feat: automatically copy codegen artifacts to paper

FabricExample/android/gradle.properties

@@ -39,3 +39,5 @@ newArchEnabled=true
 # Use this property to enable or disable the Hermes JS engine.
 # If set to false, you will be using JSC instead.
 hermesEnabled=true
+
+isGHExampleApp=true

android/build.gradle

@@ -207,3 +207,84 @@ dependencies {
     implementation "androidx.core:core-ktx:1.6.0"
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
 }
+
+def isGHExampleApp() {
+    return project.hasProperty('isGHExampleApp') && project.property('isGHExampleApp') == "true"
+}
+
+def getAbsoluteCodegenArtifactsPaperDestination() {
+    if (!project.hasProperty('codegenArtifactsPaperDestination')) {
+        throw new Exception('[react-native-gesture-handler] Please fill codegenArtifactsPaperDestination variable in android/gradle.properties to point to the correct path to generated specs for paper')
+    }
+
+    return "${project.rootDir}/../../${project.property('codegenArtifactsPaperDestination')}"
+}
+
+def getAbsoluteCodegenArtifactsSource() {
+    if (!project.hasProperty('codegenArtifactsSource')) {
+        throw new Exception('[react-native-gesture-handler] Please fill codegenArtifactsSource variable in android/gradle.properties to point to the correct path to codegenerated artifacts')
+    }
+
+    return "${project.rootDir}/../../${project.property('codegenArtifactsSource')}"
+}
+
+
+tasks.register("copyCodegenArtifacts") {
+    group 'After build tasks'
+    description 'Task which copies codegen artifacts to paper architecture'
+
+    if (!isGHExampleApp() || !isNewArchitectureEnabled()) {
+        return
+    }
+
+    dependsOn tasks.generateCodegenArtifactsFromSchema
+
+    doLast {
+
+        def absoluteCodegenArtifactsPaperDestination = getAbsoluteCodegenArtifactsPaperDestination()
+        def absoluteCodegenArtifactsSource = getAbsoluteCodegenArtifactsSource()
+
+        def existingFiles = fileTree(absoluteCodegenArtifactsPaperDestination).matching {
+            include '**/*.java'
+        }
+
+        def generatedFiles = fileTree(absoluteCodegenArtifactsSource).matching {
+            include '**/*.java'
+        }
+
+        def existingFilesMap = [:]
+
+        existingFiles.forEach { existingFile ->
+            println existingFile
+            existingFilesMap[existingFile.name] = 1
+        }
+
+        generatedFiles.forEach { generatedFile -> 
+            if (!existingFilesMap.containsKey(generatedFile.name)) {
+                logger.warn("[react-native-gesture-handler] ${generatedFile.name} not found in paper dir, if it's used on Android you need to copy it manually and implement yourself before using auto-copy feature.")
+            }
+        }
+
+        if (existingFiles.size() == 0) {
+            logger.warn("[react-native-gesture-handler] Paper destination with codegen interfaces is empty. This might be okay if you don't have any interfaces/delegates used on Android, but if that's not the case please check if codegenArtifactsPaperDestination property in android/gradle.properties is correct.")
+        }
+
+        existingFiles.forEach { existingFile -> 
+            def generatedFile = new File("${absoluteCodegenArtifactsSource}/${existingFile.name}")
+
+            if (!generatedFile.exists()) {
+                logger.warn("[react-native-gesture-handler] ${existingFile.name} file does not exist in codegen artifacts source destination. Please check if you still need this interface/delagete.")
+            }
+        }
+
+        copy {
+            from absoluteCodegenArtifactsSource
+            include existingFiles.collect { it.name }
+            into absoluteCodegenArtifactsPaperDestination
+        }
+    }
+}
+
+if (isGHExampleApp() && isNewArchitectureEnabled()) {
+    tasks.generateCodegenArtifactsFromSchema.finalizedBy('copyCodegenArtifacts')
+}

android/gradle.properties

@@ -17,3 +17,10 @@ org.gradle.jvmargs=-Xmx2048m -XX:MaxMetaspaceSize=512m -XX:+HeapDumpOnOutOfMemor
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
 RNGH_kotlinVersion=1.6.21
+
+# Path to codegen output directory with this library view managers' interfaces & delegates. Used by `copyCodegenArtifacts` task that helps to synchronize newly generated files with their Paper counterparts.
+codegenArtifactsSource=android/build/generated/source/codegen/java/com/facebook/react/viewmanagers
+
+# Path to directory with view managers' interfaces & delegates used while running on Paper architecture. This property is used as the output path for `copyCodegenArtifacts` task.
+# Used by copyCodegenArtifacts task that automates copying those interfaces/delegates after codegen is run.
+codegenArtifactsPaperDestination=android/paper/src/main/java/com/facebook/react/viewmanagers

android/paper/src/main/java/com/facebook/react/viewmanagers/RNGestureHandlerButtonManagerDelegate.java

@@ -1,11 +1,11 @@
 /**
- * This code was generated by [react-native-codegen](https://www.npmjs.com/package/react-native-codegen).
- *
- * Do not edit this file as changes may cause incorrect behavior and will be lost
- * once the code is regenerated.
- *
- * @generated by codegen project: GeneratePropsJavaDelegate.js
- */
+* This code was generated by [react-native-codegen](https://www.npmjs.com/package/react-native-codegen).
+*
+* Do not edit this file as changes may cause incorrect behavior and will be lost
+* once the code is regenerated.
+*
+* @generated by codegen project: GeneratePropsJavaDelegate.js
+*/
 
 package com.facebook.react.viewmanagers;