Table of Contents

Class PdfAChecker

Namespace
iText.Pdfa.Checker
Assembly
itext.pdfa.dll

An abstract class that will run through all necessary checks defined in the different PDF/A standards and levels.

public abstract class PdfAChecker : IValidationChecker
Inheritance
PdfAChecker
Implements
Derived
Inherited Members

Remarks

An abstract class that will run through all necessary checks defined in the different PDF/A standards and levels. A number of common checks are executed in this class, while standard-dependent specifications are implemented in the available subclasses. The standard that is followed is the series of ISO 19005 specifications, currently generations 1 through 3. The ZUGFeRD standard is derived from ISO 19005-3. While it is possible to subclass this method and implement its abstract methods in client code, this is not encouraged and will have little effect. It is not possible to plug custom implementations into iText, because iText should always refuse to create non-compliant PDF/A, which would be possible with client code implementations. Any future generations of the PDF/A standard and its derivates will get their own implementation in the iText - pdfa project.

Constructors

PdfAChecker(PdfAConformanceLevel)

Creates a PdfAChecker with the required conformance level.

protected PdfAChecker(PdfAConformanceLevel conformanceLevel)

Parameters

conformanceLevel PdfAConformanceLevel

the required conformance level

Fields

ICC_COLOR_SPACE_CMYK

The Cyan-Magenta-Yellow-Key (black) color profile as defined by the International Color Consortium.

public const string ICC_COLOR_SPACE_CMYK = "CMYK"

Field Value

string

ICC_COLOR_SPACE_GRAY

The Grayscale color profile as defined by the International Color Consortium.

public const string ICC_COLOR_SPACE_GRAY = "GRAY"

Field Value

string

ICC_COLOR_SPACE_RGB

The Red-Green-Blue color profile as defined by the International Color Consortium.

public const string ICC_COLOR_SPACE_RGB = "RGB "

Field Value

string

ICC_DEVICE_CLASS_MONITOR_PROFILE

The Monitor device class

public const string ICC_DEVICE_CLASS_MONITOR_PROFILE = "mntr"

Field Value

string

ICC_DEVICE_CLASS_OUTPUT_PROFILE

The Output device class

public const string ICC_DEVICE_CLASS_OUTPUT_PROFILE = "prtr"

Field Value

string

checkedObjects

Contains some objects that are already checked.

protected ICollection<PdfObject> checkedObjects

Field Value

ICollection<PdfObject>

Remarks

Contains some objects that are already checked. NOTE: Not all objects that were checked are stored in that set. This set is used for avoiding double checks for actions, signatures, xObjects and page objects; and for letting those objects to be manually flushed. Use this mechanism carefully: objects that are able to be changed (or at least if object's properties that shall be checked are able to be changed) shouldn't be marked as checked if they are not to be flushed immediately.

checkedObjectsColorspace 

protected IDictionary<PdfObject, PdfColorSpace> checkedObjectsColorspace

Field Value

IDictionary<PdfObject, PdfColorSpace>

cmykIsUsed 

[Obsolete]
protected bool cmykIsUsed

Field Value

bool

cmykUsedObjects 

protected ICollection<PdfObject> cmykUsedObjects

Field Value

ICollection<PdfObject>

conformanceLevel 

protected PdfAConformanceLevel conformanceLevel

Field Value

PdfAConformanceLevel

grayIsUsed 

[Obsolete]
protected bool grayIsUsed

Field Value

bool

grayUsedObjects 

protected ICollection<PdfObject> grayUsedObjects

Field Value

ICollection<PdfObject>

gsStackDepth 

protected int gsStackDepth

Field Value

int

maxGsStackDepth

The maximum Graphics State stack depth in PDF/A documents, i.e. the maximum number of graphics state operators with code q that may be opened (i.e. not yet closed by a corresponding Q) at any point in a content stream sequence.

public const int maxGsStackDepth = 28

Field Value

int

Remarks

The maximum Graphics State stack depth in PDF/A documents, i.e. the maximum number of graphics state operators with code q that may be opened (i.e. not yet closed by a corresponding Q) at any point in a content stream sequence. Defined as 28 by PDF/A-1 section 6.1.12, by referring to the PDF spec Appendix C table 1 "architectural limits".

pdfAOutputIntentColorSpace 

protected string pdfAOutputIntentColorSpace

Field Value

string

pdfAOutputIntentDestProfile 

protected PdfStream pdfAOutputIntentDestProfile

Field Value

PdfStream

rgbIsUsed 

[Obsolete]
protected bool rgbIsUsed

Field Value

bool

rgbUsedObjects 

protected ICollection<PdfObject> rgbUsedObjects

Field Value

ICollection<PdfObject>

Methods

CheckAction(PdfDictionary)

Checks if the action is allowed.

protected abstract void CheckAction(PdfDictionary action)

Parameters

action PdfDictionary

to be checked

CheckAnnotation(PdfDictionary)

Verify the conformity of the annotation dictionary.

protected abstract void CheckAnnotation(PdfDictionary annotDic)

Parameters

annotDic PdfDictionary

the annotation PdfDictionary to be checked

CheckAppearanceStream(PdfStream)

Check single annotation appearance stream.

protected virtual void CheckAppearanceStream(PdfStream appearanceStream)

Parameters

appearanceStream PdfStream

the PdfStream to check

CheckCanvasStack(char)

This method checks compliance with the graphics state architectural limitation, explained by maxGsStackDepth.

public abstract void CheckCanvasStack(char stackOperation)

Parameters

stackOperation char

the operation to check the graphics state counter for

CheckCatalog(PdfCatalog)

Verify the conformity of the pdf catalog.

[Obsolete("Will become abstract in the next major release.")]
protected virtual void CheckCatalog(PdfCatalog catalog)

Parameters

catalog PdfCatalog

the PdfCatalog of trailer to check.

CheckCatalogValidEntries(PdfDictionary)

Checks if entries in catalog dictionary are valid.

protected abstract void CheckCatalogValidEntries(PdfDictionary catalogDict)

Parameters

catalogDict PdfDictionary

the catalog PdfDictionary to be checked

CheckColor(Color, PdfDictionary, bool?, PdfStream)

This method checks compliance with the color restrictions imposed by the available color spaces in the document.

[Obsolete("in favor of checkColor(CanvasGraphicsState gState, Color color, PdfDictionary currentColorSpaces, Boolean fill, PdfStream contentStream)")]
public abstract void CheckColor(Color color, PdfDictionary currentColorSpaces, bool? fill, PdfStream contentStream)

Parameters

color Color

the color to check

currentColorSpaces PdfDictionary

a PdfDictionary containing the color spaces used in the document

fill bool?

whether the color is used for fill or stroke operations

contentStream PdfStream

current content stream

Remarks

This method checks compliance with the color restrictions imposed by the available color spaces in the document. This method will be abstract in update 7.2

CheckColor(CanvasGraphicsState, Color, PdfDictionary, bool?, PdfStream)

This method checks compliance with the color restrictions imposed by the available color spaces in the document.

[Obsolete("This method will be abstract in next major release")]
public virtual void CheckColor(CanvasGraphicsState gState, Color color, PdfDictionary currentColorSpaces, bool? fill, PdfStream contentStream)

Parameters

gState CanvasGraphicsState

canvas graphics state

color Color

the color to check

currentColorSpaces PdfDictionary

a PdfDictionary containing the color spaces used in the document

fill bool?

whether the color is used for fill or stroke operations

contentStream PdfStream

current content stream

CheckColorSpace(PdfColorSpace, PdfDictionary, bool, bool?)

This method performs a range of checks on the given color space, depending on the type and properties of that color space.

[Obsolete("in favor of checkColorSpace(PdfColorSpace colorSpace, PdfObject object, PdfDictionary currentColorSpaces, boolean checkAlternate, Boolean fill)")]
public virtual void CheckColorSpace(PdfColorSpace colorSpace, PdfDictionary currentColorSpaces, bool checkAlternate, bool? fill)

Parameters

colorSpace PdfColorSpace

the color space to check

currentColorSpaces PdfDictionary

a PdfDictionary containing the color spaces used in the document

checkAlternate bool

whether or not to also check the parent color space

fill bool?

whether the color space is used for fill or stroke operations

CheckColorSpace(PdfColorSpace, PdfObject, PdfDictionary, bool, bool?)

This method performs a range of checks on the given color space, depending on the type and properties of that color space.

[Obsolete("Will become abstract in the next major release.")]
public virtual void CheckColorSpace(PdfColorSpace colorSpace, PdfObject pdfObject, PdfDictionary currentColorSpaces, bool checkAlternate, bool? fill)

Parameters

colorSpace PdfColorSpace

the color space to check

pdfObject PdfObject

the pdf object to check color space in

currentColorSpaces PdfDictionary

a PdfDictionary containing the color spaces used in the document

checkAlternate bool

whether or not to also check the parent color space

fill bool?

whether the color space is used for fill or stroke operations

CheckColorsUsages()

Verify the conformity of used color spaces.

[Obsolete("in favor of checkPageColorsUsages(PdfDictionary pageDict, PdfDictionary pageResources)")]
protected abstract void CheckColorsUsages()

CheckContentStream(PdfStream)

Attest content stream conformance with appropriate specification.

protected abstract void CheckContentStream(PdfStream contentStream)

Parameters

contentStream PdfStream

is a content stream to validate

Remarks

Attest content stream conformance with appropriate specification. Throws PdfAConformanceException if any discrepancy was found

CheckContentStreamObject(PdfObject)

Verify the conformity of the operand of content stream with appropriate specification.

protected virtual void CheckContentStreamObject(PdfObject @object)

Parameters

object PdfObject

is an operand of content stream to validate

Remarks

Verify the conformity of the operand of content stream with appropriate specification. Throws PdfAConformanceException if any discrepancy was found

CheckCrypto(PdfObject)

Verify the conformity of encryption usage.

[Obsolete("Will become abstract in the next major release.")]
public virtual void CheckCrypto(PdfObject crypto)

Parameters

crypto PdfObject

Encryption object to verify.

CheckDocument(PdfCatalog)

This method checks a number of document-wide requirements of the PDF/A standard.

public virtual void CheckDocument(PdfCatalog catalog)

Parameters

catalog PdfCatalog

The catalog being checked

Remarks

This method checks a number of document-wide requirements of the PDF/A standard. The algorithms of some of these checks vary with the PDF/A level and thus are implemented in subclasses; others are implemented as private methods in this class.

CheckExtGState(CanvasGraphicsState, PdfStream)

Performs a number of checks on the graphics state, among others ISO 19005-1 section 6.2.8 and 6.4 and ISO 19005-2 section 6.2.5 and 6.2.10.

public abstract void CheckExtGState(CanvasGraphicsState extGState, PdfStream contentStream)

Parameters

extGState CanvasGraphicsState

the graphics state to be checked

contentStream PdfStream

current content stream

Remarks

Performs a number of checks on the graphics state, among others ISO 19005-1 section 6.2.8 and 6.4 and ISO 19005-2 section 6.2.5 and 6.2.10. This method will be abstract in the update 7.2

CheckFileSpec(PdfDictionary)

Verify the conformity of the file specification dictionary.

protected abstract void CheckFileSpec(PdfDictionary fileSpec)

Parameters

fileSpec PdfDictionary

the PdfDictionary containing file specification to be checked

CheckFlag(int, int)

Checks if the specified flag is set.

protected static bool CheckFlag(int flags, int flag)

Parameters

flags int

a set of flags specifying various characteristics of the PDF object

flag int

to be checked

Returns

bool

true if the specified flag is set

CheckFont(PdfFont)

Performs a number of checks on the font.

public abstract void CheckFont(PdfFont pdfFont)

Parameters

pdfFont PdfFont

font to be checked

Remarks

Performs a number of checks on the font. See ISO 19005-1 section 6.3, ISO 19005-2 and ISO 19005-3 section 6.2.11. Be aware that not all constraints defined in the ISO are checked in this method, for most of them we consider that iText always creates valid fonts.

CheckFontGlyphs(PdfFont, PdfStream)

Performs a check of the each font glyph as a Form XObject.

public abstract void CheckFontGlyphs(PdfFont font, PdfStream contentStream)

Parameters

font PdfFont

PdfFont to be checked

contentStream PdfStream

stream containing checked font

Remarks

Performs a check of the each font glyph as a Form XObject. See ISO 19005-2 Annex A.5. This only applies to type 3 fonts. This method will be abstract in update 7.2

CheckForm(PdfDictionary)

Verify the conformity of the form dictionary.

protected abstract void CheckForm(PdfDictionary form)

Parameters

form PdfDictionary

the form PdfDictionary to be checked

CheckFormXObject(PdfStream)

Verify the conformity of the form XObject dictionary.

protected abstract void CheckFormXObject(PdfStream form)

Parameters

form PdfStream

the PdfStream to check

CheckImage(PdfStream, PdfDictionary)

Verify the conformity of the given image.

protected abstract void CheckImage(PdfStream image, PdfDictionary currentColorSpaces)

Parameters

image PdfStream

the image to check

currentColorSpaces PdfDictionary

the PdfDictionary containing the color spaces used in the document

CheckInlineImage(PdfStream, PdfDictionary)

This method checks compliance with the inline image restrictions in the PDF/A specs, specifically filter parameters.

public abstract void CheckInlineImage(PdfStream inlineImage, PdfDictionary currentColorSpaces)

Parameters

inlineImage PdfStream

a PdfStream containing the inline image

currentColorSpaces PdfDictionary

a PdfDictionary containing the color spaces used in the document

CheckLogicalStructure(PdfDictionary)

Performs a number of checks on the logical structure of the document.

protected abstract void CheckLogicalStructure(PdfDictionary catalog)

Parameters

catalog PdfDictionary

the catalog PdfDictionary to check

CheckMetaData(PdfDictionary)

Performs a number of checks on the metadata of the document.

protected abstract void CheckMetaData(PdfDictionary catalog)

Parameters

catalog PdfDictionary

the catalog PdfDictionary to check

CheckNonSymbolicTrueTypeFont(PdfTrueTypeFont)

Verify the conformity of the non-symbolic TrueType font.

protected abstract void CheckNonSymbolicTrueTypeFont(PdfTrueTypeFont trueTypeFont)

Parameters

trueTypeFont PdfTrueTypeFont

the PdfTrueTypeFont to check

CheckOutputIntents(PdfDictionary)

Verify the conformity of the output intents array in the catalog dictionary.

protected abstract void CheckOutputIntents(PdfDictionary catalogOrPageDict)

Parameters

catalogOrPageDict PdfDictionary

the PdfDictionary of a catalog or page to check

CheckPageColorsUsages(PdfDictionary, PdfDictionary)

Verify the conformity of used color spaces on the page.

[Obsolete("Will become abstract in the next major release.")]
protected virtual void CheckPageColorsUsages(PdfDictionary pageDict, PdfDictionary pageResources)

Parameters

pageDict PdfDictionary

the PdfDictionary contains contents for colors to be checked.

pageResources PdfDictionary

the PdfDictionary contains resources for colors to be checked.

CheckPageObject(PdfDictionary, PdfDictionary)

Verify the conformity of the page dictionary.

protected abstract void CheckPageObject(PdfDictionary page, PdfDictionary pageResources)

Parameters

page PdfDictionary

the PdfDictionary to check

pageResources PdfDictionary

the page's resources dictionary

CheckPageSize(PdfDictionary)

Checks the allowable size of the page.

protected abstract void CheckPageSize(PdfDictionary page)

Parameters

page PdfDictionary

the PdfDictionary of page which size being checked

CheckPageTransparency(PdfDictionary, PdfDictionary)

Verify the conformity of the page transparency.

protected abstract void CheckPageTransparency(PdfDictionary pageDict, PdfDictionary pageResources)

Parameters

pageDict PdfDictionary

the PdfDictionary contains contents for transparency to be checked

pageResources PdfDictionary

the PdfDictionary contains resources for transparency to be checked

CheckPdfArray(PdfArray)

Verify the conformity of the PDF array.

protected abstract void CheckPdfArray(PdfArray array)

Parameters

array PdfArray

the PdfArray to check

CheckPdfDictionary(PdfDictionary)

Verify the conformity of the PDF dictionary.

protected abstract void CheckPdfDictionary(PdfDictionary dictionary)

Parameters

dictionary PdfDictionary

the PdfDictionary to check

CheckPdfName(PdfName)

Verify the conformity of the PDF name.

protected abstract void CheckPdfName(PdfName name)

Parameters

name PdfName

the PdfName to check

CheckPdfNumber(PdfNumber)

Verify the conformity of the PDF number.

protected abstract void CheckPdfNumber(PdfNumber number)

Parameters

number PdfNumber

the PdfNumber to check

CheckPdfObject(PdfObject)

This method checks the requirements that must be fulfilled by a COS object in a PDF/A document.

public virtual void CheckPdfObject(PdfObject obj)

Parameters

obj PdfObject

the COS object that must be checked

CheckPdfStream(PdfStream)

Verify the conformity of the PDF stream.

protected abstract void CheckPdfStream(PdfStream stream)

Parameters

stream PdfStream

the PdfStream to check

CheckPdfString(PdfString)

Verify the conformity of the PDF string.

protected abstract void CheckPdfString(PdfString @string)

Parameters

string PdfString

the PdfString to check

CheckRenderingIntent(PdfName)

Checks whether the rendering intent of the document is within the allowed range of intents.

public abstract void CheckRenderingIntent(PdfName intent)

Parameters

intent PdfName

the intent to be analyzed

Remarks

Checks whether the rendering intent of the document is within the allowed range of intents. This is defined in ISO 19005-1 section 6.2.9, and unchanged in newer generations of the PDF/A specification.

CheckResources(PdfDictionary)

Verify the conformity of the resources dictionary.

[Obsolete("in favor of checkResources(PdfDictionary resources, PdfObject pdfObject)")]
protected virtual void CheckResources(PdfDictionary resources)

Parameters

resources PdfDictionary

the PdfDictionary to be checked

CheckResources(PdfDictionary, PdfObject)

Verify the conformity of the resources dictionary.

protected virtual void CheckResources(PdfDictionary resources, PdfObject pdfObject)

Parameters

resources PdfDictionary

the PdfDictionary to be checked

pdfObject PdfObject

the pdf object to check resources for

CheckResourcesOfAppearanceStreams(PdfDictionary)

Checks resources of the appearance streams.

protected virtual void CheckResourcesOfAppearanceStreams(PdfDictionary appearanceStreamsDict)

Parameters

appearanceStreamsDict PdfDictionary

the dictionary with appearance streams to check.

CheckSignature(PdfDictionary)

This method checks compliance of the signature dictionary

public virtual void CheckSignature(PdfDictionary signatureDict)

Parameters

signatureDict PdfDictionary

a PdfDictionary containing the signature.

CheckSignatureType(bool)

This method checks compliance of the signature type

[Obsolete("Will become abstract in the next major release.")]
public virtual void CheckSignatureType(bool isCAdES)

Parameters

isCAdES bool

true is CAdES sig type is used, false otherwise.

CheckSinglePage(PdfPage)

This method checks all requirements that must be fulfilled by a page in a PDF/A document.

public virtual void CheckSinglePage(PdfPage page)

Parameters

page PdfPage

the page that must be checked

CheckStructure(PdfAConformanceLevel)

Checks conformance level of PDF/A standard.

protected static bool CheckStructure(PdfAConformanceLevel conformanceLevel)

Parameters

conformanceLevel PdfAConformanceLevel

the PdfAConformanceLevel to be checked

Returns

bool

true if the specified conformanceLevel is a for PDF/A-1, PDF/A-2 or PDF/A-3

CheckSymbolicTrueTypeFont(PdfTrueTypeFont)

Verify the conformity of the symbolic TrueType font.

protected abstract void CheckSymbolicTrueTypeFont(PdfTrueTypeFont trueTypeFont)

Parameters

trueTypeFont PdfTrueTypeFont

the PdfTrueTypeFont to check

CheckTagStructureElement(PdfObject)

This method checks compliance of the tag structure elements, such as struct elements or parent tree entries.

public virtual void CheckTagStructureElement(PdfObject obj)

Parameters

obj PdfObject

an object that represents tag structure element.

CheckText(string, PdfFont)

Verify the conformity of the text written by the specified font.

[Obsolete("Will become abstract in the next major release.")]
public virtual void CheckText(string text, PdfFont font)

Parameters

text string

Text to verify.

font PdfFont

Font to verify the text against.

CheckTrailer(PdfDictionary)

Verify the conformity of the trailer dictionary.

protected abstract void CheckTrailer(PdfDictionary trailer)

Parameters

trailer PdfDictionary

the PdfDictionary of trailer to check

CheckXrefTable(PdfXrefTable)

Verify the conformity of the cross-reference table.

public abstract void CheckXrefTable(PdfXrefTable xrefTable)

Parameters

xrefTable PdfXrefTable

is the Xref table

GetAllowedNamedActions()

Retrieve allowed actions in conforming document.

protected abstract ICollection<PdfName> GetAllowedNamedActions()

Returns

ICollection<PdfName>

set of PdfName with allowed named actions

GetConformanceLevel()

Gets the PdfAConformanceLevel for this file.

public virtual PdfAConformanceLevel GetConformanceLevel()

Returns

PdfAConformanceLevel

the defined conformance level for this document.

GetForbiddenActions()

Retrieve forbidden actions in conforming document.

protected abstract ICollection<PdfName> GetForbiddenActions()

Returns

ICollection<PdfName>

set of PdfName with forbidden actions

GetMaxNumberOfIndirectObjects()

Retrieve maximum allowed number of indirect objects in conforming document.

protected abstract long GetMaxNumberOfIndirectObjects()

Returns

long

maximum allowed number of indirect objects

IsAlreadyChecked(PdfDictionary)

Checks whether the specified dictionary was already checked.

protected virtual bool IsAlreadyChecked(PdfDictionary dictionary)

Parameters

dictionary PdfDictionary

the PdfDictionary to check

Returns

bool

true if the specified dictionary was checked

IsContainsTransparencyGroup(PdfDictionary)

Checks whether the specified dictionary has a transparency group.

protected static bool IsContainsTransparencyGroup(PdfDictionary dictionary)

Parameters

dictionary PdfDictionary

the PdfDictionary to check

Returns

bool

true if and only if the specified dictionary has a Group key and its value is a dictionary with Transparency subtype

IsFullCheckMode()

In full check mode all objects will be tested for ISO conformance.

public virtual bool IsFullCheckMode()

Returns

bool

true if full check mode is switched on

Remarks

In full check mode all objects will be tested for ISO conformance. If full check mode is switched off objects which were not modified might be skipped to speed up the validation of the document

See Also

ObjectIsChecked(PdfObject)

Remembers which objects have already been checked, in order to avoid redundant checks.

public virtual bool ObjectIsChecked(PdfObject @object)

Parameters

object PdfObject

the object to check

Returns

bool

whether or not the object has already been checked

SetFullCheckMode(bool)

In full check mode all objects will be tested for ISO conformance.

public virtual void SetFullCheckMode(bool fullCheckMode)

Parameters

fullCheckMode bool

is a new value for full check mode switcher

Remarks

In full check mode all objects will be tested for ISO conformance. If full check mode is switched off objects which were not modified might be skipped to speed up the validation of the document

See Also

SetPdfAOutputIntentColorSpace(PdfDictionary)

Set Pdf A output intent color space.

public virtual void SetPdfAOutputIntentColorSpace(PdfDictionary catalog)

Parameters

catalog PdfDictionary

Catalog dictionary to retrieve the color space from.

ValidateDocument(ValidationContext) 

public virtual void ValidateDocument(ValidationContext validationContext)

Parameters

validationContext ValidationContext

ValidateObject(object, IsoKey, PdfResources, PdfStream, object) 

public virtual void ValidateObject(object obj, IsoKey key, PdfResources resources, PdfStream contentStream, object extra)

Parameters

obj object
key IsoKey
resources PdfResources
contentStream PdfStream
extra object