PngChunk (PNGJ 2.1.0 API)

java.lang.Object
- ar.com.hjg.pngj.chunks.PngChunk

Direct Known Subclasses:

PngChunkMultiple, PngChunkSingle
```
public abstract class PngChunk
extends Object
```
Represents a instance of a PNG chunk.
See http://www .libpng.org/pub/png/spec/1.2/PNG-Chunks .html
Concrete classes should extend PngChunkSingle or PngChunkMultiple
Note that some methods/fields are type-specific (getOrderingConstraint(), allowsMultiple()),
some are 'almost' type-specific (id,crit,pub,safe; the exception is PngUKNOWN),
and the rest are instance-specific

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class PngChunk.ChunkOrderingConstraint
Possible ordering constraint for a PngChunk type -only relevant for ancillary chunks.

Nested Classes
Modifier and Type	Class and Description
`static class`	`PngChunk.ChunkOrderingConstraint` Possible ordering constraint for a PngChunk type -only relevant for ancillary chunks.

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`chunkGroup`
`boolean`	`crit` Autocomputed at creation time
`String`	`id` Chunk-id: 4 letters
`protected ImageInfo`	`imgInfo`
`boolean`	`pub` Autocomputed at creation time
`protected ChunkRaw`	`raw`
`boolean`	`safe` Autocomputed at creation time

Constructor Summary

Constructors
Constructor and Description

PngChunk(String id, ImageInfo imgInfo)

Constructors
Constructor and Description
`PngChunk(String id, ImageInfo imgInfo)`

Method Summary

Methods
Modifier and Type	Method and Description
`protected abstract boolean`	`allowsMultiple()` See `PngChunkMultiple` and `PngChunkSingle`
`protected ChunkRaw`	`createEmptyChunk(int len, boolean alloc)`
`protected abstract ChunkRaw`	`createRawChunk()` Creates the physical chunk.
`int`	`getChunkGroup()` In which "chunkGroup" (see `ChunksList`for definition) this chunks instance was read or written.
`int`	`getLen()`
`long`	`getOffset()`
`abstract PngChunk.ChunkOrderingConstraint`	`getOrderingConstraint()` see `PngChunk.ChunkOrderingConstraint`
`ChunkRaw`	`getRaw()`
`boolean`	`hasPriority()`
`void`	`invalidateRawData()` This signals that the raw chunk (serialized data) as invalid, so that it's regenerated on write.
`protected abstract void`	`parseFromRaw(ChunkRaw c)` Parses raw chunk and fill inside data.
`void`	`setPriority(boolean priority)`
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - id
```
public final String id
```
    Chunk-id: 4 letters
  - crit
```
public final boolean crit
```
    Autocomputed at creation time
  - pub
```
public final boolean pub
```
    Autocomputed at creation time
  - safe
```
public final boolean safe
```
    Autocomputed at creation time
  - imgInfo
```
protected final ImageInfo imgInfo
```
  - raw
```
protected ChunkRaw raw
```
  - chunkGroup
```
protected int chunkGroup
```
- Constructor Detail
  - PngChunk
```
public PngChunk(String id,
        ImageInfo imgInfo)
```
- Method Detail
  - createEmptyChunk
```
protected final ChunkRaw createEmptyChunk(int len,
                        boolean alloc)
```
  - getChunkGroup
```
public final int getChunkGroup()
```
    In which "chunkGroup" (see ChunksListfor definition) this chunks instance was read or written.
    -1 if not read or written (eg, queued)
  - hasPriority
```
public boolean hasPriority()
```
  - setPriority
```
public void setPriority(boolean priority)
```
  - createRawChunk
```
protected abstract ChunkRaw createRawChunk()
```
    Creates the physical chunk. This is used when writing (serialization). Each particular chunk class implements its own logic.
    
    Returns:
    A newly allocated and filled raw chunk
  - parseFromRaw
```
protected abstract void parseFromRaw(ChunkRaw c)
```
    Parses raw chunk and fill inside data. This is used when reading (deserialization). Each particular chunk class implements its own logic.
  - allowsMultiple
```
protected abstract boolean allowsMultiple()
```
    See PngChunkMultiple and PngChunkSingle
    
    Returns:
    true if PNG accepts multiple chunks of this class
  - getRaw
```
public ChunkRaw getRaw()
```
  - getLen
```
public int getLen()
```
    See Also:
    ChunkRaw.len
  - getOffset
```
public long getOffset()
```
    See Also:
    ChunkRaw.getOffset()
  - invalidateRawData
```
public void invalidateRawData()
```
    This signals that the raw chunk (serialized data) as invalid, so that it's regenerated on write. This should be called for the (infrequent) case of chunks that were copied from a PngReader and we want to manually modify it.
  - getOrderingConstraint
```
public abstract PngChunk.ChunkOrderingConstraint getOrderingConstraint()
```
    see PngChunk.ChunkOrderingConstraint
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class PngChunk

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

id

crit

pub

safe

imgInfo

raw

chunkGroup

Constructor Detail

PngChunk

Method Detail

createEmptyChunk

getChunkGroup

hasPriority

setPriority

createRawChunk

parseFromRaw

allowsMultiple

getRaw

getLen

getOffset

invalidateRawData

getOrderingConstraint

toString