Class PDFParser

java.lang.Object

org.openpdf.renderer.BaseWatchable

org.openpdf.renderer.PDFParser

All Implemented Interfaces:

Runnable, Watchable

public class PDFParser
extends BaseWatchable

PDFParser is the class that parses a PDF content stream and produces PDFCmds for a PDFPage. You should never ever see it run: it gets created by a PDFPage only if needed, and may even run in its own thread.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) class	PDFParser.ParserState	A class to store state needed whiel rendering.
(package private) static class	PDFParser.Tok	a token from a PDF Stream

Nested classes/interfaces inherited from class BaseWatchable

BaseWatchable.Gate

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	addAnnotation
private boolean	autoAdjustStroke
private boolean	catchexceptions
private int	clip
private PDFPage	cmds	the actual command, for use within a singe iteration.
(package private) boolean	errorwritten
private boolean	fillOverprint
private int	fillOverprintMode
private int	loc
private int	mDebugCommandIndex
private final WeakReference<PDFPage>	pageRef	a weak reference to the page we render into.
private Stack<PDFParser.ParserState>	parserStates
private GeneralPath	path
private boolean	resend
(package private) HashMap<String, PDFObject>	resources
private Stack<Object>	stack
private PDFParser.ParserState	state
(package private) byte[]	stream
private boolean	strokeOverprint
private int	strokeOverprintMode
private PDFParser.Tok	tok

Fields inherited from interface Watchable

COMPLETED, ERROR, NEEDS_DATA, NOT_STARTED, PAUSED, RUNNING, STOPPED, UNKNOWN

Constructor Summary

Constructors

Constructor	Description
PDFParser(PDFPage cmds, byte[] stream, HashMap<String, PDFObject> resources)	Don't call this constructor directly.

Method Summary

Modifier and Type	Method	Description
void	cleanup()	Cleanup when iteration is done
private void	doForm(PDFObject obj)	Inject a stream of PDF commands onto the page.
private void	doImage(PDFObject obj)	Parse image data into a Java BufferedImage and add the image command to the page.
private PDFPaint	doPattern(PatternSpace patternSpace)	Set the values into a PatternSpace
private void	doShader(PDFObject shaderObj)	build a shader from a dictionary.
private void	doXObject(PDFObject obj)	Insert a PDF object into the command stream.
private PDFObject	findResource(String name, String inDict)	get a property from a named dictionary in the resources of this content stream.
private PDFFont	getFontFrom(String fontref)	get a PDFFont from the resources, given the resource name of the font.
int	iterate()	parse the stream.
private PDFParser.Tok	nextToken()	get the next token.
private void	onNextObject(PDFParser.Tok obj)
private PDFColorSpace	parseColorSpace(PDFObject csobj)	generate a PDFColorSpace description based on a PDFObject.
private void	parseInlineImage()	Parse an inline image.
private Object	parseObject()	Parse the next object out of the PDF stream.
private Object[]	popArray()	pop an array off the stack
private float	popFloat()	pop a single float value off the stack.
private float[]	popFloat(int count)	pop an array of float values off the stack.
private float[]	popFloatArray()	pop an array of integer values off the stack.
private int	popInt()	pop a single integer value off the stack.
private PDFObject	popObject()	pop a PDFObject off the stack.
private String	popString()	pop a String off the stack.
private void	processBTCmd()	abstracted command processing for BT command.
private void	processQCmd()	abstracted command processing for Q command.
private String	readByteArray()	read a byte array from the stream.
private String	readName()	read a name (sequence of non-PDF-delimiting characters) from the stream.
private double	readNum()	read a floating point number from the stream
private String	readString()	read a String from the stream.
private void	setGSState(String name)	add graphics state commands contained within a dictionary.
protected void	setStatus(int status)	Set the status of this watchable
void	setup()	Called to prepare for some iterations
private void	tryClosingPath()	Try to close a path but don't fail with exception if this is not working.

Methods inherited from class BaseWatchable

execute, getErrorHandler, getException, getStatus, go, go, go, go, isExecutable, isFinished, isSuppressSetErrorStackTrace, run, setError, setErrorHandler, setSuppressSetErrorStackTrace, stop, waitForFinish

Methods inherited from class Object

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

Field Details

mDebugCommandIndex

private int mDebugCommandIndex

stack

private Stack<Object> stack

parserStates

private Stack<PDFParser.ParserState> parserStates

state

private PDFParser.ParserState state

path

private GeneralPath path

clip

private int clip

loc

private int loc

resend

private boolean resend

tok

private PDFParser.Tok tok

catchexceptions

private boolean catchexceptions

pageRef

private final WeakReference<PDFPage> pageRef

a weak reference to the page we render into. For the page to remain available, some other code must retain a strong reference to it.

cmds

private PDFPage cmds

the actual command, for use within a singe iteration. Note that this must be released at the end of each iteration to assure the page can be collected if not in use

stream

byte[] stream

resources

HashMap<String, PDFObject> resources

errorwritten

boolean errorwritten

autoAdjustStroke

private boolean autoAdjustStroke

strokeOverprint

private boolean strokeOverprint

strokeOverprintMode

private int strokeOverprintMode

fillOverprint

private boolean fillOverprint

fillOverprintMode

private int fillOverprintMode

addAnnotation

private boolean addAnnotation

Constructor Details

PDFParser

public PDFParser(PDFPage cmds,
 byte[] stream,
 HashMap<String, PDFObject> resources)

Don't call this constructor directly. Instead, use PDFFile.getPage(int pagenum) to get a PDFPage. There should never be any reason for a user to create, access, or hold on to a PDFParser.

Method Details

nextToken

private PDFParser.Tok nextToken()

get the next token.

readName

private String readName()

read a name (sequence of non-PDF-delimiting characters) from the stream.

readNum

private double readNum()

read a floating point number from the stream

readString

private String readString()

read a String from the stream. Strings begin with a '(' character, which has already been read, and end with a balanced ')' character. A '\' character starts an escape sequence of up to three octal digits.

Parenthesis must be enclosed by a balanced set of parenthesis, so a string may enclose balanced parenthesis.

Returns:

the string with escape sequences replaced with their values

readByteArray

private String readByteArray()

read a byte array from the stream. Byte arrays begin with a 'invalid input: '<'' character, which has already been read, and end with a '>' character. Each byte in the array is made up of two hex characters, the first being the high-order bit. We translate the byte arrays into char arrays by combining two bytes into a character, and then translate the character array into a string. [JK FIXME this is probably a really bad idea!]

Returns:

the byte array

setup

public void setup()

Called to prepare for some iterations

Overrides:

setup in class BaseWatchable

iterate

public int iterate()
            throws Exception

parse the stream. commands are added to the PDFPage initialized in the constructor as they are encountered.

Page numbers in comments refer to the Adobe PDF specification.
commands are listed in PDF spec 32000-1:2008 in Table A.1

Specified by:

iterate in class BaseWatchable

Returns:

• Watchable.RUNNING when there are commands to be processed
• Watchable.COMPLETED when the page is done and all the commands have been processed
• Watchable.STOPPED if the page we are rendering into is no longer available

Throws:

Exception

tryClosingPath

private void tryClosingPath()

Try to close a path but don't fail with exception if this is not working. This is just a workaround for some PDFs with wrong content...

onNextObject

private void onNextObject(PDFParser.Tok obj)
                   throws PDFDebugger.DebugStopException

Throws:

PDFDebugger.DebugStopException

processQCmd

private void processQCmd()

abstracted command processing for Q command. Used directly and as part of processing of mushed QBT command.

processBTCmd

private void processBTCmd()

abstracted command processing for BT command. Used directly and as part of processing of mushed QBT command.

cleanup

public void cleanup()

Cleanup when iteration is done

Overrides:

cleanup in class BaseWatchable

findResource

private PDFObject findResource(String name,
 String inDict)
                        throws IOException

get a property from a named dictionary in the resources of this content stream.

Parameters:

name - the name of the property in the dictionary

inDict - the name of the dictionary in the resources

Returns:

the value of the property in the dictionary

Throws:

IOException

doXObject

private void doXObject(PDFObject obj)
                throws IOException

Insert a PDF object into the command stream. The object must either be an Image or a Form, which is a set of PDF commands in a stream.

Parameters:

obj - the object to insert, an Image or a Form.

Throws:

IOException

doImage

private void doImage(PDFObject obj)
              throws IOException

Parse image data into a Java BufferedImage and add the image command to the page.

Parameters:

obj - contains the image data, and a dictionary describing the width, height and color space of the image.

Throws:

IOException

doForm

private void doForm(PDFObject obj)
             throws IOException

Inject a stream of PDF commands onto the page. Optimized to cache a parsed stream of commands, so that each Form object only needs to be parsed once.

Parameters:

obj - a stream containing the PDF commands, a transformation matrix, bounding box, and resources.

Throws:

IOException

doPattern

private PDFPaint doPattern(PatternSpace patternSpace)
                    throws IOException

Set the values into a PatternSpace

Throws:

IOException

parseObject

private Object parseObject()
                    throws PDFParseException,
PDFDebugger.DebugStopException

Parse the next object out of the PDF stream. This could be a Double, a String, a HashMap (dictionary), Object[] array, or a Tok containing a PDF command.

Throws:

PDFParseException

PDFDebugger.DebugStopException

parseInlineImage

private void parseInlineImage()
                       throws IOException,
PDFDebugger.DebugStopException

Parse an inline image. An inline image starts with BI (already read, contains a dictionary until ID, and then image data until EI.

Throws:

IOException

PDFDebugger.DebugStopException

doShader

private void doShader(PDFObject shaderObj)
               throws IOException

build a shader from a dictionary.

Throws:

IOException

getFontFrom

private PDFFont getFontFrom(String fontref)
                     throws IOException

get a PDFFont from the resources, given the resource name of the font.

Parameters:

fontref - the resource key for the font

Throws:

IOException

setGSState

private void setGSState(String name)
                 throws IOException

add graphics state commands contained within a dictionary.

Parameters:

name - the resource name of the graphics state dictionary

Throws:

IOException

parseColorSpace

private PDFColorSpace parseColorSpace(PDFObject csobj)
                               throws IOException

generate a PDFColorSpace description based on a PDFObject. The object could be a standard name, or the name of a resource in the ColorSpace dictionary, or a color space name with a defining dictionary or stream.

Throws:

IOException

popFloat

private float popFloat()
                throws PDFParseException

pop a single float value off the stack.

Returns:

the float value of the top of the stack

Throws:

PDFParseException - if the value on the top of the stack isn't a number

popFloat

private float[] popFloat(int count)
                  throws PDFParseException

pop an array of float values off the stack. This is equivalent to filling an array from end to front by popping values off the stack.

Parameters:

count - the number of numbers to pop off the stack

Returns:

an array of length count

Throws:

PDFParseException - if any of the values popped off the stack are not numbers.

popInt

private int popInt()
            throws PDFParseException

pop a single integer value off the stack.

Returns:

the integer value of the top of the stack

Throws:

PDFParseException - if the top of the stack isn't a number.

popFloatArray

private float[] popFloatArray()
                       throws PDFParseException

pop an array of integer values off the stack. This is equivalent to filling an array from end to front by popping values off the stack.

Parameters:

count - the number of numbers to pop off the stack

Returns:

an array of length count

Throws:

PDFParseException - if any of the values popped off the stack are not numbers.

popString

private String popString()
                  throws PDFParseException

pop a String off the stack.

Returns:

the String from the top of the stack

Throws:

PDFParseException - if the top of the stack is not a NAME or STR.

popObject

private PDFObject popObject()
                     throws PDFParseException

pop a PDFObject off the stack.

Returns:

the PDFObject from the top of the stack

Throws:

PDFParseException - if the top of the stack does not contain a PDFObject.

popArray

private Object[] popArray()
                   throws PDFParseException

pop an array off the stack

Returns:

the array of objects that is the top element of the stack

Throws:

PDFParseException - if the top element of the stack does not contain an array.

setStatus

protected void setStatus(int status)

Description copied from class: BaseWatchable

Set the status of this watchable

Overrides:

setStatus in class BaseWatchable