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