Java tutorial
/******************************************************************************* * 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.DICTIONARY_KEY_TYPE; import static net.padaf.preflight.ValidationConstants.ERROR_GRAPHIC_INVALID_PATTERN_DEFINITION; import static net.padaf.preflight.ValidationConstants.PATTERN_KEY_SHADING; import static net.padaf.preflight.ValidationConstants.PATTERN_KEY_SHADING_TYPE; import static net.padaf.preflight.ValidationConstants.TRANPARENCY_DICTIONARY_KEY_EXTGSTATE; import static net.padaf.preflight.ValidationConstants.XOBJECT_DICTIONARY_KEY_COLOR_SPACE; import java.util.ArrayList; import java.util.List; import net.padaf.preflight.DocumentHandler; import net.padaf.preflight.ValidationException; import net.padaf.preflight.ValidationResult.ValidationError; import net.padaf.preflight.graphics.color.ColorSpaceHelper; import net.padaf.preflight.graphics.color.ColorSpaceHelperFactory; import net.padaf.preflight.graphics.color.ColorSpaceHelperFactory.ColorSpaceRestriction; import net.padaf.preflight.utils.COSUtils; 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 process the validation of a ShadingPattern object. */ public class ShadingPattern implements XObjectValidator { /** * COSDictionary which represent the shading pattern. */ private COSDictionary pattern = null; /** * The COSDocument which contains the shading pattern to check. */ private COSDocument cosDoc = null; /** * The document handler which contains useful information to process the * validation. */ private DocumentHandler documentHandler = null; /** * @param _handler * DocumentHandler used to initialize "documentHandler" and "cosDoc" * attributes. * @param _pattern * COSDictionary used to initialize the shading pattern to validate. */ public ShadingPattern(DocumentHandler _handler, COSDictionary _pattern) { this.documentHandler = _handler; this.pattern = _pattern; this.cosDoc = this.documentHandler.getDocument().getDocument(); } /** * Because of a Shading Pattern can be used as an Indirect Object or Directly * define in an other dictionary, there are two ways to obtain the Shading * Pattern dictionary according to the pattern attribute. This method returns * the Shading pattern dictionary represented by the pattern attribute or * contained in it. * * This is the first method called by the validate method. * * @param errors * the list of error to update if there are no Shading pattern in the * pattern COSDictionary. * @return the ShadingPattern dictionary */ protected COSDictionary getShadingDictionary(List<ValidationError> errors) { if (!"Shading".equals(pattern.getNameAsString(COSName.getPDFName(DICTIONARY_KEY_TYPE)))) { COSBase shading = pattern.getItem(COSName.getPDFName(PATTERN_KEY_SHADING)); if (shading == null) { errors.add(new ValidationError(ERROR_GRAPHIC_INVALID_PATTERN_DEFINITION)); return null; } return COSUtils.getAsDictionary(shading, cosDoc); } else { return pattern; } } /** * Checks if the given shading pattern contains the ShadingType entry and if * the ColorSapce entry is consistent which rules of the PDF Reference and the * ISO 190005-1:2005 Specification. * * This method is called by the validate method. * * @param shadingDict * the Shading pattern dictionary to check * @param errors * the list of error to update if the validation fails * @return true if the Shading pattern is valid, false otherwise. * @throws ValidationException */ protected boolean checkShadingDictionary(COSDictionary shadingDict, List<ValidationError> errors) throws ValidationException { if (shadingDict.getItem(COSName.getPDFName(PATTERN_KEY_SHADING_TYPE)) == null) { errors.add(new ValidationError(ERROR_GRAPHIC_INVALID_PATTERN_DEFINITION)); return false; } COSBase csImg = shadingDict.getItem(COSName.getPDFName(XOBJECT_DICTIONARY_KEY_COLOR_SPACE)); ColorSpaceHelper csh = ColorSpaceHelperFactory.getColorSpaceHelper(csImg, documentHandler, ColorSpaceRestriction.NO_PATTERN); return csh.validate(errors); } /** * Check the Extended Graphic State contains in the ShadingPattern dictionary * 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 checkGraphicState(List<ValidationError> errors) throws ValidationException { COSDictionary resources = (COSDictionary) this.pattern .getDictionaryObject(TRANPARENCY_DICTIONARY_KEY_EXTGSTATE); if (resources != null) { ExtGStateContainer extContainer = new ExtGStateContainer(resources, cosDoc); return extContainer.validateTransparencyRules(errors); } return true; } /* * (non-Javadoc) * * @see net.awl.edoc.pdfa.validation.graphics.XObjectValidator#validate() */ public List<ValidationError> validate() throws ValidationException { List<ValidationError> result = new ArrayList<ValidationError>(); COSDictionary shading = getShadingDictionary(result); if (shading != null) { boolean isValid = checkShadingDictionary(shading, result); isValid = isValid && checkGraphicState(result); } return result; } }