| /* |
| * 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; |
| |
| // Java |
| import java.util.Collections; |
| import java.util.Set; |
| |
| import org.apache.fop.fonts.CodePointMapping; |
| import org.apache.fop.fonts.SingleByteEncoding; |
| |
| /** |
| * Class representing an /Encoding object. |
| * |
| * A small object expressing the base encoding name and |
| * the differences from the base encoding. |
| * |
| * The three base encodings are given by their name. |
| * |
| * Encodings are specified in section 5.5.5 of the PDF 1.4 spec. |
| */ |
| public class PDFEncoding extends PDFDictionary { |
| |
| /** the name for the standard encoding scheme */ |
| public static final String STANDARD_ENCODING = "StandardEncoding"; |
| /** the name for the Mac Roman encoding scheme */ |
| public static final String MAC_ROMAN_ENCODING = "MacRomanEncoding"; |
| /** the name for the Mac Export encoding scheme */ |
| public static final String MAC_EXPERT_ENCODING = "MacExpertEncoding"; |
| /** the name for the WinAnsi encoding scheme */ |
| public static final String WIN_ANSI_ENCODING = "WinAnsiEncoding"; |
| /** the name for the PDF document encoding scheme */ |
| public static final String PDF_DOC_ENCODING = "PDFDocEncoding"; |
| |
| /** the set of predefined encodings that can be assumed present in a PDF viewer */ |
| private static final Set PREDEFINED_ENCODINGS; |
| |
| static { |
| Set encodings = new java.util.HashSet(); |
| encodings.add(STANDARD_ENCODING); |
| encodings.add(MAC_ROMAN_ENCODING); |
| encodings.add(MAC_EXPERT_ENCODING); |
| encodings.add(WIN_ANSI_ENCODING); |
| encodings.add(PDF_DOC_ENCODING); |
| PREDEFINED_ENCODINGS = Collections.unmodifiableSet(encodings); |
| } |
| |
| /** |
| * Create a new /Encoding object. |
| * |
| * @param basename the name of the character encoding schema |
| */ |
| public PDFEncoding(String basename) { |
| super(); |
| |
| put("Type", new PDFName("Encoding")); |
| if (basename != null) { |
| put("BaseEncoding", new PDFName(basename)); |
| } |
| } |
| |
| /** |
| * Creates a PDFEncoding instance from a CodePointMapping instance. |
| * @param encoding the code point mapping (encoding) |
| * @param fontName ... |
| * @return the PDF Encoding dictionary (or a String with the predefined encoding) |
| */ |
| static Object createPDFEncoding(SingleByteEncoding encoding, String fontName) { |
| //If encoding type is null, return null which causes /Encoding to be omitted. |
| if (encoding == null) { |
| return null; |
| } |
| String encodingName = null; |
| SingleByteEncoding baseEncoding; |
| if (fontName.indexOf("Symbol") >= 0) { |
| baseEncoding = CodePointMapping.getMapping(CodePointMapping.SYMBOL_ENCODING); |
| encodingName = baseEncoding.getName(); |
| } else { |
| baseEncoding = CodePointMapping.getMapping(CodePointMapping.STANDARD_ENCODING); |
| } |
| PDFEncoding pdfEncoding = new PDFEncoding(encodingName); |
| PDFEncoding.DifferencesBuilder builder = pdfEncoding.createDifferencesBuilder(); |
| PDFArray differences = builder.buildDifferencesArray(baseEncoding, encoding); |
| // TODO This method should not be returning an Object with two different outcomes |
| // resulting in subsequent `if (X instanceof Y)` statements. |
| if (differences.length() > 0) { |
| pdfEncoding.setDifferences(differences); |
| return pdfEncoding; |
| } else { |
| return encodingName; |
| } |
| } |
| |
| /** |
| * Indicates whether a given encoding is one of the predefined encodings. |
| * @param name the encoding name (ex. "StandardEncoding") |
| * @return true if it is a predefined encoding |
| */ |
| public static boolean isPredefinedEncoding(String name) { |
| return PREDEFINED_ENCODINGS.contains(name); |
| } |
| |
| /** |
| * Indicates whether the given encoding type is that of standard encoding |
| * @param name The encoding name |
| * @return Returns true if it is of type standard encoding |
| */ |
| static boolean hasStandardEncoding(String encodingName) { |
| return encodingName.equals(STANDARD_ENCODING); |
| } |
| |
| /** |
| * Creates and returns a new DifferencesBuilder instance for constructing the Differences |
| * array. |
| * @return the DifferencesBuilder |
| */ |
| public DifferencesBuilder createDifferencesBuilder() { |
| return new DifferencesBuilder(); |
| } |
| |
| /** |
| * Sets the Differences value. |
| * @param differences the differences. |
| */ |
| public void setDifferences(PDFArray differences) { |
| put("Differences", differences); |
| } |
| |
| /** |
| * Builder class for constructing the Differences array. |
| */ |
| public class DifferencesBuilder { |
| |
| private int currentCode = -1; |
| |
| /** |
| * Creates an array containing the differences between two single-byte. |
| * font encodings. |
| * @param encodingA The first single-byte encoding |
| * @param encodingB The second single-byte encoding |
| * @return The PDFArray of differences between encodings |
| */ |
| public PDFArray buildDifferencesArray(SingleByteEncoding encodingA, |
| SingleByteEncoding encodingB) { |
| PDFArray differences = new PDFArray(); |
| int start = -1; |
| String[] baseNames = encodingA.getCharNameMap(); |
| String[] charNameMap = encodingB.getCharNameMap(); |
| for (int i = 0, ci = charNameMap.length; i < ci; i++) { |
| String basec = baseNames[i]; |
| String c = charNameMap[i]; |
| if (!basec.equals(c)) { |
| if (start != i) { |
| addDifference(i, differences); |
| start = i; |
| } |
| addName(c, differences); |
| start++; |
| } |
| } |
| return differences; |
| } |
| |
| /** |
| * Start a new difference. |
| * @param code the starting code index inside the encoding |
| * @return this builder instance |
| */ |
| private void addDifference(int code, PDFArray differences) { |
| this.currentCode = code; |
| differences.add(Integer.valueOf(code)); |
| } |
| |
| /** |
| * Adds a character name to the current difference. |
| * @param name the character name |
| * @return this builder instance |
| */ |
| private void addName(String name, PDFArray differences) { |
| if (this.currentCode < 0) { |
| throw new IllegalStateException("addDifference(int) must be called first"); |
| } |
| differences.add(new PDFName(name)); |
| } |
| } |
| |
| /* |
| * example (p. 214) |
| * 25 0 obj |
| * << |
| * /Type /Encoding |
| * /Differences [39 /quotesingle 96 /grave 128 |
| * /Adieresis /Aring /Ccedilla /Eacute /Ntilde |
| * /Odieresis /Udieresis /aacute /agrave] |
| * >> |
| * endobj |
| */ |
| } |