Module java.desktop

Package javax.swing.text

Class ElementIterator

java.lang.Object

javax.swing.text.ElementIterator

All Implemented Interfaces:

Cloneable

public class ElementIterator
extends Object
implements Cloneable

ElementIterator, as the name suggests, iterates over the Element tree. The constructor can be invoked with either Document or an Element as an argument. If the constructor is invoked with a Document as an argument then the root of the iteration is the return value of document.getDefaultRootElement().

The iteration happens in a depth-first manner. In terms of how boundary conditions are handled:

• if next() is called before first() or current(), the root will be returned
• next() returns null to indicate the end of the list
• previous() returns null when the current element is the root or next() has returned null

The ElementIterator does no locking of the Element tree. This means that it does not track any changes. It is the responsibility of the user of this class, to ensure that no changes happen during element iteration.

Simple usage example:

public void iterate() {
      ElementIterator it = new ElementIterator(root);
      Element elem;
      while (true) {
          if ((elem = it.next()) != null) {
              // process element
              System.out.println("elem: " + elem.getName());
          } else {
              break;
          }
      }
 }

Constructor Summary

Constructors

Constructor	Description
ElementIterator(Document document)	Creates a new ElementIterator.
ElementIterator(Element root)	Creates a new ElementIterator.

Method Summary

Modifier and Type	Method	Description
Object	clone()	Clones the ElementIterator.
Element	current()	Fetches the current Element.
int	depth()	Fetches the current depth of element tree.
Element	first()	Fetches the first element.
Element	next()	Fetches the next Element.
Element	previous()	Fetches the previous Element.

Methods declared in class java.lang.Object

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

Constructor Details

ElementIterator

public ElementIterator(Document document)

Creates a new ElementIterator. The root element is taken to get the default root element of the document.

Parameters:

document - a Document

ElementIterator

public ElementIterator(Element root)

Creates a new ElementIterator.

Parameters:

root - the root Element

Method Details

clone

public Object clone()

Clones the ElementIterator.

Overrides:

clone in class Object

Returns:

a cloned ElementIterator Object

See Also:

• Cloneable

first

public Element first()

Fetches the first element.

Returns:

an Element

depth

public int depth()

Fetches the current depth of element tree.

Returns:

the depth

current

public Element current()

Fetches the current Element.

Returns:

element on top of the stack or null if the root element is null

next

public Element next()

Fetches the next Element. The strategy used to locate the next element is a depth-first search.

Returns:

the next element or null at the end of the list

previous

public Element previous()

Fetches the previous Element. If however the current element is the last element, or the current element is null, then null is returned.

Returns:

previous Element if available