com.itextpdf.kernel.pdf.canvas.parser

Class PdfCanvasProcessor

java.lang.Object

com.itextpdf.kernel.pdf.canvas.parser.PdfCanvasProcessor

public class PdfCanvasProcessor
extends Object

Processor for a PDF content stream.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	PdfCanvasProcessor.PopGraphicsStateOperator A handler that implements operator (Q).

Field Summary

Fields

Modifier and Type	Field and Description
protected int	clippingRule Specifies the filling rule which should be applied while calculating new clipping path.
protected Path	currentPath
static String	DEFAULT_OPERATOR
protected IEventListener	eventListener Listener that will be notified of render events
protected boolean	isClip Indicates whether the current clipping path should be modified by intersecting it with the current path.
protected Set<EventType>	supportedEvents Cache supported events in case the user's IEventListener.getSupportedEvents() method is not very efficient

Constructor Summary

Constructors

Constructor and Description
PdfCanvasProcessor(IEventListener eventListener) Creates a new PDF Content Stream Processor that will send its output to the designated render listener.
PdfCanvasProcessor(IEventListener eventListener, Map<String,IContentOperator> additionalContentOperators) Creates a new PDF Content Stream Processor that will send its output to the designated render listener.

Method Summary

Modifier and Type	Method and Description
protected void	beginMarkedContent(PdfName tag, PdfDictionary dict) Add to the marked content stack
protected void	endMarkedContent() Remove the latest marked content from the stack.
protected void	eventOccurred(IEventData data, EventType type) This is a proxy to pass only those events to the event listener which are supported by it.
IEventListener	getEventListener() Accessor method for the IEventListener object maintained in this class.
protected PdfFont	getFont(PdfDictionary fontDict) Creates a PdfFont object by a font dictionary.
ParserGraphicsState	getGraphicsState() Gets the current ParserGraphicsState
Collection<String>	getRegisteredOperatorStrings() Gets the Collection containing all the registered operators strings.
protected PdfResources	getResources()
protected PdfStream	getXObjectStream(PdfName xobjectName)
protected void	invokeOperator(PdfLiteral operator, List<PdfObject> operands) Invokes an operator.
protected void	paintPath(int operation, int rule) Displays the current path.
protected void	populateOperators() Loads all the supported graphics and text state operators in a map.
protected void	populateXObjectDoHandlers()
void	processContent(byte[] contentBytes, PdfResources resources) Processes PDF syntax.
void	processPageContent(PdfPage page) Processes PDF syntax.
IContentOperator	registerContentOperator(String operatorString, IContentOperator operator) Registers a content operator that will be called when the specified operator string is encountered during content processing.
IXObjectDoHandler	registerXObjectDoHandler(PdfName xobjectSubType, IXObjectDoHandler handler) Registers a Do handler that will be called when Do for the provided XObject subtype is encountered during content processing.
void	reset() Resets the graphics state stack, matrices and resources.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_OPERATOR

public static final String DEFAULT_OPERATOR

See Also:

Constant Field Values

eventListener

protected final IEventListener eventListener

Listener that will be notified of render events

supportedEvents

protected final Set<EventType> supportedEvents

Cache supported events in case the user's IEventListener.getSupportedEvents() method is not very efficient

currentPath

protected Path currentPath

isClip

protected boolean isClip

Indicates whether the current clipping path should be modified by intersecting it with the current path.

clippingRule

protected int clippingRule

Specifies the filling rule which should be applied while calculating new clipping path.

Constructor Detail

PdfCanvasProcessor

public PdfCanvasProcessor(IEventListener eventListener)

Creates a new PDF Content Stream Processor that will send its output to the designated render listener.

Parameters:

eventListener - the IEventListener that will receive rendering notifications

PdfCanvasProcessor

public PdfCanvasProcessor(IEventListener eventListener,
                          Map<String,IContentOperator> additionalContentOperators)

Creates a new PDF Content Stream Processor that will send its output to the designated render listener. Also allows registration of custom IContentOperators that can influence how (and whether or not) the PDF instructions will be parsed.

Parameters:

eventListener - the IEventListener that will receive rendering notifications

additionalContentOperators - an optional map of custom IContentOperators for rendering instructions

Method Detail

registerXObjectDoHandler

public IXObjectDoHandler registerXObjectDoHandler(PdfName xobjectSubType,
                                                  IXObjectDoHandler handler)

Registers a Do handler that will be called when Do for the provided XObject subtype is encountered during content processing.
If you register a handler, it is a very good idea to pass the call on to the existing registered handler (returned by this call), otherwise you may inadvertently change the internal behavior of the processor.

Parameters:

xobjectSubType - the XObject subtype this handler will process, or PdfName.DEFAULT for a catch-all handler

handler - the handler that will receive notification when the Do operator for the specified subtype is encountered

Returns:

the existing registered handler, if any

registerContentOperator

public IContentOperator registerContentOperator(String operatorString,
                                                IContentOperator operator)

Registers a content operator that will be called when the specified operator string is encountered during content processing.
If you register an operator, it is a very good idea to pass the call on to the existing registered operator (returned by this call), otherwise you may inadvertently change the internal behavior of the processor.

Parameters:

operatorString - the operator id, or DEFAULT_OPERATOR for a catch-all operator

operator - the operator that will receive notification when the operator is encountered

Returns:

the existing registered operator, if any

getRegisteredOperatorStrings

public Collection<String> getRegisteredOperatorStrings()

Gets the Collection containing all the registered operators strings.

Returns:

Collection containing all the registered operators strings.

reset

public void reset()

Resets the graphics state stack, matrices and resources.

getGraphicsState

public ParserGraphicsState getGraphicsState()

Gets the current ParserGraphicsState

Returns:

the current ParserGraphicsState

processContent

public void processContent(byte[] contentBytes,
                           PdfResources resources)

Processes PDF syntax. Note: If you re-use a given PdfCanvasProcessor, you must call reset()

Parameters:

contentBytes - the bytes of a content stream

resources - the resources of the content stream. Must not be null.

processPageContent

public void processPageContent(PdfPage page)

Processes PDF syntax. Note: If you re-use a given PdfCanvasProcessor, you must call reset()

Parameters:

page - the page to process

getEventListener

public IEventListener getEventListener()

Accessor method for the IEventListener object maintained in this class. Necessary for implementing custom ContentOperator implementations.

Returns:

the renderListener

populateOperators

protected void populateOperators()

Loads all the supported graphics and text state operators in a map.

paintPath

protected void paintPath(int operation,
                         int rule)

Displays the current path.

Parameters:

operation - One of the possible combinations of PathRenderInfo.STROKE and PathRenderInfo.FILL values or PathRenderInfo.NO_OP

rule - Either PdfCanvasConstants.FillingRule.NONZERO_WINDING or PdfCanvasConstants.FillingRule.EVEN_ODD In case it isn't applicable pass any byte value.

invokeOperator

protected void invokeOperator(PdfLiteral operator,
                              List<PdfObject> operands)

Invokes an operator.

Parameters:

operator - the PDF Syntax of the operator

operands - a list with operands

getXObjectStream

protected PdfStream getXObjectStream(PdfName xobjectName)

getResources

protected PdfResources getResources()

populateXObjectDoHandlers

protected void populateXObjectDoHandlers()

getFont

protected PdfFont getFont(PdfDictionary fontDict)

Creates a PdfFont object by a font dictionary. The font may have been cached in case it is an indirect object.

Parameters:

fontDict - the font dictionary to create the font from

Returns:

the created font

beginMarkedContent

protected void beginMarkedContent(PdfName tag,
                                  PdfDictionary dict)

Add to the marked content stack

Parameters:

tag - the tag of the marked content

dict - the PdfDictionary associated with the marked content

endMarkedContent

protected void endMarkedContent()

Remove the latest marked content from the stack. Keeps track of the BMC, BDC and EMC operators.

eventOccurred

protected void eventOccurred(IEventData data,
                             EventType type)

This is a proxy to pass only those events to the event listener which are supported by it.

Parameters:

data - event data

type - event type