RegexUtils.java

/*
 * Overchan Android (Meta Imageboard Client)
 * Copyright (C) 2014-2016  miku-nyan <https://github.com/miku-nyan>
 *     
 * This program 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.
 * 
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package nya.miku.wishmaster.api.util;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegexUtils {
    private static final Pattern HTML_TAGS = Pattern.compile("<[^>]*>");
    private static final Pattern HTML_SPAN_TAGS = Pattern.compile("</?span[^>]*?>");
    private static final Pattern SPACES = Pattern.compile("\\s+");
    private static final Pattern LINKIFY =
            Pattern.compile("((?:^|\\s|<br ?/?>)(?:<p>)?)(https?://(?:[^<>\\s]*(?:<wbr ?/?>)?)*)", Pattern.CASE_INSENSITIVE);
    private static final Pattern WBR = Pattern.compile("<wbr/?>", Pattern.CASE_INSENSITIVE);
    
    public static String replaceAll(CharSequence source, Pattern pattern, String replacement) {
        Matcher matcher = pattern.matcher(source);
        if (!matcher.find()) return source.toString();
        
        StringBuffer buffer = new StringBuffer(source.length());
        do {
            matcher.appendReplacement(buffer, replacement);
        } while (matcher.find());
        return matcher.appendTail(buffer).toString();
    }
    
    public static String removeHtmlTags(CharSequence source) {
        return replaceAll(source, HTML_TAGS, "");
    }
    
    public static String removeHtmlSpanTags(CharSequence source) {
        return replaceAll(source, HTML_SPAN_TAGS, "");
    }
    
    public static String trimToSpace(CharSequence source) {
        return replaceAll(source, SPACES, " ");
    }
    
    public static String linkify(CharSequence source) {
        Matcher matcher = LINKIFY.matcher(source);
        if (!matcher.find()) return source.toString();
        
        StringBuffer buffer = new StringBuffer(source.length());
        do {
            matcher.appendReplacement(buffer, "$1<a href=\"" + replaceAll(matcher.group(2), WBR, "") + "\">$2</a>");
        } while (matcher.find());
        return matcher.appendTail(buffer).toString();
    }
    
}