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Package containing tasks implemented using sambox.
/*
* Created on 03/set/2015
* Copyright 2015 by Andrea Vacondio ([email protected]).
* 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 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 retainRelevantAnnotations(LookupTable relevantPages) {
LOG.debug("Filtering annotations");
for (PDPage page : relevantPages.keys()) {
try {
Set keptAnnotations = new LinkedHashSet<>();
for (PDAnnotation annotation : page.getAnnotations()) {
PDAnnotation mapped = annotationsLookup.lookup(annotation);
if (nonNull(mapped)) {
keptAnnotations.add(mapped);
} else {
// handle the scenario where the annotation page != actual render page
PDPage annotationPage = annotation.getPage();
if (annotationPage != null && !annotationPage.equals(page)) {
// inconsistent annotation, this creates problems; let's fix it
if(COSName.SCREEN.equals(annotation.getSubtype())) {
annotation.setPage(page);
} else {
annotation.setPage(null);
}
}
if (annotation instanceof PDAnnotationLink) {
processLinkAnnotation(relevantPages, keptAnnotations, (PDAnnotationLink) annotation, page);
} else {
processNonLinkAnnotation(relevantPages, keptAnnotations, annotation, page);
}
}
}
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 relevantPages, Set keptAnnotations,
PDAnnotationLink annotation, PDPage p) throws IOException {
PDPageDestination destination = getDestinationFrom(annotation);
if (nonNull(destination)) {
PDPage destPage = relevantPages.lookup(destination.getPage());
if (nonNull(destPage)) {
// relevant page dest
PDAnnotationLink duplicate = (PDAnnotationLink) duplicate(annotation, p, relevantPages);
duplicate.getCOSObject().removeItem(COSName.A);
PDPageDestination newDestination = (PDPageDestination) PDDestination
.create(destination.getCOSObject().duplicate());
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, p, relevantPages));
}
}
private void processNonLinkAnnotation(LookupTable relevantPages, Set keptAnnotations,
PDAnnotation annotation, PDPage p) {
if (isNull(p) || relevantPages.hasLookupFor(p)) {
PDAnnotation duplicate = duplicate(annotation, p, 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, p, 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, PDPage p, LookupTable relevantPages) {
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 PDPageDestination getDestinationFrom(PDAnnotationLink link) {
try {
return link.resolveToPageDestination(document.getDocumentCatalog()).orElse(null);
} catch (Exception e) {
LOG.warn("Failed to get destination for annotation", e);
return null;
}
}
}