de.intarsys.pdf.cos

Class COSObjectProxy

java.lang.Object

de.intarsys.pdf.cos.COSDocumentElement

de.intarsys.pdf.cos.COSObject

de.intarsys.pdf.cos.COSCompositeObject

de.intarsys.pdf.cos.COSObjectProxy

All Implemented Interfaces:

ICOSContainer, ICOSExceptionHandler, de.intarsys.tools.attribute.IAttributeSupport, de.intarsys.tools.component.ISaveStateSupport, Cloneable, Iterable<COSObject>

public abstract class COSObjectProxy
extends COSCompositeObject
implements Cloneable

A "proxy object" used to intercept the visitor callback from the serializer.

You can use this for example to implement an elegant solution for PDF signing, which is defined on the serialized bytes, except some defined byte range. The proxy mechanics allow for creating a placeholder for the signature data, filled in at the correct position later by some post processing.

Field Summary

Fields inherited from class de.intarsys.pdf.cos.COSObject

CONSTANT_CONTAINER, NULL_CONTAINER, SLOT_CONTAINER

Constructor Summary

Constructors

Constructor and Description
COSObjectProxy() Create a COSObjectProxy

Method Summary

Methods

Modifier and Type	Method and Description
Object	accept(ICOSObjectVisitor visitor) Accept a visitor object.
Iterator	basicIterator() An iterator over contained objects and references.
COSObject	copyDeep(Map copied) Make a deep copy of the receiver within the same document.
COSObject	copyShallow() Make a copy of the receiver.
COSObject	cosGetObject() The wrapped COSObject, according to COS level semantics.
COSObject	dereference() return the real object. this is needed for polymorphic handling of document elements. at application programming level only COSObject, never COSIndirectObject is seen.
void	ended(COSWriter writer) Attention: The user must handle encryption by himself.
int	getLength() The length within the data stream for the serialization of this.
COSObject	getObject() The object represented by the proxy.
long	getPosition() The position within the data stream for the serialization of this.
Iterator<COSObject>	iterator() An iterator over contained objects.
boolean	mayBeSwapped() true if this object may be swapped from memory by the garbage collector.
void	reserveData(int pLength) Reserve length bytes for the serialization of this.
Object	saveState()
void	setPosition(long position) Assign the position within the data stream.

Methods inherited from class de.intarsys.pdf.cos.COSCompositeObject

addObjectListener, associate, containable, copyDeep, disassociate, getAttribute, harden, isObjectListenerAvailable, isPrimitive, referenceCount, referenceIndirect, register, removeAttribute, removeObjectListener, restoreStateContainer, saveStateContainer, setAttribute, soften, willChange

Methods inherited from class de.intarsys.pdf.cos.COSObject

asArray, asBoolean, asDictionary, asFixed, asInteger, asName, asNull, asNumber, asStream, asString, beConstant, beIndirect, containable, copyOptional, copySubGraph, getContainer, getDoc, getIndirectObject, getValueBoolean, getValueBytes, getValueFloat, getValueInteger, getValueString, harden, isDangling, isIndirect, isNull, isNumber, isSwapped, restoreState, soften, stringValue, toString

Methods inherited from class de.intarsys.pdf.cos.COSDocumentElement

handleException, isReference

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface de.intarsys.pdf.cos.ICOSContainer

getDoc

Constructor Detail

COSObjectProxy

public COSObjectProxy()

Create a COSObjectProxy

Method Detail

accept

public Object accept(ICOSObjectVisitor visitor)
              throws COSVisitorException

Description copied from class: COSDocumentElement

Accept a visitor object. The receiver selects the correct implementation in the visitor by "double dispatching".

Specified by:

accept in class COSDocumentElement

Parameters:

visitor - The object visiting the receiver.

Returns:

Object An object depending on the visitor semantics.

Throws:

COSVisitorException - An exception depending on the visitor semantics.

basicIterator

public Iterator basicIterator()

Description copied from class: COSObject

An iterator over contained objects and references. The iterator is an empty iterator if this is not a container.

This iterator returns COSDocumentElements, leaving references alone.

Specified by:

basicIterator in class COSObject

Returns:

Iterator over contained objects and references.

copyDeep

public COSObject copyDeep(Map copied)

Description copied from class: COSObject

Make a deep copy of the receiver within the same document. The result is a "PDF semantic" deep copy, implementation artifacts as "attributes" and listeners are NOT copied.

The copied map is used to identify objects copied in earlier runs of this method to avoid duplicating resources used in different copy targets (for example the pages of a document). copied is modified while executing copyDeep and contains a mapping from indirect objects in the original document to copied objects.

The algorithm copies this along with all outgoing references (recursively).

Object identity is preserved.

Be careful when copying objects, as there are semantics that may NOT be recognized by this method.

Overrides:

copyDeep in class COSCompositeObject

Returns:

the object copied recursively

See Also:

COSObject.copyDeep()

copyShallow

public COSObject copyShallow()

Description copied from class: COSObject

Make a copy of the receiver.

A copy is made of the receiver and after this recursively of all not indirect objects.

Be careful when copying objects, as there are semantics that may NOT be recognized by this method.

Overrides:

copyShallow in class COSObject

Returns:

The object copied

cosGetObject

public COSObject cosGetObject()

The wrapped COSObject, according to COS level semantics. This method returns never null.

Returns:

The wrapped COSObject, according to COS level semantics.

dereference

public COSObject dereference()

Description copied from class: COSObject

return the real object. this is needed for polymorphic handling of document elements. at application programming level only COSObject, never COSIndirectObject is seen.

Overrides:

dereference in class COSObject

Returns:

COSObject

ended

public void ended(COSWriter writer)
           throws IOException

Attention: The user must handle encryption by himself. The COSWriter doesn't handle encryption in this state.

Parameters:

writer -

Throws:

IOException

getLength

public int getLength()

The length within the data stream for the serialization of this.

Returns:

The length within the data stream for the serialization of this.

getObject

public COSObject getObject()

The object represented by the proxy.

Returns:

The object represented by the proxy.

getPosition

public long getPosition()

The position within the data stream for the serialization of this.

Returns:

The position within the data stream for the serialization of this.

iterator

public Iterator<COSObject> iterator()

Description copied from class: COSObject

An iterator over contained objects. The iterator is an empty iterator if this is not a container.

This iterator returns only COSObject instances, references are dereferenced.

Specified by:

iterator in interface Iterable<COSObject>

Specified by:

iterator in class COSObject

Returns:

Iterator over contained objects.

mayBeSwapped

public boolean mayBeSwapped()

Description copied from class: COSObject

true if this object may be swapped from memory by the garbage collector.

Overrides:

mayBeSwapped in class COSCompositeObject

Returns:

true if this object may be swapped from memory by the garbage collector.

reserveData

public void reserveData(int pLength)

Reserve length bytes for the serialization of this.

Parameters:

pLength - Number of bytes to be reserved.

saveState

public Object saveState()

Specified by:

saveState in interface de.intarsys.tools.component.ISaveStateSupport

setPosition

public void setPosition(long position)

Assign the position within the data stream.

Parameters:

position - The position within the data stream.