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	Description
private static class	PdfCanvasProcessor.BeginMarkedContentDictionaryOperator	A handler that implements operator (BDC).
private static class	PdfCanvasProcessor.BeginMarkedContentOperator	A handler that implements operator (BMC).
private static class	PdfCanvasProcessor.BeginTextOperator	A handler that implements operator (BT).
private static class	PdfCanvasProcessor.ClipPathOperator	A handler that implements operator (W, W*).
private static class	PdfCanvasProcessor.CloseSubpathOperator	A handler that implements operator (h).
private static class	PdfCanvasProcessor.CurveFirstPointDuplicatedOperator	A handler that implements operator (v).
private static class	PdfCanvasProcessor.CurveFourhPointDuplicatedOperator	A handler that implements operator (y).
private static class	PdfCanvasProcessor.CurveOperator	A handler that implements operator (c).
private static class	PdfCanvasProcessor.DoOperator	A handler that implements operator (Do).
private static class	PdfCanvasProcessor.EndImageOperator	A handler that implements operator (EI).
private static class	PdfCanvasProcessor.EndMarkedContentOperator	A handler that implements operator (EMC).
private static class	PdfCanvasProcessor.EndTextOperator	A handler that implements operator (ET).
private static class	PdfCanvasProcessor.FormXObjectDoHandler	An XObject subtype handler for FORM
private static class	PdfCanvasProcessor.IgnoreOperator	A handler that implements operator (unregistered).
private static class	PdfCanvasProcessor.IgnoreXObjectDoHandler	An XObject subtype handler that does nothing
private static class	PdfCanvasProcessor.ImageXObjectDoHandler	An XObject subtype handler for IMAGE
private static class	PdfCanvasProcessor.LineToOperator	A handler that implements operator (l).
private static class	PdfCanvasProcessor.ModifyCurrentTransformationMatrixOperator	A handler that implements operator (cm).
private static class	PdfCanvasProcessor.MoveNextLineAndShowTextOperator	A handler that implements operator (').
private static class	PdfCanvasProcessor.MoveNextLineAndShowTextWithSpacingOperator	A handler that implements operator (").
private static class	PdfCanvasProcessor.MoveToOperator	A handler that implements operator (m).
private static class	PdfCanvasProcessor.PaintPathOperator	A handler that implements operator (S, s, f, F, f*, B, B*, b, b*).
protected static class	PdfCanvasProcessor.PopGraphicsStateOperator	A handler that implements operator (Q).
private static class	PdfCanvasProcessor.ProcessGraphicsStateResourceOperator	A handler that implements operator (gs).
private static class	PdfCanvasProcessor.PushGraphicsStateOperator	A handler that implements operator (q).
private static class	PdfCanvasProcessor.RectangleOperator	A handler that implements operator (re).
private static class	PdfCanvasProcessor.SetCMYKFillOperator	A handler that implements operator (k).
private static class	PdfCanvasProcessor.SetCMYKStrokeOperator	A handler that implements operator (K).
private static class	PdfCanvasProcessor.SetColorFillOperator	A handler that implements operator (sc / scn).
private static class	PdfCanvasProcessor.SetColorSpaceFillOperator	A handler that implements operator (CS).
private static class	PdfCanvasProcessor.SetColorSpaceStrokeOperator	A handler that implements operator (cs).
private static class	PdfCanvasProcessor.SetColorStrokeOperator	A handler that implements operator (SC / SCN).
private static class	PdfCanvasProcessor.SetGrayFillOperator	A handler that implements operator (g).
private static class	PdfCanvasProcessor.SetGrayStrokeOperator	A handler that implements operator (G).
private static class	PdfCanvasProcessor.SetLineCapOperator	A handler that implements operator (J).
private static class	PdfCanvasProcessor.SetLineDashPatternOperator	A handler that implements operator (d).
private static class	PdfCanvasProcessor.SetLineJoinOperator	A handler that implements operator (j).
private static class	PdfCanvasProcessor.SetLineWidthOperator	A handler that implements operator (w).
private static class	PdfCanvasProcessor.SetMiterLimitOperator	A handler that implements operator (M).
private static class	PdfCanvasProcessor.SetRGBFillOperator	A handler that implements operator (rg).
private static class	PdfCanvasProcessor.SetRGBStrokeOperator	A handler that implements operator (RG).
private static class	PdfCanvasProcessor.SetTextCharacterSpacingOperator	A handler that implements operator (Tc).
private static class	PdfCanvasProcessor.SetTextFontOperator	A handler that implements operator (Tf).
private static class	PdfCanvasProcessor.SetTextHorizontalScalingOperator	A handler that implements operator (Tz).
private static class	PdfCanvasProcessor.SetTextLeadingOperator	A handler that implements operator (TL).
private static class	PdfCanvasProcessor.SetTextRenderModeOperator	A handler that implements operator (Tr).
private static class	PdfCanvasProcessor.SetTextRiseOperator	A handler that implements operator (Ts).
private static class	PdfCanvasProcessor.SetTextWordSpacingOperator	A handler that implements operator (Tw).
private static class	PdfCanvasProcessor.ShowTextArrayOperator	A handler that implements operator (TJ).
private static class	PdfCanvasProcessor.ShowTextOperator	A handler that implements operator (Tj).
private static class	PdfCanvasProcessor.TextMoveNextLineOperator	A handler that implements operator (T*).
private static class	PdfCanvasProcessor.TextMoveStartNextLineOperator	A handler that implements operator (Td).
private static class	PdfCanvasProcessor.TextMoveStartNextLineWithLeadingOperator	A handler that implements operator (TD).
private static class	PdfCanvasProcessor.TextSetTextMatrixOperator	A handler that implements operator (Tm).

Field Summary

Fields

Modifier and Type	Field	Description
private Map<Integer, WeakReference<PdfFont>>	cachedFonts	The font cache
protected int	clippingRule	Specifies the filling rule which should be applied while calculating new clipping path.
protected Path	currentPath
static final String	DEFAULT_OPERATOR
protected final IEventListener	eventListener	Listener that will be notified of render events
private final Stack<ParserGraphicsState>	gsStack	Stack keeping track of the graphics state.
protected boolean	isClip	Indicates whether the current clipping path should be modified by intersecting it with the current path.
private Stack<CanvasTag>	markedContentStack	A stack containing marked content info.
private MemoryLimitsAwareHandler	memoryLimitsHandler	A memory limits handler.
private Map<String, IContentOperator>	operators	A map with all supported operators (PDF syntax).
private long	pageSize	Page size in bytes.
private List<PdfResources>	resourcesStack	Resources for the content stream.
protected final Set<EventType>	supportedEvents	Cache supported events in case the user's IEventListener.getSupportedEvents() method is not very efficient
private Matrix	textLineMatrix
private Matrix	textMatrix
private Map<PdfName, IXObjectDoHandler>	xobjectDoHandlers	A map with all supported XObject handlers

Constructor Summary

Constructors

Constructor	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	Description
private void	applyTextAdjust(float tj)	Adjusts the text matrix for the specified adjustment value (see TJ operator in the PDF spec for information)
protected void	beginMarkedContent(PdfName tag, PdfDictionary dict)	Add to the marked content stack
private void	beginText()	Used to trigger beginTextBlock on the renderListener
private void	displayImage(Stack<CanvasTag> canvasTagHierarchy, PdfStream imageStream, PdfName resourceName, boolean isInline)
private void	displayPdfString(PdfString string)	Displays text.
private void	displayXObject(PdfName resourceName)	Displays an XObject using the registered handler for this XObject's subtype
protected void	endMarkedContent()	Remove the latest marked content from the stack.
private void	endText()	Used to trigger endTextBlock on the renderListener
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.
private static Color	getColor(int nOperands, List<PdfObject> operands)	Gets a color based on a list of operands.
private static Color	getColor(PdfColorSpace pdfColorSpace, List<PdfObject> operands, PdfResources resources)	Gets a color based on a list of operands and Color space.
private static float[]	getColorants(List<PdfObject> operands)
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)
private void	initClippingPath(PdfPage page)
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 Object

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

Field Details

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.

operators

private Map<String, IContentOperator> operators

A map with all supported operators (PDF syntax).

resourcesStack

private List<PdfResources> resourcesStack

Resources for the content stream. Current resources are always at the top of the stack. Stack is needed in case if some "inner" content stream with it's own resources is encountered (like Form XObject).

gsStack

private final Stack<ParserGraphicsState> gsStack

Stack keeping track of the graphics state.

textMatrix

private Matrix textMatrix

textLineMatrix

private Matrix textLineMatrix

xobjectDoHandlers

private Map<PdfName, IXObjectDoHandler> xobjectDoHandlers

A map with all supported XObject handlers

cachedFonts

private Map<Integer, WeakReference<PdfFont>> cachedFonts

The font cache

markedContentStack

private Stack<CanvasTag> markedContentStack

A stack containing marked content info.

memoryLimitsHandler

private MemoryLimitsAwareHandler memoryLimitsHandler

A memory limits handler.

pageSize

private long pageSize

Page size in bytes.

Constructor Details

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 Details

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.

beginText

private void beginText()

Used to trigger beginTextBlock on the renderListener

endText

private void endText()

Used to trigger endTextBlock on the renderListener

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

displayPdfString

private void displayPdfString(PdfString string)

Displays text.

Parameters:

string - the text to display

displayXObject

private void displayXObject(PdfName resourceName)

Displays an XObject using the registered handler for this XObject's subtype

Parameters:

resourceName - the name of the XObject to retrieve from the resource dictionary

displayImage

private void displayImage(Stack<CanvasTag> canvasTagHierarchy,
 PdfStream imageStream,
 PdfName resourceName,
 boolean isInline)

applyTextAdjust

private void applyTextAdjust(float tj)

Adjusts the text matrix for the specified adjustment value (see TJ operator in the PDF spec for information)

Parameters:

tj - the text adjustment

initClippingPath

private void initClippingPath(PdfPage page)

getColor

private static Color getColor(PdfColorSpace pdfColorSpace,
 List<PdfObject> operands,
 PdfResources resources)

Gets a color based on a list of operands and Color space.

getColor

private static Color getColor(int nOperands,
 List<PdfObject> operands)

Gets a color based on a list of operands.

getColorants

private static float[] getColorants(List<PdfObject> operands)