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;
  
  /**
   * Merges two blocks using some heuristics.
   */
  public final class ContentFusion implements BoilerpipeFilter {
  
    public static final ContentFusion INSTANCE = new ContentFusion();
  
    /**
     * Creates a new {@link ContentFusion} instance.
     * 
     */
    public ContentFusion() {
    }
  
    public boolean process(TextDocument doc) throws BoilerpipeProcessingException {
      List<TextBlock> textBlocks = doc.getTextBlocks();
      if (textBlocks.size() < 2) {
        return false;
      }
  
      TextBlock prevBlock = textBlocks.get(0);
  
      boolean changes = false;
      do {
        changes = false;
        for (ListIterator<TextBlock> it = textBlocks.listIterator(1); it.hasNext();) {
          TextBlock block = it.next();
  
          if (prevBlock.isContent() && block.getLinkDensity() < 0.56
              && !block.hasLabel(DefaultLabels.STRICTLY_NOT_CONTENT)) {
  
            prevBlock.mergeNext(block);
            it.remove();
            changes = true;
          } else {
            prevBlock = block;
          }
        }
      } while (changes);
  
      return true;
    }
  
  }
  