/*******************************************************************************
* Copyright 2010 Atos Worldline SAS
*
* Licensed by Atos Worldline SAS under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* Atos Worldline SAS licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package net.padaf.preflight.graphics;
import static net.padaf.preflight.ValidationConstants.ERROR_TRANSPARENCY_EXT_GS_BLEND_MODE;
import static net.padaf.preflight.ValidationConstants.ERROR_TRANSPARENCY_EXT_GS_CA;
import static net.padaf.preflight.ValidationConstants.ERROR_TRANSPARENCY_EXT_GS_SOFT_MASK;
import static net.padaf.preflight.ValidationConstants.TRANPARENCY_DICTIONARY_KEY_EXTGSTATE;
import static net.padaf.preflight.ValidationConstants.TRANPARENCY_DICTIONARY_KEY_EXTGSTATE_ENTRY_REGEX;
import static net.padaf.preflight.ValidationConstants.TRANSPARENCY_DICTIONARY_KEY_BLEND_MODE;
import static net.padaf.preflight.ValidationConstants.TRANSPARENCY_DICTIONARY_KEY_LOWER_CA;
import static net.padaf.preflight.ValidationConstants.TRANSPARENCY_DICTIONARY_KEY_SOFT_MASK;
import static net.padaf.preflight.ValidationConstants.TRANSPARENCY_DICTIONARY_KEY_UPPER_CA;
import static net.padaf.preflight.ValidationConstants.TRANSPARENCY_DICTIONARY_VALUE_BM_COMPATIBLE;
import static net.padaf.preflight.ValidationConstants.TRANSPARENCY_DICTIONARY_VALUE_BM_NORMAL;
import static net.padaf.preflight.ValidationConstants.TRANSPARENCY_DICTIONARY_VALUE_SOFT_MASK_NONE;
import java.util.ArrayList;
import java.util.List;
import net.padaf.preflight.ValidationConstants;
import net.padaf.preflight.ValidationException;
import net.padaf.preflight.ValidationResult.ValidationError;
import net.padaf.preflight.utils.COSUtils;
import net.padaf.preflight.utils.RenderingIntents;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSDocument;
import org.apache.pdfbox.cos.COSName;
/**
* This class wraps a list of COSDictionary which represent an extended graphics
* state dictionary.
*/
public class ExtGStateContainer {
/**
* The COSDocument which contains the extended graphic states.
*/
private COSDocument cDoc = null;
/**
* A list of Extended Graphic States.
*/
private List<COSDictionary> listOfExtGState = new ArrayList<COSDictionary>(0);
/**
* Create an instance of ExtGStateContainer using a Resource dictionary and a
* COSDocument. This constructor initializes the listOfExtGState attribute
* using the given Resource dictionary and the COSDocument.
*
* @param resources
* a resource COSDictionary
* @param cDoc
* the COSDocument which contains the Resource dictionary
* @throws ValidationException
* thrown if a the Extended Graphic State isn't valid
*/
public ExtGStateContainer(COSDictionary resources, COSDocument cDoc)
throws ValidationException {
this.cDoc = cDoc;
COSBase egsEntry = resources.getItem(COSName
.getPDFName(TRANPARENCY_DICTIONARY_KEY_EXTGSTATE));
COSDictionary extGStates = COSUtils.getAsDictionary(egsEntry, cDoc);
if (extGStates != null) {
for (Object object : extGStates.keySet()) {
COSName key = (COSName) object;
if (key.getName().matches(
TRANPARENCY_DICTIONARY_KEY_EXTGSTATE_ENTRY_REGEX)) {
COSBase gsBase = extGStates.getItem(key);
COSDictionary gsDict = COSUtils.getAsDictionary(gsBase, cDoc);
if (gsDict == null) {
throw new ValidationException(
"The Extended Graphics State dictionary is invalid");
}
this.listOfExtGState.add(gsDict);
}
}
}
//else if there are no ExtGState, the list will be empty.
}
/**
* Validate all ExtGState dictionaries of this container
*
* @param error
* the list of error to update if the validation fails.
* @return true if all Graphic States are valid, false otherwise.
*/
public boolean validateTransparencyRules(List<ValidationError> error) {
boolean res = true;
for (COSDictionary egs : listOfExtGState) {
res = res && checkSoftMask(egs, error);
res = res && checkCA(egs, error);
res = res && checkBlendMode(egs, error);
res = res && checkTRKey(egs, error);
res = res && checkTR2Key(egs, error);
}
return res;
}
/**
* This method checks the SMask value of the ExtGState dictionary. The Soft
* Mask is optional but must be "None" if it is present.
*
* @param egs
* the Graphic state to check
* @param error
* the list of error to update if the validation fails.
* @return true if SMask is missing or equals to None
*/
private boolean checkSoftMask(COSDictionary egs, List<ValidationError> error) {
COSBase smVal = egs.getItem(COSName
.getPDFName(TRANSPARENCY_DICTIONARY_KEY_SOFT_MASK));
if (smVal != null) {
// ---- Soft Mask is valid only if it is a COSName equals to None
if (!(smVal instanceof COSName && TRANSPARENCY_DICTIONARY_VALUE_SOFT_MASK_NONE
.equals(((COSName) smVal).getName()))) {
error.add(new ValidationError(ERROR_TRANSPARENCY_EXT_GS_SOFT_MASK, "SoftMask must be null or None"));
return false;
}
}
return true;
}
/**
* This method checks the BM value of the ExtGState dictionary. The Blend Mode
* is optional but must be "Normal" or "Compatible" if it is present.
*
* @param egs
* the graphic state to check
* @param error
* the list of error to update if the validation fails.
* @return true if BM is missing or equals to "Normal" or "Compatible"
*/
private boolean checkBlendMode(COSDictionary egs, List<ValidationError> error) {
COSBase bmVal = egs.getItem(COSName
.getPDFName(TRANSPARENCY_DICTIONARY_KEY_BLEND_MODE));
if (bmVal != null) {
// ---- Blend Mode is valid only if it is equals to Normal or Compatible
if (!(bmVal instanceof COSName && (TRANSPARENCY_DICTIONARY_VALUE_BM_NORMAL
.equals(((COSName) bmVal).getName()) || TRANSPARENCY_DICTIONARY_VALUE_BM_COMPATIBLE
.equals(((COSName) bmVal).getName())))) {
error.add(new ValidationError(ERROR_TRANSPARENCY_EXT_GS_BLEND_MODE,"BlendMode value isn't valid (only Normal and Compatible are authorized)"));
return false;
}
}
return true;
}
/**
* This method checks the "CA" and "ca" values of the ExtGState dictionary.
* They are optional but must be 1.0 if they are present.
*
* @param egs
* the graphic state to check
* @param error
* the list of error to update if the validation fails.
* @return true if CA/ca is missing or equals to 1.0
*/
private boolean checkCA(COSDictionary egs, List<ValidationError> error) {
COSBase uCA = egs.getItem(COSName
.getPDFName(TRANSPARENCY_DICTIONARY_KEY_UPPER_CA));
COSBase lCA = egs.getItem(COSName
.getPDFName(TRANSPARENCY_DICTIONARY_KEY_LOWER_CA));
if (uCA != null) {
// ---- If CA is present only the value 1.0 is authorized
Float fca = COSUtils.getAsFloat(uCA, cDoc);
Integer ica = COSUtils.getAsInteger(uCA, cDoc);
if (!(fca != null && fca == 1.0f) && !(ica != null && ica == 1)) {
error.add(new ValidationError(ERROR_TRANSPARENCY_EXT_GS_CA,"CA entry in a ExtGState is invalid"));
return false;
}
}
if (lCA != null) {
// ---- If ca is present only the value 1.0 is authorized
Float fca = COSUtils.getAsFloat(lCA, cDoc);
Integer ica = COSUtils.getAsInteger(lCA, cDoc);
if (!(fca != null && fca == 1.0f) && !(ica != null && ica == 1)) {
error.add(new ValidationError(ERROR_TRANSPARENCY_EXT_GS_CA,"ca entry in a ExtGState is invalid."));
return false;
}
}
return true;
}
/**
* Check the TR entry. A valid ExtGState hasn't TR entry.
*
* @param egs
* the graphic state to check
* @param error
* the list of error to update if the validation fails.
* @return true if TR entry is missing, false otherwise.
*/
protected boolean checkTRKey(COSDictionary egs, List<ValidationError> error) {
if (egs.getItem(COSName.getPDFName("TR")) != null) {
error.add(new ValidationError(
ValidationConstants.ERROR_GRAPHIC_UNEXPECTED_KEY,
"No TR key expected in Extended graphics state"));
return false;
}
return true;
}
/**
* Check the TR2 entry. A valid ExtGState hasn't TR2 entry or a TR2 entry
* equals to "default".
*
* @param egs
* the graphic state to check
* @param error
* the list of error to update if the validation fails.
* @return true if TR2 entry is missing or equals to "default", false
* otherwise.
*/
protected boolean checkTR2Key(COSDictionary egs, List<ValidationError> error) {
if (egs.getItem(COSName.getPDFName("TR2")) != null) {
String s = egs.getNameAsString(COSName.getPDFName("TR2"));
if (!"default".equals(s)) {
error.add(new ValidationError(
ValidationConstants.ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY,
"TR2 key only expect 'default' value, not '" + s + "'"));
return false;
}
}
return true;
}
/**
* Check the RI entry of the Graphic State. If the rendering intent entry is
* present, the value must be one of the four values defined in the PDF
* reference. (@see net.awl.edoc.pdfa.validation.utils.RenderingIntents)
*
* @param egs
* the graphic state to check
* @param error
* the list of error to update if the validation fails.
* @return true if RI entry is valid, false otherwise.
*/
protected boolean checkRIKey(COSDictionary egs, List<ValidationError> error) {
String rendenringIntent = egs.getNameAsString(COSName.getPDFName("RI"));
if (rendenringIntent != null && !"".equals(rendenringIntent)
&& !RenderingIntents.contains(rendenringIntent)) {
error.add(new ValidationError(
ValidationConstants.ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY,
"Invalid rendering intent value in Extended graphics state"));
return false;
}
return true;
}
}