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 android.content.res;
18 
19 import android.compat.annotation.UnsupportedAppUsage;
20 import android.graphics.drawable.Drawable;
21 
22 /**
23  * Class which can be used to cache Drawable resources against a theme.
24  */
25 class DrawableCache extends ThemedResourceCache<Drawable.ConstantState> {
26 
27     @UnsupportedAppUsage
DrawableCache()28     DrawableCache() {
29     }
30 
31     /**
32      * If the resource is cached, creates and returns a new instance of it.
33      *
34      * @param key a key that uniquely identifies the drawable resource
35      * @param resources a Resources object from which to create new instances.
36      * @param theme the theme where the resource will be used
37      * @return a new instance of the resource, or {@code null} if not in
38      *         the cache
39      */
40     @UnsupportedAppUsage
getInstance(long key, Resources resources, Resources.Theme theme)41     public Drawable getInstance(long key, Resources resources, Resources.Theme theme) {
42         final Drawable.ConstantState entry = get(key, theme);
43         if (entry != null) {
44             return entry.newDrawable(resources, theme);
45         }
46 
47         return null;
48     }
49 
50     @Override
shouldInvalidateEntry(Drawable.ConstantState entry, int configChanges)51     public boolean shouldInvalidateEntry(Drawable.ConstantState entry, int configChanges) {
52         return Configuration.needNewResources(configChanges, entry.getChangingConfigurations());
53     }
54 }
55