src/javajs/export/PDFObject.java

   1 package javajs.export;\r
   2 \r
   3 import java.io.ByteArrayOutputStream;\r
   4 import java.io.IOException;\r
   5 import java.io.OutputStream;\r
   6 import java.util.Hashtable;\r
   7 import java.util.Map;\r
   8 import java.util.Map.Entry;\r
   9 import java.util.zip.Deflater;\r
  10 import java.util.zip.DeflaterOutputStream;\r
  11 \r
  12 import javajs.util.SB;\r
  13 \r
  14 \r
  15 /**\r
  16  * A rudimentary class for working with PDF document creation.\r
  17  * Written from scratch based on PDF Reference 13.\r
  18  * \r
  19  * @author hansonr  Bob Hanson hansonr@stolaf.edu  10/28/2013\r
  20  * \r
  21  */\r
  22 class PDFObject extends SB {    \r
  23         private Map<String, Object> dictionary;\r
  24         private byte[] stream;\r
  25         private int index;\r
  26         String type;\r
  27         int len;\r
  28         int pt;\r
  29         \r
  30         PDFObject(int index) {\r
  31                 this.index = index;\r
  32         }\r
  33 \r
  34         String getRef() {\r
  35                 return index + " 0 R";\r
  36         }\r
  37         \r
  38         String getID() {\r
  39                 return type.substring(0, 1) + index;\r
  40         }\r
  41         \r
  42         boolean isFont() {\r
  43                 return "Font".equals(type);\r
  44         }\r
  45 \r
  46         void setStream(byte[] stream) {\r
  47                 this.stream = stream;\r
  48         }\r
  49 \r
  50         Object getDef(String key) {\r
  51                 return dictionary.get(key);\r
  52         }\r
  53         \r
  54         void addDef(String key, Object value) {\r
  55                 if (dictionary  == null)\r
  56                         dictionary = new Hashtable<String, Object>();\r
  57                 dictionary.put(key, value);\r
  58                 if (key.equals("Type"))\r
  59                         type = ((String) value).substring(1);\r
  60         }\r
  61         \r
  62         void setAsStream() {\r
  63                 stream = toBytes(0, -1);\r
  64                 setLength(0);\r
  65         }\r
  66         \r
  67         int output(OutputStream os) throws IOException {\r
  68                 if (index > 0) {\r
  69                         String s = index + " 0 obj\n";\r
  70                         write(os, s.getBytes(), 0);\r
  71                 }\r
  72                 int streamLen = 0;\r
  73                 if (dictionary != null) {\r
  74                         if (dictionary.containsKey("Length")) {\r
  75                                 if (stream == null)\r
  76                                         setAsStream();\r
  77                                 streamLen = stream.length;\r
  78                                 boolean doDeflate = (streamLen > 1000);\r
  79         if (doDeflate) {\r
  80           Deflater deflater = new Deflater(9);\r
  81           ByteArrayOutputStream outBytes = new ByteArrayOutputStream(1024);\r
  82           DeflaterOutputStream compBytes = new DeflaterOutputStream(outBytes,\r
  83               deflater);\r
  84           compBytes.write(stream, 0, streamLen);\r
  85           compBytes.finish();\r
  86           stream = outBytes.toByteArray();\r
  87           dictionary.put("Filter", "/FlateDecode");\r
  88           streamLen = stream.length;\r
  89         }\r
  90                                 dictionary.put("Length", "" + streamLen);\r
  91                         }\r
  92                         write(os, getDictionaryText(dictionary, "\n").getBytes(), 0);\r
  93                 }\r
  94                 if (length() > 0)\r
  95                         write(os, this.toString().getBytes(), 0);\r
  96                 if (stream != null) {\r
  97                         write(os, "stream\r\n".getBytes(), 0);\r
  98                         write(os, stream, streamLen);\r
  99                         write(os, "\r\nendstream\r\n".getBytes(), 0);\r
 100                 }\r
 101                 if (index > 0)\r
 102                         write(os, "endobj\n".getBytes(), 0);\r
 103                 return len;\r
 104         }\r
 105 \r
 106         private void write(OutputStream os, byte[] bytes, int nBytes) throws IOException {\r
 107                 if (nBytes == 0)\r
 108                         nBytes = bytes.length;\r
 109                 len += nBytes;\r
 110                 os.write(bytes, 0, nBytes);\r
 111         }\r
 112 \r
 113         @SuppressWarnings("unchecked")\r
 114         private String getDictionaryText(Map<String, Object> d, String nl) {\r
 115                 SB sb = new SB();\r
 116                 sb.append("<<");\r
 117                 if (d.containsKey("Type"))\r
 118                         sb.append("/Type").appendO(d.get("Type"));\r
 119                 for (Entry<String, Object> e : d.entrySet()) {\r
 120                         String s = e.getKey();\r
 121                         if (s.equals("Type") || s.startsWith("!"))\r
 122                                 continue;\r
 123                         sb.append("/" + s);\r
 124                         Object o = e.getValue();\r
 125                         if (o instanceof Map<?, ?>) {\r
 126                                 sb.append((getDictionaryText((Map<String, Object>) o, "")));\r
 127                                 continue;\r
 128                         }\r
 129                         s = (String) e.getValue();\r
 130                         if (!s.startsWith("/"))\r
 131                                 sb.append(" ");\r
 132                         sb.appendO(s);\r
 133                 }\r
 134                 return (sb.length() > 3 ? sb.append(">>").append(nl).toString() : "");\r
 135         }\r
 136 \r
 137         @SuppressWarnings("unchecked")\r
 138         private Map<String, Object> createSubdict(Map<String, Object> d0, String dict) {\r
 139                 Map<String, Object> d = (Map<String, Object>) d0.get(dict);\r
 140                 if (d == null)\r
 141                         d0.put(dict, d = new Hashtable<String, Object>());\r
 142                 return d;\r
 143         }\r
 144 \r
 145         void addResource(String type, String key, String value) {\r
 146                 Map<String, Object> r = createSubdict(dictionary, "Resources");\r
 147                 if (type != null)\r
 148                         r = createSubdict(r, type);\r
 149                 r.put(key, value);\r
 150         }\r
 151         \r
 152 }\r