LiveDataQueryResultBinderProvider.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.LifecyclesTypeNames
import androidx.room.processor.Context
import androidx.room.solver.ObservableQueryResultBinderProvider
import androidx.room.solver.query.result.LiveDataQueryResultBinder
import androidx.room.solver.query.result.QueryResultAdapter
import androidx.room.solver.query.result.QueryResultBinder
import javax.lang.model.type.DeclaredType
import javax.lang.model.type.TypeMirror
class LiveDataQueryResultBinderProvider(context: Context) :
ObservableQueryResultBinderProvider(context) {
private val liveDataTypeMirror: TypeMirror? by lazy {
context.processingEnv.elementUtils
.getTypeElement(LifecyclesTypeNames.LIVE_DATA.toString())?.asType()
}
override fun extractTypeArg(declared: DeclaredType): TypeMirror = declared.typeArguments.first()
override fun create(
typeArg: TypeMirror,
resultAdapter: QueryResultAdapter?,
tableNames: Set<String>
): QueryResultBinder {
return LiveDataQueryResultBinder(
typeArg = typeArg,
tableNames = tableNames,
adapter = resultAdapter)
}
override fun matches(declared: DeclaredType): Boolean =
declared.typeArguments.size == 1 && isLiveData(declared)
private fun isLiveData(declared: DeclaredType): Boolean {
if (liveDataTypeMirror == null) {
return false
}
val erasure = context.processingEnv.typeUtils.erasure(declared)
return context.processingEnv.typeUtils.isAssignable(liveDataTypeMirror, erasure)
}
}