edu.harvard.hul.ois.jhove.module.pdf

Class DocNode

java.lang.Object

edu.harvard.hul.ois.jhove.module.pdf.DocNode

Direct Known Subclasses:

PageObject, PageTreeNode

public abstract class DocNode
extends Object

Abstract class for nodes of a PDF document tree.

Field Summary

Fields

Modifier and Type	Field and Description
protected PdfDictionary	_dict The dictionary which defines this node.
protected PdfModule	_module The PdfModule this node is associated with.
protected boolean	_pageObjectFlag True if this node is a PageObject.
protected PageTreeNode	_parent The parent node of this node.
protected boolean	_walkFinished Set to true when all subnodes of this node have been iterated through following a StartWalk.

Constructor Summary

Constructors

Constructor and Description
DocNode(PdfModule module, PageTreeNode parent, PdfDictionary dict) Superclass constructor.

Method Summary

Modifier and Type	Method and Description
PdfObject	get(String key, boolean inheritable) Get an named property.
PdfDictionary	getDict() Returns the page object or page tree node dictionary from which this object was constructed.
PdfDictionary	getFontResources() Returns the dictionary of fonts within the node's Resources dictionary, if both exist.
PdfArray	getMediaBox() Get the MediaBox of this node.
DocNode	getParent() Returns the parent of this node.
PdfDictionary	getResources() Get the Resources dictionary.
boolean	isPageObject() Returns true if this node is a PageObject.
abstract DocNode	nextDocNode() Get the next DocNode which is under this node.
abstract PageObject	nextPageObject() Get the next PageObject which is under this node.
abstract void	startWalk() Initialize an iterator through the descendants of this node.

Methods inherited from class java.lang.Object

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

Field Detail

_module

protected PdfModule _module

The PdfModule this node is associated with.

_parent

protected PageTreeNode _parent

The parent node of this node.

_dict

protected PdfDictionary _dict

The dictionary which defines this node.

_pageObjectFlag

protected boolean _pageObjectFlag

True if this node is a PageObject.

_walkFinished

protected boolean _walkFinished

Set to true when all subnodes of this node have been iterated through following a StartWalk.

Constructor Detail

DocNode

public DocNode(PdfModule module,
               PageTreeNode parent,
               PdfDictionary dict)

Superclass constructor.

Parameters:

module - The PdfModule under which we're operating

parent - The parent node in the document tree; may be null only for the root node

dict - The dictionary object on which this node is based

Method Detail

isPageObject

public boolean isPageObject()

Returns true if this node is a PageObject.

startWalk

public abstract void startWalk()

Initialize an iterator through the descendants of this node.

nextPageObject

public abstract PageObject nextPageObject()
                                   throws PdfMalformedException

Get the next PageObject which is under this node.

Throws:

PdfMalformedException

nextDocNode

public abstract DocNode nextDocNode()
                             throws PdfMalformedException

Get the next DocNode which is under this node. All PageTreeNodes and PageObjects are eventually returned by walking through a structure with nextNode.

Throws:

PdfMalformedException

getParent

public DocNode getParent()

Returns the parent of this node.

getDict

public PdfDictionary getDict()

Returns the page object or page tree node dictionary from which this object was constructed.

getResources

public PdfDictionary getResources()
                           throws PdfException

Get the Resources dictionary. Either a PageTreeNode or a PageObject can have a Resources dictionary. Returns null if there is no Resources dictionary. The object may be referenced indirectly.

Throws:

PdfException

getFontResources

public PdfDictionary getFontResources()
                               throws PdfException

Returns the dictionary of fonts within the node's Resources dictionary, if both exist. Otherwise returns null. The dictionary will most often have indirect object references as values. What is returned is not a Font dictionary, but rather a dictionary of Font dictionaries.

Throws:

PdfException

getMediaBox

public PdfArray getMediaBox()
                     throws PdfInvalidException

Get the MediaBox of this node. MediaBox is an inheritable property, so it walks up the chain of ancestors if it doesn't contain one. Returns null if none. Throws a PdfInvalidException if an invalid MediaBox is found.

Throws:

PdfInvalidException

get

public PdfObject get(String key,
                     boolean inheritable)

Get an named property. If this object doesn't have the specified property and inheritable is true, walks up the chain of ancestors to try to find one. If no ancestor has the property or inheritable is false, returns null.