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.english;
  
  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 all blocks as "non-content" that occur after blocks that have been marked
   * {@link DefaultLabels#INDICATES_END_OF_TEXT}, and after any content block. This filter can be used
   * in conjunction with an upstream {@link TerminatingBlocksFinder}.
   * 
   * @see TerminatingBlocksFinder
   */
  public final class IgnoreBlocksAfterContentFromEndFilter extends HeuristicFilterBase implements
      BoilerpipeFilter {
    public static final IgnoreBlocksAfterContentFromEndFilter INSTANCE =
        new IgnoreBlocksAfterContentFromEndFilter();
  
    private IgnoreBlocksAfterContentFromEndFilter() {
    }
  
    public boolean process(TextDocument doc) throws BoilerpipeProcessingException {
      boolean changes = false;
  
      int words = 0;
  
      List<TextBlock> blocks = doc.getTextBlocks();
      if (!blocks.isEmpty()) {
        ListIterator<TextBlock> it = blocks.listIterator(blocks.size());
  
        TextBlock tb;
  
        while (it.hasPrevious()) {
          tb = it.previous();
          if (tb.hasLabel(DefaultLabels.INDICATES_END_OF_TEXT)) {
            tb.addLabel(DefaultLabels.STRICTLY_NOT_CONTENT);
            tb.removeLabel(DefaultLabels.MIGHT_BE_CONTENT);
            tb.setIsContent(false);
            changes = true;
          } else if (tb.isContent()) {
            words += tb.getNumWords();
            if (words > 200) {
              break;
            }
          }
  
        }
      }
  
      return changes;
    }
  }
  