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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
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*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing,
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package org.apache.padaf.preflight.graphics;
import static org.apache.padaf.preflight.ValidationConstants.DICTIONARY_KEY_TYPE;
import static org.apache.padaf.preflight.ValidationConstants.ERROR_GRAPHIC_INVALID_BBOX;
import static org.apache.padaf.preflight.ValidationConstants.ERROR_GRAPHIC_MISSING_FIELD;
import static org.apache.padaf.preflight.ValidationConstants.ERROR_GRAPHIC_TRANSPARENCY_GROUP;
import static org.apache.padaf.preflight.ValidationConstants.PATTERN_KEY_SHADING;
import static org.apache.padaf.preflight.ValidationConstants.XOBJECT_DICTIONARY_KEY_BBOX;
import static org.apache.padaf.preflight.ValidationConstants.XOBJECT_DICTIONARY_KEY_GROUP;
import static org.apache.padaf.preflight.ValidationConstants.XOBJECT_DICTIONARY_KEY_GROUP_S;
import static org.apache.padaf.preflight.ValidationConstants.XOBJECT_DICTIONARY_VALUE_S_TRANSPARENCY;
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.contentstream.ContentStreamWrapper;
import org.apache.padaf.preflight.utils.COSUtils;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSStream;
import org.apache.pdfbox.pdmodel.PDResources;
import org.apache.pdfbox.pdmodel.graphics.xobject.PDXObjectForm;
/**
* This class validates XObject with the Form subtype.
*/
public class XObjFormValidator extends AbstractXObjValidator {
/**
* High level object which represents the XObjectForm
*/
PDXObjectForm pdXObj = null;
public XObjFormValidator(DocumentHandler handler, COSStream xobj) {
super(handler, xobj);
this.pdXObj = new PDXObjectForm(xobj);
}
/*
* (non-Javadoc)
*
* @see net.awl.edoc.pdfa.validation.graphics.AbstractXObjValidator#validate()
*/
@Override
public List<ValidationError> validate() throws ValidationException {
List<ValidationError> result = super.validate();
checkExtGraphicState(result);
checkGroup(result);
checkSubtype2Value(result);
validateXObjectContent(result);
validateShadingPattern(result);
return result;
}
/*
* (non-Javadoc)
*
* @seenet.awl.edoc.pdfa.validation.graphics.AbstractXObjValidator#
* checkMandatoryFields(java.util.List)
*/
@Override
protected boolean checkMandatoryFields(List<ValidationError> result) {
boolean lastMod = this.xobject.getItem(COSName.getPDFName("LastModified")) != null;
boolean pieceInfo = this.xobject.getItem(COSName.getPDFName("PieceInfo")) != null;
// type and subtype checked before to create the Validator.
if (lastMod ^ pieceInfo) {
result.add(new ValidationError(ERROR_GRAPHIC_MISSING_FIELD));
return false;
}
COSBase bbBase = this.xobject.getItem(COSName
.getPDFName(XOBJECT_DICTIONARY_KEY_BBOX));
// ---- BBox is an Array (Rectangle)
if (bbBase == null || !COSUtils.isArray(bbBase, cosDocument)) {
result.add(new ValidationError(ERROR_GRAPHIC_INVALID_BBOX));
return false;
}
return true;
}
/**
* An Form XObject is a ContentStream. This method method uses an instance of
* ContentStreamWrapper to check the Stream of this Form XObject.
*
* @param result
* the list of error to update if the validation fails.
* @return true if the validation succeed, false otherwise.
* @throws ValidationException
*/
protected boolean validateXObjectContent(List<ValidationError> result)
throws ValidationException {
ContentStreamWrapper csWrapper = new ContentStreamWrapper(handler);
List<ValidationError> csParseErrors = csWrapper
.validXObjContentStream(pdXObj);
if (csParseErrors == null
|| (csParseErrors != null && csParseErrors.isEmpty())) {
return true;
}
result.addAll(csParseErrors);
return false;
}
/**
* A Form XObject may contain a Group object (Key =" Group"). If a Group
* object is present, this method checks if the S entry is present and if its
* value is different from "Transparency".
*
* @param error
* the list of error to update if the validation fails.
* @return true if the validation succeed, false otherwise
* @throws ValidationException
*/
protected boolean checkGroup(List<ValidationError> error)
throws ValidationException {
COSBase baseGroup = this.xobject.getItem(COSName
.getPDFName(XOBJECT_DICTIONARY_KEY_GROUP));
COSDictionary groupDictionary = COSUtils.getAsDictionary(baseGroup,
cosDocument);
if (groupDictionary != null) {
if (!XOBJECT_DICTIONARY_KEY_GROUP.equals(groupDictionary
.getNameAsString(DICTIONARY_KEY_TYPE))) {
throw new ValidationException(
"The Group dictionary hasn't Group as Type value");
}
String sVal = groupDictionary
.getNameAsString(XOBJECT_DICTIONARY_KEY_GROUP_S);
if (sVal == null || XOBJECT_DICTIONARY_VALUE_S_TRANSPARENCY.equals(sVal)) {
error.add(new ValidationError(ERROR_GRAPHIC_TRANSPARENCY_GROUP , "Group has a transparency S entry or the S entry is null."));
return false;
}
}
return true;
}
/**
* Check the Extended Graphic State contains in the Form XObject if it is
* present. To check this ExtGState, this method uses the
* net.awl.edoc.pdfa.validation.graphics.ExtGStateContainer object.
*
* @param errors
* the list of error to update if the validation fails
* @return true is the ExtGState is missing or valid, false otherwise.
* @throws ValidationException
*/
protected boolean checkExtGraphicState(List<ValidationError> error)
throws ValidationException {
PDResources resources = this.pdXObj.getResources();
if (resources != null) {
ExtGStateContainer extContainer = new ExtGStateContainer(resources
.getCOSDictionary(), this.cosDocument);
return extContainer.validateTransparencyRules(error);
}
return true;
}
/**
* This method check the Shading entry of the resource dictionary if exists.
* To process this validation, an instance of ShadinPattern is used.
*
* @param result
* the list of error to update if the validation fails
* @return true if the validation succeed, false otherwise.
* @throws ValidationException
*/
protected boolean validateShadingPattern(List<ValidationError> result)
throws ValidationException {
PDResources resources = this.pdXObj.getResources();
boolean res = true;
if (resources != null) {
COSDictionary shadings = (COSDictionary) resources.getCOSDictionary()
.getDictionaryObject(PATTERN_KEY_SHADING);
if (shadings != null) {
for (Object key : shadings.keySet()) {
COSDictionary aShading = (COSDictionary) shadings
.getDictionaryObject((COSName) key);
ShadingPattern sp = new ShadingPattern(handler, aShading);
List<ValidationError> lErrors = sp.validate();
if (lErrors != null && !lErrors.isEmpty()) {
result.addAll(lErrors);
res = false;
}
}
}
}
return res;
}
/**
* Check if there are no PS entry in the Form XObject dictionary
*
* @param errors
* the list of error to update if the validation fails.
* @return true if PS entry is missing, false otherwise
*/
protected boolean checkPS(List<ValidationError> errors) {
// 6.2.4 and 6.2.5 no PS
if (this.xobject.getItem(COSName.getPDFName("PS")) != null) {
errors.add(new ValidationError(
ValidationConstants.ERROR_GRAPHIC_UNEXPECTED_KEY,
"Unexpected 'PS' Key"));
return false;
}
return true;
}
/**
* Check the SUbtype2 entry according to the §6.2.5 of the ISO 190005-1:2005
* specification.
*
* @param errors
* the list of error to update if the validation fails.
* @return true if Subtype2 is missing or different from PS, false otherwise
*/
protected boolean checkSubtype2Value(List<ValidationError> errors) {
// 6.2.5 if Subtype2, value not PS
if (this.xobject.getItem(COSName.getPDFName("Subtype2")) != null) {
if ("PS".equals(this.xobject.getNameAsString(COSName
.getPDFName("Subtype2")))) {
errors.add(new ValidationError(
ValidationConstants.ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY,
"Unexpected 'PS' value for 'Subtype2' Key"));
return false;
}
}
return true;
}
}