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
17package android.content.res;
18
19import com.android.layoutlib.bridge.Bridge;
20
21import android.content.res.AssetManager;
22
23public class BridgeAssetManager extends AssetManager {
24
25    /**
26     * This initializes the static field {@link AssetManager#mSystem} which is used
27     * by methods who get a global asset manager using {@link AssetManager#getSystem()}.
28     * <p/>
29     * They will end up using our bridge asset manager.
30     * <p/>
31     * {@link Bridge} calls this method after setting up a new bridge.
32     */
33    public static AssetManager initSystem() {
34        if (!(AssetManager.sSystem instanceof BridgeAssetManager)) {
35            // Note that AssetManager() creates a system AssetManager and we override it
36            // with our BridgeAssetManager.
37            AssetManager.sSystem = new BridgeAssetManager();
38            AssetManager.sSystem.makeStringBlocks(false);
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     */
47    public static void clearSystem() {
48        AssetManager.sSystem = null;
49    }
50
51    private BridgeAssetManager() {
52    }
53}
54