de.rwth.utils
Interface TreeIterator

All Superinterfaces:

java.util.Iterator, java.util.ListIterator

All Known Implementing Classes:

AbstractTreeIterator

public interface TreeIterator

extends java.util.ListIterator

The TreeIterator interface provides a means for traversing a tree. The methods inherited from the ListIterator interface traverse up and down in the tree, the new methods declared here move to the left and right.

Version:

$Id: TreeIterator.java,v 1.2 2002/09/17 06:53:53 mohnen Exp $

Author:

Markus Mohnen

Method Summary

java.lang.Object	current() Returns the current element.
int	currentIndex() Returns the index of the current element among the children of the current parent.
boolean	hasCurrent() Returns true iff there is a current element available.
boolean	hasLeft() Checks if there is an element to the left in the tree.
boolean	hasRight() Checks if there is an element to the right in the tree.
java.lang.Object	left() Returns the element to the left.
int	leftIndex() Returns the index of the left element among the children of the current parent.
Position	position() Gets the current position in this tree.
java.lang.Object	right() Returns the element to the right.
int	rightIndex() Returns the index of the right element among the children of the current parent.

Methods inherited from interface java.util.ListIterator

add, hasNext, hasPrevious, next, nextIndex, previous, previousIndex, remove, set

Method Detail

hasCurrent

public boolean hasCurrent()

Returns true iff there is a current element available. In other words, it will return false iff no call to getNext has been done.

Returns:

true iff there is a current element available

current

public java.lang.Object current()
                         throws java.util.NoSuchElementException

Returns the current element.

Returns:

The current Object

Throws:

java.util.NoSuchElementException - if there is no current element.

currentIndex

public int currentIndex()

Returns the index of the current element among the children of the current parent. The first element after a call to next has index 0.

Returns:

the index of the current element of -1 if there is no current element.

hasLeft

public boolean hasLeft()

Checks if there is an element to the left in the tree. After a call to the method next this method will always return false.

Returns:

true iff there is an element to the left in the tree.

hasRight

public boolean hasRight()

Checks if there is an element to the right in the tree.

Returns:

true iff there is an element to the right in the tree.

left

public java.lang.Object left()
                      throws java.util.NoSuchElementException

Returns the element to the left.

Returns:

the Object to the left.

Throws:

java.util.NoSuchElementException - if there is no element to the left.

right

public java.lang.Object right()
                       throws java.util.NoSuchElementException

Returns the element to the right.

Returns:

the Object to the right.

Throws:

java.util.NoSuchElementException - if there is no element to the right

leftIndex

public int leftIndex()

Returns the index of the left element among the children of the current parent.

Returns:

index of the left element; -1 if there is no element to the left

rightIndex

public int rightIndex()

Returns the index of the right element among the children of the current parent.

Returns:

index of the right element; -1 if there is no element to the right

position

public Position position()

Gets the current position in this tree.

Returns:

a value of type Position