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.COSFloat;
22 import org.apache.pdfbox.cos.COSName;
23 import org.apache.pdfbox.cos.COSStream;
24 import org.apache.pdfbox.pdmodel.PDDocument;
25 import org.apache.pdfbox.pdmodel.common.PDRange;
26 import org.apache.pdfbox.pdmodel.common.PDStream;
27
28 /**
29 * This class represents a function in a PDF document.
30 *
31 * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
32 * @version $Revision: 1.3 $
33 */
34 public abstract class PDStreamFunction extends PDFunction
35 {
36 private PDStream function = null;
37
38 /**
39 * Constructor to create a new blank function, should only be called by
40 * subclasses.
41 *
42 * @param doc The document that this function is part of.
43 * @param functionType An integer describing the function type, only 0,2,3,4
44 * are defined by the PDF sepc.
45 */
46 protected PDStreamFunction( PDDocument doc, int functionType )
47 {
48 function = new PDStream( doc );
49 function.getStream().setInt( "FunctionType", functionType );
50 }
51
52 /**
53 * Constructor.
54 *
55 * @param functionDictionary The prepopulated function dictionary.
56 */
57 public PDStreamFunction( PDStream functionDictionary )
58 {
59 function = functionDictionary;
60 }
61
62 /**
63 * Convert this standard java object to a COS object.
64 *
65 * @return The cos object that matches this Java object.
66 */
67 public COSBase getCOSObject()
68 {
69 return function.getCOSObject();
70 }
71
72 /**
73 * This will get the underlying array value.
74 *
75 * @return The cos object that this object wraps.
76 */
77 public COSStream getCOSStream()
78 {
79 return function.getStream();
80 }
81
82 private COSArray getRangeArray( String fieldName, int n )
83 {
84 COSArray rangeArray = (COSArray)function.getStream().getDictionaryObject( COSName.getPDFName( "Range" ) );
85 if( rangeArray == null )
86 {
87 rangeArray = new COSArray();
88 function.getStream().setItem( fieldName, rangeArray );
89 while( rangeArray.size() < n*2 )
90 {
91 rangeArray.add( new COSFloat( 0 ) );
92 rangeArray.add( new COSFloat( 0 ) );
93 }
94 }
95 return rangeArray;
96 }
97
98 /**
99 * This will get the number of output parameters that
100 * have a range specified. A range for output parameters
101 * is optional so this may return zero for a function
102 * that does have output parameters, this will simply return the
103 * number that have the rnage specified.
104 *
105 * @return The number of input parameters that have a range
106 * specified.
107 */
108 public int getNumberOfOutputParameters()
109 {
110 COSArray array = getRangeArray( "Range", 0 );
111 return array.size() / 2;
112 }
113
114 /**
115 * This will get the range for a certain output parameters. This is will never
116 * return null. If it is not present then the range 0 to 0 will
117 * be returned.
118 *
119 * @param n The output parameter number to get the range for.
120 *
121 * @return The range for this component.
122 */
123 public PDRange getRangeForOutput( int n )
124 {
125 COSArray rangeArray = getRangeArray( "Range", n );
126 return new PDRange( rangeArray, n );
127 }
128
129 /**
130 * This will set the a range for output parameter.
131 *
132 * @param range The new range for the output parameter.
133 * @param n The ouput parameter number to set the range for.
134 */
135 public void setRangeForOutput( PDRange range, int n )
136 {
137 COSArray rangeArray = getRangeArray("Range", n );
138 rangeArray.set( n*2, new COSFloat( range.getMin() ) );
139 rangeArray.set( n*2+1, new COSFloat( range.getMax() ) );
140 }
141
142 /**
143 * This will get the number of input parameters that
144 * have a domain specified.
145 *
146 * @return The number of input parameters that have a domain
147 * specified.
148 */
149 public int getNumberOfInputParameters()
150 {
151 COSArray array = getRangeArray( "Domain", 0 );
152 return array.size() / 2;
153 }
154
155 /**
156 * This will get the range for a certain input parameter. This is will never
157 * return null. If it is not present then the range 0 to 0 will
158 * be returned.
159 *
160 * @param n The parameter number to get the domain for.
161 *
162 * @return The domain range for this component.
163 */
164 public PDRange getDomainForInput( int n )
165 {
166 COSArray rangeArray = getRangeArray( "Domain", n );
167 return new PDRange( rangeArray, n );
168 }
169
170 /**
171 * This will set the domain for the input values.
172 *
173 * @param range The new range for the input.
174 * @param n The number of the input parameter to set the domain for.
175 */
176 public void setDomainForInput( PDRange range, int n )
177 {
178 COSArray rangeArray = getRangeArray("Domain", n );
179 rangeArray.set( n*2, new COSFloat( range.getMin() ) );
180 rangeArray.set( n*2+1, new COSFloat( range.getMax() ) );
181 }
182 }