org.apache.fop.pdf.PDFPageLabels Maven / Gradle / Ivy
/*
* 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: PDFPageLabels.java 1421233 2012-12-13 11:30:57Z phancock $ */
package org.apache.fop.pdf;
import java.util.regex.Pattern;
/**
* Class representing a PDF /PageLabels dictionary.
*/
public class PDFPageLabels extends PDFNumberTreeNode {
private static final int DECIMAL = 1; // '0*1'
private static final int LOWER_ALPHA = 2; // 'a'
private static final int UPPER_ALPHA = 3; // 'A'
private static final int LOWER_ROMAN = 4; // 'i'
private static final int UPPER_ROMAN = 5; // 'I'
private static final int PREFIX = 6;
private static final PDFName S_DECIMAL = new PDFName("D");
private static final PDFName S_UPPER_ROMAN = new PDFName("R");
private static final PDFName S_LOWER_ROMAN = new PDFName("r");
private static final PDFName S_UPPER_ALPHA = new PDFName("A");
private static final PDFName S_LOWER_ALPHA = new PDFName("a");
private static final Pattern MATCH_DECIMAL = Pattern.compile("\\d+");
private static final Pattern MATCH_ROMAN = Pattern.compile(
"^M{0,3}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$", Pattern.CASE_INSENSITIVE);
private static final Pattern MATCH_LETTER = Pattern.compile("^[a-zA-Z]$");
private int lastPageLabelType;
private int lastPageNumber;
private String lastZeroPaddingPrefix = "";
/**
* Create the /PageLabels dictionary
*/
public PDFPageLabels() {
super();
}
/**
* Adds a new entry, if necessary, to the /PageLabels dictionary.
* @param index the page index (0 for page 1)
* @param pageLabel the page number as a string
*/
public void addPageLabel(int index, String pageLabel) {
boolean addNewPageLabel = false;
String padding = "00000000";
int currentPageNumber = 0;
int currentPageLabelType = 0;
String currentZeroPaddingPrefix = "";
if (MATCH_DECIMAL.matcher(pageLabel).matches()) {
// since an integer is the most common case we start with that
currentPageLabelType = DECIMAL;
currentPageNumber = Integer.parseInt(pageLabel);
int zeroPadding = 0;
if (pageLabel.charAt(zeroPadding) == '0') {
do {
zeroPadding++;
} while (pageLabel.charAt(zeroPadding) == '0');
currentZeroPaddingPrefix = padding.substring(0, zeroPadding);
if (currentZeroPaddingPrefix.length() != lastZeroPaddingPrefix.length()) {
addNewPageLabel = true;
}
} else {
if (lastZeroPaddingPrefix.length() != 0) {
addNewPageLabel = true;
}
}
} else if (MATCH_ROMAN.matcher(pageLabel).matches()) {
if (pageLabel.toLowerCase().equals(pageLabel)) {
currentPageLabelType = LOWER_ROMAN;
} else {
currentPageLabelType = UPPER_ROMAN;
}
currentPageNumber = romanToArabic(pageLabel);
} else if (MATCH_LETTER.matcher(pageLabel).matches()) {
char c = pageLabel.charAt(0);
if (c > 'Z') {
currentPageLabelType = LOWER_ALPHA;
} else {
currentPageLabelType = UPPER_ALPHA;
}
currentPageNumber = alphabeticToArabic(c);
} else {
// alphabetic numbering in XSL_FO and labelling in PDF are different after AA (AB versus BB)
// we will use the /P (prefix) label in that case
currentPageLabelType = PREFIX;
addNewPageLabel = true;
}
if (lastPageLabelType != currentPageLabelType) {
addNewPageLabel = true;
}
if (lastPageNumber != currentPageNumber - 1) {
addNewPageLabel = true;
}
if (addNewPageLabel) {
PDFNumsArray nums = getNums();
PDFDictionary dict = new PDFDictionary(nums);
PDFName pdfName = null;
switch (currentPageLabelType) {
case PREFIX:
dict.put("P", pageLabel);
break;
default:
switch (currentPageLabelType) {
case DECIMAL:
pdfName = S_DECIMAL;
if (currentZeroPaddingPrefix.length() != 0) {
dict.put("P", currentZeroPaddingPrefix);
}
break;
case LOWER_ROMAN:
pdfName = S_LOWER_ROMAN;
break;
case UPPER_ROMAN:
pdfName = S_UPPER_ROMAN;
break;
case LOWER_ALPHA:
pdfName = S_LOWER_ALPHA;
break;
case UPPER_ALPHA:
pdfName = S_UPPER_ALPHA;
break;
default:
}
dict.put("S", pdfName);
if (currentPageNumber != 1) {
dict.put("St", currentPageNumber);
}
}
nums.put(index, dict);
}
lastPageLabelType = currentPageLabelType;
lastPageNumber = currentPageNumber;
lastZeroPaddingPrefix = currentZeroPaddingPrefix;
}
private int romanToArabic(String roman) {
int arabic = 0;
int previousValue = 0;
int newValue = 0;
String upperRoman = roman.toUpperCase();
for (int i = 0; i < upperRoman.length(); i++) {
char romanDigit = upperRoman.charAt(i);
switch (romanDigit) {
case 'I':
newValue = 1;
break;
case 'V':
newValue = 5;
break;
case 'X':
newValue = 10;
break;
case 'L':
newValue = 50;
break;
case 'C':
newValue = 100;
break;
case 'D':
newValue = 500;
break;
case 'M':
newValue = 1000;
break;
default:
}
if (previousValue < newValue) {
arabic -= previousValue;
} else {
arabic += previousValue;
}
previousValue = newValue;
}
arabic += previousValue;
return arabic;
}
private int alphabeticToArabic(char c) {
int arabic = Character.toLowerCase(c) - 'a' + 1;
return arabic;
}
}