/*
* Copyright 2009 Andrew Shu
*
* This file is part of "reddit is fun".
*
* "reddit is fun" is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* "reddit is fun" 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with "reddit is fun". If not, see <http://www.gnu.org/licenses/>.
*/
package com.andrewshu.android.reddit.markdown;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Map;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import android.text.SpannableString;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.style.ForegroundColorSpan;
import android.util.Log;
import com.andrewshu.android.reddit.common.Constants;
import com.andrewshu.android.reddit.common.util.Util;
import dk.brics.automaton.AutomatonMatcher;
import dk.brics.automaton.RegExp;
import dk.brics.automaton.RunAutomaton;
/**
This class taken and adapted from MarkdownJ. See lib/MarkdownJ.txt for license.
Original MarkdownJ copyright notice follows:
Copyright (c) 2005, Martian Software
Authors: Pete Bevin, John Mutchek
http://www.martiansoftware.com/markdownj
All rights reserved.
*/
public class Markdown {
// private Random rnd = new Random();
// private static final MarkdownCharacterProtector CHAR_PROTECTOR = new MarkdownCharacterProtector();
static final String TAG = "Markdown";
static final RunAutomaton inlineLinkAutomaton = new RunAutomaton(new RegExp("(" + // Whole match = $1
"\\[([^\\]]*)\\]" + // Link text = $2
"\\(" +
"([^\\)\\\\]|(\\\\.))+" + // 3 cases: 1. simple URL. 2. escaped right-paren in URL. 3. escaped anything in URL.
"\\)" +
")", RegExp.NONE).toAutomaton());
// Use inlineLinkAutomaton to check for whole match, then use inlineLink to capture groups
static final Pattern inlineLink = Pattern.compile("(" + // Whole match = $1
"\\[(.*?)\\]" + // Link text = $2
"\\(" +
"[ \\t]*" +
"<?(.*?)>?" + // href = $3
"[ \\t]*" +
"(" +
"(['\"])" + // Quote character = $5
"(.*?)" + // Title = $6
"\\5" +
")?" +
"\\)" +
")", Pattern.DOTALL);
static final RunAutomaton autoLinkUrlAutomaton = new RunAutomaton(new RegExp("((https?|ftp):([^'\"> \t\r\n])+)", RegExp.NONE).toAutomaton());
// static final Pattern autoLinkEmail = Pattern.compile("<([-.\\w]+\\@[-a-z0-9]+(\\.[-a-z0-9]+)*\\.[a-z]+)>");
static final RunAutomaton subredditAutomaton = new RunAutomaton(new RegExp("/[rR]/[a-zA-Z0-9]+/?", RegExp.NONE).toAutomaton());
/**
* @param txt input
* @param urls out URLs
*/
public void getURLs(String txt, ArrayList<MarkdownURL> urls) {
if (txt == null) {
txt = "";
}
// Standardize line endings:
txt.replaceAll("\\r\\n", "\n"); // DOS to Unix
txt.replaceAll("\\r", "\n"); // Mac to Unix
txt.replaceAll("^[ \\t]+$", "");
// // Make sure $text ends with a couple of newlines:
// text.append("\n\n");
// text.detabify();
txt.replaceAll("^[ ]+$", "");
urls.clear();
TreeMap<Integer, Integer> startToEndOffsetMap = new TreeMap<Integer, Integer>();
// doAnchors originally called from runBlockGamut -> formParagraphs -> runSpanGamut
txt = doAnchorURLs(txt, urls, startToEndOffsetMap);
txt = doAutoLinkURLs(txt, urls, startToEndOffsetMap);
txt = doAutoLinkSubredditURLs(txt, urls, startToEndOffsetMap);
startToEndOffsetMap.clear();
Collections.sort(urls);
}
/**
* Perform the conversion from Markdown to HTML.
*
* @param txt - input in markdown format
* @return HTML block corresponding to txt passed in.
*/
@Deprecated
public SpannableStringBuilder markdown(String txt, SpannableStringBuilder ssb, ArrayList<MarkdownURL> urls) {
if (txt == null) {
txt = "";
}
// Standardize line endings:
txt.replaceAll("\\r\\n", "\n"); // DOS to Unix
txt.replaceAll("\\r", "\n"); // Mac to Unix
txt.replaceAll("^[ \\t]+$", "");
// // Make sure $text ends with a couple of newlines:
// text.append("\n\n");
// text.detabify();
txt.replaceAll("^[ ]+$", "");
ssb.append(txt);
// doAnchors originally called from runBlockGamut -> formParagraphs -> runSpanGamut
urls.clear();
doAnchors(ssb, urls);
doAutoLinks(ssb, urls);
// hashHTMLBlocks(text);
// stripLinkDefinitions(text);
// text = runBlockGamut(text);
// unEscapeSpecialChars(text);
// text.append("\n");
Collections.sort(urls);
return ssb;
}
private boolean isOverlapping(int start, int end, TreeMap<Integer, Integer> startToEndOffsetMap) {
for (Map.Entry<Integer, Integer> startEnd : startToEndOffsetMap.entrySet()) {
int entryStart = startEnd.getKey();
int entryEnd = startEnd.getValue();
if (entryStart <= start && entryEnd > start)
return true;
else if (entryStart >= start && entryEnd <= end)
return true;
else if (entryStart >= end)
return false;
}
return false;
}
private void saveStartAndEnd(int start, int end, TreeMap<Integer, Integer> startToEndOffsetMap) {
startToEndOffsetMap.put(start, end);
}
/**
* @param txt input text
* @param urls Out URLs from anchors
* @return updated text with anchors replaced
*/
private String doAnchorURLs(String txt, ArrayList<MarkdownURL> urls, TreeMap<Integer, Integer> startToEndOffsetMap) {
// Inline-style links: [link text](url "optional title")
AutomatonMatcher am = inlineLinkAutomaton.newMatcher(txt);
// The offset into the entire original string
int start = 0;
while (am.find()) {
// The offsets from start (offset into orig. string = start + anchorStart)
int anchorStart = am.start();
int anchorEnd = am.end();
Matcher m = inlineLink.matcher(am.group());
if (!m.find())
continue;
String linkText = m.group(2);
String url = m.group(3);
String title = m.group(6);
int linkTextLength = linkText.length();
if (Constants.LOGGING) Log.d(TAG, "pos="+(start + anchorStart) + " linkText="+linkText + " url="+url + " title="+ title);
// protect emphasis (* and _) within urls
// url = url.replaceAll("\\*", CHAR_PROTECTOR.encode("*"));
// url = url.replaceAll("_", CHAR_PROTECTOR.encode("_"));
if (!isOverlapping(start + anchorStart, start + anchorStart + linkTextLength, startToEndOffsetMap)) {
saveStartAndEnd(start + anchorStart, start + anchorStart + linkTextLength, startToEndOffsetMap);
urls.add(new MarkdownURL(start + anchorStart, Util.absolutePathToURL(url), linkText));
}
// StringBuffer result = new StringBuffer();
// TODO: Show title (if any) alongside url in popup menu
// if (title != null) {
// // protect emphasis (* and _) within urls
// title = title.replaceAll("\\*", CHAR_PROTECTOR.encode("*"));
// title = title.replaceAll("_", CHAR_PROTECTOR.encode("_"));
// title.replaceAll("\"", """);
// result.append(" title=\"");
// result.append(title);
// result.append("\"");
// }
txt = new StringBuilder(txt.substring(0, start + anchorStart))
.append(linkText)
.append(txt.substring(start + anchorEnd, txt.length()))
.toString();
// Skip past what we just replaced
am = inlineLinkAutomaton.newMatcher(txt, start + anchorStart + linkTextLength, txt.length());
start += anchorStart + linkTextLength;
}
return txt;
}
/**
* @param txt input text
* @param urls Out URLs from autolinks
* @return txt, unchanged
*/
private String doAutoLinkURLs(String txt, ArrayList<MarkdownURL> urls, TreeMap<Integer, Integer> startToEndOffsetMap) {
// Colorize URLs
AutomatonMatcher am = autoLinkUrlAutomaton.newMatcher(txt);
while (am.find()) {
String linkText = am.group();
String url = Util.absolutePathToURL(am.group());
if (Constants.LOGGING) Log.d(TAG, "pos="+am.start() + " linkText="+linkText + " url="+url);
if (!isOverlapping(am.start(), am.start() + linkText.length(), startToEndOffsetMap)) {
saveStartAndEnd(am.start(), am.start() + linkText.length(), startToEndOffsetMap);
urls.add(new MarkdownURL(am.start(), url, null));
}
}
// Don't autolink emails for now. Neither does reddit.com
// m = autoLinkEmail.matcher(ssb);
// int start = 0;
// while (m.find(start)) {
// String address = m.group(1);
// TextEditor ed = new TextEditor(address);
// unEscapeSpecialChars(ed);
// String addr = encodeEmail(ed.toString());
// String url = encodeEmail("mailto:" + ed.toString());
//
// urls.add(url);
// ssb.replace(m.start(), m.end(), addr);
// ForegroundColorSpan fcs = new ForegroundColorSpan(Constants.MARKDOWN_LINK_COLOR);
// ssb.setSpan(fcs, m.start(), m.end(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
// // Skip what we just replaced
// m = autoLinkEmail.matcher(ssb);
// start = m.start() + addr.length();
// }
return txt;
}
/**
* @param txt input text
* @param urls Out URLs from subreddit references
* @return txt, unchanged
*/
private String doAutoLinkSubredditURLs(String txt, ArrayList<MarkdownURL> urls, TreeMap<Integer, Integer> startToEndOffsetMap) {
AutomatonMatcher am = subredditAutomaton.newMatcher(txt);
while (am.find()) {
String subreddit = am.group();
if (Constants.LOGGING) Log.d(TAG, "pos="+am.start() + " subreddit="+subreddit);
if (!isOverlapping(am.start(), am.start() + subreddit.length(), startToEndOffsetMap)) {
saveStartAndEnd(am.start(), am.start() + subreddit.length(), startToEndOffsetMap);
urls.add(new MarkdownURL(am.start(), Util.absolutePathToURL(subreddit), subreddit));
}
}
return txt;
}
/** Adapted from MarkdownJ. Convert links, return URL */
private SpannableStringBuilder doAnchors(SpannableStringBuilder ssb, ArrayList<MarkdownURL> urls) {
// Inline-style links: [link text](url "optional title")
AutomatonMatcher am = inlineLinkAutomaton.newMatcher(ssb);
// The offset into the entire original string
int start = 0;
while (am.find()) {
// The offsets from start (offset into orig. string = start + anchorStart)
int anchorStart = am.start();
int anchorEnd = am.end();
Matcher m = inlineLink.matcher(am.group());
if (!m.find())
continue;
String linkText = m.group(2);
String url = m.group(3);
String title = m.group(6);
int linkTextLength = linkText.length();
if (Constants.LOGGING) Log.d(TAG, "pos="+am.start() + " linkText="+linkText + " url="+url + " title="+ title);
// protect emphasis (* and _) within urls
// url = url.replaceAll("\\*", CHAR_PROTECTOR.encode("*"));
// url = url.replaceAll("_", CHAR_PROTECTOR.encode("_"));
urls.add(new MarkdownURL(start + anchorStart, url, linkText));
// StringBuffer result = new StringBuffer();
// TODO: Show title (if any) alongside url in popup menu
// if (title != null) {
// // protect emphasis (* and _) within urls
// title = title.replaceAll("\\*", CHAR_PROTECTOR.encode("*"));
// title = title.replaceAll("_", CHAR_PROTECTOR.encode("_"));
// title.replaceAll("\"", """);
// result.append(" title=\"");
// result.append(title);
// result.append("\"");
// }
// Replace whole anchor thing with just linkText, colored different color
SpannableString ss = new SpannableString(linkText);
ForegroundColorSpan fcs = new ForegroundColorSpan(Constants.MARKDOWN_LINK_COLOR);
ss.setSpan(fcs, 0, linkTextLength, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
ssb = ssb.replace(start + anchorStart, start + anchorEnd, ss);
// Skip past what we just replaced
am = inlineLinkAutomaton.newMatcher(ssb, start + anchorStart + linkTextLength, ssb.length());
start += anchorStart + linkTextLength;
}
return ssb;
}
private SpannableStringBuilder doAutoLinks(SpannableStringBuilder ssb, ArrayList<MarkdownURL> urls) {
// Colorize URLs
AutomatonMatcher am = autoLinkUrlAutomaton.newMatcher(ssb);
while (am.find()) {
ForegroundColorSpan fcs = new ForegroundColorSpan(Constants.MARKDOWN_LINK_COLOR);
ssb.setSpan(fcs, am.start(), am.end(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
urls.add(new MarkdownURL(am.start(), am.group(), null));
}
// Don't autolink emails for now. Neither does reddit.com
// m = autoLinkEmail.matcher(ssb);
// int start = 0;
// while (m.find(start)) {
// String address = m.group(1);
// TextEditor ed = new TextEditor(address);
// unEscapeSpecialChars(ed);
// String addr = encodeEmail(ed.toString());
// String url = encodeEmail("mailto:" + ed.toString());
//
// urls.add(url);
// ssb.replace(m.start(), m.end(), addr);
// ForegroundColorSpan fcs = new ForegroundColorSpan(Constants.MARKDOWN_LINK_COLOR);
// ssb.setSpan(fcs, m.start(), m.end(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
// // Skip what we just replaced
// m = autoLinkEmail.matcher(ssb);
// start = m.start() + addr.length();
// }
return ssb;
}
// private String encodeEmail(String s) {
// StringBuffer sb = new StringBuffer();
// char[] email = s.toCharArray();
// for (char ch : email) {
// double r = rnd.nextDouble();
// if (r < 0.45) { // Decimal
// sb.append("&#");
// sb.append((int) ch);
// sb.append(';');
// } else if (r < 0.9) { // Hex
// sb.append("&#x");
// sb.append(Integer.toString((int) ch, 16));
// sb.append(';');
// } else {
// sb.append(ch);
// }
// }
// return sb.toString();
// }
//
// private void unEscapeSpecialChars(TextEditor ed) {
// for (String hash : CHAR_PROTECTOR.getAllEncodedTokens()) {
// String plaintext = CHAR_PROTECTOR.decode(hash);
// ed.replaceAllLiteral(hash, plaintext);
// }
// }
}