git-svn-id: svn://svn.code.sf.net/p/writer2latex/code/trunk@26 f0f2a975-2e09-46c8-9428-3b39399b9f3c

source/java/org/openoffice/da/comp/writer4latex/DeTeXtive.java

@@ -0,0 +1,221 @@
+/************************************************************************
+ *
+ *  DeTeXtive.java
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License version 2.1, as published by the Free Software Foundation.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ *  MA  02111-1307  USA
+ *
+ *  Copyright: 2002-2009 by Henrik Just
+ *
+ *  All Rights Reserved.
+ * 
+ *  Version 1.2 (2009-06-19)
+ *
+ */ 
+ 
+package org.openoffice.da.comp.writer4latex;
+
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.IOException;
+import java.util.HashSet;
+
+import org.openoffice.da.comp.w2lcommon.tex.tokenizer.Mouth;
+import org.openoffice.da.comp.w2lcommon.tex.tokenizer.Token;
+import org.openoffice.da.comp.w2lcommon.tex.tokenizer.TokenType;
+
+/** This class analyzes a stream and detects if it is a TeX stream.
+ *  Currently it is able to identify LaTeX and XeLaTeX (ConTeXt and plain TeX may be
+ *  added later).
+ */
+public class DeTeXtive {
+	private Mouth mouth;
+	private Token token;
+	
+	private HashSet<String> packages;
+	
+	/** Construct a new DeTeXtive
+	 */
+	public DeTeXtive() {
+	}
+	
+	/** Detect the format of a given stream
+	 * 
+	 * @param is the input stream
+	 * @return a string representing the detected format; null if the format is unknown.
+	 * Currently the values "LaTeX", "XeLaTeX" are supported.
+	 * @throws IOException if we fail to read the stream 
+	 */
+	public String deTeXt(InputStream is) throws IOException {
+		// It makes no harm to assume that the stream uses ISO Latin1 - we only consider ASCII characters
+		mouth = new Mouth(new InputStreamReader(is,"ISO8859_1"));
+		token = mouth.getTokenObject();
+		
+		packages = new HashSet<String>();
+		
+		mouth.getToken();
+
+		if (parseHeader() && parsePreamble()) {
+			if (packages.contains("xunicode")) {
+				return "XeLaTeX";
+			}
+			else {
+				return "LaTeX";
+			}
+		}
+
+		// Unknown format
+		return null;
+		
+	}
+	
+	// The parser!
+	
+	// Parse a LaTeX header such as \documentclass[a4paper]{article}
+	// Return true in case of success
+	private boolean parseHeader() throws IOException {
+		skipBlanks();
+		if (token.isCS("documentclass") || token.isCS("documentstyle")) {
+			// The first non-blank token is \documentclass or \documentstyle => could be a LaTeX document
+			System.out.println("** Found "+token.toString());
+			mouth.getToken();
+			skipSpaces();
+			// Skip options, if any
+			if (token.is('[',TokenType.OTHER)) {
+				skipOptional();
+				skipSpaces();
+			}
+			if (token.getType()==TokenType.BEGIN_GROUP) {
+				// Get class name
+				String sClassName = parseArgumentAsString();
+				System.out.println("** Found the class name "+sClassName);
+				// Accept any class name of one or more characters
+				if (sClassName.length()>0) { return true; }
+			}
+		}
+		System.out.println("** Doesn't look like LaTeX; failed to get class name");
+		return false;
+	}
+	
+	// Parse a LaTeX preamble 
+	// Return true in case of success (that is, \begin{document} was found)
+	private boolean parsePreamble() throws IOException {
+		while (token.getType()!=TokenType.ENDINPUT) {
+			if (token.isCS("usepackage")) {
+				// We collect the names of all used packages, but discard their options
+				// (Recall that this is only relevant for LaTeX 2e)
+				mouth.getToken();
+				skipSpaces();
+				if (token.is('[',TokenType.OTHER)) {
+					skipOptional();
+					skipSpaces();
+				}
+				String sName = parseArgumentAsString();
+				System.out.println("** Found package "+sName);
+				packages.add(sName);
+			}
+			else if (token.getType()==TokenType.BEGIN_GROUP) {
+				// We ignore anything inside a group
+				skipGroup();
+			}
+			else if (token.isCS("begin")) {
+				// This would usually indicate the end of the preamble
+				mouth.getToken();
+				skipSpaces();
+				if ("document".equals(parseArgumentAsString())) {
+					System.out.println("Found \\begin{document}");
+					return true;
+				}
+			}
+			else {
+				// Any other content in the preamble is simply ignored
+				mouth.getToken();
+			}
+		}
+		System.out.println("** Doesn't look like LaTeX; failed to find \\begin{document}");
+		return false;
+	}
+
+	private void skipBlanks() throws IOException {
+		while (token.getType()==TokenType.SPACE || token.isCS("par")) {
+			mouth.getToken();
+		}
+	}
+	
+	private void skipSpaces() throws IOException {
+		// Actually, we will never get two space tokens in a row
+		while (token.getType()==TokenType.SPACE) {
+			mouth.getToken();
+		}
+	}
+	
+	private void skipOptional() throws IOException {
+		assert token.is('[', TokenType.OTHER);
+		
+		mouth.getToken(); // skip the [
+		while (!token.is(']',TokenType.OTHER) && token.getType()!=TokenType.ENDINPUT) {
+			if (token.getType()==TokenType.BEGIN_GROUP) {
+				skipGroup();
+			}
+			else {
+				mouth.getToken(); // skip this token
+			}
+		}
+		mouth.getToken(); // skip the ]
+	}
+	
+	private void skipGroup() throws IOException {
+		assert token.getType()==TokenType.BEGIN_GROUP;
+
+		mouth.getToken(); // skip the {
+		while (token.getType()!=TokenType.END_GROUP && token.getType()!=TokenType.ENDINPUT) {
+			if (token.getType()==TokenType.BEGIN_GROUP) {
+				skipGroup();
+			}
+			else {
+				mouth.getToken(); // skip this token
+			}
+		}
+		mouth.getToken(); // skip the }
+	}
+	
+	private String parseArgumentAsString() throws IOException {
+		if (token.getType()==TokenType.BEGIN_GROUP) {
+			// Argument is contained in a group
+			mouth.getToken(); // skip the {
+			StringBuilder sb = new StringBuilder();
+			while (token.getType()!=TokenType.END_GROUP && token.getType()!=TokenType.ENDINPUT) {
+				if (token.getType()!=TokenType.COMMAND_SEQUENCE) { 
+					// should not include cs, ignore if it happens
+					sb.append(token.getChar());
+				}
+				mouth.getToken();
+			}
+			mouth.getToken(); // skip the }
+			return sb.toString();
+		}
+		else {
+			// Argument is a single token
+			String s = "";
+			if (token.getType()!=TokenType.COMMAND_SEQUENCE) { 
+				// should not include cs, ignore if it happens
+				s = token.getString();
+			}
+			mouth.getToken();
+			return s;
+		}
+	}
+
+
+}