RxCallableQueryResultBinderProvider.kt

/*
 * Copyright (C) 2017 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.binderprovider

import androidx.room.ext.RoomRxJava2TypeNames
import androidx.room.ext.typeName
import androidx.room.parser.ParsedQuery
import androidx.room.processor.Context
import androidx.room.processor.ProcessorErrors
import androidx.room.solver.QueryResultBinderProvider
import androidx.room.solver.query.result.QueryResultBinder
import androidx.room.solver.query.result.RxCallableQueryResultBinder
import javax.lang.model.type.DeclaredType

sealed class RxCallableQueryResultBinderProvider(
    val context: Context,
    val rxType: RxCallableQueryResultBinder.RxType
) :
    QueryResultBinderProvider {
    private val hasRxJava2Artifact by lazy {
        context.processingEnv.elementUtils
                .getTypeElement(RoomRxJava2TypeNames.RX_ROOM.toString()) != null
    }

    override fun provide(declared: DeclaredType, query: ParsedQuery): QueryResultBinder {
        val typeArg = declared.typeArguments.first()
        val adapter = context.typeAdapterStore.findQueryResultAdapter(typeArg, query)
        return RxCallableQueryResultBinder(rxType, typeArg, adapter)
    }

    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)
        val match = erasure.typeName() == rxType.className
        if (match && !hasRxJava2Artifact) {
            context.logger.e(ProcessorErrors.MISSING_ROOM_RXJAVA2_ARTIFACT)
        }
        return match
    }
}

class RxSingleQueryResultBinderProvider(context: Context) :
    RxCallableQueryResultBinderProvider(context, RxCallableQueryResultBinder.RxType.SINGLE)

class RxMaybeQueryResultBinderProvider(context: Context) :
    RxCallableQueryResultBinderProvider(context, RxCallableQueryResultBinder.RxType.MAYBE)