feat: Make Reanimated optional (disable Frame Processors if REA v2 is not installed) (#412)

* Fix building iOS without Reanimated

* Conditionally compile Frame Processors (gradle)

* Conditionally use externalNativeBuild

* Remove Reanimated import

* fix: Conditionally load REA/VisionCamera libraries

* fix: Add disable FP to docs

* fix: Fix dummy placeholder for Scheduler.mm

* fix: Fix dummy `Scheduler` declaration

* fix: Only init `CameraView` C++ side if frame processors are enabled

* fix: Install JSI Bindings on Frame Processor Manager ctor

* fix: Wrong conditional

* whoops

android/build.gradle

@@ -84,6 +84,9 @@ def getExtOrIntegerDefault(name) {
   return rootProject.ext.has(name) ? rootProject.ext.get(name) : (project.properties['VisionCamera_' + name]).toInteger()
 }
 
+def reanimated = rootProject.subprojects.find { it.name == 'react-native-reanimated' }
+def ENABLE_FRAME_PROCESSORS = !getExtOrDefault("disableFrameProcessors") && reanimated != null
+
 android {
   compileSdkVersion getExtOrIntegerDefault('compileSdkVersion')
   buildToolsVersion getExtOrDefault('buildToolsVersion')
@@ -93,6 +96,7 @@ android {
     minSdkVersion 21
     targetSdkVersion getExtOrIntegerDefault('targetSdkVersion')
 
+    if (ENABLE_FRAME_PROCESSORS) {
       externalNativeBuild {
         cmake {
           cppFlags "-fexceptions", "-frtti", "-std=c++1y", "-DONANDROID"
@@ -104,16 +108,19 @@ android {
         }
       }
     }
+  }
 
   dexOptions {
     javaMaxHeapSize "4g"
   }
 
+  if (ENABLE_FRAME_PROCESSORS) {
     externalNativeBuild {
       cmake {
         path "CMakeLists.txt"
       }
     }
+  }
 
   packagingOptions {
     // Exclude all Libraries that are already present in the user's app (through React Native or by him installing REA)
@@ -217,6 +224,8 @@ def kotlin_version = getExtOrDefault('kotlinVersion')
 dependencies {
   // noinspection GradleDynamicVersion
   implementation 'com.facebook.react:react-native:+'
+
+  if (ENABLE_FRAME_PROCESSORS) {
     implementation project(':react-native-reanimated')
 
     //noinspection GradleDynamicVersion
@@ -236,6 +245,7 @@ dependencies {
     def reaAAR = "${rootDir}/../node_modules/react-native-reanimated/android/react-native-reanimated-${minor}-${jsEngine}.aar"
 
     extractJNI(files(rnAAR, jscAAR, reaAAR))
+  }
 
   implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
   implementation "org.jetbrains.kotlinx:kotlinx-coroutines-guava:1.5.2"
@@ -252,6 +262,8 @@ dependencies {
   implementation "androidx.exifinterface:exifinterface:1.3.3"
 }
 
+
+if (ENABLE_FRAME_PROCESSORS) {
   // third-party-ndk deps headers
   // mostly a copy of https://github.com/software-mansion/react-native-reanimated/blob/master/android/build.gradle#L115
 
@@ -485,3 +497,4 @@ tasks.whenTaskAdded { task ->
       task.dependsOn(prepareThirdPartyNdkHeaders)
     }
   }
+}

android/gradle.properties

@@ -16,5 +16,6 @@ VisionCamera_compileSdkVersion=31
 VisionCamera_kotlinVersion=1.5.30
 VisionCamera_targetSdkVersion=31
 VisionCamera_ndkVersion=21.4.7075529
+VisionCamera_disableFrameProcessors=false
 android.enableJetifier=true
 android.useAndroidX=true

android/src/main/java/com/mrousavy/camera/CameraView.kt

@@ -26,6 +26,7 @@ import com.facebook.proguard.annotations.DoNotStrip
 import com.facebook.react.bridge.*
 import com.facebook.react.uimanager.events.RCTEventEmitter
 import com.mrousavy.camera.frameprocessor.FrameProcessorPerformanceDataCollector
+import com.mrousavy.camera.frameprocessor.FrameProcessorRuntimeManager
 import com.mrousavy.camera.utils.*
 import kotlinx.coroutines.*
 import kotlinx.coroutines.guava.await
@@ -159,7 +160,7 @@ class CameraView(context: Context, private val frameProcessorThread: ExecutorSer
     }
 
   @DoNotStrip
-  private var mHybridData: HybridData
+  private var mHybridData: HybridData? = null
 
   @Suppress("LiftReturnOrAssignment", "RedundantIf")
   internal val fallbackToSnapshot: Boolean
@@ -192,7 +193,9 @@ class CameraView(context: Context, private val frameProcessorThread: ExecutorSer
     }
 
   init {
+    if (FrameProcessorRuntimeManager.enableFrameProcessors) {
       mHybridData = initHybrid()
+    }
 
     previewView = PreviewView(context)
     previewView.layoutParams = LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)

android/src/main/java/com/mrousavy/camera/CameraViewModule.kt

@@ -57,10 +57,6 @@ class CameraViewModule(reactContext: ReactApplicationContext) : ReactContextBase
     if (frameProcessorManager == null) {
       frameProcessorThread.execute {
         frameProcessorManager = FrameProcessorRuntimeManager(reactApplicationContext, frameProcessorThread)
-
-        reactApplicationContext.runOnJSQueueThread {
-          frameProcessorManager!!.installJSIBindings()
-        }
       }
     }
   }

android/src/main/java/com/mrousavy/camera/frameprocessor/FrameProcessorRuntimeManager.kt

@@ -8,7 +8,6 @@ import com.facebook.react.bridge.ReactApplicationContext
 import com.facebook.react.turbomodule.core.CallInvokerHolderImpl
 import com.mrousavy.camera.CameraView
 import com.mrousavy.camera.ViewNotFoundError
-import com.swmansion.reanimated.Scheduler
 import java.lang.ref.WeakReference
 import java.util.concurrent.ExecutorService
 
@@ -17,23 +16,30 @@ class FrameProcessorRuntimeManager(context: ReactApplicationContext, frameProces
   companion object {
     const val TAG = "FrameProcessorRuntime"
     val Plugins: ArrayList<FrameProcessorPlugin> = ArrayList()
+    var enableFrameProcessors = true
 
     init {
+      try {
         System.loadLibrary("reanimated")
         System.loadLibrary("VisionCamera")
+      } catch (e: UnsatisfiedLinkError) {
+        Log.w(TAG, "Failed to load Reanimated/VisionCamera C++ library. Frame Processors are disabled!")
+        enableFrameProcessors = false
+      }
     }
   }
 
   @DoNotStrip
-  private var mHybridData: HybridData
-  private var mContext: WeakReference<ReactApplicationContext>
-  private var mScheduler: VisionCameraScheduler
+  private var mHybridData: HybridData? = null
+  private var mContext: WeakReference<ReactApplicationContext>? = null
+  private var mScheduler: VisionCameraScheduler? = null
 
   init {
+    if (enableFrameProcessors) {
       val holder = context.catalystInstance.jsCallInvokerHolder as CallInvokerHolderImpl
       mScheduler = VisionCameraScheduler(frameProcessorThread)
       mContext = WeakReference(context)
-    mHybridData = initHybrid(context.javaScriptContextHolder.get(), holder, mScheduler)
+      mHybridData = initHybrid(context.javaScriptContextHolder.get(), holder, mScheduler!!)
       initializeRuntime()
 
       Log.i(TAG, "Installing Frame Processor Plugins...")
@@ -41,15 +47,21 @@ class FrameProcessorRuntimeManager(context: ReactApplicationContext, frameProces
         registerPlugin(plugin)
       }
       Log.i(TAG, "Successfully installed ${Plugins.count()} Frame Processor Plugins!")
+
+      Log.i(TAG, "Installing JSI Bindings on JS Thread...")
+      context.runOnJSQueueThread {
+        installJSIBindings()
+      }
+    }
   }
 
   @Suppress("unused")
   @DoNotStrip
   @Keep
   fun findCameraViewById(viewId: Int): CameraView {
-    Log.d(TAG, "finding view $viewId...")
-    val view = mContext.get()?.currentActivity?.findViewById<CameraView>(viewId)
-    Log.d(TAG, "found view $viewId! is null: ${view == null}")
+    Log.d(TAG, "Finding view $viewId...")
+    val view = mContext?.get()?.currentActivity?.findViewById<CameraView>(viewId)
+    Log.d(TAG,  if (view != null) "Found view $viewId!" else "Couldn't find view $viewId!")
     return view ?: throw ViewNotFoundError(viewId)
   }
 
@@ -61,7 +73,5 @@ class FrameProcessorRuntimeManager(context: ReactApplicationContext, frameProces
   ): HybridData
   private external fun initializeRuntime()
   private external fun registerPlugin(plugin: FrameProcessorPlugin)
-
-  // public C++ funcs
-  external fun installJSIBindings()
+  private external fun installJSIBindings()
 }

docs/docs/guides/FRAME_PROCESSORS.mdx

@@ -208,7 +208,21 @@ The Frame Processor gets called with a `Frame` object, which is a **JSI HostObje
 
 ### Disabling Frame Processors
 
-The Frame Processor API spawns a secondary JavaScript Runtime which consumes a small amount of extra CPU and RAM. If you're not using Frame Processors at all, you can disable them by setting the `VISION_CAMERA_DISABLE_FRAME_PROCESSORS` flag. Inside your `project.pbxproj`, find the `GCC_PREPROCESSOR_DEFINITIONS` parameter and add the flag:
+The Frame Processor API spawns a secondary JavaScript Runtime which consumes a small amount of extra CPU and RAM. Additionally, compile time increases since Frame Processors are written in native C++. If you're not using Frame Processors at all, you can disable them:
+
+#### Android
+
+Inside your `gradle.properties` file, add the `disableFrameProcessors` flag:
+
+```
+disableFrameProcessors=true
+```
+
+Then, clean and rebuild your project.
+
+#### iOS
+
+Inside your `project.pbxproj`, find the `GCC_PREPROCESSOR_DEFINITIONS` group and add the flag:
 
 ```txt {3}
 GCC_PREPROCESSOR_DEFINITIONS = (

ios/Frame Processor/FrameProcessorRuntimeManager.mm

@@ -25,6 +25,7 @@
       #import <RNReanimated/RuntimeManager.h>
       #import <RNReanimated/RuntimeDecorator.h>
       #import <RNReanimated/REAIOSErrorHandler.h>
+      #import "VisionCameraScheduler.h"
       #define ENABLE_FRAME_PROCESSORS
     #else
       #warning Your react-native-reanimated version is not compatible with VisionCamera, Frame Processors are disabled. Make sure you're using reanimated 2.2.0 or above!
@@ -36,7 +37,6 @@
 
 #import "FrameProcessorUtils.h"
 #import "FrameProcessorCallback.h"
-#import "VisionCameraScheduler.h"
 #import "../React Utils/MakeJSIRuntime.h"
 #import "../React Utils/JSIUtils.h"
 

ios/Frame Processor/VisionCameraScheduler.h

@@ -8,16 +8,28 @@
 
 #pragma once
 
-#import <RNReanimated/Scheduler.h>
+#include <functional>
 #import <React-callinvoker/ReactCommon/CallInvoker.h>
 
+#if __has_include(<RNReanimated/RuntimeManager.h>)
+  #import <RNReanimated/Scheduler.h>
+#else
+  // dummy placeholder
+  namespace reanimated {
+    class Scheduler {
+    public:
+      virtual void scheduleOnUI(std::function<void()> job);
+    protected:
+      std::shared_ptr<facebook::react::CallInvoker> jsCallInvoker_;
+    };
+  }
+#endif
+
 namespace vision {
 
-using namespace facebook;
-
 class VisionCameraScheduler : public reanimated::Scheduler {
 public:
-  VisionCameraScheduler(std::shared_ptr<react::CallInvoker> jsInvoker);
+  VisionCameraScheduler(std::shared_ptr<facebook::react::CallInvoker> jsInvoker);
   virtual ~VisionCameraScheduler();
 
   void scheduleOnUI(std::function<void()> job) override;