// Circular.java
// (c) 1997 Kim Bruce; Modified 1999 Andrea Danyluk

/** Interface for collection of objects in a circular arrangement.	**/
public interface Circular 
{

  // pre:  this is non-empty
  // post: moves current to successor position in arrangement
  public void next();

  // pre:
  // post: returns number of elts in object
  public int size();

  // pre:  this is non-empty
  // post: returns the current element
  public Object getCurrent();
  
  // pre: this is non-empty
  // post:  Current elt is deleted, if non-empty, successor of
  //  old current is new current elt
  public void removeCurrent();
  
  // pre:
  // post:  If this was empty, obj is inserted as only elt, owise
  //        added after current elt
  //	    Either way, obj is now current elt
  public void addAfterCurrent(Object obj);

  // pre:
  // post:  collection of objects is now empty
  public void clear();

  // pre:
  // post:  returns true if this is empty; false otherwise.
  public boolean isEmpty();

}