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 java.util.List;
  import java.util.ListIterator;
  
  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 trailing headlines ({@link TextBlock}s that have the label {@link DefaultLabels#HEADING})
   * as boilerplate. Trailing means they are marked content and are below any other content block.
   */
  public final class TrailingHeadlineToBoilerplateFilter implements BoilerpipeFilter {
    public static final TrailingHeadlineToBoilerplateFilter INSTANCE =
        new TrailingHeadlineToBoilerplateFilter();
  
    /**
     * Returns the singleton instance for ExpandTitleToContentFilter.
     */
    public static TrailingHeadlineToBoilerplateFilter getInstance() {
      return INSTANCE;
    }
  
    public boolean process(TextDocument doc) throws BoilerpipeProcessingException {
      boolean changes = false;
  
      List<TextBlock> list = doc.getTextBlocks();
  
      for (ListIterator<TextBlock> it = list.listIterator(list.size()); it.hasPrevious();) {
        TextBlock tb = it.previous();
        if (tb.isContent()) {
          if (tb.hasLabel(DefaultLabels.HEADING)) {
            tb.setIsContent(false);
            changes = true;
          } else {
            break;
          }
        }
      }
  
      return changes;
    }
  
  }
  