mondrian.olap
Class Walker

java.lang.Object
  mondrian.olap.Walker

All Implemented Interfaces:

Enumeration

public class Walker
extends Object
implements Enumeration

Walks over a tree, returning nodes in prefix order. Objects which are an instance of Walkable supply their children using getChildren(); other objects are assumed to have no children.

If the tree is modified during the enumeration, strange things may happen.

Example use:

    Tree t;
    Walker w = new Walker(t);
    while (w.hasMoreElements()) {
      Tree node = (Tree) w.nextNode();
      System.out.println(node.toString());
    }
 

Constructor Summary

Walker(Walkable root)

Method Summary

Object	currentElement() returns the current object.
Object	getAncestor(int iDepth)
int	getAncestorOrdinal(int iDepth) get the ordinal within its parent node of the iDepthth ancestor.
Object[]	getChildren(Object node) Override this function to prune the tree, or to allow objects which are not Walkable to have children.
int	getOrdinal() get the ordinal within its parent node of the current node.
Object	getParent()
boolean	hasMoreElements()
int	level() returns level in the tree of the current element (that is, last element returned from nextElement()).
static void	main(String[] args)
Object	nextElement()
void	prune() Tell walker that we don't want to visit any (more) children of this node.
void	pruneSiblings()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Walker

public Walker(Walkable root)

Method Detail

hasMoreElements

public boolean hasMoreElements()

Specified by:

hasMoreElements in interface Enumeration

nextElement

public Object nextElement()

Specified by:

nextElement in interface Enumeration

prune

public void prune()

Tell walker that we don't want to visit any (more) children of this node. The next node visited will be (a return visit to) the node's parent. Not valid until nextElement() has been called.

pruneSiblings

public void pruneSiblings()

currentElement

public Object currentElement()

returns the current object. Not valid until nextElement() has been called.

level

public int level()

returns level in the tree of the current element (that is, last element returned from nextElement()). The level of the root element is 0.

getParent

public final Object getParent()

getAncestor

public final Object getAncestor(int iDepth)

getOrdinal

public int getOrdinal()

get the ordinal within its parent node of the current node. Returns 0 for the root element. Equivalent to getAncestorOrdinal(0).

getAncestorOrdinal

public int getAncestorOrdinal(int iDepth)

get the ordinal within its parent node of the iDepthth ancestor.

getChildren

public Object[] getChildren(Object node)

Override this function to prune the tree, or to allow objects which are not Walkable to have children.

main

public static void main(String[] args)