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package org.apache.pdfbox.preflight.xobject;
import static org.apache.pdfbox.preflight.PreflightConstants.ERROR_GRAPHIC_TRANSPARENCY_SMASK;
import static org.apache.pdfbox.preflight.PreflightConstants.ERROR_GRAPHIC_UNEXPECTED_KEY;
import static org.apache.pdfbox.preflight.PreflightConstants.ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY;
import static org.apache.pdfbox.preflight.PreflightConstants.TRANSPARENCY_DICTIONARY_VALUE_SOFT_MASK_NONE;
import static org.apache.pdfbox.preflight.PreflightConstants.XOBJECT_DICTIONARY_VALUE_SUBTYPE_POSTSCRIPT;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSDocument;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSStream;
import org.apache.pdfbox.preflight.PreflightContext;
import org.apache.pdfbox.preflight.ValidationResult.ValidationError;
import org.apache.pdfbox.preflight.exception.ValidationException;
import org.apache.pdfbox.preflight.utils.COSUtils;
/**
* This class processes commons validations of XObjects.
*/
public abstract class AbstractXObjValidator implements XObjectValidator
{
/**
* The XObject to validate as a COSStream.
*/
protected COSStream xobject = null;
/**
* The validation context which contains useful information to process validation.
*/
protected PreflightContext context = null;
/**
* The PDF document as COSDocument.
*/
protected COSDocument cosDocument = null;
public AbstractXObjValidator(PreflightContext context, COSStream xobj)
{
this.xobject = xobj;
this.context = context;
this.cosDocument = context.getDocument().getDocument();
}
/**
* This method checks the SMask entry in the XObject dictionary. According to the PDF Reference, a SMask in a
* XObject is a Stream. So if it is not null, it should be an error but a SMask with the name None is authorized in
* the PDF/A Specification 6.4. If the validation fails (SMask not null and different from None), the error list is
* updated with the error code ERROR_GRAPHIC_TRANSPARENCY_SMASK (2.2.2).
*
*/
protected void checkSMask()
{
COSBase smask = xobject.getItem(COSName.SMASK);
if (smask != null
&& !(COSUtils.isString(smask, cosDocument) && TRANSPARENCY_DICTIONARY_VALUE_SOFT_MASK_NONE
.equals(COSUtils.getAsString(smask, cosDocument))))
{
context.addValidationError(new ValidationError(ERROR_GRAPHIC_TRANSPARENCY_SMASK,
"Soft Mask must be null or None ["+xobject.toString()+"]"));
}
}
/**
* According the ISO 190005:1-2005 specification, a XObject can't have an OPI entry in its dictionary. If the
* XObject has a OPI entry, the error list is updated with the error code ERROR_GRAPHIC_UNEXPECTED_KEY (2.3).
*
*/
protected void checkOPI()
{
// 6.2.4 and 6.2.5 no OPI
if (this.xobject.getItem(COSName.getPDFName("OPI")) != null)
{
context.addValidationError(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_KEY, "Unexpected 'OPI' Key"));
}
}
/**
* According the ISO 190005:1-2005 specification, a XObject can't have an Ref entry in its dictionary. If the
* XObject has a Ref entry, the error list is updated with the error code ERROR_GRAPHIC_UNEXPECTED_KEY (2.3).
*
*/
protected void checkReferenceXObject()
{
// 6.2.6 No reference xobject
if (this.xobject.getItem("Ref") != null)
{
context.addValidationError(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_KEY,
"No reference Xobject allowed in PDF/A"));
}
}
/**
* According the ISO 190005:1-2005 specification, PostSCript XObject are forbidden. If the XObject is a PostScript
* XObject, the error list is updated with the error code ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY (2.3.2).
*
* To know the if the object a Postscript XObject, "Subtype" and "Subtype2" entries are checked.
*/
protected void checkPostscriptXObject()
{
// 6.2.7 No PostScript XObjects
String subtype = this.xobject.getNameAsString(COSName.SUBTYPE);
if (subtype != null && XOBJECT_DICTIONARY_VALUE_SUBTYPE_POSTSCRIPT.equals(subtype))
{
context.addValidationError(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY,
"No Postscript Xobject allowed in PDF/A"));
return;
}
if (this.xobject.getItem(COSName.getPDFName("Subtype2")) != null)
{
context.addValidationError(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY,
"No Postscript Xobject allowed in PDF/A (Subtype2)"));
return;
}
}
/**
* This method checks if required fields are present.
*
*/
protected abstract void checkMandatoryFields();
/*
* (non-Javadoc)
*
* @see net.awl.edoc.pdfa.validation.graphics.XObjectValidator#validate()
*/
public void validate() throws ValidationException
{
checkMandatoryFields();
checkOPI();
checkSMask();
checkReferenceXObject();
checkPostscriptXObject();
}
}