Mark generated source dirs in IDEA (#477)

Adds generated code to IDEA module as generated source so that it is correctly marked as generated in IDEA and users are warned if they try to edit those files.

Author: oehme

src/main/groovy/com/google/protobuf/gradle/ProtobufPlugin.groovy

@@ -527,17 +527,17 @@ class ProtobufPlugin implements Plugin<Project> {
         getSourceSets().each { sourceSet ->
           SourceDirectorySet protoSrcDirSet = sourceSet.proto
           protoSrcDirSet.srcDirs.each { File protoDir ->
-            Utils.addToIdeSources(project, Utils.isTest(sourceSet.name), protoDir)
+            Utils.addToIdeSources(project, Utils.isTest(sourceSet.name), protoDir, false)
           }
         }
         // Make the extracted proto dirs known to IDEs
         project.tasks.withType(ProtobufExtract).each { ProtobufExtract extractProtoTask ->
-          Utils.addToIdeSources(project, extractProtoTask.isTest, extractProtoTask.destDir)
+          Utils.addToIdeSources(project, extractProtoTask.isTest, extractProtoTask.destDir, true)
         }
         // Make the generated code dirs known to IDEs
         project.tasks.withType(GenerateProtoTask).each { GenerateProtoTask generateProtoTask ->
           generateProtoTask.getOutputSourceDirectorySet().srcDirs.each { File outputDir ->
-            Utils.addToIdeSources(project, generateProtoTask.isTest, outputDir)
+            Utils.addToIdeSources(project, generateProtoTask.isTest, outputDir, true)
           }
         }
       }

src/main/groovy/com/google/protobuf/gradle/Utils.groovy

@@ -125,16 +125,17 @@ class Utils {
    * Adds the file to the IDE plugin's set of sources / resources. If the directory does
    * not exist, it will be created before the IDE task is run.
    */
-  static void addToIdeSources(Project project, boolean isTest, File f) {
+  static void addToIdeSources(Project project, boolean isTest, File f, boolean isGenerated) {
     IdeaModel model = project.getExtensions().findByType(IdeaModel)
     if (model != null) {
-      // TODO(zpencer): switch to model.module.generatedSourceDirs when that API becomes stable
-      // For now, just hint to the IDE that it's a source dir or a test source dir.
       if (isTest) {
         model.module.testSourceDirs += f
       } else {
         model.module.sourceDirs += f
       }
+      if (isGenerated) {
+        model.module.generatedSourceDirs += f
+      }
       project.tasks.withType(GenerateIdeaModule).each {
         it.doFirst {
           // This is required because the intellij plugin does not allow adding source directories

src/test/groovy/com/google/protobuf/gradle/ProtobufJavaPluginTest.groovy

@@ -363,12 +363,16 @@ class ProtobufJavaPluginTest extends Specification {
 
     Set<String> sourceDir = [] as Set
     Set<String> testSourceDir = [] as Set
+    Set<String> generatedDirs = [] as Set
     rootMgr.content.sourceFolder[0].each {
       if (Boolean.parseBoolean(it.@isTestSource)) {
         testSourceDir.add(it.@url)
       } else {
         sourceDir.add(it.@url)
       }
+      if (Boolean.parseBoolean(it.@generated)) {
+        generatedDirs.add(it.@url)
+      }
     }
 
     Set<String> expectedSourceDir = ImmutableSet.builder()
@@ -390,8 +394,21 @@ class ProtobufJavaPluginTest extends Specification {
         .add('file://$MODULE_DIR$/build/extracted-include-protos/test')
         .add('file://$MODULE_DIR$/build/generated/source/proto/test/java')
         .build()
+    Set<String> expectedGeneratedDirs = [
+      'file://$MODULE_DIR$/build/extracted-include-protos/grpc',
+      'file://$MODULE_DIR$/build/extracted-protos/main',
+      'file://$MODULE_DIR$/build/extracted-include-protos/main',
+      'file://$MODULE_DIR$/build/extracted-protos/grpc',
+      'file://$MODULE_DIR$/build/generated/source/proto/grpc/java',
+      'file://$MODULE_DIR$/build/generated/source/proto/grpc/grpc_output',
+      'file://$MODULE_DIR$/build/generated/source/proto/main/java',
+      'file://$MODULE_DIR$/build/extracted-protos/test',
+      'file://$MODULE_DIR$/build/extracted-include-protos/test',
+      'file://$MODULE_DIR$/build/generated/source/proto/test/java',
+    ]
     assert Objects.equals(expectedSourceDir, sourceDir)
     assert Objects.equals(expectedTestSourceDir, testSourceDir)
+    Objects.equals(expectedGeneratedDirs, generatedDirs)
 
     where:
     gradleVersion << GRADLE_VERSIONS