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 package com.android.customization.model.theme.custom;
17 
18 import android.content.Context;
19 import android.content.pm.PackageManager.NameNotFoundException;
20 import android.content.res.Resources;
21 import android.os.UserHandle;
22 
23 import com.android.customization.model.CustomizationManager.OptionsFetchedListener;
24 import com.android.customization.model.ResourceConstants;
25 import com.android.customization.model.theme.OverlayManagerCompat;
26 
27 import java.util.ArrayList;
28 import java.util.List;
29 
30 /**
31  * Base class used to retrieve Custom Theme Component options (eg, different fonts)
32  * from the system.
33  */
34 public abstract class ThemeComponentOptionProvider<T extends ThemeComponentOption> {
35 
36     protected final Context mContext;
37     protected final List<String> mOverlayPackages;
38     protected List<T> mOptions;
39 
ThemeComponentOptionProvider(Context context, OverlayManagerCompat manager, String... categories)40     public ThemeComponentOptionProvider(Context context, OverlayManagerCompat manager,
41             String... categories) {
42         mContext = context;
43         mOverlayPackages = new ArrayList<>();
44         for (String category : categories) {
45             mOverlayPackages.addAll(manager.getOverlayPackagesForCategory(category,
46                     UserHandle.myUserId(), ResourceConstants.getPackagesToOverlay(mContext)));
47         }
48     }
49 
50     /**
51      * Returns whether there are options for this component available in the current setup.
52      */
isAvailable()53     public boolean isAvailable() {
54         return !mOverlayPackages.isEmpty();
55     }
56 
57     /**
58      * Retrieve the available options for this component.
59      * @param callback called when the themes have been retrieved (or immediately if cached)
60      * @param reload whether to reload themes if they're cached.
61      */
fetch(OptionsFetchedListener<T> callback, boolean reload)62     public void fetch(OptionsFetchedListener<T> callback, boolean reload) {
63         if (mOptions == null || reload) {
64             mOptions = new ArrayList<>();
65             loadOptions();
66         }
67 
68         if(callback != null) {
69             callback.onOptionsLoaded(mOptions);
70         }
71     }
72 
loadOptions()73     protected abstract void loadOptions();
74 
getOverlayResources(String overlayPackage)75     protected Resources getOverlayResources(String overlayPackage) throws NameNotFoundException {
76         return mContext.getPackageManager().getResourcesForApplication(overlayPackage);
77     }
78 }
79