DataSourceFactoryQueryResultBinderProvider.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.PagingTypeNames
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.DataSourceFactoryQueryResultBinder
import androidx.room.solver.query.result.ListQueryResultAdapter
import androidx.room.solver.query.result.PositionalDataSourceQueryResultBinder
import androidx.room.solver.query.result.QueryResultBinder
import javax.lang.model.type.DeclaredType
import javax.lang.model.type.TypeMirror
class DataSourceFactoryQueryResultBinderProvider(val context: Context) : QueryResultBinderProvider {
private val dataSourceFactoryTypeMirror: TypeMirror? by lazy {
context.processingEnv.elementUtils
.getTypeElement(PagingTypeNames.DATA_SOURCE_FACTORY.toString())?.asType()
}
override fun provide(declared: DeclaredType, query: ParsedQuery): QueryResultBinder {
if (query.tables.isEmpty()) {
context.logger.e(ProcessorErrors.OBSERVABLE_QUERY_NOTHING_TO_OBSERVE)
}
val typeArg = declared.typeArguments[1]
val adapter = context.typeAdapterStore.findRowAdapter(typeArg, query)?.let {
ListQueryResultAdapter(it)
}
val tableNames = ((adapter?.accessedTableNames() ?: emptyList()) +
query.tables.map { it.name }).toSet()
val countedBinder = PositionalDataSourceQueryResultBinder(adapter, tableNames)
return DataSourceFactoryQueryResultBinder(countedBinder)
}
override fun matches(declared: DeclaredType): Boolean =
declared.typeArguments.size == 2 && isLivePagedList(declared)
private fun isLivePagedList(declared: DeclaredType): Boolean {
if (dataSourceFactoryTypeMirror == null) {
return false
}
val erasure = context.processingEnv.typeUtils.erasure(declared)
// we don't want to return paged list unless explicitly requested
return context.processingEnv.typeUtils.isAssignable(dataSourceFactoryTypeMirror, erasure)
}
}