weka.gui
Class HierarchyPropertyParser

java.lang.Object
  |
  +--weka.gui.HierarchyPropertyParser
All Implemented Interfaces:
java.io.Serializable

public class HierarchyPropertyParser
extends java.lang.Object
implements java.io.Serializable

This class implements a parser to read properties that have a hierarchy(i.e. tree) structure. Conceptually it's similar to the XML DOM/SAX parser but of course is much simpler and uses dot as the seperator of levels instead of back-slash.
It provides interfaces to both build a parser tree and traverse the tree.
Note that this implementation does not lock the tree when different threads are traversing it simultaneously, i.e. it's NOT synchronized and multi-thread safe. It is recommended that later implementation extending this class provide a locking scheme and override the functions with the "synchronized" modifier (most of them are goToXXX() and information accessing functions).

Version:
$Revision: 1.2 $
Author:
Xin Xu (xx5@cs.waikato.ac.nz)
See Also:
Serialized Form

Constructor Summary
HierarchyPropertyParser()
          Default constructor
HierarchyPropertyParser(java.lang.String p, java.lang.String delim)
          Constructor that builds a tree from the given property with the given delimitor
 
Method Summary
 void add(java.lang.String property)
          Add the given item of property to the tree
 void build(java.lang.String p, java.lang.String delim)
          Build a tree from the given property with the given delimitor
 java.lang.String[] childrenValues()
          The value in the children nodes.
 boolean contains(java.lang.String string)
          Whether the HierarchyPropertyParser contains the given string
 java.lang.String context()
          The context of the current node, i.e.
 int depth()
          Get the depth of the tree, i.e.
 java.lang.String fullValue()
          The full value of the current node, i.e.
 int getLevel()
          Get the level of current node.
 java.lang.String getSeperator()
          Get the seperator between levels.
 java.lang.String getValue()
          Get the value of current node
 boolean goDown(java.lang.String path)
          Go to a certain node of the tree down from the current node according to the specified relative path.
 boolean goTo(java.lang.String path)
          Go to a certain node of the tree according to the specified path Note that the path must be absolute path from the root.
 void goToChild(int pos)
          Go to one child node from the current position in the tree according to the given position
 boolean goToChild(java.lang.String value)
          Go to one child node from the current position in the tree according to the given value
If the child node with the given value cannot be found it returns false, true otherwise.
 void goToParent()
          Go to the parent from the current position in the tree If the current position is the root, it stays there and does not move
 void goToRoot()
          Go to the root of the tree
 boolean isHierachic(java.lang.String string)
          Whether the given string has a hierachy structure with the seperators
 boolean isLeafReached()
          Whether the current position is a leaf
 boolean isRootReached()
          Whether the current position is the root
static void main(java.lang.String[] args)
          Tests out the parser.
 int numChildren()
          The number of the children nodes.
 java.lang.String parentValue()
          The value in the parent node.
 int search(java.util.Vector vct, java.lang.String target)
          Helper function to search for the given target string in a given vector in which the elements' value may hopefully is equal to the target.
 void setSeperator(java.lang.String s)
          Set the seperator between levels.
 java.lang.String showTree()
          Show the whole tree in text format
 java.lang.String[] tokenize(java.lang.String rawString)
          Tokenize the given string based on the seperator and put the tokens into an array of strings
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

HierarchyPropertyParser

public HierarchyPropertyParser()
Default constructor


HierarchyPropertyParser

public HierarchyPropertyParser(java.lang.String p,
                               java.lang.String delim)
                        throws java.lang.Exception
Constructor that builds a tree from the given property with the given delimitor

Parameters:
p - the given property string
delim - the given dilimitor
Method Detail

setSeperator

public void setSeperator(java.lang.String s)
Set the seperator between levels. Default is dot.

Parameters:
s - the seperator symbol

getSeperator

public java.lang.String getSeperator()
Get the seperator between levels. Default is dot.

Returns:
the seperator symbol

build

public void build(java.lang.String p,
                  java.lang.String delim)
           throws java.lang.Exception
Build a tree from the given property with the given delimitor

Parameters:
p - the given property
delim - the given delimitor
java.lang.Exception

add

public void add(java.lang.String property)
Add the given item of property to the tree

Parameters:
property - the given item

tokenize

public java.lang.String[] tokenize(java.lang.String rawString)
Tokenize the given string based on the seperator and put the tokens into an array of strings

Parameters:
rawString - the given string
Returns:
an array of strings

contains

public boolean contains(java.lang.String string)
Whether the HierarchyPropertyParser contains the given string

Parameters:
string - the given string
Returns:
whether contains

isHierachic

public boolean isHierachic(java.lang.String string)
Whether the given string has a hierachy structure with the seperators

Parameters:
string - the given string

search

public int search(java.util.Vector vct,
                  java.lang.String target)
Helper function to search for the given target string in a given vector in which the elements' value may hopefully is equal to the target. If such elements are found the first index is returned, otherwise -1

Parameters:
vct - the given vector
target - the given target string
Returns:
the index of the found element, -1 if not found

goTo

public boolean goTo(java.lang.String path)
Go to a certain node of the tree according to the specified path Note that the path must be absolute path from the root.
For relative path, see goDown(String path).

Parameters:
path - the given absolute path
Returns:
whether the path exists, if false the current position does not move

goDown

public boolean goDown(java.lang.String path)
Go to a certain node of the tree down from the current node according to the specified relative path. The path does not contain the value of current node

Parameters:
path - the given relative path
Returns:
whether the path exists, if false the current position does not move

goToRoot

public void goToRoot()
Go to the root of the tree


goToParent

public void goToParent()
Go to the parent from the current position in the tree If the current position is the root, it stays there and does not move


goToChild

public boolean goToChild(java.lang.String value)
Go to one child node from the current position in the tree according to the given value
If the child node with the given value cannot be found it returns false, true otherwise. If false, the current position does not change

Parameters:
value - the value of the given child
Returns:
whether the child can be found

goToChild

public void goToChild(int pos)
               throws java.lang.Exception
Go to one child node from the current position in the tree according to the given position

Parameters:
pos - the position of the given child
Throws:
if - the position is out of range or leaf is reached
java.lang.Exception

numChildren

public int numChildren()
The number of the children nodes. If current node is leaf, it returns 0.

Returns:
the number of the children nodes of the current position

childrenValues

public java.lang.String[] childrenValues()
The value in the children nodes. If current node is leaf, it returns null.

Returns:
the value in the children nodes

parentValue

public java.lang.String parentValue()
The value in the parent node. If current node is root, it returns null.

Returns:
the value in the parent node

isLeafReached

public boolean isLeafReached()
Whether the current position is a leaf

Returns:
whether the current position is a leaf

isRootReached

public boolean isRootReached()
Whether the current position is the root

Returns:
whether the current position is the root

getValue

public java.lang.String getValue()
Get the value of current node

Returns:
value level

getLevel

public int getLevel()
Get the level of current node. Note the level starts from 0

Returns:
the level

depth

public int depth()
Get the depth of the tree, i.e. (the largest level)+1

Returns:
the depth of the tree

context

public java.lang.String context()
The context of the current node, i.e. the path from the root to the parent node of the current node, seperated by the seperator. If root, it returns null

Returns:
the context path

fullValue

public java.lang.String fullValue()
The full value of the current node, i.e. its context + seperator + its value. For root, only its value.

Returns:
the context path

showTree

public java.lang.String showTree()
Show the whole tree in text format

Returns:
the whole tree in text format

main

public static void main(java.lang.String[] args)
Tests out the parser.

Parameters:
args - should contain nothing


Copyright (c) 2003 David Lindsay, Computer Learning Research Centre, Dept. Computer Science, Royal Holloway, University of London