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+package de.danoeh.antennapod.ui.cleaner;
+
+import android.text.TextUtils;
+
+import org.apache.commons.lang3.StringUtils;
+import org.jsoup.Jsoup;
+import org.jsoup.internal.StringUtil;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.jsoup.nodes.Node;
+import org.jsoup.nodes.TextNode;
+import org.jsoup.select.NodeTraversor;
+import org.jsoup.select.NodeVisitor;
+
+import java.util.regex.Pattern;
+
+/**
+ * This class is based on <code>HtmlToPlainText</code> from jsoup's examples package.
+ *
+ * HTML to plain-text. This example program demonstrates the use of jsoup to convert HTML input to lightly-formatted
+ * plain-text. That is divergent from the general goal of jsoup's .text() methods, which is to get clean data from a
+ * scrape.
+ * <p>
+ * Note that this is a fairly simplistic formatter -- for real world use you'll want to embrace and extend.
+ * </p>
+ * <p>
+ * To invoke from the command line, assuming you've downloaded the jsoup jar to your current directory:</p>
+ * <p><code>java -cp jsoup.jar org.jsoup.examples.HtmlToPlainText url [selector]</code></p>
+ * where <i>url</i> is the URL to fetch, and <i>selector</i> is an optional CSS selector.
+ *
+ * @author Jonathan Hedley, jonathan@hedley.net
+ * @author AntennaPod open source community
+ */
+public class HtmlToPlainText {
+
+ /**
+ * Use this method to strip off HTML encoding from given text.
+ * Replaces bullet points with *, ignores colors/bold/...
+ *
+ * @param str String with any encoding
+ * @return Human readable text with minimal HTML formatting
+ */
+ public static String getPlainText(String str) {
+ if (!TextUtils.isEmpty(str) && isHtml(str)) {
+ HtmlToPlainText formatter = new HtmlToPlainText();
+ Document feedDescription = Jsoup.parse(str);
+ str = StringUtils.trim(formatter.getPlainText(feedDescription));
+ } else if (TextUtils.isEmpty(str)) {
+ str = "";
+ }
+
+ return str;
+ }
+
+ /**
+ * Use this method to determine if a given text has any HTML tag
+ *
+ * @param str String to be tested for presence of HTML content
+ * @return <b>True</b> if text contains any HTML tags<br /><b>False</b> is no HTML tag is found
+ */
+ private static boolean isHtml(String str) {
+ final String htmlTagPattern = "<(\"[^\"]*\"|'[^']*'|[^'\">])*>";
+ return Pattern.compile(htmlTagPattern).matcher(str).find();
+ }
+
+ /**
+ * Format an Element to plain-text
+ * @param element the root element to format
+ * @return formatted text
+ */
+ public String getPlainText(Element element) {
+ FormattingVisitor formatter = new FormattingVisitor();
+ // walk the DOM, and call .head() and .tail() for each node
+ NodeTraversor.traverse(formatter, element);
+
+ return formatter.toString();
+ }
+
+ // the formatting rules, implemented in a breadth-first DOM traverse
+ private static class FormattingVisitor implements NodeVisitor {
+
+ private final StringBuilder accum = new StringBuilder(); // holds the accumulated text
+
+ // hit when the node is first seen
+ public void head(Node node, int depth) {
+ String name = node.nodeName();
+ if (node instanceof TextNode) {
+ append(((TextNode) node).text()); // TextNodes carry all user-readable text in the DOM.
+ } else if (name.equals("li")) {
+ append("\n * ");
+ } else if (name.equals("dt")) {
+ append(" ");
+ } else if (StringUtil.in(name, "p", "h1", "h2", "h3", "h4", "h5", "tr")) {
+ append("\n");
+ }
+ }
+
+ // hit when all of the node's children (if any) have been visited
+ public void tail(Node node, int depth) {
+ String name = node.nodeName();
+ if (StringUtil.in(name, "br", "dd", "dt", "p", "h1", "h2", "h3", "h4", "h5")) {
+ append("\n");
+ } else if (name.equals("a")) {
+ append(String.format(" <%s>", node.absUrl("href")));
+ }
+ }
+
+ // appends text to the string builder with a simple word wrap method
+ private void append(String text) {
+ if (text.equals(" ") &&
+ (accum.length() == 0 || StringUtil.in(accum.substring(accum.length() - 1), " ", "\n"))) {
+ return; // don't accumulate long runs of empty spaces
+ }
+
+ accum.append(text);
+ }
+
+ @Override
+ public String toString() {
+ return accum.toString();
+ }
+ }
+}