| /* |
| * Copyright 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.processor.view.inspector; |
| |
| import static javax.tools.Diagnostic.Kind.ERROR; |
| |
| import androidx.annotation.NonNull; |
| |
| import com.squareup.javapoet.ClassName; |
| |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.Optional; |
| import java.util.Set; |
| |
| import javax.annotation.processing.AbstractProcessor; |
| import javax.annotation.processing.RoundEnvironment; |
| import javax.annotation.processing.SupportedAnnotationTypes; |
| import javax.lang.model.SourceVersion; |
| import javax.lang.model.element.Element; |
| import javax.lang.model.element.ElementKind; |
| import javax.lang.model.element.Modifier; |
| import javax.lang.model.element.TypeElement; |
| import javax.lang.model.util.ElementFilter; |
| |
| /** |
| * An annotation processor for the platform inspectable annotations. |
| * |
| * It mostly delegates to {@link InspectablePropertyProcessor} and |
| * {@link InspectionCompanionGenerator}. This modular architecture allows the core generation code |
| * to be reused for comparable annotations outside the platform. |
| * |
| * @see android.view.inspector.InspectableProperty |
| */ |
| @SupportedAnnotationTypes({PlatformInspectableProcessor.ANNOTATION_QUALIFIED_NAME}) |
| public final class PlatformInspectableProcessor extends AbstractProcessor { |
| static final String ANNOTATION_QUALIFIED_NAME = |
| "android.view.inspector.InspectableProperty"; |
| |
| @Override |
| public SourceVersion getSupportedSourceVersion() { |
| return SourceVersion.latest(); |
| } |
| |
| @Override |
| public boolean process( |
| @NonNull Set<? extends TypeElement> annotations, |
| @NonNull RoundEnvironment roundEnv) { |
| final Map<String, InspectableClassModel> modelMap = new HashMap<>(); |
| |
| for (TypeElement annotation : annotations) { |
| if (annotation.getQualifiedName().contentEquals(ANNOTATION_QUALIFIED_NAME)) { |
| processProperties(roundEnv.getElementsAnnotatedWith(annotation), modelMap); |
| } else { |
| fail("Unexpected annotation type", annotation); |
| } |
| } |
| |
| final InspectionCompanionGenerator generator = |
| new InspectionCompanionGenerator(processingEnv.getFiler(), getClass()); |
| |
| for (InspectableClassModel model : modelMap.values()) { |
| try { |
| generator.generate(model); |
| } catch (IOException ioException) { |
| fail(String.format( |
| "Unable to generate inspection companion for %s due to %s", |
| model.getClassName().toString(), |
| ioException.getMessage())); |
| } |
| } |
| |
| return true; |
| } |
| |
| /** |
| * Runs {@link PlatformInspectableProcessor} on a set of annotated elements. |
| * |
| * @param elements A set of annotated elements to process |
| * @param modelMap A map of qualified class names to class models to update |
| */ |
| private void processProperties( |
| @NonNull Set<? extends Element> elements, |
| @NonNull Map<String, InspectableClassModel> modelMap) { |
| final InspectablePropertyProcessor processor = |
| new InspectablePropertyProcessor(ANNOTATION_QUALIFIED_NAME, processingEnv); |
| |
| for (Element element : elements) { |
| final Optional<TypeElement> classElement = enclosingClassElement(element); |
| |
| if (!classElement.isPresent()) { |
| fail("Element not contained in a class", element); |
| break; |
| } |
| |
| final Set<Modifier> classModifiers = classElement.get().getModifiers(); |
| |
| if (classModifiers.contains(Modifier.PRIVATE)) { |
| fail("Enclosing class cannot be private", element); |
| } |
| |
| final InspectableClassModel model = modelMap.computeIfAbsent( |
| classElement.get().getQualifiedName().toString(), |
| k -> { |
| if (hasNestedInspectionCompanion(classElement.get())) { |
| fail( |
| String.format( |
| "Class %s already has an inspection companion.", |
| classElement.get().getQualifiedName().toString()), |
| element); |
| } |
| return new InspectableClassModel(ClassName.get(classElement.get())); |
| }); |
| |
| processor.process(element, model); |
| } |
| } |
| |
| /** |
| * Determine if a class has a nested class named {@code InspectionCompanion}. |
| * |
| * @param typeElement A type element representing the class to check |
| * @return f the class contains a class named {@code InspectionCompanion} |
| */ |
| private static boolean hasNestedInspectionCompanion(@NonNull TypeElement typeElement) { |
| for (TypeElement nestedClass : ElementFilter.typesIn(typeElement.getEnclosedElements())) { |
| if (nestedClass.getSimpleName().toString().equals("InspectionCompanion")) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Get the nearest enclosing class if there is one. |
| * |
| * If {@param element} represents a class, it will be returned wrapped in an optional. |
| * |
| * @param element An element to search from |
| * @return A TypeElement of the nearest enclosing class or an empty optional |
| */ |
| @NonNull |
| private static Optional<TypeElement> enclosingClassElement(@NonNull Element element) { |
| Element cursor = element; |
| |
| while (cursor != null) { |
| if (cursor.getKind() == ElementKind.CLASS) { |
| return Optional.of((TypeElement) cursor); |
| } |
| |
| cursor = cursor.getEnclosingElement(); |
| } |
| |
| return Optional.empty(); |
| } |
| |
| /** |
| * Print message and fail the build. |
| * |
| * @param message Message to print |
| */ |
| private void fail(@NonNull String message) { |
| processingEnv.getMessager().printMessage(ERROR, message); |
| } |
| |
| /** |
| * Print message and fail the build. |
| * |
| * @param message Message to print |
| * @param element The element that failed |
| */ |
| private void fail(@NonNull String message, @NonNull Element element) { |
| processingEnv.getMessager().printMessage(ERROR, message, element); |
| } |
| } |