/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.
*/
/* $Id$ */
package org.apache.fop.pdf;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Locale;
import org.apache.fop.accessibility.StructureTreeElement;
import org.apache.fop.pdf.StandardStructureAttributes.Table;
import org.apache.fop.util.LanguageTags;
/**
* Class representing a PDF Structure Element.
*/
public class PDFStructElem extends StructureHierarchyMember
implements StructureTreeElement, CompressedObject {
private StructureType structureType;
protected PDFStructElem parentElement;
/**
* Elements to be added to the kids array.
*/
protected List<PDFObject> kids;
private List<PDFDictionary> attributes;
/**
* Creates PDFStructElem with no entries.
*/
public PDFStructElem() {
}
/**
* Creates a new structure element.
*
* @param parent parent of this element
* @param structureType the structure type of this element
*/
public PDFStructElem(PDFObject parent, StructureType structureType) {
this(parent);
this.structureType = structureType;
put("S", structureType.getName());
setParent(parent);
}
private PDFStructElem(PDFObject parent) {
if (parent instanceof PDFStructElem) {
parentElement = (PDFStructElem) parent;
}
}
/**
* Returns the parent of this structure element.
*
* @return the parent, <code>null</code> if the parent is not a structure
* element (i.e., is the structure tree root)
*/
public PDFStructElem getParentStructElem() {
return parentElement;
}
/** {@inheritDoc} */
public void setParent(PDFObject parent) {
if (parent != null && parent.hasObjectNumber()) {
put("P", new PDFReference(parent));
}
}
/**
* Adds a kid to this structure element.
*
* @param kid element to be added
*/
@Override
public void addKid(PDFObject kid) {
if (kids == null) {
kids = new ArrayList<PDFObject>();
}
kids.add(kid);
}
/**
* Sets the given mcid as the kid of this structure element. This element
* will then add itself to its parent structure element if it has not
* already, and so will the parent, and so on.
*
* @param mcid mcid of the marked-content sequence corresponding to this
* structure element's kid
*/
public void setMCIDKid(int mcid) {
put("K", mcid);
}
/**
* Sets the page reference of this structure element.
*
* @param page value for the Pg entry
*/
public void setPage(PDFPage page) {
put("Pg", page);
}
/**
* Returns the structure type of this structure element.
*
* @return the value of the S entry
*/
public StructureType getStructureType() {
return structureType;
}
/**
* Sets the language of this structure element.
* @param language the language (as defined in the section about
* "Natural Language Specification")
*/
private void setLanguage(String language) {
put("Lang", language);
}
/**
* Sets the language of this structure element.
*
* @param language a value for the Lang entry
*/
public void setLanguage(Locale language) {
setLanguage(LanguageTags.toLanguageTag(language));
}
/**
* Returns the language of this structure element.
*
* @return the value of the Lang entry (<code>null</code> if no language was specified)
*/
public String getLanguage() {
return (String) get("Lang");
}
@Override
protected void writeDictionary(OutputStream out, StringBuilder textBuffer) throws IOException {
attachKids();
attachAttributes();
super.writeDictionary(out, textBuffer);
}
private void attachAttributes() {
if (attributes != null) {
if (attributes.size() == 1) {
put("A", attributes.get(0));
} else {
PDFArray array = new PDFArray(attributes);
put("A", array);
}
}
}
public void addKidInSpecificOrder(int position, PDFStructElem kid) {
if (kids == null) {
addKid(kid);
} else {
if ((kids.size() - 1) < position) {
kids.add(kid);
} else if (kids.get(position) == null) {
kids.set(position, kid);
} else {
if (!kids.contains(kid)) {
kids.add(position, kid);
}
}
}
}
/**
* Attaches all valid kids to the kids array.
*
* @return true iff 1+ kids were added to the kids array
*/
protected boolean attachKids() {
List<PDFObject> validKids = new ArrayList<PDFObject>();
if (kids != null) {
for (PDFObject kid : kids) {
if (kid instanceof Placeholder) {
if (((Placeholder) kid).attachKids()) {
validKids.add(kid);
}
} else {
validKids.add(kid);
}
}
}
boolean kidsAttached = !validKids.isEmpty();
if (kidsAttached) {
PDFArray array = new PDFArray();
for (PDFObject ob : validKids) {
array.add(ob);
}
put("K", array);
}
return kidsAttached;
}
public void setTableAttributeColSpan(int colSpan) {
setTableAttributeRowColumnSpan("ColSpan", colSpan);
}
public void setTableAttributeRowSpan(int rowSpan) {
setTableAttributeRowColumnSpan("RowSpan", rowSpan);
}
private void setTableAttributeRowColumnSpan(String typeSpan, int span) {
PDFDictionary attribute = new PDFDictionary();
attribute.put("O", Table.NAME);
attribute.put(typeSpan, span);
if (attributes == null) {
attributes = new ArrayList<PDFDictionary>(2);
}
attributes.add(attribute);
}
public List<PDFObject> getKids() {
return this.kids;
}
public int output(OutputStream stream) throws IOException {
if (getDocument().getProfile().getPDFUAMode().isEnabled()) {
if (entries.containsKey("Alt") && "".equals(get("Alt"))) {
put("Alt", "No alternate text specified");
} else if (kids != null) {
for (PDFObject kid : kids) {
if (kid instanceof PDFStructElem
&& !(kid instanceof Placeholder)
&& structureType.toString().equals("P")
&& isBSLE(((PDFStructElem) kid).getStructureType().toString())) {
structureType = StandardStructureTypes.Grouping.DIV;
put("S", StandardStructureTypes.Grouping.DIV.getName());
break;
}
}
}
}
return super.output(stream);
}
private boolean isBSLE(String type) {
String[] blseValues = {"Table", "L", "P"};
return Arrays.asList(blseValues).contains(type);
}
/**
* Class representing a placeholder for a PDF Structure Element.
*/
public static class Placeholder extends PDFStructElem {
@Override
public void outputInline(OutputStream out, StringBuilder textBuffer) throws IOException {
if (kids != null) {
assert kids.size() > 0;
for (int i = 0; i < kids.size(); i++) {
if (i > 0) {
textBuffer.append(' ');
}
Object obj = kids.get(i);
if (obj instanceof PDFStructElem) {
((PDFStructElem) obj).setParent(parentElement);
}
formatObject(obj, out, textBuffer);
}
}
}
public Placeholder(PDFObject parent) {
super(parent);
}
}
}