code: /**
   * boilerpipe
   *
   * Copyright (c) 2009, 2014 Christian Kohlschütter
   *
   * The author licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.kohlschutter.boilerpipe.filters.heuristics;
  
  import com.kohlschutter.boilerpipe.BoilerpipeFilter;
  import com.kohlschutter.boilerpipe.BoilerpipeProcessingException;
  import com.kohlschutter.boilerpipe.document.TextBlock;
  import com.kohlschutter.boilerpipe.document.TextDocument;
  import com.kohlschutter.boilerpipe.labels.DefaultLabels;
  
  /**
   * Marks all {@link TextBlock}s "content" which are between the headline and the part that has
   * already been marked content, if they are marked {@link DefaultLabels#MIGHT_BE_CONTENT}.
   * 
   * This filter is quite specific to the news domain.
   */
  public final class ExpandTitleToContentFilter implements BoilerpipeFilter {
    public static final ExpandTitleToContentFilter INSTANCE = new ExpandTitleToContentFilter();
  
    /**
     * Returns the singleton instance for ExpandTitleToContentFilter.
     */
    public static ExpandTitleToContentFilter getInstance() {
      return INSTANCE;
    }
  
    public boolean process(TextDocument doc) throws BoilerpipeProcessingException {
      int i = 0;
      int title = -1;
      int contentStart = -1;
      for (TextBlock tb : doc.getTextBlocks()) {
        if (contentStart == -1 && tb.hasLabel(DefaultLabels.TITLE)) {
          title = i;
          contentStart = -1;
        }
        if (contentStart == -1 && tb.isContent()) {
          contentStart = i;
        }
  
        i++;
      }
  
      if (contentStart <= title || title == -1) {
        return false;
      }
      boolean changes = false;
      for (TextBlock tb : doc.getTextBlocks().subList(title, contentStart)) {
        if (tb.hasLabel(DefaultLabels.MIGHT_BE_CONTENT)) {
          changes = tb.setIsContent(true) | changes;
        }
      }
      return changes;
    }
  
  }
  