/*******************************************************************************
* Copyright (c) 2000, 2006 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.ui.examples.readmetool;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Hashtable;
import java.util.Vector;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IAdaptable;
/**
* This class is a simple parser implementing the IReadmeFileParser
* interface. It parses a Readme file into sections based on the
* existence of numbered section tags in the input. A line beginning
* with a number followed by a dot will be taken as a section indicator
* (for example, 1., 2., or 12.).
* As well, a line beginning with a subsection-style series of numbers
* will also be taken as a section indicator, and can be used to
* indicate subsections (for example, 1.1, or 1.1.12).
*/
public class DefaultSectionsParser implements IReadmeFileParser {
/**
* Returns the mark element that is the logical parent
* of the given mark number. Each dot in a mark number
* represents a parent-child separation. For example,
* the parent of 1.2 is 1, the parent of 1.4.1 is 1.4.
* Returns null if there is no appropriate parent.
*/
protected IAdaptable getParent(Hashtable<String, MarkElement> toc, String number) {
int lastDot = number.lastIndexOf('.');
if (lastDot < 0)
return null;
String parentNumber = number.substring(0, lastDot);
return toc.get(parentNumber);
}
/**
* Returns a string containing the contents of the given
* file. Returns an empty string if there were any errors
* reading the file.
*/
protected String getText(IFile file) {
try {
InputStream in = file.getContents();
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int read = in.read(buf);
while (read > 0) {
out.write(buf, 0, read);
read = in.read(buf);
}
return out.toString();
} catch (CoreException e) {
// do nothing
} catch (IOException e) {
// do nothing
}
return ""; //$NON-NLS-1$
}
/**
* Parses the input given by the argument.
*
* @param file the element containing the input text
* @return an element collection representing the parsed input
*/
@Override
public MarkElement[] parse(IFile file) {
Hashtable<String, MarkElement> markTable = new Hashtable<>(40);
Vector<MarkElement> topLevel = new Vector<>();
String s = getText(file);
int start = 0;
int end = -1;
int lineno = 0;
int lastlineno = 0;
MarkElement lastme = null;
int ix;
// parse content for headings
ix = s.indexOf('\n', start);
while (ix != -1) {
start = end + 1;
end = ix = s.indexOf('\n', start);
lineno++;
if (ix != -1) {
// skip blanks
while (s.charAt(start) == ' ' || s.charAt(start) == '\t') {
start++;
}
if (Character.isDigit(s.charAt(start))) {
if (lastme != null) {
lastme.setNumberOfLines(lineno - lastlineno - 1);
}
lastlineno = lineno;
String markName = parseHeading(s, start, end);
//get the parent mark, if any.
String markNumber = parseNumber(markName);
IAdaptable parent = getParent(markTable, markNumber);
if (parent == null)
parent = file;
MarkElement me = new MarkElement(parent, markName, start,
end - start);
lastme = me;
markTable.put(markNumber, me);
if (parent == file) {
topLevel.add(me);
}
}
}
}
if (lastme != null) {
// set the number of lines for the last section
lastme.setNumberOfLines(lineno - lastlineno - 1);
}
MarkElement[] results = new MarkElement[topLevel.size()];
topLevel.copyInto(results);
return results;
}
/**
* Creates a section name from the buffer and trims trailing
* space characters.
*
* @param buffer the string from which to create the section name
* @param start the start index
* @param end the end index
* @return a section name
*/
private String parseHeading(String buffer, int start, int end) {
while (Character.isWhitespace(buffer.charAt(end - 1)) && end > start) {
end--;
}
return buffer.substring(start, end);
}
/**
* Returns the number for this heading. A heading consists
* of a number (an arbitrary string of numbers and dots), followed by
* arbitrary text.
*/
protected String parseNumber(String heading) {
int start = 0;
int end = heading.length();
char c;
do {
c = heading.charAt(start++);
} while ((c == '.' || Character.isDigit(c)) && start < end);
//disregard trailing dots
while (heading.charAt(start - 1) == '.' && start > 0) {
start--;
}
return heading.substring(0, start);
}
}