fix(Android): prevent crash with InsetsObserverProxy already register…

…ed (#2526)

## Description

Activity restarts do not invalidate JVM state entirely (at least it
seems so), therefore InsetsObserverProxy
kept being registered on some decorview between activity restarts
(context recreations) leading to crash
(we guard against multiple registrations).

Fixes #2519
Possibly fixes #2507

## Changes

`InsetsOberverProxy` row registers for context lifecycle, when it's
destroyed it cleans its state.

## Test code and steps to reproduce

Haven't managed to reproduce this myself, but got confirmation in #2507
that this patch works.

## Checklist

- [ ] Included code example that can be used to test this change
- [ ] Updated TS types
- [ ] Updated documentation: <!-- For adding new props to native-stack
-->
- [ ]
https://github.com/software-mansion/react-native-screens/blob/main/guides/GUIDE_FOR_LIBRARY_AUTHORS.md
- [ ]
https://github.com/software-mansion/react-native-screens/blob/main/native-stack/README.md
- [ ]
https://github.com/software-mansion/react-native-screens/blob/main/src/types.tsx
- [ ]
https://github.com/software-mansion/react-native-screens/blob/main/src/native-stack/types.tsx
- [ ] Ensured that CI passes

android/src/main/java/com/swmansion/rnscreens/InsetsObserverProxy.kt

@@ -1,12 +1,15 @@
 package com.swmansion.rnscreens
 
+import android.util.Log
 import android.view.View
 import androidx.core.view.OnApplyWindowInsetsListener
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
+import com.facebook.react.bridge.LifecycleEventListener
+import com.facebook.react.bridge.ReactApplicationContext
 import java.lang.ref.WeakReference
 
-object InsetsObserverProxy : OnApplyWindowInsetsListener {
+object InsetsObserverProxy : OnApplyWindowInsetsListener, LifecycleEventListener {
     private val listeners: ArrayList<OnApplyWindowInsetsListener> = arrayListOf()
     private var eventSourceView: WeakReference<View> = WeakReference(null)
 
@@ -15,8 +18,16 @@ object InsetsObserverProxy : OnApplyWindowInsetsListener {
     // whether this observer has been initially registered.
     private var hasBeenRegistered: Boolean = false
 
+    // Mainly debug variable to log warnings in case we missed some code path regarding
+    // context lifetime handling.
+    private var isObservingContextLifetime: Boolean = false
+
     private var shouldForwardInsetsToView = true
 
+    // Allow only when we have not been registered yet or the view we're observing has been
+    // invalidated due to some lifecycle we have not observed.
+    private val allowRegistration get() = !hasBeenRegistered || eventSourceView.get() == null
+
     override fun onApplyWindowInsets(
         v: View,
         insets: WindowInsetsCompat,
@@ -34,6 +45,34 @@ object InsetsObserverProxy : OnApplyWindowInsetsListener {
         return rollingInsets
     }
 
+    // Call this method to ensure that the observer proxy is
+    // unregistered when apps is destroyed or we change activity.
+    fun registerWithContext(context: ReactApplicationContext) {
+        if (isObservingContextLifetime) {
+            Log.w(
+                "[RNScreens]",
+                "InsetObserverProxy registers on new context while it has not been invalidated on the old one. Please report this as issue at https://github.com/software-mansion/react-native-screens/issues",
+            )
+        }
+
+        isObservingContextLifetime = true
+        context.addLifecycleEventListener(this)
+    }
+
+    override fun onHostResume() = Unit
+
+    override fun onHostPause() = Unit
+
+    override fun onHostDestroy() {
+        val observedView = getObservedView()
+        if (hasBeenRegistered && observedView != null) {
+            ViewCompat.setOnApplyWindowInsetsListener(observedView, null)
+            hasBeenRegistered = false
+            eventSourceView.clear()
+        }
+        isObservingContextLifetime = false
+    }
+
     fun addOnApplyWindowInsetsListener(listener: OnApplyWindowInsetsListener) {
         listeners.add(listener)
     }
@@ -42,16 +81,17 @@ object InsetsObserverProxy : OnApplyWindowInsetsListener {
         listeners.remove(listener)
     }
 
-    fun registerOnView(view: View) {
-        if (!hasBeenRegistered) {
+    /**
+     * @return boolean whether the proxy registered as a listener on a view
+     */
+    fun registerOnView(view: View): Boolean {
+        if (allowRegistration) {
             ViewCompat.setOnApplyWindowInsetsListener(view, this)
             eventSourceView = WeakReference(view)
             hasBeenRegistered = true
-        } else if (getObservedView() != view) {
-            throw IllegalStateException(
-                "[RNScreens] Attempt to register InsetsObserverProxy on $view while it has been already registered on ${getObservedView()}",
-            )
+            return true
         }
+        return false
     }
 
     fun unregister() {

android/src/main/java/com/swmansion/rnscreens/RNScreensPackage.kt

@@ -29,6 +29,10 @@ class RNScreensPackage : TurboReactPackage() {
             screenDummyLayoutHelper = ScreenDummyLayoutHelper(reactContext)
         }
 
+        // Proxy needs to register for lifecycle events in order to unregister itself
+        // on activity restarts.
+        InsetsObserverProxy.registerWithContext(reactContext)
+
         return listOf<ViewManager<*, *>>(
             ScreenContainerViewManager(),
             ScreenViewManager(),

android/src/main/java/com/swmansion/rnscreens/bottomsheet/DimmingFragment.kt

@@ -208,7 +208,7 @@ class DimmingFragment(
     override fun onStart() {
         // This is the earliest we can access child fragment manager & present another fragment
         super.onStart()
-        insetsProxy.registerOnView(requireRootView())
+        insetsProxy.registerOnView(requireDecorView())
         presentNestedFragment()
     }
 
@@ -307,7 +307,7 @@ class DimmingFragment(
             }
     }
 
-    private fun requireRootView(): View =
+    private fun requireDecorView(): View =
         checkNotNull(screen.reactContext.currentActivity) { "[RNScreens] Attempt to access activity on detached context" }
             .window.decorView