/*
* Created on 03/set/2015
* Copyright 2015 by Andrea Vacondio (andrea.vacondio@gmail.com).
* This file is part of Sejda.
*
* Sejda is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Sejda is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with Sejda. If not, see <http://www.gnu.org/licenses/>.
*/
package org.sejda.impl.sambox.component;
import static java.util.Objects.isNull;
import static java.util.Objects.nonNull;
import static java.util.Optional.ofNullable;
import static org.sejda.util.RequireUtils.requireNotNullArg;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;
import org.sejda.common.LookupTable;
import org.sejda.sambox.cos.COSName;
import org.sejda.sambox.pdmodel.PDDocument;
import org.sejda.sambox.pdmodel.PDPage;
import org.sejda.sambox.pdmodel.interactive.action.PDAction;
import org.sejda.sambox.pdmodel.interactive.action.PDActionGoTo;
import org.sejda.sambox.pdmodel.interactive.annotation.PDAnnotation;
import org.sejda.sambox.pdmodel.interactive.annotation.PDAnnotationLink;
import org.sejda.sambox.pdmodel.interactive.annotation.PDAnnotationMarkup;
import org.sejda.sambox.pdmodel.interactive.annotation.PDAnnotationPopup;
import org.sejda.sambox.pdmodel.interactive.documentnavigation.destination.PDDestination;
import org.sejda.sambox.pdmodel.interactive.documentnavigation.destination.PDNamedDestination;
import org.sejda.sambox.pdmodel.interactive.documentnavigation.destination.PDPageDestination;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Component that can distill pages annotations filtering out those pointing to irrelevant pages and updating the annotationsif necessasy.
*
* @author Andrea Vacondio
*
*/
public final class AnnotationsDistiller {
private static final Logger LOG = LoggerFactory.getLogger(AnnotationsDistiller.class);
private PDDocument document;
private LookupTable<PDAnnotation> annotationsLookup = new LookupTable<>();
/**
* Document where pages and annotations come from, it's used to resolve named destinations.
*
* @param document
*/
public AnnotationsDistiller(PDDocument document) {
requireNotNullArg(document, "Cannot process annotations for a null document");
this.document = document;
}
/**
* Removes from the given set of pages all the annotations pointing to a page that is not in the lookup (an irrelevant page) and replaces annotations pointing to an old page
* with a new one pointing to the looked up page.
*
* @param relevantPages
* @return the lookup table to retrieve newly created annotations based on the old ones
*/
public LookupTable<PDAnnotation> retainRelevantAnnotations(LookupTable<PDPage> relevantPages) {
LOG.debug("Filtering annotations");
for (PDPage page : relevantPages.keys()) {
try {
Set<PDAnnotation> keptAnnotations = new HashSet<>();
for (PDAnnotation annotation : page.getAnnotations()) {
if (!annotationsLookup.hasLookupFor(annotation)) {
if (annotation instanceof PDAnnotationLink) {
processLinkAnnotation(relevantPages, keptAnnotations, (PDAnnotationLink) annotation);
} else {
processNonLinkAnnotation(relevantPages, keptAnnotations, annotation);
}
}
}
relevantPages.lookup(page).setAnnotations(new ArrayList<>(keptAnnotations));
} catch (IOException e) {
LOG.warn("Failed to process annotations for page", e);
}
}
return annotationsLookup;
}
private void processLinkAnnotation(LookupTable<PDPage> relevantPages, Set<PDAnnotation> keptAnnotations,
PDAnnotationLink annotation) throws IOException {
PDDestination destination = getDestinationFrom(annotation);
if (destination instanceof PDPageDestination) {
PDPage destPage = relevantPages.lookup(((PDPageDestination) destination).getPage());
if (nonNull(destPage)) {
// relevant page dest
PDAnnotationLink duplicate = (PDAnnotationLink) duplicate(annotation, relevantPages);
duplicate.getCOSObject().removeItem(COSName.A);
PDPageDestination newDestination = (PDPageDestination) PDDestination.create(destination.getCOSObject());
newDestination.setPage(destPage);
duplicate.setDestination(newDestination);
keptAnnotations.add(duplicate);
} else {
LOG.trace("Removing not relevant link annotation");
}
} else {
// not a page dest
keptAnnotations.add(duplicate(annotation, relevantPages));
}
}
private void processNonLinkAnnotation(LookupTable<PDPage> relevantPages, Set<PDAnnotation> keptAnnotations,
PDAnnotation annotation) {
PDPage p = annotation.getPage();
if (isNull(p) || relevantPages.hasLookupFor(p)) {
PDAnnotation duplicate = duplicate(annotation, relevantPages);
if (duplicate instanceof PDAnnotationMarkup) {
PDAnnotationPopup popup = ((PDAnnotationMarkup) duplicate).getPopup();
if (nonNull(popup)) {
COSName subtype = popup.getCOSObject().getCOSName(COSName.SUBTYPE);
if (COSName.POPUP.equals(subtype)) {
PDAnnotationPopup popupDuplicate = ofNullable(
(PDAnnotationPopup) annotationsLookup.lookup(popup))
.orElseGet(() -> (PDAnnotationPopup) duplicate(popup, relevantPages));
((PDAnnotationMarkup) duplicate).setPopup(popupDuplicate);
if (nonNull(popupDuplicate.getParent())) {
popupDuplicate.setParent((PDAnnotationMarkup) duplicate);
LOG.trace("Popup parent annotation updated");
}
keptAnnotations.add(popupDuplicate);
} else {
((PDAnnotationMarkup) duplicate).setPopup(null);
LOG.warn("Removed Popup annotation of unexpected subtype {}", subtype);
}
}
}
keptAnnotations.add(duplicate);
}
}
private PDAnnotation duplicate(PDAnnotation annotation, LookupTable<PDPage> relevantPages) {
PDPage p = annotation.getPage();
PDAnnotation duplicate = PDAnnotation.createAnnotation(annotation.getCOSObject().duplicate());
if (nonNull(p)) {
duplicate.setPage(relevantPages.lookup(p));
LOG.trace("Updated annotation page reference with the looked up page");
}
annotationsLookup.addLookupEntry(annotation, duplicate);
return duplicate;
}
private PDDestination getDestinationFrom(PDAnnotationLink link) {
try {
PDDestination destination = link.getDestination();
if (destination == null) {
PDAction action = link.getAction();
if (action instanceof PDActionGoTo) {
destination = ((PDActionGoTo) action).getDestination();
}
}
if (destination instanceof PDNamedDestination) {
return document.getDocumentCatalog().findNamedDestinationPage((PDNamedDestination) destination);
}
return destination;
} catch (Exception e) {
LOG.warn("Failed to get destination for annotation", e);
return null;
}
}
}