content: /*
   * Copyright (C) 2015 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.graphics.drawable;
  
  import android.annotation.NonNull;
  
  /**
   * Abstract class that drawables supporting animations and callbacks should extend.
   */
  public interface Animatable2 extends Animatable {
  
      /**
       * Adds a callback to listen to the animation events.
       *
       * @param callback Callback to add.
       */
      void registerAnimationCallback(@NonNull AnimationCallback callback);
  
      /**
       * Removes the specified animation callback.
       *
       * @param callback Callback to remove.
       * @return {@code false} if callback didn't exist in the call back list, or {@code true} if
       *         callback has been removed successfully.
       */
      boolean unregisterAnimationCallback(@NonNull AnimationCallback callback);
  
      /**
       * Removes all existing animation callbacks.
       */
      void clearAnimationCallbacks();
  
      public static abstract class AnimationCallback {
          /**
           * Called when the animation starts.
           *
           * @param drawable The drawable started the animation.
           */
          public void onAnimationStart(Drawable drawable) {};
          /**
           * Called when the animation ends.
           *
           * @param drawable The drawable finished the animation.
           */
          public void onAnimationEnd(Drawable drawable) {};
      }
  }
  