text: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF 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 org.apache.pdfbox.pdmodel.interactive.annotation;
  
  import java.util.HashMap;
  import java.util.Map;
  import org.apache.pdfbox.cos.COSBase;
  import org.apache.pdfbox.cos.COSDictionary;
  import org.apache.pdfbox.cos.COSName;
  import org.apache.pdfbox.cos.COSStream;
  import org.apache.pdfbox.pdmodel.common.COSDictionaryMap;
  import org.apache.pdfbox.pdmodel.common.COSObjectable;
  
  /**
   * An entry in an appearance dictionary. May contain either a single appearance stream or an appearance subdictionary.
   *
   * @author John Hewson
   */
  public class PDAppearanceEntry implements COSObjectable
  {
      private COSDictionary entry;
  
      private PDAppearanceEntry()
      {
      }
  
      /**
       * Constructor for reading.
       * 
       * @param entry
       */
      public PDAppearanceEntry(COSDictionary entry)
      {
          this.entry = entry;
      }
  
      @Override
      public COSDictionary getCOSObject()
      {
          return entry;
      }
  
      /**
       * Returns true if this entry is an appearance subdictionary.
       */
      public boolean isSubDictionary()
      {
          return !(this.entry instanceof COSStream);
      }
  
      /**
       * Returns true if this entry is an appearance stream.
       */
      public boolean isStream()
      {
          return this.entry instanceof COSStream;
      }
  
      /**
       * Returns the entry as an appearance stream.
       *
       * @throws IllegalStateException if this entry is not an appearance stream
       */
      public PDAppearanceStream getAppearanceStream()
      {
          if (!isStream())
          {
              throw new IllegalStateException("This entry is not an appearance stream");
          }
          return new PDAppearanceStream((COSStream) entry);
      }
  
      /**
       * Returns the entry as an appearance subdictionary.
       *
       * @throws IllegalStateException if this entry is not an appearance subdictionary
       */
      public Map<COSName, PDAppearanceStream> getSubDictionary()
      {
          if (!isSubDictionary())
          {
              throw new IllegalStateException("This entry is not an appearance subdictionary");
          }
  
          COSDictionary dict = entry;
          Map<COSName, PDAppearanceStream> map = new HashMap<>();
  
          for (COSName name : dict.keySet())
          {
              COSBase value = dict.getDictionaryObject(name);
  
              // the file from PDFBOX-1599 contains /null as its entry, so we skip non-stream entries
              if (value instanceof COSStream)
              {
                  map.put(name, new PDAppearanceStream((COSStream) value));
              }
          }
  
          return new COSDictionaryMap<>(map, dict);
      }
  }
  