RxCallableDeleteOrUpdateMethodBinderProvider.kt
/*
* Copyright 2018 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.solver.shortcut.binderprovider
import androidx.room.ext.L
import androidx.room.ext.RxJava2TypeNames
import androidx.room.ext.T
import androidx.room.ext.typeName
import androidx.room.processor.Context
import androidx.room.solver.shortcut.binder.CallableDeleteOrUpdateMethodBinder.Companion.createDeleteOrUpdateBinder
import androidx.room.solver.shortcut.binder.DeleteOrUpdateMethodBinder
import com.squareup.javapoet.ClassName
import javax.lang.model.type.DeclaredType
import javax.lang.model.type.TypeMirror
/**
* Provider for Rx Callable binders.
*/
sealed class RxCallableDeleteOrUpdateMethodBinderProvider(
val context: Context,
private val rxType: RxType
) : DeleteOrUpdateMethodBinderProvider {
/**
* [Single] and [Maybe] are generics but [Completable] is not so each implementation of this
* class needs to define how to extract the type argument.
*/
abstract fun extractTypeArg(declared: DeclaredType): TypeMirror
override fun matches(declared: DeclaredType): Boolean =
declared.typeArguments.size == 1 && matchesRxType(declared)
private fun matchesRxType(declared: DeclaredType): Boolean {
val erasure = context.processingEnv.typeUtils.erasure(declared)
return erasure.typeName() == rxType.className
}
override fun provide(declared: DeclaredType): DeleteOrUpdateMethodBinder {
val typeArg = extractTypeArg(declared)
val adapter = context.typeAdapterStore.findDeleteOrUpdateAdapter(typeArg)
return createDeleteOrUpdateBinder(typeArg, adapter) { callableImpl, _ ->
addStatement("return $T.fromCallable($L)", rxType.className, callableImpl)
}
}
/**
* Supported types for delete and update
*/
enum class RxType(val className: ClassName) {
SINGLE(RxJava2TypeNames.SINGLE),
MAYBE(RxJava2TypeNames.MAYBE),
COMPLETABLE(RxJava2TypeNames.COMPLETABLE)
}
}
class RxSingleDeleteOrUpdateMethodBinderProvider(context: Context) :
RxCallableDeleteOrUpdateMethodBinderProvider(context, RxType.SINGLE) {
override fun extractTypeArg(declared: DeclaredType): TypeMirror = declared.typeArguments.first()
}
class RxMaybeDeleteOrUpdateMethodBinderProvider(context: Context) :
RxCallableDeleteOrUpdateMethodBinderProvider(context, RxType.MAYBE) {
override fun extractTypeArg(declared: DeclaredType): TypeMirror = declared.typeArguments.first()
}
class RxCompletableDeleteOrUpdateMethodBinderProvider(context: Context) :
RxCallableDeleteOrUpdateMethodBinderProvider(context, RxType.COMPLETABLE) {
private val completableTypeMirror: TypeMirror? by lazy {
context.processingEnv.elementUtils
.getTypeElement(RxJava2TypeNames.COMPLETABLE.toString())?.asType()
}
/**
* Since Completable is not a generic, the supported return type should be Void.
* Like this, the generated Callable.call method will return Void.
*/
override fun extractTypeArg(declared: DeclaredType): TypeMirror =
context.COMMON_TYPES.VOID
override fun matches(declared: DeclaredType): Boolean = isCompletable(declared)
private fun isCompletable(declared: DeclaredType): Boolean {
if (completableTypeMirror == null) {
return false
}
val erasure = context.processingEnv.typeUtils.erasure(declared)
return context.processingEnv.typeUtils.isAssignable(completableTypeMirror, erasure)
}
}