PicassoImageLoader.java 文件源码

/**
 * Lazy instantiation of the list of transformations used during the image download. This method
 * returns a List<Transformation> because Picasso doesn't support a null instance as
 * transformation.
 */
private List<Transformation> getTransformations() {
  if (transformations == null) {
    transformations = new LinkedList<Transformation>();
    if (useCircularTransformation) {
      transformations.add(new CircleTransformation());
    }
  }
  return transformations;
}