Exemplo n.º 1
0
 /**
  * Make a new entry from a bunch of bytes.
  *
  * This method will create the proper subclass of {@link PelEntry}
  * corresponding to the {@link PelTag} and {@link PelFormat} given.
  * The entry will be initialized with the data given.
  *
  * Please note that the data you pass to this method should come
  * from an image, that is, it should be raw bytes.  If instead you
  * want to create an entry for holding, say, an short integer, then
  * create a {@link PelEntryShort} object directly and load the data
  * into it.
  *
  * A {@link PelUnexpectedFormatException} is thrown if a mismatch is
  * discovered between the tag and format, and likewise a {@link
  * PelWrongComponentCountException} is thrown if the number of
  * components does not match the requirements of the tag.  The
  * requirements for a given tag (if any) can be found in the
  * documentation for {@link PelTag}.
  *
  * @param PelTag the tag of the entry.
  *
  * @param PelFormat the format of the entry.
  *
  * @param int the components in the entry.
  *
  * @param PelDataWindow the data which will be used to construct the
  * entry.
  *
  * @return PelEntry a newly created entry, holding the data given.
  */
 function newEntryFromData($tag, $format, $components, PelDataWindow $data)
 {
     /* First handle tags for which we have a specific PelEntryXXX
      * class. */
     switch ($this->type) {
         case self::IFD0:
         case self::IFD1:
         case self::EXIF:
         case self::INTEROPERABILITY:
             switch ($tag) {
                 case PelTag::DATE_TIME:
                 case PelTag::DATE_TIME_ORIGINAL:
                 case PelTag::DATE_TIME_DIGITIZED:
                     if ($format != PelFormat::ASCII) {
                         throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::ASCII);
                     }
                     if ($components != 20) {
                         throw new PelWrongComponentCountException($this->type, $tag, $components, 20);
                     }
                     // TODO: handle timezones.
                     return new PelEntryTime($tag, $data->getBytes(0, -1), PelEntryTime::EXIF_STRING);
                 case PelTag::COPYRIGHT:
                     if ($format != PelFormat::ASCII) {
                         throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::ASCII);
                     }
                     $v = explode("", trim($data->getBytes(), ' '));
                     return new PelEntryCopyright($v[0], $v[1]);
                 case PelTag::EXIF_VERSION:
                 case PelTag::FLASH_PIX_VERSION:
                 case PelTag::INTEROPERABILITY_VERSION:
                     if ($format != PelFormat::UNDEFINED) {
                         throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::UNDEFINED);
                     }
                     return new PelEntryVersion($tag, $data->getBytes() / 100);
                 case PelTag::USER_COMMENT:
                     if ($format != PelFormat::UNDEFINED) {
                         throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::UNDEFINED);
                     }
                     if ($data->getSize() < 8) {
                         return new PelEntryUserComment();
                     } else {
                         return new PelEntryUserComment($data->getBytes(8), rtrim($data->getBytes(0, 8)));
                     }
                 case PelTag::XP_TITLE:
                 case PelTag::XP_COMMENT:
                 case PelTag::XP_AUTHOR:
                 case PelTag::XP_KEYWORDS:
                 case PelTag::XP_SUBJECT:
                     if ($format != PelFormat::BYTE) {
                         throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::BYTE);
                     }
                     $v = '';
                     for ($i = 0; $i < $components; $i++) {
                         $b = $data->getByte($i);
                         /* Convert the byte to a character if it is non-null ---
                          * information about the character encoding of these entries
                          * would be very nice to have!  So far my tests have shown
                          * that characters in the Latin-1 character set are stored in
                          * a single byte followed by a NULL byte. */
                         if ($b != 0) {
                             $v .= chr($b);
                         }
                     }
                     return new PelEntryWindowsString($tag, $v);
             }
         case self::GPS:
         default:
             /* Then handle the basic formats. */
             switch ($format) {
                 case PelFormat::BYTE:
                     $v = new PelEntryByte($tag);
                     for ($i = 0; $i < $components; $i++) {
                         $v->addNumber($data->getByte($i));
                     }
                     return $v;
                 case PelFormat::SBYTE:
                     $v = new PelEntrySByte($tag);
                     for ($i = 0; $i < $components; $i++) {
                         $v->addNumber($data->getSByte($i));
                     }
                     return $v;
                 case PelFormat::ASCII:
                     return new PelEntryAscii($tag, $data->getBytes(0, -1));
                 case PelFormat::SHORT:
                     $v = new PelEntryShort($tag);
                     for ($i = 0; $i < $components; $i++) {
                         $v->addNumber($data->getShort($i * 2));
                     }
                     return $v;
                 case PelFormat::SSHORT:
                     $v = new PelEntrySShort($tag);
                     for ($i = 0; $i < $components; $i++) {
                         $v->addNumber($data->getSShort($i * 2));
                     }
                     return $v;
                 case PelFormat::LONG:
                     $v = new PelEntryLong($tag);
                     for ($i = 0; $i < $components; $i++) {
                         $v->addNumber($data->getLong($i * 4));
                     }
                     return $v;
                 case PelFormat::SLONG:
                     $v = new PelEntrySLong($tag);
                     for ($i = 0; $i < $components; $i++) {
                         $v->addNumber($data->getSLong($i * 4));
                     }
                     return $v;
                 case PelFormat::RATIONAL:
                     $v = new PelEntryRational($tag);
                     for ($i = 0; $i < $components; $i++) {
                         $v->addNumber($data->getRational($i * 8));
                     }
                     return $v;
                 case PelFormat::SRATIONAL:
                     $v = new PelEntrySRational($tag);
                     for ($i = 0; $i < $components; $i++) {
                         $v->addNumber($data->getSRational($i * 8));
                     }
                     return $v;
                 case PelFormat::UNDEFINED:
                     return new PelEntryUndefined($tag, $data->getBytes());
                 default:
                     throw new PelException('Unsupported format: %s', PelFormat::getName($format));
             }
     }
 }