content: /*
   * Copyright (C) 2009 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.view.animation;
  
  import android.content.Context;
  import android.util.AttributeSet;
  
  import com.android.internal.view.animation.HasNativeInterpolator;
  import com.android.internal.view.animation.NativeInterpolatorFactory;
  import com.android.internal.view.animation.NativeInterpolatorFactoryHelper;
  
  /**
   * An interpolator where the change bounces at the end.
   */
  @HasNativeInterpolator
  public class BounceInterpolator extends BaseInterpolator implements NativeInterpolatorFactory {
      public BounceInterpolator() {
      }
  
      @SuppressWarnings({"UnusedDeclaration"})
      public BounceInterpolator(Context context, AttributeSet attrs) {
      }
  
      private static float bounce(float t) {
          return t * t * 8.0f;
      }
  
      public float getInterpolation(float t) {
          // _b(t) = t * t * 8
          // bs(t) = _b(t) for t < 0.3535
          // bs(t) = _b(t - 0.54719) + 0.7 for t < 0.7408
          // bs(t) = _b(t - 0.8526) + 0.9 for t < 0.9644
          // bs(t) = _b(t - 1.0435) + 0.95 for t <= 1.0
          // b(t) = bs(t * 1.1226)
          t *= 1.1226f;
          if (t < 0.3535f) return bounce(t);
          else if (t < 0.7408f) return bounce(t - 0.54719f) + 0.7f;
          else if (t < 0.9644f) return bounce(t - 0.8526f) + 0.9f;
          else return bounce(t - 1.0435f) + 0.95f;
      }
  
      /** @hide */
      @Override
      public long createNativeInterpolator() {
          return NativeInterpolatorFactoryHelper.createBounceInterpolator();
      }
  }