1 /*
2  * Copyright (C) 2019 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 com.android.car.settings.common;
18 
19 import android.annotation.Nullable;
20 import android.content.Context;
21 
22 import androidx.loader.content.AsyncTaskLoader;
23 
24 /**
25  * This class fills in some boilerplate for AsyncTaskLoader to actually load things.
26  * Classes that extend {@link AsyncLoader} need to properly implement required methods expressed in
27  * {@link AsyncTaskLoader}
28  *
29  * <p>Taken from {@link com.android.settingslib.utils.AsyncLoader}. Only change to extend from
30  * support library {@link AsyncTaskLoader}
31  *
32  * @param <T> the data type to be loaded.
33  */
34 public abstract class AsyncLoader<T> extends AsyncTaskLoader<T> {
35     @Nullable
36     private T mResult;
37 
AsyncLoader(Context context)38     public AsyncLoader(Context context) {
39         super(context);
40     }
41 
42     @Override
onStartLoading()43     protected void onStartLoading() {
44         if (mResult != null) {
45             deliverResult(mResult);
46         }
47 
48         if (takeContentChanged() || mResult == null) {
49             forceLoad();
50         }
51     }
52 
53     @Override
onStopLoading()54     protected void onStopLoading() {
55         cancelLoad();
56     }
57 
58     @Override
deliverResult(T data)59     public void deliverResult(T data) {
60         if (isReset()) {
61             return;
62         }
63         mResult = data;
64         if (isStarted()) {
65             super.deliverResult(data);
66         }
67     }
68 
69     @Override
onReset()70     protected void onReset() {
71         super.onReset();
72         onStopLoading();
73         mResult = null;
74     }
75 }
76