| /* |
| * Copyright 2020 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 androidx.hilt.lifecycle |
| |
| import androidx.hilt.AndroidXHiltProcessor |
| import androidx.hilt.ClassNames |
| import androidx.hilt.ext.hasAnnotation |
| import com.google.auto.common.MoreElements |
| import com.squareup.javapoet.TypeName |
| import javax.annotation.processing.ProcessingEnvironment |
| import javax.lang.model.element.Element |
| import javax.lang.model.element.ExecutableElement |
| import javax.lang.model.element.Modifier |
| import javax.lang.model.element.NestingKind |
| import javax.lang.model.element.TypeElement |
| import javax.lang.model.util.ElementFilter |
| import javax.tools.Diagnostic |
| |
| /** |
| * Processing step that generates code enabling assisted injection of ViewModels using Hilt. |
| */ |
| class ViewModelInjectStep( |
| private val processingEnv: ProcessingEnvironment |
| ) : AndroidXHiltProcessor.Step { |
| |
| private val elements = processingEnv.elementUtils |
| private val types = processingEnv.typeUtils |
| private val messager = processingEnv.messager |
| |
| override fun annotation() = ClassNames.VIEW_MODEL_INJECT.canonicalName() |
| |
| override fun process(annotatedElements: Set<Element>) { |
| val parsedElements = mutableSetOf<TypeElement>() |
| annotatedElements.forEach { element -> |
| val constructorElement = MoreElements.asExecutable(element) |
| val typeElement = MoreElements.asType(constructorElement.enclosingElement) |
| if (parsedElements.add(typeElement)) { |
| parse(typeElement, constructorElement)?.let { viewModel -> |
| ViewModelGenerator( |
| processingEnv, |
| viewModel |
| ).generate() |
| } |
| } |
| } |
| } |
| |
| private fun parse( |
| typeElement: TypeElement, |
| constructorElement: ExecutableElement |
| ): ViewModelInjectElements? { |
| var valid = true |
| |
| if (elements.getTypeElement(ClassNames.VIEW_MODEL_ASSISTED_FACTORY.toString()) == null) { |
| error( |
| "To use @ViewModelInject you must add the 'lifecycle-viewmodel' " + |
| "artifact. androidx.hilt:hilt-lifecyclew-viewmodel:<version>" |
| ) |
| valid = false |
| } |
| |
| if (!types.isSubtype( |
| typeElement.asType(), |
| elements.getTypeElement(ClassNames.VIEW_MODEL.toString()).asType() |
| ) |
| ) { |
| error( |
| "@ViewModelInject is only supported on types that subclass " + |
| "${ClassNames.VIEW_MODEL}." |
| ) |
| valid = false |
| } |
| |
| ElementFilter.constructorsIn(typeElement.enclosedElements).filter { |
| it.hasAnnotation(ClassNames.VIEW_MODEL_INJECT.canonicalName()) |
| }.let { constructors -> |
| if (constructors.size > 1) { |
| error("Multiple @ViewModelInject annotated constructors found.", typeElement) |
| valid = false |
| } |
| constructors.filter { it.modifiers.contains(Modifier.PRIVATE) }.forEach { |
| error("@ViewModelInject annotated constructors must not be private.", it) |
| valid = false |
| } |
| } |
| |
| if (typeElement.nestingKind == NestingKind.MEMBER && |
| !typeElement.modifiers.contains(Modifier.STATIC) |
| ) { |
| error( |
| "@ViewModelInject may only be used on inner classes if they are static.", |
| typeElement |
| ) |
| valid = false |
| } |
| |
| // Validate there is at most one SavedStateHandle constructor arg. |
| constructorElement.parameters.filter { |
| TypeName.get(it.asType()) == ClassNames.SAVED_STATE_HANDLE |
| }.apply { |
| if (size > 1) { |
| error( |
| "Expected zero or one constructor argument of type " + |
| "${ClassNames.SAVED_STATE_HANDLE}, found $size", |
| constructorElement |
| ) |
| valid = false |
| } |
| firstOrNull()?.let { |
| if (!it.hasAnnotation(ClassNames.ANDROIDX_ASSISTED.canonicalName())) { |
| error("Missing @Assisted annotation in param '${it.simpleName}'.", it) |
| valid = false |
| } |
| } |
| } |
| |
| if (!valid) return null |
| |
| return ViewModelInjectElements( |
| typeElement, |
| constructorElement |
| ) |
| } |
| |
| private fun error(message: String, element: Element? = null) { |
| messager.printMessage(Diagnostic.Kind.ERROR, message, element) |
| } |
| } |