FieldGetter.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.vo
import androidx.room.compiler.codegen.CodeLanguage
import androidx.room.compiler.codegen.XCodeBlock
import androidx.room.compiler.processing.XNullability
import androidx.room.compiler.processing.XType
import androidx.room.ext.capitalize
import androidx.room.solver.CodeGenScope
import androidx.room.solver.types.StatementValueBinder
import java.util.Locale
data class FieldGetter(
val fieldName: String,
val jvmName: String,
val type: XType,
val callType: CallType,
) {
fun writeGet(ownerVar: String, outVar: String, builder: XCodeBlock.Builder) {
builder.addLocalVariable(
name = outVar,
typeName = type.asTypeName(),
assignExpr = getterExpression(ownerVar, builder.language)
)
}
fun writeGetToStatement(
ownerVar: String,
stmtParamVar: String,
indexVar: String,
binder: StatementValueBinder,
scope: CodeGenScope
) {
val varExpr = getterExpression(ownerVar, scope.language)
// A temporary local val is needed in Kotlin whenever the getter method returns nullable or
// the field / property is nullable such that a smart cast can be properly performed. Even
// if the field / property are immutable (val), we still use a local val in case the
// property is declared in another module, which would make the smart cast impossible.
if (scope.language == CodeLanguage.KOTLIN && type.nullability != XNullability.NONNULL) {
val tmpField = scope.getTmpVar("_tmp${fieldName.capitalize(Locale.US)}")
scope.builder.addLocalVariable(
name = tmpField,
typeName = type.asTypeName(),
assignExpr = varExpr
)
binder.bindToStmt(stmtParamVar, indexVar, tmpField, scope)
} else {
binder.bindToStmt(stmtParamVar, indexVar, varExpr.toString(), scope)
}
}
private fun getterExpression(ownerVar: String, codeLanguage: CodeLanguage): XCodeBlock {
return when (codeLanguage) {
CodeLanguage.JAVA -> when (callType) {
CallType.FIELD -> "%L.%L"
CallType.METHOD, CallType.SYNTHETIC_METHOD -> "%L.%L()"
CallType.CONSTRUCTOR -> error("Getters should never be of type 'constructor'!")
}.let { expr ->
XCodeBlock.of(codeLanguage, expr, ownerVar, jvmName)
}
CodeLanguage.KOTLIN -> when (callType) {
CallType.FIELD, CallType.SYNTHETIC_METHOD ->
XCodeBlock.of(codeLanguage, "%L.%L", ownerVar, fieldName)
CallType.METHOD ->
XCodeBlock.of(codeLanguage, "%L.%L()", ownerVar, jvmName)
CallType.CONSTRUCTOR -> error("Getters should never be of type 'constructor'!")
}
}
}
}