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.graphics.drawable.Drawable;
20 
21 /**
22  * Class which can be used to cache Drawable resources against a theme.
23  */
24 class DrawableCache extends ThemedResourceCache<Drawable.ConstantState> {
25     private final Resources mResources;
26 
27     /**
28      * Creates a cache for the given Resources instance.
29      *
30      * @param resources the resources to use when creating new instances
31      */
DrawableCache(Resources resources)32     public DrawableCache(Resources resources) {
33         mResources = resources;
34     }
35 
36     /**
37      * If the resource is cached, creates and returns a new instance of it.
38      *
39      * @param key a key that uniquely identifies the drawable resource
40      * @param theme the theme where the resource will be used
41      * @return a new instance of the resource, or {@code null} if not in
42      *         the cache
43      */
getInstance(long key, Resources.Theme theme)44     public Drawable getInstance(long key, Resources.Theme theme) {
45         final Drawable.ConstantState entry = get(key, theme);
46         if (entry != null) {
47             return entry.newDrawable(mResources, theme);
48         }
49 
50         return null;
51     }
52 
53     @Override
shouldInvalidateEntry(Drawable.ConstantState entry, int configChanges)54     public boolean shouldInvalidateEntry(Drawable.ConstantState entry, int configChanges) {
55         return Configuration.needNewResources(configChanges, entry.getChangingConfigurations());
56     }
57 }
58