fix: make play/pause control the experimental render loop (iOS + Android) (#285)

## Problem
On the experimental backend, `play()`/`pause()`/`reset()` were no-ops —
animations couldn't be paused/resumed and `autoPlay={false}` was
ignored.
- **iOS**: only mutated a private `isPaused` flag never forwarded to
`RiveUIView`.
- **Android**: empty bodies; the render loop advanced unconditionally
and `autoPlay` was never consumed.

Additionally, `useRiveTrigger` never fired on Android experimental —
three separate issues:
1. `awaitViewReady()` resolved at end of `configure()`, before the
TextureView surface existed. Triggers fired before the surface was up
were lost.
2. `getTriggerFlow` has `replay=0` (no initial value on subscription);
`drop=1` was silently eating the first real trigger.
3. The listener coroutine was launched with `DEFAULT` start, so it was
merely queued on `Dispatchers.Default` and could miss a trigger fired
before it reached `collect()`.

Also, `dataBind={{ byName }}` on Android always bound from
`vmNames.first()` (first VM in file) instead of the artboard's default
ViewModel.

## Fix
- **iOS** (`ios/new/RiveReactNativeView.swift`): forward `isPaused` to
`RiveUIView` in play/pause/playIfNeeded, pass it into
`RiveUIView(rive:isPaused:)`, set it from `autoPlay`.
- **Android** (`android/src/new/.../RiveReactNativeView.kt`): gate
`advanceStateMachine` on a `paused` flag toggled by play/pause, honor
`autoPlay`. Signal `awaitViewReady()` on first rendered frame (not end
of configure).
- **Android triggers**: use `drop=0` for trigger flow (no initial value
to skip); launch listener coroutine with `CoroutineStart.UNDISPATCHED`.
- **Android byName**: use `ViewModelSource.DefaultForArtboard(art)`
instead of `Named(vmNames.first())`, matching iOS and the Auto path.
- **reset()**: deprecated. Neither experimental backend has a reset
primitive — marked `@deprecated` in the spec, experimental impl logs an
error and does nothing.

## Verification
- `autoplay.harness.tsx`: pause freezes `ypos`, play resumes it,
`autoPlay={false}` holds. Green on both platforms.
- `use-rive-trigger.harness.tsx`: both stable and unstable-callback
tests now pass on Android.
- `viewmodel-instance-lookup.harness.tsx`: byName regression test
verifies `artboard2 + byName("vmi1") → _id="vm2.vmi1.id"` (not vm1).
- CI: legacy iOS `pod install` step clears `Podfile.lock` to avoid
external `fast_float` checksum rejection.

Author: mfazekas

.github/workflows/ci.yml

@@ -120,6 +120,11 @@ jobs:
         if: env.turbo_cache_hit != 1
         run: |
           /bin/bash -c "yes | $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager --licenses > /dev/null"
+          for i in 1 2 3; do
+            $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager "ndk;27.1.12297006" && break
+            echo "NDK install attempt $i failed, retrying..."
+            sleep 10
+          done
 
       - name: Cache Gradle
         if: env.turbo_cache_hit != 1
@@ -387,6 +392,10 @@ jobs:
       - name: Debug - Check for console logs
         if: failure() || cancelled()
         run: |
+          echo "=== Metro health ==="
+          curl -s --max-time 5 http://localhost:8081/status || echo "Metro not responding"
+          echo "=== Metro process ==="
+          lsof -i:8081 | head -5 || echo "Nothing on port 8081"
           echo "=== Simulator logs (last 5m) ==="
           xcrun simctl spawn booted log show --predicate 'processImagePath CONTAINS "RiveExample"' --last 5m --style compact 2>&1 | tail -200 || echo "No logs found"
           echo "=== System log for Metro/Node ==="
@@ -413,6 +422,11 @@ jobs:
       - name: Finalize Android SDK
         run: |
           /bin/bash -c "yes | $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager --licenses > /dev/null"
+          for i in 1 2 3; do
+            $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager "ndk;27.1.12297006" && break
+            echo "NDK install attempt $i failed, retrying..."
+            sleep 10
+          done
 
       - name: Cache Gradle
         uses: actions/cache@v4
@@ -582,6 +596,10 @@ jobs:
       - name: Debug - Check for console logs
         if: failure()
         run: |
+          echo "=== Metro health ==="
+          curl -s --max-time 5 http://localhost:8081/status || echo "Metro not responding"
+          echo "=== Metro process ==="
+          lsof -i:8081 | head -5 || echo "Nothing on port 8081"
           echo "=== Checking simulator logs for errors ==="
           xcrun simctl spawn booted log show --predicate 'processImagePath CONTAINS "RiveExample"' --last 5m --style compact 2>&1 | tail -200 || echo "No logs found"
 
@@ -606,6 +624,11 @@ jobs:
       - name: Finalize Android SDK
         run: |
           /bin/bash -c "yes | $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager --licenses > /dev/null"
+          for i in 1 2 3; do
+            $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager "ndk;27.1.12297006" && break
+            echo "NDK install attempt $i failed, retrying..."
+            sleep 10
+          done
 
       - name: Enable legacy Rive backend
         run: |

.gitignore

@@ -93,3 +93,6 @@ example/src/reproducers/local/*
 
 # Test coverage
 coverage/
+
+# Kotlin build artifacts
+**/.kotlin/

android/src/main/java/com/margelo/nitro/rive/BaseHybridViewModelPropertyImpl.kt

@@ -12,14 +12,13 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.drop
 import java.lang.ref.WeakReference
 import java.util.UUID
-import java.util.concurrent.ConcurrentHashMap
 
 @Keep
 @DoNotStrip
 class BaseHybridViewModelPropertyImpl<T> : BaseHybridViewModelProperty<T> {
   override var scope: CoroutineScope? = null
   override var job: Job? = null
-  override val listeners = ConcurrentHashMap<String, (T) -> Unit>()
+  override val listeners = mutableMapOf<String, (T) -> Unit>()
 
   override fun ensureValueListenerJob(valueFlow: Flow<T>, drop: Int) {
     if (scope == null) {

android/src/new/java/com/margelo/nitro/rive/HybridViewModelTriggerProperty.kt

@@ -18,8 +18,7 @@ class HybridViewModelTriggerProperty(
 
   override fun addListener(onChanged: () -> Unit): () -> Unit {
     val remover = addListenerInternal { _ -> onChanged() }
-    // Triggers use drop=0: getTriggerFlow has replay=0 and emits nothing on
-    // subscription, so there is no initial value to skip.
+    // drop=0: getTriggerFlow (replay=0) emits nothing on subscription, unlike number/boolean flows.
     ensureValueListenerJob(instance.getTriggerFlow(path), 0)
     return remover
   }

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

@@ -18,6 +18,7 @@ import app.rive.core.RiveSurface
 import app.rive.core.StateMachineHandle
 import com.facebook.react.uimanager.ThemedReactContext
 import com.margelo.nitro.rive.RiveErrorLogger
+import com.margelo.nitro.rive.RiveLog
 import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -77,6 +78,9 @@ class RiveReactNativeView(context: ThemedReactContext) : FrameLayout(context) {
   private var lastFrameTimeNs = 0L
   private var frameCount = 0L
 
+  @Volatile
+  private var paused = false
+
   private val textureView = TextureView(context).apply {
     layoutParams = LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)
     surfaceTextureListener = object : TextureView.SurfaceTextureListener {
@@ -129,13 +133,13 @@ class RiveReactNativeView(context: ThemedReactContext) : FrameLayout(context) {
 
       if (worker != null && art != null && sm != null && rs != null) {
         try {
-          worker.advanceStateMachine(sm, deltaTime)
+          if (!paused) {
+            worker.advanceStateMachine(sm, deltaTime)
+          }
           worker.draw(art, sm, rs, activeFit)
           frameCount++
-          // Signal readiness only once the state machine is actually running
-          // (surface created + first frame drawn), so callers awaiting
-          // awaitViewReady() before firing triggers don't fire too early.
-          if (frameCount == 1L) {
+          val isFirstFrame = frameCount == 1L
+          if (isFirstFrame) {
             viewReadyDeferred.complete(true)
           }
         } catch (e: Exception) {
@@ -200,6 +204,7 @@ class RiveReactNativeView(context: ThemedReactContext) : FrameLayout(context) {
 
       Log.d(TAG, "configure: artboard=${artboardHandle != null} sm=${stateMachineHandle != null} surface=${riveSurface != null}")
 
+      paused = !config.autoPlay
       startRenderLoop()
     }
 
@@ -208,7 +213,6 @@ class RiveReactNativeView(context: ThemedReactContext) : FrameLayout(context) {
     if (dataBindingChanged || initialUpdate) {
       applyDataBinding(config.bindData, config.riveFile)
     }
-
   }
 
   private fun resizeArtboardIfLayout() {
@@ -312,14 +316,11 @@ class RiveReactNativeView(context: ThemedReactContext) : FrameLayout(context) {
       }
       is BindData.ByName -> {
         try {
-          val vmNames = kotlinx.coroutines.runBlocking { riveFile.getViewModelNames() }
-          if (vmNames.isNotEmpty()) {
-            val vmSource = ViewModelSource.Named(vmNames.first())
-            val source = vmSource.namedInstance(bindData.name)
-            val instance = ViewModelInstance.fromFile(riveFile, source)
-            boundInstance = instance
-            bindInstanceToStateMachine(instance)
-          }
+          val art = artboard ?: return
+          val source = ViewModelSource.DefaultForArtboard(art).namedInstance(bindData.name)
+          val instance = ViewModelInstance.fromFile(riveFile, source)
+          boundInstance = instance
+          bindInstanceToStateMachine(instance)
         } catch (e: Exception) {
           Log.e(TAG, "Failed to create named instance", e)
         }
@@ -337,13 +338,22 @@ class RiveReactNativeView(context: ThemedReactContext) : FrameLayout(context) {
     }
   }
 
-  fun play() { /* controlled by render loop */ }
+  fun play() {
+    paused = false
+  }
 
-  fun pause() { /* controlled by render loop */ }
+  fun pause() {
+    paused = true
+  }
 
-  fun reset() { /* controlled by render loop */ }
+  // Deprecated: the experimental Rive runtime has no reset primitive.
+  fun reset() {
+    RiveLog.e(TAG, "reset() is deprecated and not supported on the experimental backend")
+  }
 
-  fun playIfNeeded() { /* controlled by render loop */ }
+  fun playIfNeeded() {
+    paused = false
+  }
 
   fun setNumberInputValue(name: String, value: Double, path: String?) {
     throw UnsupportedOperationException("SMI inputs not supported in experimental API")