1/*
2 * Copyright (C) 2014 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
17package android.content.res;
18
19import android.content.pm.ActivityInfo.Config;
20
21/**
22 * A Cache class which can be used to cache resource objects that are easy to clone but more
23 * expensive to inflate.
24 *
25 * @hide For internal use only.
26 */
27public class ConfigurationBoundResourceCache<T> extends ThemedResourceCache<ConstantState<T>> {
28    /**
29     * If the resource is cached, creates and returns a new instance of it.
30     *
31     * @param key a key that uniquely identifies the drawable resource
32     * @param resources a Resources object from which to create new instances.
33     * @param theme the theme where the resource will be used
34     * @return a new instance of the resource, or {@code null} if not in
35     *         the cache
36     */
37    public T getInstance(long key, Resources resources, Resources.Theme theme) {
38        final ConstantState<T> entry = get(key, theme);
39        if (entry != null) {
40            return entry.newInstance(resources, theme);
41        }
42
43        return null;
44    }
45
46    @Override
47    public boolean shouldInvalidateEntry(ConstantState<T> entry, @Config int configChanges) {
48        return Configuration.needNewResources(configChanges, entry.getChangingConfigurations());
49    }
50}
51