1 /*
2  * Copyright (C) 2023 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 
18 package com.android.wallpaper.picker.undo.domain.interactor
19 
20 import com.android.wallpaper.picker.undo.shared.model.RestorableSnapshot
21 
22 interface SnapshotStore {
retrievenull23     fun retrieve(): RestorableSnapshot
24     fun store(snapshot: RestorableSnapshot)
25 
26     /** A "no op" implementation of [SnapshotStore] that's safe to call. */
27     object NOOP : SnapshotStore {
28         override fun retrieve(): RestorableSnapshot {
29             return RestorableSnapshot(emptyMap())
30         }
31 
32         override fun store(snapshot: RestorableSnapshot) = Unit
33     }
34 }
35