Package net.sf.molae.pipe.tree

This package contains utility classes to work with tree like structures.


Interface Summary
Composition<E> This Interface indicates that a class implements the composition design pattern.
CompositionView<T> A Composition View defines for each class the children to be regarded.

Class Summary
CompositionView.DefaultCompositionView Default implementation of a CompositionView.
DepthFirstCollection<E> A collection based on the DepthFirstIterator.
DepthFirstIterator<E> Provides an Iterator that runs depth first through a tree.
LeafFilter<E> Filters all leafs of a tree defined by a CompositionView.

Package net.sf.molae.pipe.tree Description

This package contains utility classes to work with tree like structures.

As an example here are two classes, one representing a web page consisting of several forms:
public class Page{
    Collection forms;
and one class representing a form consisting of several input fields.
public class Form{
    Collection fields;
To retrieve all fields in a page a programmer would usually write code like this:
Page page;
Iterator pit = page.forms.iterator();
    Form form = (Form);
    Iterator fit = form.fields.iterator();
    while (fit.hasNext()){
        Field field = (Field);
        ... do something
With this package you could achieve the same result by describing the structure of the page:
public class PageView implements CompositionView{
    public Collection getChildren(Object o){
        if (o instanceof Page) return ((Page) o).forms;
        else if (o instanceof Form) return ((Form) o).fields;
and then use the leaf iterator
Page page;
Iterator fit = new LeafIterator(page, new PageView());
while (fit.hasNext());
    Field field = (Field);
The advantage of this way of programming is the explicit representation of structural information over implicit representation,