1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package androidx.room.solver.query.result
18 
19 import androidx.room.ext.L
20 import androidx.room.ext.T
21 import androidx.room.ext.typeName
22 import androidx.room.solver.CodeGenScope
23 import defaultValue
24 
25 /**
26  * Wraps a row adapter when there is only 1 item in the result
27  */
28 class SingleEntityQueryResultAdapter(rowAdapter: RowAdapter) : QueryResultAdapter(rowAdapter) {
29     val type = rowAdapter.out
convertnull30     override fun convert(outVarName: String, cursorVarName: String, scope: CodeGenScope) {
31         scope.builder().apply {
32             rowAdapter?.onCursorReady(cursorVarName, scope)
33             addStatement("final $T $L", type.typeName(), outVarName)
34             beginControlFlow("if($L.moveToFirst())", cursorVarName)
35                 rowAdapter?.convert(outVarName, cursorVarName, scope)
36             nextControlFlow("else").apply {
37                 addStatement("$L = $L", outVarName, rowAdapter?.out?.defaultValue())
38             }
39             endControlFlow()
40             rowAdapter?.onCursorFinished()?.invoke(scope)
41         }
42     }
43 }
44