Package com.mcgath.jhove.module.png

Class PNGChunk

java.lang.Object
com.mcgath.jhove.module.png.PNGChunk
Direct Known Subclasses:
BkgdChunk, ChrmChunk, GamaChunk, GeneralTextChunk, HistChunk, IccpChunk, IdatChunk, IendChunk, IhdrChunk, PhysChunk, PlteChunk, SbitChunk, SpltChunk, SrgbChunk, TimeChunk, TrnsChunk, UnknownChunk
public abstract class PNGChunk extends Object

  • Field Details

  • Constructor Details

    • PNGChunk

      public PNGChunk()

  • Method Details

    • makePNGChunk

      public static PNGChunk makePNGChunk(long length, int sig)
      Construct a PNGChunk object of the appropriate subtype based on the chunk type.

    • setNisoMetadata

      public void setNisoMetadata(NisoImageMetadata nmd)
      Hand the chunk the NISO metadata object if it needs to put information into it.

    • setPropertyList

      public void setPropertyList(List<Property> lst)
      Hand the main property list to the chunk

    • setModule

      public void setModule(PngModule mdl)
      Give the chunk a reference to the PNG module.

    • setInputStream

      public void setInputStream(DataInputStream dstrm)
      Give the chunk a reference to the data stream.

    • getLength

      public long getLength()

    • getChunkType

      public int getChunkType()

    • getChunkData

      public char[] getChunkData()

    • getCRC

      public long getCRC()

    • processChunk

      public void processChunk(RepInfo info) throws Exception
      Process a chunk. When this is called, the input stream needs to have read the type and length and be positioned at the start of the data. The default behavior is to eat the chunk. This should be the behavior only for UnknownChunk when we're done.
      Throws:
      Exception

    • processChunkCommon

      public void processChunkCommon(RepInfo info) throws PNGException
      Common code to call at the start of every processChunk method.
      Throws:
      PNGException

    • readUnsignedInt

      public long readUnsignedInt() throws IOException
      Read a 4-byte unsigned integer and update the CRC
      Throws:
      IOException

    • readUnsignedShort

      public int readUnsignedShort() throws IOException
      Read a 2-byte unsigned integer and update the CRC
      Throws:
      IOException

    • readUnsignedByte

      public int readUnsignedByte() throws IOException
      Read a single byte and update the CRC
      Throws:
      IOException

    • skipBytes

      public void skipBytes(int count) throws IOException
      Skip over all the bytes, updating the CRC
      Throws:
      IOException

    • readCRC

      public long readCRC() throws IOException
      Read the CRC itself. Naturally, this doesn't update the CRC.
      Throws:
      IOException

    • chunkTypeString

      public String chunkTypeString()