/*******************************************************************************
* Copyright (c) 2000, 2016 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
* QNX Software System
*******************************************************************************/
package org.eclipse.cdt.internal.autotools.ui;
import java.io.IOException;
import java.io.PushbackReader;
import java.io.Reader;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import org.eclipse.jface.text.TextPresentation;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
/**
* Reads the text contents from a reader of HTML contents and translates
* the tags or cut them out.
*/
public class HTML2TextReader extends SubstitutionTextReader {
private static final String LINE_DELIM= System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
private static final Map<String, String> fgEntityLookup;
private static final Set<String> fgTags;
static {
fgTags= new HashSet<>();
fgTags.add("b"); //$NON-NLS-1$
fgTags.add("br"); //$NON-NLS-1$
fgTags.add("h5"); //$NON-NLS-1$
fgTags.add("p"); //$NON-NLS-1$
fgTags.add("dl"); //$NON-NLS-1$
fgTags.add("dt"); //$NON-NLS-1$
fgTags.add("dd"); //$NON-NLS-1$
fgTags.add("li"); //$NON-NLS-1$
fgTags.add("ul"); //$NON-NLS-1$
fgEntityLookup= new HashMap<>(7);
fgEntityLookup.put("lt", "<"); //$NON-NLS-1$ //$NON-NLS-2$
fgEntityLookup.put("gt", ">"); //$NON-NLS-1$ //$NON-NLS-2$
fgEntityLookup.put("nbsp", " "); //$NON-NLS-1$ //$NON-NLS-2$
fgEntityLookup.put("amp", "&"); //$NON-NLS-1$ //$NON-NLS-2$
fgEntityLookup.put("circ", "^"); //$NON-NLS-1$ //$NON-NLS-2$
fgEntityLookup.put("tilde", "~"); //$NON-NLS-2$ //$NON-NLS-1$
fgEntityLookup.put("quot", "\""); //$NON-NLS-1$ //$NON-NLS-2$
}
private int fCounter= 0;
private TextPresentation fTextPresentation;
private int fBold= 0;
private int fStartOffset= -1;
private boolean fInParagraph= false;
/**
* Transforms the html text from the reader to formatted text.
* @param presentation If not <code>null</code>, formattings will be applied to
* the presentation.
*/
public HTML2TextReader(Reader reader, TextPresentation presentation) {
super(new PushbackReader(reader));
fTextPresentation= presentation;
}
@Override
public int read() throws IOException {
int c= super.read();
if (c != -1)
++ fCounter;
return c;
}
protected void startBold() {
if (fBold == 0)
fStartOffset= fCounter;
++ fBold;
}
protected void stopBold() {
-- fBold;
if (fBold == 0) {
if (fTextPresentation != null) {
fTextPresentation.addStyleRange(new StyleRange(fStartOffset, fCounter - fStartOffset, null, null, SWT.BOLD));
}
fStartOffset= -1;
}
}
@Override
protected String computeSubstitution(int c) throws IOException {
if (c == '<')
return processHTMLTag();
else if (c == '&')
return processEntity();
return null;
}
private String html2Text(String html) {
String tag= html;
if ('/' == tag.charAt(0))
tag= tag.substring(1);
if (!fgTags.contains(tag))
return ""; //$NON-NLS-1$
if ("b".equals(html)) { //$NON-NLS-1$
startBold();
return ""; //$NON-NLS-1$
}
if ("h5".equals(html) || "dt".equals(html)) { //$NON-NLS-1$ //$NON-NLS-2$
startBold();
return ""; //$NON-NLS-1$
}
if ("dl".equals(html)) //$NON-NLS-1$
return LINE_DELIM;
if ("dd".equals(html)) //$NON-NLS-1$
return "\t"; //$NON-NLS-1$
if ("li".equals(html)) //$NON-NLS-1$
return LINE_DELIM + "\t" + "-"; //$NON-NLS-1$ //$NON-NLS-2$
if ("/b".equals(html)) { //$NON-NLS-1$
stopBold();
return ""; //$NON-NLS-1$
}
if ("p".equals(html)) { //$NON-NLS-1$
fInParagraph= true;
return LINE_DELIM;
}
if ("br".equals(html)) //$NON-NLS-1$
return LINE_DELIM;
if ("/p".equals(html)) { //$NON-NLS-1$
boolean inParagraph= fInParagraph;
fInParagraph= false;
return inParagraph ? "" : LINE_DELIM; //$NON-NLS-1$
}
if ("/h5".equals(html) || "/dt".equals(html)) { //$NON-NLS-1$ //$NON-NLS-2$
stopBold();
return LINE_DELIM;
}
if ("/dd".equals(html)) //$NON-NLS-1$
return LINE_DELIM;
return ""; //$NON-NLS-1$
}
/*
* A '<' has been read. Process a html tag
*/
private String processHTMLTag() throws IOException {
StringBuilder buf= new StringBuilder();
int ch;
do {
ch= nextChar();
while (ch != -1 && ch != '>') {
buf.append(Character.toLowerCase((char) ch));
ch= nextChar();
if (ch == '"'){
buf.append(Character.toLowerCase((char) ch));
ch= nextChar();
while (ch != -1 && ch != '"'){
buf.append(Character.toLowerCase((char) ch));
ch= nextChar();
}
}
if (ch == '<'){
unread(ch);
return '<' + buf.toString();
}
}
if (ch == -1)
return null;
int tagLen= buf.length();
// needs special treatment for comments
if ((tagLen >= 3 && "!--".equals(buf.substring(0, 3))) //$NON-NLS-1$
&& !(tagLen >= 5 && "--!".equals(buf.substring(tagLen - 3)))) { //$NON-NLS-1$
// unfinished comment
buf.append(ch);
} else {
break;
}
} while (true);
return html2Text(buf.toString());
}
private void unread(int ch) throws IOException {
((PushbackReader) getReader()).unread(ch);
}
protected String entity2Text(String symbol) {
if (symbol.length() > 1 && symbol.charAt(0) == '#') {
int ch;
try {
if (symbol.charAt(1) == 'x') {
ch= Integer.parseInt(symbol.substring(2), 16);
} else {
ch= Integer.parseInt(symbol.substring(1), 10);
}
return "" + (char)ch; //$NON-NLS-1$
} catch (NumberFormatException e) {
}
} else {
String str= fgEntityLookup.get(symbol);
if (str != null) {
return str;
}
}
return "&" + symbol; // not found //$NON-NLS-1$
}
/*
* A '&' has been read. Process a entity
*/
private String processEntity() throws IOException {
StringBuilder buf= new StringBuilder();
int ch= nextChar();
while (Character.isLetterOrDigit((char)ch) || ch == '#') {
buf.append((char) ch);
ch= nextChar();
}
if (ch == ';')
return entity2Text(buf.toString());
buf.insert(0, '&');
if (ch != -1)
buf.append((char) ch);
return buf.toString();
}
}