1 /*
2  * Copyright (C) 2008 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 package android.content.res;
17 
18 import android.annotation.NonNull;
19 import android.annotation.Nullable;
20 import com.android.ide.common.rendering.api.AssetRepository;
21 import com.android.layoutlib.bridge.Bridge;
22 
23 public class BridgeAssetManager extends AssetManager {
24     @Nullable private AssetRepository mAssetRepository;
25 
26     /**
27      * This initializes the static field {@link AssetManager#sSystem} which is used
28      * by methods who get a global asset manager using {@link AssetManager#getSystem()}.
29      * <p/>
30      * They will end up using our bridge asset manager.
31      * <p/>
32      * {@link Bridge} calls this method after setting up a new bridge.
33      */
initSystem()34     public static AssetManager initSystem() {
35         if (!(AssetManager.sSystem instanceof BridgeAssetManager)) {
36             // Note that AssetManager() creates a system AssetManager and we override it
37             // with our BridgeAssetManager.
38             AssetManager.sSystem = new BridgeAssetManager();
39         }
40         return AssetManager.sSystem;
41     }
42 
43     /**
44      * Clears the static {@link AssetManager#sSystem} to make sure we don't leave objects
45      * around that would prevent us from unloading the library.
46      */
clearSystem()47     public static void clearSystem() {
48         AssetManager.sSystem = null;
49     }
50 
setAssetRepository(@onNull AssetRepository assetRepository)51     public void setAssetRepository(@NonNull AssetRepository assetRepository) {
52         mAssetRepository = assetRepository;
53     }
54 
55     /**
56      * Clears the AssetRepository reference.
57      */
releaseAssetRepository()58     public void releaseAssetRepository() {
59         mAssetRepository = null;
60     }
61 
62     @NonNull
getAssetRepository()63     public AssetRepository getAssetRepository() {
64         if (mAssetRepository == null) {
65             throw new IllegalStateException("Asset repository is not set");
66         }
67         return mAssetRepository;
68     }
69 
BridgeAssetManager()70     public BridgeAssetManager() {
71     }
72 }
73