Class PNGChunk

public static final int TYPE_DATA

Field Value:

1229209940

public static final int TYPE_END

Field Value:

1229278788

public static final int TYPE_GAMMA

Field Value:

1732332865

public static final int TYPE_HEADER

(recognized) PNG chunk types.

Field Value:

1229472850

public static final int TYPE_PALETTE

Field Value:

1347179589

public static final int TYPE_PHYS

Field Value:

1883789683

public static final int TYPE_PROFILE

Field Value:

1766015824

public static final int TYPE_TIME

Field Value:

1950960965

protected byte[] data

The chunk data

protected PNGChunk(int type)

Constructor for creating new chunks. (only used by subclasses - creating a generic chunk is rather useless)

protected PNGChunk(int type,
                   byte[] data,
                   int crc)

Constructor for reading a generic chunk.

public static byte[] getInt(int intValue)

Convenience method. Cast an int to four bytes (big endian). (Now why doesn't java have a simple way of doing this?)

public int getType()

Returns the chunk type.

public boolean isEmpty()

Return whether the chunk contains any data.

public boolean isValidChunk()

Validates the chunk

public static PNGChunk readChunk(InputStream in,
                                 boolean strict)
            throws IOException,
                   PNGException

Loads a chunk from an InputStream. Does not perform validation, but will throw an IOException if the read fails.

Parameters:

in - - th einputstream to read from

strict - - if true, a PNGException is thrown on all invalid chunks, if false, only critical chunks will throw PNGExceptions.

public String toString()

Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() and such.

It is typical, but not required, to ensure that this method never completes abruptly with a RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).

Overrides:

toString in interface Object

Returns:

the String representing this Object, which may be null

See Also:

getClass(), Object.hashCode(), Class.getName(), Integer.toHexString(int)

public void writeChunk(OutputStream out)
            throws IOException

Writes a PNG chunk to an output stream, performing the CRC calculation as well.