platform/util/src/com/intellij/util/text/MarkdownUtil.java - platform/tools/idea - Git at Google

 package com.intellij.util.text;

 import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.text.StringUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

 import java.util.ArrayList;
 import java.util.List;

 /**
  * @author Sergey Simonchik
  */
 public class MarkdownUtil {

   private MarkdownUtil() {}

   /**
    * Replaces headers in markdown with HTML.
    * Unfortunately, library used for markdown processing
    * <a href="https://code.google.com/p/markdownj">markdownj</a>
    * doesn't support that.
    */
   public static void replaceHeaders(@NotNull List<String> lines) {
     for (int i = 0; i < lines.size(); i++) {
       String line = lines.get(i);
       int ind = 0;
       while (ind < line.length() && line.charAt(ind) == '#') {
         ind++;
       }
       if (ind < line.length() && line.charAt(ind) == ' ') {
         if (0 < ind && ind <= 9) {
           int endInd = line.length() - 1;
           while (endInd >= 0 && line.charAt(endInd) == '#') {
             endInd--;
           }
           line = line.substring(ind + 1, endInd + 1);
           line = "<h" + ind + ">" + line + "</h" + ind + ">";
           lines.set(i, line);
         }
       }
     }
   }

   /**
    * Removes images in the markdown text.
    * @param lines List of String in markdown format
    */
   public static void removeImages(@NotNull List<String> lines) {
     for (int i = 0; i < lines.size(); i++) {
       String newText = removeAllImages(lines.get(i));
       lines.set(i, newText);
     }
   }

   @NotNull
   private static String removeAllImages(@NotNull String text) {
     int n = text.length();
     List<TextRange> intervals = null;
     int i = 0;
     while (i < n) {
       int imageEndIndex = findImageEndIndexInclusive(text, i);
       if (imageEndIndex != -1) {
         TextRange linkRange = findEnclosingLink(text, i, imageEndIndex);
         if (intervals == null) {
           intervals = new ArrayList<TextRange>(1);
         }
         final TextRange range;
         if (linkRange != null) {
           range = linkRange;
         }
         else {
           range = new TextRange(i, imageEndIndex);
         }
         intervals.add(range);
         i = range.getEndOffset();
       }
       i++;
     }
     if (intervals == null) {
       return text;
     }
     StringBuilder buf = new StringBuilder(text);
     for (int intervalInd = intervals.size() - 1; intervalInd >= 0; intervalInd--) {
       TextRange range = intervals.get(intervalInd);
       buf.delete(range.getStartOffset(), range.getEndOffset() + 1);
     }
     return buf.toString();
   }

   private static int findImageEndIndexInclusive(@NotNull String text, int imageStartIndex) {
     int n = text.length();
     if (text.charAt(imageStartIndex) == '!'
         && imageStartIndex + 1 < n
         && text.charAt(imageStartIndex + 1) == '[') {
       int i = imageStartIndex + 2;
       while (i < n && text.charAt(i) != ']') {
         i++;
       }
       if (i < n && i + 1 < n && text.charAt(i + 1) == '(') {
         i += 2;
         while (i < n && text.charAt(i) != ')') {
           i++;
         }
         if (i < n) {
           return i;
         }
       }
     }
     return -1;
   }

   @Nullable
   private static TextRange findEnclosingLink(@NotNull String text,
                                              int imageStartIndInc,
                                              int imageEndIndInc) {
     int linkStartIndInc = imageStartIndInc - 1;
     if (linkStartIndInc >= 0 && text.charAt(linkStartIndInc) == '[') {
       int n = text.length();
       int i = imageEndIndInc + 1;
       if (text.charAt(i) == ']' && i + 1 < n && text.charAt(i + 1) == '(') {
         i += 2;
         while (i < n && text.charAt(i) != ')') {
           i++;
         }
         if (i < n) {
           return new TextRange(linkStartIndInc, i);
         }
       }
     }
     return null;
   }

   public static void replaceCodeBlock(@NotNull List<String> lines) {
     new CodeBlockProcessor(lines).process();
   }

   private static class CodeBlockProcessor {

     private static final String START_TAGS = "<pre><code>";
     private static final String END_TAGS = "</code></pre>";

     private final List<String> myLines;

     private boolean myGlobalCodeBlockStarted = false;
     private boolean myCodeBlockStarted = false;

     private CodeBlockProcessor(@NotNull List<String> lines) {
       myLines = lines;
     }

     public void process() {
       for (int i = 0; i < myLines.size(); i++) {
         final String line = myLines.get(i);
         if (line.startsWith("```")) {
           finishCodeBlock(i - 1);
           myGlobalCodeBlockStarted = !myGlobalCodeBlockStarted;
           String out = myGlobalCodeBlockStarted ? START_TAGS : END_TAGS;
           myLines.set(i, out);
         }
         else {
           if (!myGlobalCodeBlockStarted) {
             handleLocalCodeBlock(i, line);
           }
         }
       }
       finishCodeBlock(myLines.size() - 1);
     }

     private void handleLocalCodeBlock(int ind, @NotNull String line) {
       boolean codeBlock = false;
       if (line.startsWith("    ")) {
         line = line.substring(4);
         codeBlock = true;
       }
       else if (line.startsWith("\t")) {
         line = line.substring(1);
         codeBlock = true;
       }

       if (!myCodeBlockStarted) {
         if (codeBlock) {
           myCodeBlockStarted = true;
           myLines.set(ind, START_TAGS + line);
         }
       }
       else {
         if (codeBlock) {
           myLines.set(ind, line);
         }
         else {
           finishCodeBlock(ind - 1);
         }
       }
     }

     private void finishCodeBlock(int lastCodeBlockLineInd) {
       if (myCodeBlockStarted) {
         myLines.set(lastCodeBlockLineInd, myLines.get(lastCodeBlockLineInd) + END_TAGS);
         myCodeBlockStarted = false;
       }
     }
   }

   public static void generateLists(@NotNull List<String> lines) {
     new ListItemProcessor(lines).process();
   }

   private static class ListItemProcessor {

     private final List<String> myLines;

     private boolean myInsideBlockQuote = false;
     private ListItem myFirstListItem = null;
     private int myLastListItemLineInd = -1;

     private ListItemProcessor(@NotNull List<String> lines) {
       myLines = lines;
     }

     public void process() {
       for (int i = 0; i < myLines.size(); i++) {
         final String line = myLines.get(i);
         if (line.startsWith("```")) {
           myInsideBlockQuote = !myInsideBlockQuote;
         }
         if (!myInsideBlockQuote) {
           handle(i, line);
         }
       }
       finishLastListItem(true);
     }

     private void handle(int ind, @NotNull String line) {
       ListItem listItem = toListItem(line);
       if (listItem != null) {
         finishLastListItem(false);
         String out = "<li>" + listItem.getBody();
         if (myFirstListItem == null) {
           myFirstListItem = listItem;
           if (listItem.isUnordered()) {
             out = "<ul>" + out;
           }
           else {
             out = "<ol>" + out;
           }
         }
         myLines.set(ind, out);
         myLastListItemLineInd = ind;
       }
       else if (myFirstListItem != null &&
           !line.isEmpty() &&
           !StringUtil.isEmptyOrSpaces(line)) {
         if (ind - 1 >= 0
             && StringUtil.isEmptyOrSpaces(myLines.get(ind - 1))
             && !Character.isWhitespace(line.charAt(0))) {
           finishLastListItem(true);
         }
         else {
           String m = StringUtil.trimLeading(line);
           myLines.set(ind, m);
           myLastListItemLineInd = ind;
         }
       }
     }

     private void finishLastListItem(boolean finishList) {
       if (myLastListItemLineInd != -1) {
         String l = myLines.get(myLastListItemLineInd);
         l += "</li>";
         if (finishList) {
           if (myFirstListItem.isUnordered()) {
             l += "</ul>";
           }
           else {
             l += "</ol>";
           }
           myFirstListItem = null;
         }
         myLines.set(myLastListItemLineInd, l);
         myLastListItemLineInd = -1;
       }
     }
   }

   @Nullable
   private static ListItem toListItem(@NotNull String line) {
     line = StringUtil.trimLeading(line);
     if (line.length() >= 2) {
       char firstChar = line.charAt(0);
       char secondChar = line.charAt(1);
       if (firstChar == '*' || firstChar == '+' || firstChar == '-') {
         if (Character.isWhitespace(secondChar)) {
           return new ListItem(true, StringUtil.trimLeading(line.substring(1)));
         }
       }
     }
     int i = 0;
     while (i < line.length() && Character.isDigit(line.charAt(i))) {
       i++;
     }
     if (i > 0 && i < line.length() - 1) {
       if (line.charAt(i) == '.' && Character.isWhitespace(line.charAt(i + 1))) {
         return new ListItem(false, StringUtil.trimLeading(line.substring(i + 1)));
       }
     }
     return null;
   }

   private static class ListItem {

     private final boolean myUnordered;
     private final String myBody;

     private ListItem(boolean unordered, @NotNull String body) {
       myUnordered = unordered;
       myBody = body;
     }

     private boolean isUnordered() {
       return myUnordered;
     }

     @NotNull
     private String getBody() {
       return myBody;
     }
   }

 }
	package com.intellij.util.text;

	import com.intellij.openapi.util.TextRange;
	import com.intellij.openapi.util.text.StringUtil;
	import org.jetbrains.annotations.NotNull;
	import org.jetbrains.annotations.Nullable;

	import java.util.ArrayList;
	import java.util.List;

	/**
	* @author Sergey Simonchik
	*/
	public class MarkdownUtil {

	private MarkdownUtil() {}

	/**
	* Replaces headers in markdown with HTML.
	* Unfortunately, library used for markdown processing
	* <a href="https://code.google.com/p/markdownj">markdownj</a>
	* doesn't support that.
	*/
	public static void replaceHeaders(@NotNull List<String> lines) {
	for (int i = 0; i < lines.size(); i++) {
	String line = lines.get(i);
	int ind = 0;
	while (ind < line.length() && line.charAt(ind) == '#') {
	ind++;
	}
	if (ind < line.length() && line.charAt(ind) == ' ') {
	if (0 < ind && ind <= 9) {
	int endInd = line.length() - 1;
	while (endInd >= 0 && line.charAt(endInd) == '#') {
	endInd--;
	}
	line = line.substring(ind + 1, endInd + 1);
	line = "<h" + ind + ">" + line + "</h" + ind + ">";
	lines.set(i, line);
	}
	}
	}
	}

	/**
	* Removes images in the markdown text.
	* @param lines List of String in markdown format
	*/
	public static void removeImages(@NotNull List<String> lines) {
	for (int i = 0; i < lines.size(); i++) {
	String newText = removeAllImages(lines.get(i));
	lines.set(i, newText);
	}
	}

	@NotNull
	private static String removeAllImages(@NotNull String text) {
	int n = text.length();
	List<TextRange> intervals = null;
	int i = 0;
	while (i < n) {
	int imageEndIndex = findImageEndIndexInclusive(text, i);
	if (imageEndIndex != -1) {
	TextRange linkRange = findEnclosingLink(text, i, imageEndIndex);
	if (intervals == null) {
	intervals = new ArrayList<TextRange>(1);
	}
	final TextRange range;
	if (linkRange != null) {
	range = linkRange;
	}
	else {
	range = new TextRange(i, imageEndIndex);
	}
	intervals.add(range);
	i = range.getEndOffset();
	}
	i++;
	}
	if (intervals == null) {
	return text;
	}
	StringBuilder buf = new StringBuilder(text);
	for (int intervalInd = intervals.size() - 1; intervalInd >= 0; intervalInd--) {
	TextRange range = intervals.get(intervalInd);
	buf.delete(range.getStartOffset(), range.getEndOffset() + 1);
	}
	return buf.toString();
	}

	private static int findImageEndIndexInclusive(@NotNull String text, int imageStartIndex) {
	int n = text.length();
	if (text.charAt(imageStartIndex) == '!'
	&& imageStartIndex + 1 < n
	&& text.charAt(imageStartIndex + 1) == '[') {
	int i = imageStartIndex + 2;
	while (i < n && text.charAt(i) != ']') {
	i++;
	}
	if (i < n && i + 1 < n && text.charAt(i + 1) == '(') {
	i += 2;
	while (i < n && text.charAt(i) != ')') {
	i++;
	}
	if (i < n) {
	return i;
	}
	}
	}
	return -1;
	}

	@Nullable
	private static TextRange findEnclosingLink(@NotNull String text,
	int imageStartIndInc,
	int imageEndIndInc) {
	int linkStartIndInc = imageStartIndInc - 1;
	if (linkStartIndInc >= 0 && text.charAt(linkStartIndInc) == '[') {
	int n = text.length();
	int i = imageEndIndInc + 1;
	if (text.charAt(i) == ']' && i + 1 < n && text.charAt(i + 1) == '(') {
	i += 2;
	while (i < n && text.charAt(i) != ')') {
	i++;
	}
	if (i < n) {
	return new TextRange(linkStartIndInc, i);
	}
	}
	}
	return null;
	}

	public static void replaceCodeBlock(@NotNull List<String> lines) {
	new CodeBlockProcessor(lines).process();
	}

	private static class CodeBlockProcessor {

	private static final String START_TAGS = "<pre><code>";
	private static final String END_TAGS = "</code></pre>";

	private final List<String> myLines;

	private boolean myGlobalCodeBlockStarted = false;
	private boolean myCodeBlockStarted = false;

	private CodeBlockProcessor(@NotNull List<String> lines) {
	myLines = lines;
	}

	public void process() {
	for (int i = 0; i < myLines.size(); i++) {
	final String line = myLines.get(i);
	if (line.startsWith("```")) {
	finishCodeBlock(i - 1);
	myGlobalCodeBlockStarted = !myGlobalCodeBlockStarted;
	String out = myGlobalCodeBlockStarted ? START_TAGS : END_TAGS;
	myLines.set(i, out);
	}
	else {
	if (!myGlobalCodeBlockStarted) {
	handleLocalCodeBlock(i, line);
	}
	}
	}
	finishCodeBlock(myLines.size() - 1);
	}

	private void handleLocalCodeBlock(int ind, @NotNull String line) {
	boolean codeBlock = false;
	if (line.startsWith(" ")) {
	line = line.substring(4);
	codeBlock = true;
	}
	else if (line.startsWith("\t")) {
	line = line.substring(1);
	codeBlock = true;
	}

	if (!myCodeBlockStarted) {
	if (codeBlock) {
	myCodeBlockStarted = true;
	myLines.set(ind, START_TAGS + line);
	}
	}
	else {
	if (codeBlock) {
	myLines.set(ind, line);
	}
	else {
	finishCodeBlock(ind - 1);
	}
	}
	}

	private void finishCodeBlock(int lastCodeBlockLineInd) {
	if (myCodeBlockStarted) {
	myLines.set(lastCodeBlockLineInd, myLines.get(lastCodeBlockLineInd) + END_TAGS);
	myCodeBlockStarted = false;
	}
	}
	}

	public static void generateLists(@NotNull List<String> lines) {
	new ListItemProcessor(lines).process();
	}

	private static class ListItemProcessor {

	private final List<String> myLines;

	private boolean myInsideBlockQuote = false;
	private ListItem myFirstListItem = null;
	private int myLastListItemLineInd = -1;

	private ListItemProcessor(@NotNull List<String> lines) {
	myLines = lines;
	}

	public void process() {
	for (int i = 0; i < myLines.size(); i++) {
	final String line = myLines.get(i);
	if (line.startsWith("```")) {
	myInsideBlockQuote = !myInsideBlockQuote;
	}
	if (!myInsideBlockQuote) {
	handle(i, line);
	}
	}
	finishLastListItem(true);
	}

	private void handle(int ind, @NotNull String line) {
	ListItem listItem = toListItem(line);
	if (listItem != null) {
	finishLastListItem(false);
	String out = "<li>" + listItem.getBody();
	if (myFirstListItem == null) {
	myFirstListItem = listItem;
	if (listItem.isUnordered()) {
	out = "<ul>" + out;
	}
	else {
	out = "<ol>" + out;
	}
	}
	myLines.set(ind, out);
	myLastListItemLineInd = ind;
	}
	else if (myFirstListItem != null &&
	!line.isEmpty() &&
	!StringUtil.isEmptyOrSpaces(line)) {
	if (ind - 1 >= 0
	&& StringUtil.isEmptyOrSpaces(myLines.get(ind - 1))
	&& !Character.isWhitespace(line.charAt(0))) {
	finishLastListItem(true);
	}
	else {
	String m = StringUtil.trimLeading(line);
	myLines.set(ind, m);
	myLastListItemLineInd = ind;
	}
	}
	}

	private void finishLastListItem(boolean finishList) {
	if (myLastListItemLineInd != -1) {
	String l = myLines.get(myLastListItemLineInd);
	l += "</li>";
	if (finishList) {
	if (myFirstListItem.isUnordered()) {
	l += "</ul>";
	}
	else {
	l += "</ol>";
	}
	myFirstListItem = null;
	}
	myLines.set(myLastListItemLineInd, l);
	myLastListItemLineInd = -1;
	}
	}
	}

	@Nullable
	private static ListItem toListItem(@NotNull String line) {
	line = StringUtil.trimLeading(line);
	if (line.length() >= 2) {
	char firstChar = line.charAt(0);
	char secondChar = line.charAt(1);
	if (firstChar == '*' \|\| firstChar == '+' \|\| firstChar == '-') {
	if (Character.isWhitespace(secondChar)) {
	return new ListItem(true, StringUtil.trimLeading(line.substring(1)));
	}
	}
	}
	int i = 0;
	while (i < line.length() && Character.isDigit(line.charAt(i))) {
	i++;
	}
	if (i > 0 && i < line.length() - 1) {
	if (line.charAt(i) == '.' && Character.isWhitespace(line.charAt(i + 1))) {
	return new ListItem(false, StringUtil.trimLeading(line.substring(i + 1)));
	}
	}
	return null;
	}

	private static class ListItem {

	private final boolean myUnordered;
	private final String myBody;

	private ListItem(boolean unordered, @NotNull String body) {
	myUnordered = unordered;
	myBody = body;
	}

	private boolean isUnordered() {
	return myUnordered;
	}

	@NotNull
	private String getBody() {
	return myBody;
	}
	}

	}