import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Circular shifting implementation using a list and Collections.rotate.
 * 
 * @author Alexander Schaap
 * 
 */
public class CircularShifter2 extends CircularShifterAbstract {
  /**
   * Another implementation of circular shifting, this time using an ArrayList
   * and rotating it, copying to result array one line at the time.
   */
  public StorageInterface<StorageInterface<WordInterface<?>>> circularShifts(
      StorageInterface<WordInterface<?>> line) {
    StorageInterface<StorageInterface<WordInterface<?>>> result = new StorageObservableArrayList<StorageInterface<WordInterface<?>>>();
    result.add(line);
    List<WordInterface<?>> tmp = new ArrayList<WordInterface<?>>();
    for (int i = 0; i < line.length(); i++) {
      tmp.add(line.get(i));
    }
    for (int i = 1; i < line.length(); i++) {
      Collections.rotate(tmp, 1);
      StorageInterface<WordInterface<?>> tmp2 = new StorageObservableArrayList<WordInterface<?>>();

      for (int j = 0; j < line.length(); j++) {
        tmp2.add(tmp.get(j));
      }
      result.add(tmp2);
    }
    return result;
  }
}