PageSelectedEvent(host.id, position)
-                    )
-                }
-
-                override fun onPageScrollStateChanged(state: Int) {
-                    super.onPageScrollStateChanged(state)
-                    val pageScrollState: String = when (state) {
-                        ViewPager2.SCROLL_STATE_IDLE -> "idle"
-                        ViewPager2.SCROLL_STATE_DRAGGING -> "dragging"
-                        ViewPager2.SCROLL_STATE_SETTLING -> "settling"
-                        else -> throw IllegalStateException("Unsupported pageScrollState")
+            vp.registerOnPageChangeCallback(
+                    object : OnPageChangeCallback() {
+                        override fun onPageScrolled(
+                                position: Int,
+                                positionOffset: Float,
+                                positionOffsetPixels: Int
+                        ) {
+                            super.onPageScrolled(position, positionOffset, positionOffsetPixels)
+                            UIManagerHelper.getEventDispatcherForReactTag(reactContext, host.id)
+                                    ?.dispatchEvent(
+                                            PageScrollEvent(host.id, position, positionOffset)
+                                    )
+                        }
+
+                        override fun onPageSelected(position: Int) {
+                            super.onPageSelected(position)
+                            UIManagerHelper.getEventDispatcherForReactTag(reactContext, host.id)
+                                    ?.dispatchEvent(PageSelectedEvent(host.id, position))
+                        }
+
+                        override fun onPageScrollStateChanged(state: Int) {
+                            super.onPageScrollStateChanged(state)
+                            val pageScrollState: String =
+                                    when (state) {
+                                        ViewPager2.SCROLL_STATE_IDLE -> "idle"
+                                        ViewPager2.SCROLL_STATE_DRAGGING -> "dragging"
+                                        ViewPager2.SCROLL_STATE_SETTLING -> "settling"
+                                        else ->
+                                                throw IllegalStateException(
+                                                        "Unsupported pageScrollState"
+                                                )
+                                    }
+                            UIManagerHelper.getEventDispatcherForReactTag(reactContext, host.id)
+                                    ?.dispatchEvent(
+                                            PageScrollStateChangedEvent(host.id, pageScrollState)
+                                    )
+                        }
                     }
-                    UIManagerHelper.getEventDispatcherForReactTag(reactContext, host.id)?.dispatchEvent(
-                            PageScrollStateChangedEvent(host.id, pageScrollState)
-                    )
-                }
-            })
-            UIManagerHelper.getEventDispatcherForReactTag(reactContext, host.id)?.dispatchEvent(
-                    PageSelectedEvent(host.id, vp.currentItem)
             )
+            UIManagerHelper.getEventDispatcherForReactTag(reactContext, host.id)
+                    ?.dispatchEvent(PageSelectedEvent(host.id, vp.currentItem))
         }
         host.addView(vp)
         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) {
+        try {
+            val viewPager = PagerViewViewManagerImpl.getViewPager(view)
+            // Access private mRecyclerView field using reflection
+            val recyclerViewField = ViewPager2::class.java.getDeclaredField("mRecyclerView")
+            recyclerViewField.isAccessible = true
+            val recyclerView = recyclerViewField.get(viewPager) as RecyclerView
+
+            // Stop any scroll/drag in progress first
+            recyclerView.stopScroll()
+
+            // Suppress layout to prevent any pending layout operations from executing
+            recyclerView.suppressLayout(true)
+
+            // Access and stop the ViewFlinger directly via reflection - do this early
+            try {
+                val viewFlingerField = RecyclerView::class.java.getDeclaredField("mViewFlinger")
+                viewFlingerField.isAccessible = true
+                val viewFlinger = viewFlingerField.get(recyclerView) as? Runnable
+                viewFlinger?.let {
+                    recyclerView.removeCallbacks(it)
+                    // Also try to stop it via reflection if it has a stop method
+                    try {
+                        val stopMethod = viewFlinger.javaClass.getDeclaredMethod("stop")
+                        stopMethod.isAccessible = true
+                        stopMethod.invoke(viewFlinger)
+                    } catch (ignored: Exception) {}
+                }
+            } catch (ignored: Exception) {
+                // ViewFlinger reflection may fail on some versions
+            }
+
+            // Clear the recycler's scrap views before clearing adapter
+            try {
+                val recyclerField = RecyclerView::class.java.getDeclaredField("mRecycler")
+                recyclerField.isAccessible = true
+                val recycler = recyclerField.get(recyclerView)
+
+                // Clear scrap heaps
+                val clearScrapMethod = recycler.javaClass.getDeclaredMethod("clear")
+                clearScrapMethod.isAccessible = true
+                clearScrapMethod.invoke(recycler)
+            } catch (ignored: Exception) {
+                // Recycler reflection may fail on some versions
+            }
+
+            // Clear any pending animations and layout transitions
+            recyclerView.clearAnimation()
+            recyclerView.itemAnimator = null
+            recyclerView.layoutTransition = null
+            recyclerView.recycledViewPool.clear()
+
+            // Remove all pending operations and choreographer callbacks
+            recyclerView.removeCallbacks(null)
+
+            // Try to clear any pending adapter updates
+            try {
+                val adapterHelperField = RecyclerView::class.java.getDeclaredField("mAdapterHelper")
+                adapterHelperField.isAccessible = true
+                val adapterHelper = adapterHelperField.get(recyclerView)
+                val resetMethod = adapterHelper.javaClass.getDeclaredMethod("reset")
+                resetMethod.isAccessible = true
+                resetMethod.invoke(adapterHelper)
+            } catch (ignored: Exception) {}
+
+            // Clear the adapter to prevent recycling during teardown
+            viewPager.adapter = null
+
+            // Unsuppress layout after clearing adapter (won't do anything as view is being
+            // destroyed)
+            recyclerView.suppressLayout(false)
+        } catch (e: Exception) {
+            // View might already be in an invalid state
+        }
+        super.onDropViewInstance(view)
+    }
+
     override fun addView(host: NestedScrollableHost, child: View, index: Int) {
         PagerViewViewManagerImpl.addView(host, child, index)
     }
 
-    override fun getChildCount(parent: NestedScrollableHost) = PagerViewViewManagerImpl.getChildCount(parent)
+    override fun getChildCount(parent: NestedScrollableHost) =
+            PagerViewViewManagerImpl.getChildCount(parent)
 
     override fun getChildAt(parent: NestedScrollableHost, index: Int): View {
         return PagerViewViewManagerImpl.getChildAt(parent, index)
     }
 
     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)
     }
 
@@ -180,7 +296,11 @@ class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>(), RNCViewPa
         val view = PagerViewViewManagerImpl.getViewPager(root)
         Assertions.assertNotNull(view)
         val childCount = view.adapter?.itemCount
-        val canScroll = childCount != null && childCount > 0 && selectedPage >= 0 && selectedPage < childCount
+        val canScroll =
+                childCount != null &&
+                        childCount > 0 &&
+                        selectedPage >= 0 &&
+                        selectedPage < childCount
         if (canScroll) {
             PagerViewViewManagerImpl.setCurrentItem(view, selectedPage, scrollWithAnimation)
         }
@@ -200,10 +320,15 @@ class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>(), RNCViewPa
         }
     }
 
-    override fun getExportedCustomDirectEventTypeConstants(): MutableMap<String, Map<String, String>> {
+    override fun getExportedCustomDirectEventTypeConstants():
+            MutableMap<String, Map<String, String>> {
         return MapBuilder.of(
-                PageScrollEvent.EVENT_NAME, MapBuilder.of("registrationName", "onPageScroll"),
-                PageScrollStateChangedEvent.EVENT_NAME, MapBuilder.of("registrationName", "onPageScrollStateChanged"),
-                PageSelectedEvent.EVENT_NAME, MapBuilder.of("registrationName", "onPageSelected"))
+                PageScrollEvent.EVENT_NAME,
+                MapBuilder.of("registrationName", "onPageScroll"),
+                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)
     }