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.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      * If the resource is cached, creates and returns a new instance of it.
28      *
29      * @param key a key that uniquely identifies the drawable resource
30      * @param resources a Resources object from which to create new instances.
31      * @param theme the theme where the resource will be used
32      * @return a new instance of the resource, or {@code null} if not in
33      *         the cache
34      */
35     @UnsupportedAppUsage
getInstance(long key, Resources resources, Resources.Theme theme)36     public Drawable getInstance(long key, Resources resources, Resources.Theme theme) {
37         final Drawable.ConstantState entry = get(key, theme);
38         if (entry != null) {
39             return entry.newDrawable(resources, theme);
40         }
41 
42         return null;
43     }
44 
45     @Override
shouldInvalidateEntry(Drawable.ConstantState entry, int configChanges)46     public boolean shouldInvalidateEntry(Drawable.ConstantState entry, int configChanges) {
47         return Configuration.needNewResources(configChanges, entry.getChangingConfigurations());
48     }
49 }
50