ChunkReader (PNGJ 2.0.1 API)

java.lang.Object
- ar.com.hjg.pngj.ChunkReader

Direct Known Subclasses:

DeflatedChunkReader
```
public abstract class ChunkReader
extends Object
```
Parses a PNG chunk, consuming bytes in one mode: ChunkReader.ChunkReaderMode.BUFFER, ChunkReader.ChunkReaderMode.PROCESS, ChunkReader.ChunkReaderMode.SKIP.
It calls chunkDone() when done. Also calls processData(byte[], int, int) if PROCESS mode. Apart from thas, it's totally agnostic (it doesn't know about IDAT chunks, or PNG general structure)
The object wraps a ChunkRaw instance (content filled only if BUFFER mode); it should be short lived (one instance created for each chunk, and discarded after reading), but the wrapped chunkRaw can be (usually is) long lived.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class ChunkReader.ChunkReaderMode
Modes of ChunkReader chunk processing.

Nested Classes
Modifier and Type	Class and Description
`static class`	`ChunkReader.ChunkReaderMode` Modes of ChunkReader chunk processing.

Field Summary

Fields
Modifier and Type Field and Description

protected ChunkReader.ChunkReaderMode mode

protected int read
How many bytes have been read for this chunk, data only

Fields
Modifier and Type	Field and Description
`protected ChunkReader.ChunkReaderMode`	`mode`
`protected int`	`read` How many bytes have been read for this chunk, data only

Constructor Summary

Constructors
Constructor and Description
`ChunkReader(int clen, String id, long offsetInPng, ChunkReader.ChunkReaderMode mode)` The constructor creates also a chunkRaw, preallocated if mode = ChunkReaderMode.BUFFER

Method Summary

Methods
Modifier and Type	Method and Description
`protected abstract void`	`chunkDone()` This method will be called (in all modes) when the full chunk -including crc- has been read
`boolean`	`equals(Object obj)` Equality (and hash) is basically delegated to the ChunkRaw
`int`	`feedBytes(byte[] buf, int off, int len)` Consumes data for the chunk (data and CRC).
`ChunkRaw`	`getChunkRaw()` Returns raw chunk (data can be empty or not, depending on ChunkReaderMode)
`int`	`hashCode()`
`boolean`	`isDone()` Chunks has been read
`protected abstract void`	`processData(byte[] buf, int off, int len)` This method will only be called in PROCESS mode, probably several times, each time with a new fragment of data It's guaranteed that the data to read has non-zero length and it corresponds exclusively to this chunk data (no crc, no data from no other chunks, )
`void`	`setCrcCheck(boolean crcCheck)` Determines if CRC should be checked.
`String`	`toString()`

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

- Field Detail
  - mode
```
protected final ChunkReader.ChunkReaderMode mode
```
  - read
```
protected int read
```
    How many bytes have been read for this chunk, data only
- Constructor Detail
  - ChunkReader
```
public ChunkReader(int clen,
           String id,
           long offsetInPng,
           ChunkReader.ChunkReaderMode mode)
```
    The constructor creates also a chunkRaw, preallocated if mode = ChunkReaderMode.BUFFER
    
    Parameters:
    clen -
    id -
    offsetInPng - Informational, is stored in chunkRaw
    mode -
- Method Detail
  - getChunkRaw
```
public ChunkRaw getChunkRaw()
```
    Returns raw chunk (data can be empty or not, depending on ChunkReaderMode)
    
    Returns:
    Raw chunk - never null
  - feedBytes
```
public final int feedBytes(byte[] buf,
            int off,
            int len)
```
    Consumes data for the chunk (data and CRC). This never consumes more bytes than for this chunk. In HOT_PROCESS can call processData() (not more than once) If this ends the chunk (included CRC) it checks CRC (if checking) and calls chunkDone()
    
    Parameters:
    buf -
    off -
    len -
    
    Returns:
    How many bytes have been consumed
  - isDone
```
public final boolean isDone()
```
    Chunks has been read
    
    Returns:
    true if we have read all chunk, including trailing CRC
  - setCrcCheck
```
public void setCrcCheck(boolean crcCheck)
```
    Determines if CRC should be checked. This should be called before starting reading.
    
    Parameters:
    crcCheck -
  - processData
```
protected abstract void processData(byte[] buf,
               int off,
               int len)
```
    This method will only be called in PROCESS mode, probably several times, each time with a new fragment of data It's guaranteed that the data to read has non-zero length and it corresponds exclusively to this chunk data (no crc, no data from no other chunks, )
  - chunkDone
```
protected abstract void chunkDone()
```
    This method will be called (in all modes) when the full chunk -including crc- has been read
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object obj)
```
    Equality (and hash) is basically delegated to the ChunkRaw
    
    Overrides:
    
    equals in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class ChunkReader

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

mode

read

Constructor Detail

ChunkReader

Method Detail

getChunkRaw

feedBytes

isDone

setCrcCheck

processData

chunkDone

hashCode

equals

toString