org.eclipse.swt.internal.image

Class GIFFileFormat

java.lang.Object

org.eclipse.swt.internal.image.FileFormat

org.eclipse.swt.internal.image.GIFFileFormat

public final class GIFFileFormat
extends FileFormat

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int	backgroundPixel
(package private) int	bitsPerPixel
(package private) int	defaultDepth
(package private) int	delayTime
(package private) int	disposalMethod
(package private) static int	GIF_APPLICATION_EXTENSION_BLOCK_ID
(package private) static int	GIF_COMMENT_BLOCK_ID
(package private) static int	GIF_EXTENSION_BLOCK_ID
(package private) static int	GIF_GRAPHICS_CONTROL_BLOCK_ID
(package private) static int	GIF_IMAGE_BLOCK_ID
(package private) static int	GIF_PLAIN_TEXT_BLOCK_ID
(package private) static int	GIF_TRAILER_ID
(package private) static byte[]	GIF89a
(package private) static byte[]	NETSCAPE2_0
(package private) int	repeatCount
(package private) int	screenHeight
(package private) int	screenWidth
(package private) java.lang.String	signature
(package private) int	transparentPixel

Fields inherited from class org.eclipse.swt.internal.image.FileFormat

compression, FORMAT_PACKAGE, FORMAT_SUFFIX, FORMATS, inputStream, loader, outputStream

Constructor Summary

Constructors

Constructor and Description
GIFFileFormat()

Method Summary

Methods

Modifier and Type	Method and Description
(package private) void	getExtensions() Read extensions until an image descriptor appears.
(package private) static PaletteData	grayRamp(int numGrays) Answer a palette containing numGrays shades of gray, ranging from black to white.
(package private) boolean	isFileFormat(LEDataInputStream stream) Return whether or not the specified input stream represents a supported file format.
(package private) ImageData[]	loadFromByteStream() Load the GIF image(s) stored in the input stream.
(package private) byte[]	readApplicationExtension() We have just read the Application extension identifier from the input stream.
(package private) byte[]	readCommentExtension() We have just read the Comment extension identifier from the input stream.
(package private) byte[]	readExtension() Read a control extension.
(package private) byte[]	readGraphicsControlExtension() We have just read the GraphicsControl extension identifier from the input stream.
(package private) int	readID() Read and return the next block or extension identifier from the file.
(package private) ImageData	readImageBlock(PaletteData defaultPalette) Return a DeviceIndependentImage representing the image block at the current position in the input stream.
(package private) PaletteData	readPalette(int numColors) Read a palette from the input stream.
(package private) byte[]	readPlainTextExtension() We have just read the PlainText extension identifier from the input stream.
(package private) void	unloadIntoByteStream(ImageLoader loader)
(package private) void	writeGraphicsControlBlock(ImageData image) Write out a GraphicsControlBlock to describe the specified device independent image.
(package private) void	writePalette(PaletteData palette, int depth) Write the specified palette to the output stream.

Methods inherited from class org.eclipse.swt.internal.image.FileFormat

load, loadFromStream, save, unloadIntoStream

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

signature

java.lang.String signature

screenWidth

int screenWidth

screenHeight

int screenHeight

backgroundPixel

int backgroundPixel

bitsPerPixel

int bitsPerPixel

defaultDepth

int defaultDepth

disposalMethod

int disposalMethod

delayTime

int delayTime

transparentPixel

int transparentPixel

repeatCount

int repeatCount

GIF_APPLICATION_EXTENSION_BLOCK_ID

static final int GIF_APPLICATION_EXTENSION_BLOCK_ID

See Also:

Constant Field Values

GIF_GRAPHICS_CONTROL_BLOCK_ID

static final int GIF_GRAPHICS_CONTROL_BLOCK_ID

See Also:

Constant Field Values

GIF_PLAIN_TEXT_BLOCK_ID

static final int GIF_PLAIN_TEXT_BLOCK_ID

See Also:

Constant Field Values

GIF_COMMENT_BLOCK_ID

static final int GIF_COMMENT_BLOCK_ID

See Also:

Constant Field Values

GIF_EXTENSION_BLOCK_ID

static final int GIF_EXTENSION_BLOCK_ID

See Also:

Constant Field Values

GIF_IMAGE_BLOCK_ID

static final int GIF_IMAGE_BLOCK_ID

See Also:

Constant Field Values

GIF_TRAILER_ID

static final int GIF_TRAILER_ID

See Also:

Constant Field Values

GIF89a

static final byte[] GIF89a

NETSCAPE2_0

static final byte[] NETSCAPE2_0

Constructor Detail

GIFFileFormat

public GIFFileFormat()

Method Detail

grayRamp

static PaletteData grayRamp(int numGrays)

Answer a palette containing numGrays shades of gray, ranging from black to white.

isFileFormat

boolean isFileFormat(LEDataInputStream stream)

Description copied from class: FileFormat

Return whether or not the specified input stream represents a supported file format.

Specified by:

isFileFormat in class FileFormat

loadFromByteStream

ImageData[] loadFromByteStream()

Load the GIF image(s) stored in the input stream. Return an array of ImageData representing the image(s).

Specified by:

loadFromByteStream in class FileFormat

readID

int readID()

Read and return the next block or extension identifier from the file.

getExtensions

void getExtensions()

Read extensions until an image descriptor appears. In the future, if we care about the extensions, they should be properly grouped with the image data before which they appeared. Right now, the interesting parts of some extensions are kept, but the rest is discarded. Throw an error if an error occurs.

readExtension

byte[] readExtension()

Read a control extension. Return the extension block data.

readCommentExtension

byte[] readCommentExtension()

We have just read the Comment extension identifier from the input stream. Read in the rest of the comment and return it. GIF comment blocks are variable size.

readPlainTextExtension

byte[] readPlainTextExtension()

We have just read the PlainText extension identifier from the input stream. Read in the plain text info and text, and return the text. GIF plain text blocks are variable size.

readGraphicsControlExtension

byte[] readGraphicsControlExtension()

We have just read the GraphicsControl extension identifier from the input stream. Read in the control information, store it, and return it.

readApplicationExtension

byte[] readApplicationExtension()

We have just read the Application extension identifier from the input stream. Read in the rest of the extension, look for and store 'number of repeats', and return the data.

readImageBlock

ImageData readImageBlock(PaletteData defaultPalette)

Return a DeviceIndependentImage representing the image block at the current position in the input stream. Throw an error if an error occurs.

readPalette

PaletteData readPalette(int numColors)

Read a palette from the input stream.

unloadIntoByteStream

void unloadIntoByteStream(ImageLoader loader)

Specified by:

unloadIntoByteStream in class FileFormat

writeGraphicsControlBlock

void writeGraphicsControlBlock(ImageData image)

Write out a GraphicsControlBlock to describe the specified device independent image.

writePalette

void writePalette(PaletteData palette,
                int depth)

Write the specified palette to the output stream.