Home | History | Annotate | Download | only in processor 
      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package androidx.room.processor
     18 
     19 import androidx.room.Entity
     20 import androidx.room.ext.extendsBound
     21 import androidx.room.ext.hasAnnotation
     22 import androidx.room.vo.ShortcutQueryParameter
     23 import com.google.auto.common.MoreTypes
     24 import javax.lang.model.element.TypeElement
     25 import javax.lang.model.element.VariableElement
     26 import javax.lang.model.type.ArrayType
     27 import javax.lang.model.type.DeclaredType
     28 import javax.lang.model.type.TypeMirror
     29 import javax.lang.model.util.ElementFilter
     30 
     31 /**
     32  * Processes parameters of methods that are annotated with Insert, Delete.
     33  */
     34 class ShortcutParameterProcessor(baseContext: Context,
     35                                  val containing: DeclaredType,
     36                                  val element: VariableElement) {
     37     val context = baseContext.fork(element)
     38     fun process(): ShortcutQueryParameter {
     39         val asMember = MoreTypes.asMemberOf(context.processingEnv.typeUtils, containing, element)
     40         val name = element.simpleName.toString()
     41         context.checker.check(!name.startsWith("_"), element,
     42                 ProcessorErrors.QUERY_PARAMETERS_CANNOT_START_WITH_UNDERSCORE)
     43 
     44         val (entityType, isMultiple) = extractEntityType(asMember)
     45         context.checker.check(entityType != null, element,
     46                 ProcessorErrors.CANNOT_FIND_ENTITY_FOR_SHORTCUT_QUERY_PARAMETER)
     47 
     48         return ShortcutQueryParameter(
     49                 name = name,
     50                 type = asMember,
     51                 entityType = entityType,
     52                 isMultiple = isMultiple
     53         )
     54     }
     55 
     56     @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN")
     57     fun extractEntityType(typeMirror: TypeMirror): Pair<TypeMirror?, Boolean> {
     58 
     59         val elementUtils = context.processingEnv.elementUtils
     60         val typeUtils = context.processingEnv.typeUtils
     61 
     62         fun verifyAndPair(entityType: TypeMirror, isMultiple: Boolean): Pair<TypeMirror?, Boolean> {
     63             if (!MoreTypes.isType(entityType)) {
     64                 // kotlin may generate ? extends T so we should reduce it.
     65                 val boundedVar = entityType.extendsBound()
     66                 return boundedVar?.let {
     67                     verifyAndPair(boundedVar, isMultiple)
     68                 } ?: Pair(null, isMultiple)
     69             }
     70             val entityElement = MoreTypes.asElement(entityType)
     71             return if (entityElement.hasAnnotation(Entity::class)) {
     72                 Pair(entityType, isMultiple)
     73             } else {
     74                 Pair(null, isMultiple)
     75             }
     76         }
     77 
     78         fun extractEntityTypeFromIterator(iterableType: DeclaredType): TypeMirror {
     79             ElementFilter.methodsIn(elementUtils
     80                     .getAllMembers(typeUtils.asElement(iterableType) as TypeElement)).forEach {
     81                 if (it.simpleName.toString() == "iterator") {
     82                     return MoreTypes.asDeclared(MoreTypes.asExecutable(
     83                             typeUtils.asMemberOf(iterableType, it)).returnType)
     84                             .typeArguments.first()
     85                 }
     86             }
     87             throw IllegalArgumentException("iterator() not found in Iterable $iterableType")
     88         }
     89 
     90         val iterableType = typeUtils.erasure(elementUtils
     91                 .getTypeElement("java.lang.Iterable").asType())
     92         if (typeUtils.isAssignable(typeMirror, iterableType)) {
     93             val declared = MoreTypes.asDeclared(typeMirror)
     94             val entity = extractEntityTypeFromIterator(declared)
     95             return verifyAndPair(entity, true)
     96         }
     97         if (typeMirror is ArrayType) {
     98             val entity = typeMirror.componentType
     99             return verifyAndPair(entity, true)
    100         }
    101         return verifyAndPair(typeMirror, false)
    102     }
    103 }
    104