docs: Add Kotlin & Swift FP plugins examples (#1902)

* chore(docs): add Kotlin FP example

* chore(docs): add Swift FP plugin

package/example/android/app/build.gradle

@@ -1,5 +1,6 @@
 apply plugin: "com.android.application"
 apply plugin: "com.facebook.react"
+apply plugin: "kotlin-android"
 
 import com.android.build.OutputFile
 

package/example/android/app/src/main/java/com/mrousavy/camera/example/ExampleKotlinFrameProcessorPlugin.kt

@@ -0,0 +1,35 @@
+package com.mrousavy.camera.example
+
+import android.util.Log
+import com.mrousavy.camera.frameprocessor.Frame
+import com.mrousavy.camera.frameprocessor.FrameProcessorPlugin
+
+class ExampleKotlinFrameProcessorPlugin: FrameProcessorPlugin() {
+    override fun callback(frame: Frame, params: Map<String, Any>?): Any? {
+        if (params == null) {
+            return null
+        }
+
+        val image = frame.image
+        Log.d(
+            "ExampleKotlinPlugin",
+            image.width.toString() + " x " + image.height + " Image with format #" + image.format + ". Logging " + params.size + " parameters:"
+        )
+
+        for (key in params.keys) {
+            val value = params[key]
+            Log.d("ExampleKotlinPlugin", "  -> " + if (value == null) "(null)" else value.toString() + " (" + value.javaClass.name + ")")
+        }
+
+        return hashMapOf<String, Any>(
+            "example_str" to "KotlinTest",
+            "example_bool" to false,
+            "example_double" to 6.7,
+            "example_array" to arrayListOf<Any>(
+                "Good bye",
+                false,
+                21.37
+            )
+        )
+    }
+}

package/example/android/app/src/main/java/com/mrousavy/camera/example/MainApplication.java

@@ -66,5 +66,6 @@ public class MainApplication extends Application implements ReactApplication {
     }
 
     FrameProcessorPluginRegistry.addFrameProcessorPlugin("example_plugin", options -> new ExampleFrameProcessorPlugin());
+    FrameProcessorPluginRegistry.addFrameProcessorPlugin("example_kotlin_swift_plugin", options -> new ExampleKotlinFrameProcessorPlugin());
   }
 }

package/example/android/build.gradle

@@ -15,5 +15,6 @@ buildscript {
     dependencies {
         classpath('com.android.tools.build:gradle:7.4.1')
         classpath("com.facebook.react:react-native-gradle-plugin")
+        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.7.22")
     }
 }

package/example/ios/Frame Processor Plugins/Example Plugin/ExampleFrameProcessorPlugin.m

@@ -18,7 +18,7 @@
 
 @implementation ExampleFrameProcessorPlugin
 
-- (id)callback:(Frame *)frame withArguments:(NSArray<id> *)arguments {
+- (id)callback:(Frame *)frame withArguments:(NSDictionary *)arguments {
   CVPixelBufferRef imageBuffer = CMSampleBufferGetImageBuffer(frame.buffer);
   NSLog(@"ExamplePlugin: %zu x %zu Image. Logging %lu parameters:", CVPixelBufferGetWidth(imageBuffer), CVPixelBufferGetHeight(imageBuffer), (unsigned long)arguments.count);
 
@@ -28,11 +28,11 @@
 
   return @{
     @"example_str": @"Test",
-    @"example_bool": @true,
+    @"example_bool": @(YES),
     @"example_double": @5.3,
     @"example_array": @[
       @"Hello",
-      @true,
+      @(YES),
       @17.38
     ]
   };

package/example/ios/Frame Processor Plugins/Example Swift Plugin/ExampleSwiftFrameProcessor.m

@@ -0,0 +1,31 @@
+//
+//  ExampleSwiftFrameProcessor.m
+//  VisionCameraExample
+//
+//  Created by Mateusz Medrek on 02/10/2023.
+//
+
+#if __has_include(<VisionCamera/FrameProcessorPlugin.h>)
+#import <Foundation/Foundation.h>
+#import <VisionCamera/FrameProcessorPlugin.h>
+#import <VisionCamera/FrameProcessorPluginRegistry.h>
+#import <VisionCamera/Frame.h>
+
+#import "VisionCameraExample-Swift.h"
+
+// Example for a Swift Frame Processor plugin automatic registration
+@interface ExampleSwiftFrameProcessorPlugin (FrameProcessorPluginLoader)
+@end
+
+@implementation ExampleSwiftFrameProcessorPlugin (FrameProcessorPluginLoader)
+
++ (void)load
+{
+  [FrameProcessorPluginRegistry addFrameProcessorPlugin:@"example_kotlin_swift_plugin" withInitializer:^FrameProcessorPlugin * _Nonnull(NSDictionary * _Nullable options) {
+    return [[ExampleSwiftFrameProcessorPlugin alloc] init];
+  }];
+}
+
+@end
+
+#endif

package/example/ios/Frame Processor Plugins/Example Swift Plugin/ExampleSwiftFrameProcessor.swift

@@ -0,0 +1,42 @@
+//
+//  ExampleSwiftFrameProcessor.swift
+//  VisionCameraExample
+//
+//  Created by Mateusz Medrek on 02/10/2023.
+//
+
+#if VISION_CAMERA_ENABLE_FRAME_PROCESSORS
+import VisionCamera
+
+// Example for a Swift Frame Processor plugin
+@objc(ExampleSwiftFrameProcessorPlugin)
+public class ExampleSwiftFrameProcessorPlugin: FrameProcessorPlugin {
+  public override func callback(_ frame: Frame, withArguments arguments: [AnyHashable: Any]?) -> Any? {
+    let imageBuffer = CMSampleBufferGetImageBuffer(frame.buffer)
+
+    if let arguments, let imageBuffer {
+      let width = CVPixelBufferGetWidth(imageBuffer)
+      let height = CVPixelBufferGetHeight(imageBuffer)
+      let count = arguments.count
+
+      print(
+        "ExampleSwiftPlugin: \(width) x \(height) Image. Logging \(count) parameters:"
+      )
+
+      for key in arguments.keys {
+        let value = arguments[key]
+        let valueString = String(describing: value)
+        let valueClassString = String(describing: value.self)
+        print("ExampleSwiftPlugin:   -> \(valueString) (\(valueClassString))")
+      }
+    }
+
+    return [
+      "example_str": "SwiftTest",
+      "example_bool": false,
+      "example_double": 6.7,
+      "example_array": ["Good bye", false, 21.37]
+    ]
+  }
+}
+#endif

package/example/ios/Podfile

@@ -5,6 +5,8 @@ require Pod::Executable.execute_command('node', ['-p',
     {paths: [process.argv[1]]},
   )', __dir__]).strip
 
+require_relative './vc_example_cocoapod_utils.rb'
+
 platform :ios, min_ios_version_supported
 prepare_react_native_project!
 
@@ -46,5 +48,8 @@ target 'VisionCameraExample' do
       :mac_catalyst_enabled => false
     )
     __apply_Xcode_12_5_M1_post_install_workaround(installer)
+
+    # Define "VISION_CAMERA_ENABLE_FRAME_PROCESSORS" Swift compiler flag if frame processor are enabled
+    set_frame_processor_swift_flag_in_example_project(installer)
   end
 end

package/example/ios/Podfile.lock

@@ -736,6 +736,6 @@ SPEC CHECKSUMS:
   VisionCamera: cb27c70cea1439e9a946bf2acdc059f8fb1bc68c
   Yoga: 8796b55dba14d7004f980b54bcc9833ee45b28ce
 
-PODFILE CHECKSUM: ab9c06b18c63e741c04349c0fd630c6d3145081c
+PODFILE CHECKSUM: 27f53791141a3303d814e09b55770336416ff4eb
 
 COCOAPODS: 1.13.0

package/example/ios/VisionCameraExample-Bridging-Header.h

@@ -1,8 +1,3 @@
 //
 //  Use this file to import your target's public headers that you would like to expose to Swift.
 //
-
-#if VISION_CAMERA_ENABLE_FRAME_PROCESSORS
-#import <VisionCamera/FrameProcessorPlugin.h>
-#import <VisionCamera/Frame.h>
-#endif

package/example/ios/VisionCameraExample.xcodeproj/project.pbxproj

@@ -11,7 +11,8 @@
 		13B07FBF1A68108700A75B9A /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 13B07FB51A68108700A75B9A /* Images.xcassets */; };
 		13B07FC11A68108700A75B9A /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = 13B07FB71A68108700A75B9A /* main.m */; };
 		81AB9BB82411601600AC10FF /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 81AB9BB72411601600AC10FF /* LaunchScreen.storyboard */; };
-		B8DB3BD5263DE8B7004C18D7 /* BuildFile in Sources */ = {isa = PBXBuildFile; };
+		839E2C632ACB2E330037BC2B /* ExampleSwiftFrameProcessor.m in Sources */ = {isa = PBXBuildFile; fileRef = 839E2C622ACB2E330037BC2B /* ExampleSwiftFrameProcessor.m */; };
+		839E2C652ACB2E420037BC2B /* ExampleSwiftFrameProcessor.swift in Sources */ = {isa = PBXBuildFile; fileRef = 839E2C642ACB2E420037BC2B /* ExampleSwiftFrameProcessor.swift */; };
 		B8DB3BDC263DEA31004C18D7 /* ExampleFrameProcessorPlugin.m in Sources */ = {isa = PBXBuildFile; fileRef = B8DB3BD8263DEA31004C18D7 /* ExampleFrameProcessorPlugin.m */; };
 		B8F0E10825E0199F00586F16 /* File.swift in Sources */ = {isa = PBXBuildFile; fileRef = B8F0E10725E0199F00586F16 /* File.swift */; };
 		C0B129659921D2EA967280B2 /* libPods-VisionCameraExample.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 3CDCFE89C25C89320B98945E /* libPods-VisionCameraExample.a */; };
@@ -27,6 +28,8 @@
 		13B07FB71A68108700A75B9A /* main.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = main.m; path = VisionCameraExample/main.m; sourceTree = "<group>"; };
 		3CDCFE89C25C89320B98945E /* libPods-VisionCameraExample.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-VisionCameraExample.a"; sourceTree = BUILT_PRODUCTS_DIR; };
 		81AB9BB72411601600AC10FF /* LaunchScreen.storyboard */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = file.storyboard; name = LaunchScreen.storyboard; path = VisionCameraExample/LaunchScreen.storyboard; sourceTree = "<group>"; };
+		839E2C622ACB2E330037BC2B /* ExampleSwiftFrameProcessor.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = ExampleSwiftFrameProcessor.m; sourceTree = "<group>"; };
+		839E2C642ACB2E420037BC2B /* ExampleSwiftFrameProcessor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ExampleSwiftFrameProcessor.swift; sourceTree = "<group>"; };
 		B8DB3BD8263DEA31004C18D7 /* ExampleFrameProcessorPlugin.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ExampleFrameProcessorPlugin.m; sourceTree = "<group>"; };
 		B8F0E10625E0199F00586F16 /* VisionCameraExample-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "VisionCameraExample-Bridging-Header.h"; sourceTree = "<group>"; };
 		B8F0E10725E0199F00586F16 /* File.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = File.swift; sourceTree = "<group>"; };
@@ -91,6 +94,15 @@
 			name = Libraries;
 			sourceTree = "<group>";
 		};
+		839E2C612ACB2E140037BC2B /* Example Swift Plugin */ = {
+			isa = PBXGroup;
+			children = (
+				839E2C622ACB2E330037BC2B /* ExampleSwiftFrameProcessor.m */,
+				839E2C642ACB2E420037BC2B /* ExampleSwiftFrameProcessor.swift */,
+			);
+			path = "Example Swift Plugin";
+			sourceTree = "<group>";
+		};
 		83CBB9F61A601CBA00E9B192 = {
 			isa = PBXGroup;
 			children = (
@@ -117,6 +129,7 @@
 			isa = PBXGroup;
 			children = (
 				B8DB3BD7263DEA31004C18D7 /* Example Plugin */,
+				839E2C612ACB2E140037BC2B /* Example Swift Plugin */,
 			);
 			path = "Frame Processor Plugins";
 			sourceTree = "<group>";
@@ -375,7 +388,8 @@
 			files = (
 				13B07FBC1A68108700A75B9A /* AppDelegate.mm in Sources */,
 				B8DB3BDC263DEA31004C18D7 /* ExampleFrameProcessorPlugin.m in Sources */,
-				B8DB3BD5263DE8B7004C18D7 /* BuildFile in Sources */,
+				839E2C652ACB2E420037BC2B /* ExampleSwiftFrameProcessor.swift in Sources */,
+				839E2C632ACB2E330037BC2B /* ExampleSwiftFrameProcessor.m in Sources */,
 				B8F0E10825E0199F00586F16 /* File.swift in Sources */,
 				13B07FC11A68108700A75B9A /* main.m in Sources */,
 			);
@@ -396,6 +410,7 @@
 				INFOPLIST_FILE = VisionCameraExample/Info.plist;
 				INFOPLIST_KEY_CFBundleDisplayName = "Vision Camera";
 				INFOPLIST_KEY_LSApplicationCategoryType = "public.app-category.photography";
+				IPHONEOS_DEPLOYMENT_TARGET = 12.4;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				OTHER_LDFLAGS = (
 					"$(inherited)",
@@ -426,6 +441,7 @@
 				INFOPLIST_FILE = VisionCameraExample/Info.plist;
 				INFOPLIST_KEY_CFBundleDisplayName = "Vision Camera";
 				INFOPLIST_KEY_LSApplicationCategoryType = "public.app-category.photography";
+				IPHONEOS_DEPLOYMENT_TARGET = 12.4;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				OTHER_LDFLAGS = (
 					"$(inherited)",
@@ -504,6 +520,7 @@
 				ONLY_ACTIVE_ARCH = YES;
 				OTHER_CFLAGS = "$(inherited)";
 				OTHER_CPLUSPLUSFLAGS = "$(inherited)";
+				OTHER_SWIFT_FLAGS = "$(inherited) -DVISION_CAMERA_ENABLE_FRAME_PROCESSORS";
 				REACT_NATIVE_PATH = "${PODS_ROOT}/../../node_modules/react-native";
 				SDKROOT = iphoneos;
 			};
@@ -561,6 +578,7 @@
 				MTL_ENABLE_DEBUG_INFO = NO;
 				OTHER_CFLAGS = "$(inherited)";
 				OTHER_CPLUSPLUSFLAGS = "$(inherited)";
+				OTHER_SWIFT_FLAGS = "$(inherited) -DVISION_CAMERA_ENABLE_FRAME_PROCESSORS";
 				REACT_NATIVE_PATH = "${PODS_ROOT}/../../node_modules/react-native";
 				SDKROOT = iphoneos;
 				SWIFT_COMPILATION_MODE = wholemodule;

package/example/ios/VisionCameraExample/AppDelegate.mm

@@ -1,10 +1,6 @@
 #import "AppDelegate.h"
 
 #import <React/RCTBundleURLProvider.h>
-#import "VisionCameraExample-Swift.h"
-#if VISION_CAMERA_ENABLE_FRAME_PROCESSORS
-#import <VisionCamera/FrameProcessorPlugin.h>
-#endif
 
 @implementation AppDelegate
 
@@ -15,10 +11,6 @@
   // They will be passed down to the ViewController used by React Native.
   self.initialProps = @{};
 
-#if VISION_CAMERA_ENABLE_FRAME_PROCESSORS
-  [FrameProcessorPlugin registerPlugin:[[ExamplePluginSwift alloc] init]];
-#endif
-
   return [super application:application didFinishLaunchingWithOptions:launchOptions];
 }
 

package/example/ios/vc_example_cocoapod_utils.rb

@@ -0,0 +1,63 @@
+# Let's use ReactNativePodsUtils utility class to make it more maintainable
+require Pod::Executable.execute_command('node', ['-p',
+  'require.resolve(
+    "react-native/scripts/cocoapods/utils.rb",
+    {paths: [process.argv[1]]},
+  )', __dir__]).strip
+
+#
+# In order to compile the project with disabled frame processors mode
+# the codebase of example swift frame processor plugin needs to be put
+# behind the swift compiler flag
+# 
+# Let's set the flag based on the same logic like in library's podspec file
+# 
+def set_frame_processor_swift_flag_in_example_project(installer)
+  has_worklets = does_example_have_worklets_enabled(installer)
+  set_swift_compiler_flag_in_project(installer, has_worklets)
+end
+
+def does_example_have_worklets_enabled(installer)
+  forceDisableFrameProcessors = false
+  if defined?($VCDisableFrameProcessors)
+    forceDisableFrameProcessors = true
+  end
+  has_worklets = ReactNativePodsUtils.has_pod(installer, "react-native-worklets-core") && !forceDisableFrameProcessors
+end
+
+# 
+# It's similar to:
+# - [`ReactNativePodsUtils.add_compiler_flag_to_project`](https://github.com/facebook/react-native/blob/ad5213718377017ec6d2a057541f6d4c57e0507d/packages/react-native/scripts/cocoapods/utils.rb#L384)
+# - [`ReactNativePodsUtils.remove_compiler_flag_from_project`](https://github.com/facebook/react-native/blob/ad5213718377017ec6d2a057541f6d4c57e0507d/packages/react-native/scripts/cocoapods/utils.rb#L395)
+# but uses utils for setting "OTHER_SWIFT_FLAGS" compiler flag, which is unsupported by ReactNativePodsUtils
+# 
+def set_swift_compiler_flag_in_project(installer, has_worklets)
+  projects = ReactNativePodsUtils.extract_projects(installer)
+  projects.each do |project|
+    project.build_configurations.each do |config|
+      flag = "-DVISION_CAMERA_ENABLE_FRAME_PROCESSORS"
+      if has_worklets
+        set_swift_flag_in_config(config, flag)
+      else
+        remove_swift_flag_in_config(config, flag)
+      end
+    end
+    project.save()
+  end
+end
+
+# 
+# It's similar to [`ReactNativePodsUtils.set_flag_in_config`](https://github.com/facebook/react-native/blob/ad5213718377017ec6d2a057541f6d4c57e0507d/packages/react-native/scripts/cocoapods/utils.rb#L414),
+# but supports "OTHER_SWIFT_FLAGS" compiler flag
+# 
+def set_swift_flag_in_config(config, flag)
+  ReactNativePodsUtils.add_flag_for_key(config, flag, "OTHER_SWIFT_FLAGS")
+end
+
+# 
+# It's similar to [`ReactNativePodsUtils.remove_flag_in_config`](https://github.com/facebook/react-native/blob/ad5213718377017ec6d2a057541f6d4c57e0507d/packages/react-native/scripts/cocoapods/utils.rb#L421),
+# but supports "OTHER_SWIFT_FLAGS" compiler flag
+# 
+def remove_swift_flag_in_config(config, flag)
+  ReactNativePodsUtils.remove_flag_for_key(config, flag, "OTHER_SWIFT_FLAGS")
+end

package/example/src/frame-processors/ExampleKotlinSwiftPlugin.ts

@@ -0,0 +1,17 @@
+import { VisionCameraProxy, Frame } from 'react-native-vision-camera'
+
+const plugin = VisionCameraProxy.getFrameProcessorPlugin('example_kotlin_swift_plugin')
+
+export function exampleKotlinSwiftPlugin(frame: Frame): string[] {
+  'worklet'
+
+  if (plugin == null) throw new Error('Failed to load Frame Processor Plugin "example_kotlin_swift_plugin"!')
+
+  return plugin.call(frame, {
+    someString: 'hello!',
+    someBoolean: true,
+    someNumber: 42,
+    someObject: { test: 0, second: 'test' },
+    someArray: ['another test', 5],
+  }) as string[]
+}