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* to you under the Apache License, Version 2.0 (the
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package org.apache.padaf.preflight.graphics;
import java.util.ArrayList;
import java.util.List;
import org.apache.padaf.preflight.DocumentHandler;
import org.apache.padaf.preflight.ValidationConstants;
import org.apache.padaf.preflight.ValidationException;
import org.apache.padaf.preflight.ValidationResult.ValidationError;
import org.apache.padaf.preflight.utils.COSUtils;
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 static org.apache.padaf.preflight.ValidationConstants.*;
/**
* 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 document handler which contains useful information to process
* validation.
*/
protected DocumentHandler handler = null;
/**
* The PDF document as COSDocument.
*/
protected COSDocument cosDocument = null;
public AbstractXObjValidator(DocumentHandler handler, COSStream xobj) {
this.xobject = xobj;
this.handler = handler;
this.cosDocument = handler.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).
*
* @param error
* the list of error to update if the validation fails
* @return true if the SMask is valid, false otherwise.
*/
protected boolean checkSMask(List<ValidationError> error) {
COSBase smask = xobject.getItem(COSName
.getPDFName(TRANSPARENCY_DICTIONARY_KEY_SOFT_MASK));
//
if (smask != null
&& !(COSUtils.isString(smask, cosDocument) && TRANSPARENCY_DICTIONARY_VALUE_SOFT_MASK_NONE
.equals(COSUtils.getAsString(smask, cosDocument)))) {
error.add(new ValidationError(ERROR_GRAPHIC_TRANSPARENCY_SMASK, "Soft Mask must be null or None"));
return false;
}
return true;
}
/**
* 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).
*
* @param errors
* the list of error to update if the validation fails.
* @return true if the OPI is missing, false otherwise.
*/
protected boolean checkOPI(List<ValidationError> errors) {
// 6.2.4 and 6.2.5 no OPI
if (this.xobject.getItem(COSName.getPDFName("OPI")) != null) {
errors.add(new ValidationError(
ValidationConstants.ERROR_GRAPHIC_UNEXPECTED_KEY,
"Unexpected 'OPI' Key"));
return false;
}
return true;
}
/**
* 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).
*
* @param errors
* the list of error to update if the validation fails.
* @return true if the Ref is missing, false otherwise.
*/
protected boolean checkReferenceXObject(List<ValidationError> errors) {
// 6.2.6 No reference xobject
if (this.xobject.getItem(COSName.getPDFName("Ref")) != null) {
errors.add(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_KEY,
"No reference Xobject allowed in PDF/A"));
return false;
}
return true;
}
/**
* 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.
*
* @param errors
* the list of error to update if the validation fails.
* @return true if the XObject isn't a Postscript XObject, false otherwise.
*/
protected boolean checkPostscriptXObject(List<ValidationError> errors) {
// 6.2.7 No PostScript XObjects
if (this.xobject.getItem(COSName.SUBTYPE) != null
&& XOBJECT_DICTIONARY_VALUE_SUBTYPE_POSTSCRIPT.equals(this.xobject
.getNameAsString(COSName.SUBTYPE))) {
errors.add(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY,
"No Postscript Xobject allowed in PDF/A"));
return false;
}
if (this.xobject.getItem(COSName.getPDFName("Subtype2")) != null) {
errors.add(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY,
"No Postscript Xobject allowed in PDF/A (Subtype2)"));
return false;
}
return true;
}
/**
* This method checks if required fields are present.
*
* @param result
* the list of error to update if the validation fails.
* @return true if all fields are present, false otherwise.
*/
protected abstract boolean checkMandatoryFields(List<ValidationError> result);
/*
* (non-Javadoc)
*
* @see net.awl.edoc.pdfa.validation.graphics.XObjectValidator#validate()
*/
public List<ValidationError> validate() throws ValidationException {
List<ValidationError> result = new ArrayList<ValidationError>(0);
if (checkMandatoryFields(result)) {
checkOPI(result);
checkSMask(result);
checkReferenceXObject(result);
checkPostscriptXObject(result);
}
return result;
}
}