ShortcutParameterProcessor.kt
/*
* Copyright (C) 2016 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.room.processor
import androidx.room.ext.extendsBound
import androidx.room.vo.ShortcutQueryParameter
import com.google.auto.common.MoreTypes
import javax.lang.model.element.TypeElement
import javax.lang.model.element.VariableElement
import javax.lang.model.type.ArrayType
import javax.lang.model.type.DeclaredType
import javax.lang.model.type.TypeMirror
import javax.lang.model.util.ElementFilter
/**
* Processes parameters of methods that are annotated with Insert, Update or Delete.
*/
class ShortcutParameterProcessor(
baseContext: Context,
val containing: DeclaredType,
val element: VariableElement
) {
val context = baseContext.fork(element)
fun process(): ShortcutQueryParameter {
val asMember = MoreTypes.asMemberOf(context.processingEnv.typeUtils, containing, element)
val name = element.simpleName.toString()
context.checker.check(!name.startsWith("_"), element,
ProcessorErrors.QUERY_PARAMETERS_CANNOT_START_WITH_UNDERSCORE)
val (pojoType, isMultiple) = extractPojoType(asMember)
return ShortcutQueryParameter(
element = element,
name = name,
type = asMember,
pojoType = pojoType,
isMultiple = isMultiple
)
}
@Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN")
private fun extractPojoType(typeMirror: TypeMirror): Pair<TypeMirror?, Boolean> {
val elementUtils = context.processingEnv.elementUtils
val typeUtils = context.processingEnv.typeUtils
fun verifyAndPair(pojoType: TypeMirror, isMultiple: Boolean): Pair<TypeMirror?, Boolean> {
if (!MoreTypes.isType(pojoType)) {
// kotlin may generate ? extends T so we should reduce it.
val boundedVar = pojoType.extendsBound()
return boundedVar?.let {
verifyAndPair(boundedVar, isMultiple)
} ?: Pair(null, isMultiple)
}
return Pair(pojoType, isMultiple)
}
fun extractPojoTypeFromIterator(iterableType: DeclaredType): TypeMirror {
ElementFilter.methodsIn(elementUtils
.getAllMembers(typeUtils.asElement(iterableType) as TypeElement)).forEach {
if (it.simpleName.toString() == "iterator") {
return MoreTypes.asDeclared(MoreTypes.asExecutable(
typeUtils.asMemberOf(iterableType, it)).returnType)
.typeArguments.first()
}
}
throw IllegalArgumentException("iterator() not found in Iterable $iterableType")
}
val iterableType = typeUtils.erasure(elementUtils
.getTypeElement("java.lang.Iterable").asType())
if (typeUtils.isAssignable(typeMirror, iterableType)) {
val declared = MoreTypes.asDeclared(typeMirror)
val pojo = extractPojoTypeFromIterator(declared)
return verifyAndPair(pojo, true)
}
if (typeMirror is ArrayType) {
val pojo = typeMirror.componentType
return verifyAndPair(pojo, true)
}
return verifyAndPair(typeMirror, false)
}
}