1 /*
2  * Copyright (C) 2015 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.camera.util;
18 
19 import android.content.Context;
20 import androidx.annotation.NonNull;
21 
22 /**
23  * Initializable singleton for providing the application level context
24  * object instead of initializing each singleton separately.
25  */
26 public class AndroidContext {
27     private static AndroidContext sInstance;
28 
29     /**
30      * The android context object cannot be created until the android
31      * has created the application object. The AndroidContext object
32      * must be initialized before other singletons can use it.
33      */
initialize(@onNull Context context)34     public static void initialize(@NonNull Context context) {
35         if (sInstance == null) {
36             sInstance = new AndroidContext(context);
37         }
38     }
39 
40     /**
41      * Return a previously initialized instance, throw if it has not been
42      * initialized yet.
43      */
instance()44     public static AndroidContext instance() {
45         if (sInstance == null) {
46             throw new IllegalStateException("Android context was not initialized.");
47         }
48         return sInstance;
49     }
50 
51     private final Context mContext;
AndroidContext(Context context)52     private AndroidContext(Context context) {
53         mContext = context;
54     }
55 
get()56     public Context get() {
57         return mContext;
58     }
59 }