Hjg.Pngcs.Chunks.ChunkHelper Class Reference

Static utility methods for CHunks More...

Static Public Member Functions
static byte[]	ToBytes (String x)
	Converts to bytes using Latin1 (ISO-8859-1)
static String	ToString (byte[] x)
	Converts to String using Latin1 (ISO-8859-1)
static String	ToString (byte[] x, int offset, int len)
	Converts to String using Latin1 (ISO-8859-1)
static byte[]	ToBytesUTF8 (String x)
	Converts to bytes using UTF-8
static String	ToStringUTF8 (byte[] x)
	Converts to string using UTF-8
static String	ToStringUTF8 (byte[] x, int offset, int len)
	Converts to string using UTF-8
static void	WriteBytesToStream (Stream stream, byte[] bytes)
	Writes full array of bytes to stream
static bool	IsCritical (String id)
	Critical chunks: first letter is uppercase
static bool	IsPublic (String id)
	Public chunks: second letter is uppercase
static bool	IsSafeToCopy (String id)
	Safe to copy chunk: fourth letter is lower case
static bool	IsUnknown (PngChunk chunk)
	We consider a chunk as "unknown" if our chunk factory (even when it has been augmented by client code) doesn't recognize it
static int	PosNullByte (byte[] bytes)
	Finds position of null byte in array
static bool	ShouldLoad (String id, ChunkLoadBehaviour behav)
	Decides if a chunk should be loaded, according to a ChunkLoadBehaviour
static List< PngChunk >	FilterList (List< PngChunk > list, ChunkPredicate predicateKeep)
	Filters a list of Chunks, keeping those which match the predicate
static int	TrimList (List< PngChunk > list, ChunkPredicate predicateRemove)
	Filters a list of Chunks, removing those which match the predicate
static bool	Equivalent (PngChunk c1, PngChunk c2)
	Ad-hoc criteria for 'equivalent' chunks.
static bool	IsText (PngChunk c)

Detailed Description

Static utility methods for CHunks

Client code should rarely need this, see PngMetada and ChunksList

Member Function Documentation

static byte [] Hjg.Pngcs.Chunks.ChunkHelper.ToBytes ( String  x )

static

Converts to bytes using Latin1 (ISO-8859-1)

Parameters

x

Returns

static String Hjg.Pngcs.Chunks.ChunkHelper.ToString ( byte[]  x )

static

Converts to String using Latin1 (ISO-8859-1)

Parameters

x

Returns

static String Hjg.Pngcs.Chunks.ChunkHelper.ToString ( byte[]  x, int  offset, int  len  )

static

Converts to String using Latin1 (ISO-8859-1)

Parameters

x
offset
len

Returns

static byte [] Hjg.Pngcs.Chunks.ChunkHelper.ToBytesUTF8 ( String  x )

static

Converts to bytes using UTF-8

Parameters

x

Returns

static String Hjg.Pngcs.Chunks.ChunkHelper.ToStringUTF8 ( byte[]  x )

static

Converts to string using UTF-8

Parameters

x

Returns

static String Hjg.Pngcs.Chunks.ChunkHelper.ToStringUTF8 ( byte[]  x, int  offset, int  len  )

static

Converts to string using UTF-8

Parameters

x
offset
len

Returns

static void Hjg.Pngcs.Chunks.ChunkHelper.WriteBytesToStream ( Stream  stream, byte[]  bytes  )

static

Writes full array of bytes to stream

Parameters

stream
bytes

static bool Hjg.Pngcs.Chunks.ChunkHelper.IsCritical ( String  id )

static

Critical chunks: first letter is uppercase

Parameters

id

Returns

static bool Hjg.Pngcs.Chunks.ChunkHelper.IsPublic ( String  id )

static

Public chunks: second letter is uppercase

Parameters

id

Returns

static bool Hjg.Pngcs.Chunks.ChunkHelper.IsSafeToCopy ( String  id )

static

Safe to copy chunk: fourth letter is lower case

Parameters

id

Returns

static bool Hjg.Pngcs.Chunks.ChunkHelper.IsUnknown ( PngChunk  chunk )

static

We consider a chunk as "unknown" if our chunk factory (even when it has been augmented by client code) doesn't recognize it

Parameters

chunk

Returns

static int Hjg.Pngcs.Chunks.ChunkHelper.PosNullByte ( byte[]  bytes )

static

Finds position of null byte in array

Parameters

bytes

Returns

-1 if not found

static bool Hjg.Pngcs.Chunks.ChunkHelper.ShouldLoad ( String  id, ChunkLoadBehaviour  behav  )

static

Decides if a chunk should be loaded, according to a ChunkLoadBehaviour

Parameters

id
behav

Returns

static List<PngChunk> Hjg.Pngcs.Chunks.ChunkHelper.FilterList ( List< PngChunk >  list, ChunkPredicate  predicateKeep  )

static

Filters a list of Chunks, keeping those which match the predicate

The original list is not altered

Parameters

list
predicateKeep

Returns

static int Hjg.Pngcs.Chunks.ChunkHelper.TrimList ( List< PngChunk >  list, ChunkPredicate  predicateRemove  )

static

Filters a list of Chunks, removing those which match the predicate

The original list is not altered

Parameters

list
predicateRemove

Returns

static bool Hjg.Pngcs.Chunks.ChunkHelper.Equivalent ( PngChunk  c1, PngChunk  c2  )

static

Ad-hoc criteria for 'equivalent' chunks.

Two chunks are equivalent if they have the same Id AND either: 1. they are Single 2. both are textual and have the same key 3. both are SPLT and have the same palette name Bear in mind that this is an ad-hoc, non-standard, nor required (nor wrong) criterion. Use it only if you find it useful. Notice that PNG allows to have repeated textual keys with same keys.

Parameters

c1	Chunk1
c2	Chunk1

Returns

true if equivalent

static bool Hjg.Pngcs.Chunks.ChunkHelper.IsText ( PngChunk  c )

static