package com.swtSample.text;

import java.util.*;

/**
 * This class manages the syntax coloring and styling data
 */
public class SyntaxManager {
  // Lazy cache of SyntaxData objects
  private static Map data = new Hashtable();

  /**
   * Gets the syntax data for an extension
   */
  public static synchronized SyntaxData getSyntaxData(String extension) {
    // Check in cache
    SyntaxData sd = (SyntaxData) data.get(extension);
    if (sd == null) {
      // Not in cache; load it and put in cache
      sd = loadSyntaxData(extension);
      if (sd != null) data.put(sd.getExtension(), sd);
    }
    return sd;
  }

  /**
   * Loads the syntax data for an extension
   * 
   * @param extension the extension to load
   * @return SyntaxData
   */
  private static SyntaxData loadSyntaxData(String extension) {
    SyntaxData sd = null;
    try {
      ResourceBundle rb = ResourceBundle.getBundle("examples.ch11." + extension);
      sd = new SyntaxData(extension);
      sd.setComment(rb.getString("comment"));
      sd.setMultiLineCommentStart(rb.getString("multilinecommentstart"));
      sd.setMultiLineCommentEnd(rb.getString("multilinecommentend"));

      // Load the keywords
      Collection keywords = new ArrayList();
      for (StringTokenizer st = new StringTokenizer(rb.getString("keywords"), " "); st
          .hasMoreTokens();) {
        keywords.add(st.nextToken());
      }
      sd.setKeywords(keywords);

      // Load the punctuation
      sd.setPunctuation(rb.getString("punctuation"));
    } catch (MissingResourceException e) {
      // Ignore
    }
    return sd;
  }
}