fix(android): drop the extra native ref on legacy view model instances

android/build.gradle

@@ -47,6 +47,7 @@ android {
     minSdkVersion getExtOrIntegerDefault("minSdkVersion")
     targetSdkVersion getExtOrIntegerDefault("targetSdkVersion")
     buildConfigField "boolean", "RIVE_SKIP_SETUP", "$skipSetup"
+    buildConfigField "String", "RIVE_ANDROID_VERSION", "\"${getRiveAndroidVersion()}\""
 
     externalNativeBuild {
       cmake {

android/src/legacy/java/com/margelo/nitro/rive/HybridViewModel.kt

@@ -22,7 +22,7 @@ class HybridViewModel(private val viewModel: ViewModel) : HybridViewModelSpec()
   override fun createInstanceByIndex(index: Double): HybridViewModelInstanceSpec? {
     if (index < 0) return null
     try {
-      val vmi = viewModel.createInstanceFromIndex(index.toInt())
+      val vmi = viewModel.createInstanceFromIndex(index.toInt()).dropExtraNativeRef()
       return HybridViewModelInstance(vmi)
     } catch (e: ViewModelException) {
       return null
@@ -31,7 +31,7 @@ class HybridViewModel(private val viewModel: ViewModel) : HybridViewModelSpec()
 
   override fun createInstanceByName(name: String): HybridViewModelInstanceSpec? {
     try {
-      val vmi = viewModel.createInstanceFromName(name)
+      val vmi = viewModel.createInstanceFromName(name).dropExtraNativeRef()
       return HybridViewModelInstance(vmi)
     } catch (e: ViewModelException) {
       return null
@@ -40,7 +40,7 @@ class HybridViewModel(private val viewModel: ViewModel) : HybridViewModelSpec()
 
   override fun createDefaultInstance(): HybridViewModelInstanceSpec? {
     try {
-      val vmi = viewModel.createDefaultInstance()
+      val vmi = viewModel.createDefaultInstance().dropExtraNativeRef()
       return HybridViewModelInstance(vmi)
     } catch (e: ViewModelException) {
       return null
@@ -49,7 +49,7 @@ class HybridViewModel(private val viewModel: ViewModel) : HybridViewModelSpec()
 
   override fun createInstance(): HybridViewModelInstanceSpec? {
     try {
-      val vmi = viewModel.createBlankInstance()
+      val vmi = viewModel.createBlankInstance().dropExtraNativeRef()
       return HybridViewModelInstance(vmi)
     } catch (e: ViewModelException) {
       return null

android/src/legacy/java/com/margelo/nitro/rive/ViewModelInstanceExtraRef.kt

@@ -0,0 +1,35 @@
+package com.margelo.nitro.rive
+
+import android.util.Log
+import app.rive.runtime.kotlin.core.ViewModelInstance
+import com.rive.BuildConfig
+
+// rive-android's ViewModel.create*Instance hands Kotlin a pointer that already
+// owns one native ref, and the ViewModelInstance constructor takes a second that
+// release() never drops, so created instances (and images bound to them) outlive
+// their File. Dropping it on a release without the bug would free an instance
+// still in use, so only versions known to be affected are patched.
+private val AFFECTED_VERSIONS = versionCode(10, 4, 5)..versionCode(11, 14, 3)
+
+private fun versionCode(major: Int, minor: Int, patch: Int) =
+  major * 1_000_000L + minor * 1_000L + patch
+
+private fun parseVersion(version: String): Long? {
+  val parts = version.substringBefore('-').split('.').map { it.toIntOrNull() ?: return null }
+  if (parts.size != 3) return null
+  return versionCode(parts[0], parts[1], parts[2])
+}
+
+private val derefInstance = runCatching {
+  val version = parseVersion(BuildConfig.RIVE_ANDROID_VERSION)
+  if (version == null || version !in AFFECTED_VERSIONS) return@runCatching null
+  ViewModelInstance::class.java
+    .getDeclaredMethod("cppDerefInstance", Long::class.javaPrimitiveType)
+    .apply { isAccessible = true }
+}.onFailure { Log.w("RiveViewModelInstance", "Can't drop the extra native ref", it) }
+  .getOrNull()
+
+internal fun ViewModelInstance.dropExtraNativeRef(): ViewModelInstance {
+  derefInstance?.invoke(this, cppPointer)
+  return this
+}

android/src/legacy/java/com/rive/RiveReactNativeView.kt

@@ -24,6 +24,7 @@ import app.rive.runtime.kotlin.core.errors.ViewModelException
 import com.margelo.nitro.rive.EventPropertiesOutput
 import com.margelo.nitro.rive.EventPropertiesOutputExtensions as EPO
 import com.margelo.nitro.rive.RiveEventType
+import com.margelo.nitro.rive.dropExtraNativeRef
 import com.margelo.nitro.rive.UnifiedRiveEvent as RNEvent
 import kotlinx.coroutines.CompletableDeferred
 
@@ -398,7 +399,7 @@ class RiveReactNativeView(context: ThemedReactContext) : FrameLayout(context) {
           } catch (e: ViewModelException) {
             null
           }?.let {
-            val instance = it.createDefaultInstance()
+            val instance = it.createDefaultInstance().dropExtraNativeRef()
             stateMachine.viewModelInstance = instance
           }
         }
@@ -411,7 +412,7 @@ class RiveReactNativeView(context: ThemedReactContext) : FrameLayout(context) {
         val file = riveAnimationView?.controller?.file
         if (artboard != null && file != null) {
           val viewModel = file.defaultViewModelForArtboard(artboard)
-          val instance = viewModel.createInstanceFromName(bindData.name)
+          val instance = viewModel.createInstanceFromName(bindData.name).dropExtraNativeRef()
           stateMachine.viewModelInstance = instance
         }
       }