1   /*
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements.  See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache License, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License.  You may obtain a copy of the License at
    8    *
    9    *      http://www.apache.org/licenses/LICENSE-2.0
   10    *
   11    * Unless required by applicable law or agreed to in writing, software
   12    * distributed under the License is distributed on an "AS IS" BASIS,
   13    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   14    * See the License for the specific language governing permissions and
   15    * limitations under the License.
   16    */
   17   package org.apache.pdfbox.pdmodel.common.function;
   18   
   19   import org.apache.pdfbox.cos.COSArray;
   20   import org.apache.pdfbox.cos.COSBase;
   21   import org.apache.pdfbox.cos.COSDictionary;
   22   import org.apache.pdfbox.cos.COSFloat;
   23   import org.apache.pdfbox.cos.COSName;
   24   import org.apache.pdfbox.pdmodel.common.PDRange;
   25   
   26   /**
   27    * This class represents a function in a PDF document.
   28    *
   29    * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
   30    * @version $Revision: 1.3 $
   31    */
   32   public abstract class PDDictionaryFunction extends PDFunction
   33   {
   34       private COSDictionary function = null;
   35   
   36       /**
   37        * Constructor to create a new blank function, should only be called by
   38        * subclasses.
   39        *
   40        *  @param functionType An integer describing the function type, only 0,2,3,4
   41        *  are defined by the PDF sepc.
   42        */
   43       protected PDDictionaryFunction( int functionType )
   44       {
   45           function = new COSDictionary();
   46           function.setInt( "FunctionType", functionType );
   47       }
   48   
   49       /**
   50        * Constructor.
   51        *
   52        * @param functionDictionary The prepopulated function dictionary.
   53        */
   54       public PDDictionaryFunction( COSDictionary functionDictionary )
   55       {
   56           function = functionDictionary;
   57       }
   58   
   59       /**
   60        * {@inheritDoc}
   61        */
   62       public COSBase getCOSObject()
   63       {
   64           return function;
   65       }
   66   
   67       /**
   68        * Get the underlying cos dictionary.
   69        *
   70        * @return The underlying cos dictionary.
   71        */
   72       public COSDictionary getCOSDictionary()
   73       {
   74           return function;
   75       }
   76   
   77       protected COSArray getRangeArray( String fieldName, int n )
   78       {
   79           COSArray rangeArray = (COSArray)function.getDictionaryObject( COSName.getPDFName( "Range" ) );
   80           if( rangeArray == null )
   81           {
   82               rangeArray = new COSArray();
   83               function.setItem( fieldName, rangeArray );
   84               while( rangeArray.size() < n*2 )
   85               {
   86                   rangeArray.add( new COSFloat( 0 ) );
   87                   rangeArray.add( new COSFloat( 0 ) );
   88               }
   89           }
   90           return rangeArray;
   91       }
   92   
   93       /**
   94        * {@inheritDoc}
   95        */
   96       public int getNumberOfOutputParameters()
   97       {
   98           COSArray array = getRangeArray( "Range", 0 );
   99           return array.size() / 2;
  100       }
  101   
  102       /**
  103        * {@inheritDoc}
  104        */
  105       public PDRange getRangeForOutput( int n )
  106       {
  107           COSArray rangeArray = getRangeArray( "Range", n );
  108           return new PDRange( rangeArray, n );
  109       }
  110   
  111       /**
  112        * {@inheritDoc}
  113        */
  114       public void setRangeForOutput( PDRange range, int n )
  115       {
  116           COSArray rangeArray = getRangeArray("Range", n );
  117           rangeArray.set( n*2, new COSFloat( range.getMin() ) );
  118           rangeArray.set( n*2+1, new COSFloat( range.getMax() ) );
  119       }
  120   
  121       /**
  122        * {@inheritDoc}
  123        */
  124       public int getNumberOfInputParameters()
  125       {
  126           COSArray array = getRangeArray( "Domain", 0 );
  127           return array.size() / 2;
  128       }
  129   
  130       /**
  131        * {@inheritDoc}
  132        */
  133       public PDRange getDomainForInput( int n )
  134       {
  135           COSArray rangeArray = getRangeArray( "Domain", n );
  136           return new PDRange( rangeArray, n );
  137       }
  138   
  139       /**
  140        * {@inheritDoc}
  141        */
  142       public void setDomainForInput( PDRange range, int n )
  143       {
  144           COSArray rangeArray = getRangeArray("Domain", n );
  145           rangeArray.set( n*2, new COSFloat( range.getMin() ) );
  146           rangeArray.set( n*2+1, new COSFloat( range.getMax() ) );
  147       }
  148   }