GifDecoder (WebLaF core library 1.2.13 API)

java.lang.Object
- com.alee.graphics.image.gif.GifDecoder

```
public class GifDecoder
extends Object
```
Version:

1.01 July 2001

Author:

Kevin Weiner, FM Software; LZW decoder adapted from John Cristy's ImageMagick.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`STATUS_FORMAT_ERROR` File read status: Error decoding file (may be partially decoded)
`static int`	`STATUS_OK` File read status: No errors.
`static int`	`STATUS_OPEN_ERROR` File read status: Unable to open source.

Constructor Summary

Constructors
Constructor and Description

GifDecoder()

Constructors
Constructor and Description
`GifDecoder()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`decodeImageData()` Decodes LZW image data into pixel array.
`protected boolean`	`err()` Returns whether or not an error was encountered during reading/decoding.
`BufferedImage`	`getCurrentBufImg()` Gets the first (or only) image read.
`int`	`getDelay(int n)` Gets display duration for specified frame.
`BufferedImage`	`getFrame(int n)` Gets the image contents of frame n.
`int`	`getFrameCount()` Gets the number of frames read from file.
`int`	`getLoopCount()` Gets the "Netscape" iteration count, if any.
`int`	`getPixelAspect()` Returns pixel aspect ratio.
`int`	`getStatus()` Returns decoder status.
`protected void`	`init()` Initializes or re-initializes reader
`protected int`	`read()` Reads a single byte from the input stream.
`int`	`read(BufferedInputStream is)`
`int`	`read(String name)` Reads GIF file from specified source (file or URL string)
`protected int`	`readBlock()` Reads next variable length block from input.
`protected int[]`	`readColorTable(int ncolors)` Reads color table as 256 RGB integer values
`protected void`	`readContents()` Main file parser.
`protected void`	`readGraphicControlExt()` Reads Graphics Control Extension values
`protected void`	`readHeader()` Reads GIF file header information.
`protected void`	`readImage()` Reads next frame image
`protected void`	`readLSD()` Reads Logical Screen Descriptor
`protected void`	`readNetscapeExt()` Reads Netscape extension to obtain iteration count
`protected int`	`readShort()` Reads next 16-bit value, LSB first.
`protected void`	`resetFrame()` Resets frame state for reading next image.
`protected void`	`setPixels()` Creates new frame image from current data (and previous frames as specified by their disposition codes).
`protected void`	`skip()` Skips variable length blocks up to and including next zero length block.

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

- Field Detail
  - STATUS_OK
```
public static final int STATUS_OK
```
    File read status: No errors.
    
    See Also:
    
    Constant Field Values
  - STATUS_FORMAT_ERROR
```
public static final int STATUS_FORMAT_ERROR
```
    File read status: Error decoding file (may be partially decoded)
    
    See Also:
    
    Constant Field Values
  - STATUS_OPEN_ERROR
```
public static final int STATUS_OPEN_ERROR
```
    File read status: Unable to open source.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - GifDecoder
```
public GifDecoder()
```
- Method Detail
  - getPixelAspect
```
public int getPixelAspect()
```
    Returns pixel aspect ratio.
    
    Returns:
    
    pixel aspect ratio
  - getDelay
```
public int getDelay(int n)
```
    Gets display duration for specified frame.
    
    Parameters:
    
    n - int index of frame
    
    Returns:
    
    delay in milliseconds
  - getFrame
```
public BufferedImage getFrame(int n)
```
    Gets the image contents of frame n.
    
    Parameters:
    
    n - frame number
    
    Returns:
    
    BufferedImage representation of frame, or null if n is invalid
  - getFrameCount
```
public int getFrameCount()
```
    Gets the number of frames read from file.
    
    Returns:
    
    frame count
  - getCurrentBufImg
```
public BufferedImage getCurrentBufImg()
```
    Gets the first (or only) image read.
    
    Returns:
    
    BufferedImage containing first frame, or null if none.
  - getLoopCount
```
public int getLoopCount()
```
    Gets the "Netscape" iteration count, if any. A count of 0 means repeat indefinitely.
    
    Returns:
    
    iteration count if one was specified, else 1.
  - read
```
public int read(BufferedInputStream is)
```
    Parameters:
    
    is - An inputStream with gif animation
    
    Returns:
    
    status code (0=no error)
  - read
```
public int read(String name)
```
    Reads GIF file from specified source (file or URL string)
    
    Parameters:
    
    name - String containing source
    
    Returns:
    
    read status code (0 = no errors)
  - decodeImageData
```
protected void decodeImageData()
```
    Decodes LZW image data into pixel array. Adapted from John Cristy's ImageMagick.
  - err
```
protected boolean err()
```
    Returns whether or not an error was encountered during reading/decoding.
    
    Returns:
    
    true if an error was encountered during reading/decoding, false otherwise
  - init
```
protected void init()
```
    Initializes or re-initializes reader
  - read
```
protected int read()
```
    Reads a single byte from the input stream.
    
    Returns:
    
    single byte from the input stream
  - readBlock
```
protected int readBlock()
```
    Reads next variable length block from input.
    
    Returns:
    
    number of bytes stored in "buffer"
  - readColorTable
```
protected int[] readColorTable(int ncolors)
```
    Reads color table as 256 RGB integer values
    
    Parameters:
    
    ncolors - int number of colors to read
    
    Returns:
    
    int array containing 256 colors (packed ARGB with full alpha)
  - readContents
```
protected void readContents()
```
    Main file parser. Reads GIF content blocks.
  - readGraphicControlExt
```
protected void readGraphicControlExt()
```
    Reads Graphics Control Extension values
  - readHeader
```
protected void readHeader()
```
    Reads GIF file header information.
  - readImage
```
protected void readImage()
```
    Reads next frame image
  - readLSD
```
protected void readLSD()
```
    Reads Logical Screen Descriptor
  - readNetscapeExt
```
protected void readNetscapeExt()
```
    Reads Netscape extension to obtain iteration count
  - readShort
```
protected int readShort()
```
    Reads next 16-bit value, LSB first.
    
    Returns:
    
    next 16-bit value, LSB first
  - resetFrame
```
protected void resetFrame()
```
    Resets frame state for reading next image.
  - setPixels
```
protected void setPixels()
```
    Creates new frame image from current data (and previous frames as specified by their disposition codes).
  - skip
```
protected void skip()
```
    Skips variable length blocks up to and including next zero length block.
  - getStatus
```
public int getStatus()
```
    Returns decoder status.
    
    Returns:
    
    decoder status

Class GifDecoder

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

STATUS_OK

STATUS_FORMAT_ERROR

STATUS_OPEN_ERROR

Constructor Detail

GifDecoder

Method Detail

getPixelAspect

getDelay

getFrame

getFrameCount

getCurrentBufImg

getLoopCount

read

read

decodeImageData

err

init

read

readBlock

readColorTable

readContents

readGraphicControlExt

readHeader

readImage

readLSD

readNetscapeExt

readShort

resetFrame

setPixels

skip

getStatus