content: /*
  * Copyright (C) 2014 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
  package android.content.res;
  
  import android.content.pm.ActivityInfo.Config;
  
  /**
   * A cache class that can provide new instances of a particular resource which may change
   * depending on the current {@link Resources.Theme} or {@link Configuration}.
   * <p>
   * A constant state should be able to return a bitmask of changing configurations, which
   * identifies the type of configuration changes that may invalidate this resource. These
   * configuration changes can be obtained from {@link android.util.TypedValue}. Entities such as
   * {@link android.animation.Animator} also provide a changing configuration method to include
   * their dependencies (e.g. An AnimatorSet's changing configuration is the union of the
   * changing configurations of each Animator in the set)
   * @hide
   */
  abstract public class ConstantState<T> {
  
      /**
       * Return a bit mask of configuration changes that will impact
       * this resource (and thus require completely reloading it).
       */
      abstract public @Config int getChangingConfigurations();
  
      /**
       * Create a new instance without supplying resources the caller
       * is running in.
       */
      public abstract T newInstance();
  
      /**
       * Create a new instance from its constant state.  This
       * must be implemented for resources that change based on the target
       * density of their caller (that is depending on whether it is
       * in compatibility mode).
       */
      public T newInstance(Resources res) {
          return newInstance();
      }
  
      /**
       * Create a new instance from its constant state.  This must be
       * implemented for resources that can have a theme applied.
       */
      public T newInstance(Resources res, Resources.Theme theme) {
          return newInstance(res);
      }
  }
  