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      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     /**
     26      * If the resource is cached, creates and returns a new instance of it.
     27      *
     28      * @param key a key that uniquely identifies the drawable resource
     29      * @param resources a Resources object from which to create new instances.
     30      * @param theme the theme where the resource will be used
     31      * @return a new instance of the resource, or {@code null} if not in
     32      *         the cache
     33      */
     34     public Drawable getInstance(long key, Resources resources, Resources.Theme theme) {
     35         final Drawable.ConstantState entry = get(key, theme);
     36         if (entry != null) {
     37             return entry.newDrawable(resources, theme);
     38         }
     39 
     40         return null;
     41     }
     42 
     43     @Override
     44     public boolean shouldInvalidateEntry(Drawable.ConstantState entry, int configChanges) {
     45         return Configuration.needNewResources(configChanges, entry.getChangingConfigurations());
     46     }
     47 }
     48