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.transition;
  
  import android.content.Context;
  import android.graphics.Path;
  import android.util.AttributeSet;
  
  /**
   * This base class can be extended to provide motion along a Path to Transitions.
   *
   * <p>
   * Transitions such as {@link android.transition.ChangeBounds} move Views, typically
   * in a straight path between the start and end positions. Applications that desire to
   * have these motions move in a curve can change how Views interpolate in two dimensions
   * by extending PathMotion and implementing {@link #getPath(float, float, float, float)}.
   * </p>
   * <p>This may be used in XML as an element inside a transition.</p>
   * <pre>
   * {@code
   * <changeBounds>
   *     <pathMotion class="my.app.transition.MyPathMotion"/>
   * </changeBounds>
   * }
   * </pre>
   */
  public abstract class PathMotion {
  
      public PathMotion() {}
  
      public PathMotion(Context context, AttributeSet attrs) {}
  
      /**
       * Provide a Path to interpolate between two points <code>(startX, startY)</code> and
       * <code>(endX, endY)</code>. This allows controlled curved motion along two dimensions.
       *
       * @param startX The x coordinate of the starting point.
       * @param startY The y coordinate of the starting point.
       * @param endX   The x coordinate of the ending point.
       * @param endY   The y coordinate of the ending point.
       * @return A Path along which the points should be interpolated. The returned Path
       * must start at point <code>(startX, startY)</code>, typically using
       * {@link android.graphics.Path#moveTo(float, float)} and end at <code>(endX, endY)</code>.
       */
      public abstract Path getPath(float startX, float startY, float endX, float endY);
  }
  