to.etc.sjit

Class AnimGifEncoder

java.lang.Object

to.etc.sjit.AnimGifEncoder

public class AnimGifEncoder
extends Object

This class can be used to write an animated GIF file by combining several images. It is loosely based on the Acme GIF encoder.

The characteristics of the generated Gif 89a image are:

• Only a single color table is used (no local tables). This table is created by combining the colors from all other images.

An example of how to save an image to GIF is:

 import to.etc.sjit.*;   // Simple Java Imaging Tools

 private void saveGIF(File f, Image i2) throws IOException
 {
     OutputStream    ros = new FileOutputStream(f);
     try
     {
         AnimGifEncoder  ge  = new AnimGifEncoder(ros);
         ge.add(i);
         ge.encode();
     }
     finally
     {
         try { if(ros != null) ros.close(); } catch {}
     }
 }
 

Author:

Frits Jalvingh

Field Summary

Fields

Modifier and Type	Field and Description
boolean	m_no_opt

Constructor Summary

Constructors

Constructor and Description
AnimGifEncoder(OutputStream os) This constructor creates an empty default codec.
AnimGifEncoder(OutputStream os, boolean interlace) Creates a codec and specify interlace (not implemented yet).

Method Summary

Modifier and Type	Method and Description
void	add(Image ima) Adds the specified image to the list of images.
void	add(Image ima, int delay) Adds the specified image to the list of images.
void	add(Image ima, int delaytime, boolean interlace, int px, int py) Adds the specified image to the list of images.
void	encode() Creates the GIF file from all images added to the encoder.
void	flush() Releases ALL cached resources.
void	setLoop(boolean loop) For animated GIF's the default is to LOOP all images in the GIF file.

Methods inherited from class java.lang.Object

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

Field Detail

m_no_opt

public boolean m_no_opt

Constructor Detail

AnimGifEncoder

public AnimGifEncoder(OutputStream os)

This constructor creates an empty default codec.

AnimGifEncoder

public AnimGifEncoder(OutputStream os,
                      boolean interlace)

Creates a codec and specify interlace (not implemented yet).

Method Detail

setLoop

public void setLoop(boolean loop)

For animated GIF's the default is to LOOP all images in the GIF file. This means that after displaying all images in the file the first image is redisplayed ad infinitum.

To prevent the images from looping call setLoop(false) before calling the encode() method.

The current version does not allow the number of repetitions to be specified.

flush

public void flush()

Releases ALL cached resources.

add

public void add(Image ima,
                int delaytime,
                boolean interlace,
                int px,
                int py)
         throws IOException

Adds the specified image to the list of images. While adding, the image is converted to pixels; each color is added to the color table and the resulting 8-bit pixelset is saved. After this call the image is released, and only the pixelset remains until the encode call is made. Calling encode will release the pixelset.

Throws:

IOException

add

public void add(Image ima)
         throws IOException

Adds the specified image to the list of images.

Throws:

IOException

add

public void add(Image ima,
                int delay)
         throws IOException

Adds the specified image to the list of images.

Throws:

IOException

encode

public void encode()
            throws IOException

Creates the GIF file from all images added to the encoder.

Throws:

IOException