content: /*
   * Copyright (C) 2010 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 com.hx.curtain.drawer.nineoldandroids.animation;
  
  /**
   * This evaluator can be used to perform type interpolation between <code>float</code> values.
   */
  public class FloatEvaluator implements TypeEvaluator<Number> {
  
      /**
       * This function returns the result of linearly interpolating the start and end values, with
       * <code>fraction</code> representing the proportion between the start and end values. The
       * calculation is a simple parametric calculation: <code>result = x0 + t * (v1 - v0)</code>,
       * where <code>x0</code> is <code>startValue</code>, <code>x1</code> is <code>endValue</code>,
       * and <code>t</code> is <code>fraction</code>.
       *
       * @param fraction   The fraction from the starting to the ending values
       * @param startValue The start value; should be of type <code>float</code> or
       *                   <code>Float</code>
       * @param endValue   The end value; should be of type <code>float</code> or <code>Float</code>
       * @return A linear interpolation between the start and end values, given the
       *         <code>fraction</code> parameter.
       */
      public Float evaluate(float fraction, Number startValue, Number endValue) {
          float startFloat = startValue.floatValue();
          return startFloat + fraction * (endValue.floatValue() - startFloat);
      }
  }