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

ios/Frame Processor/FrameHostObject.h

@@ -25,7 +25,7 @@ public:
 
 public:
   Frame* frame;
-  
+
 private:
   void assertIsFrameStrong(jsi::Runtime& runtime, const std::string& accessedPropName);
 };

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"
 
@@ -153,7 +153,7 @@ __attribute__((objc_runtime_name("_TtC12VisionCamera10CameraView")))
 
       dispatch_async(CameraQueues.frameProcessorQueue, [=]() {
         NSLog(@"FrameProcessorBindings: Converting worklet to Objective-C callback...");
-        
+
         auto& rt = *runtimeManager->runtime;
         auto function = worklet->getValue(rt).asObject(rt).asFunction(rt);
 

ios/Frame Processor/VisionCameraScheduler.h

@@ -8,18 +8,30 @@
 
 #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;
 };
 

ios/Frame Processor/VisionCameraScheduler.mm

@@ -18,9 +18,9 @@ __attribute__((objc_runtime_name("_TtC12VisionCamera12CameraQueues")))
 @end
 
 namespace vision {
-  
+
 using namespace facebook;
-  
+
 VisionCameraScheduler::VisionCameraScheduler(std::shared_ptr<react::CallInvoker> jsInvoker) {
   this->jsCallInvoker_ = jsInvoker;
 }
@@ -34,6 +34,6 @@ void VisionCameraScheduler::scheduleOnUI(std::function<void()> job) {
 
 VisionCameraScheduler::~VisionCameraScheduler(){
 }
-  
-  
+
+
 } // namespace vision