jbarcode.jar

package net.jmge.gif; import java.awt.Color; import java.awt.Dimension; import java.awt.Image; import java.awt.Toolkit; import java.io.BufferedOutputStream; import java.io.BufferedReader; import java.io.FileOutputStream; import java.io.FileReader; import java.io.IOException; import java.io.OutputStream; import java.util.Vector; //============================================================================== /** This is the central class of a JDK 1.1 compatible GIF encoder that, AFAIK, * supports more features of the extended GIF spec than any other Java open * source encoder. Some sections of the source are lifted or adapted from Jef * Poskanzer's <cite>Acme GifEncoder</cite> (so please see the * <a href="../readme.txt">readme</a> containing his notice), but much of it, * including nearly all of the present class, is original code. My main * motivation for writing a new encoder was to support animated GIFs, but the * package also adds support for embedded textual comments. * <p> * There are still some limitations. For instance, animations are limited to * a single global color table. But that is usually what you want anyway, so * as to avoid irregularities on some displays. (So this is not really a * limitation, but a "disciplinary feature" :) Another rather more serious * restriction is that the total number of RGB colors in a given input-batch * mustn't exceed 256. Obviously, there is an opening here for someone who * would like to add a color-reducing preprocessor. * <p> * The encoder, though very usable in its present form, is at bottom only a * partial implementation skewed toward my own particular needs. Hence a * couple of caveats are in order. (1) During development it was in the back * of my mind that an encoder object should be reusable - i.e., you should be * able to make multiple calls to encode() on the same object, with or without * intervening frame additions or changes to options. But I haven't reviewed * the code with such usage in mind, much less tested it, so it's likely I * overlooked something. (2) The encoder classes aren't thread safe, so use * caution in a context where access is shared by multiple threads. (Better * yet, finish the library and re-release it :) * <p> * There follow a couple of simple examples illustrating the most common way to * use the encoder, i.e., to encode AWT Image objects created elsewhere in the * program. Use of some of the most popular format options is also shown, * though you will want to peruse the API for additional features. * * <p> * <strong>Animated GIF Example</strong> * <pre> * import net.jmge.gif.Gif89Encoder; * // ... * void writeAnimatedGIF(Image[] still_images, * String annotation, * boolean looped, * double frames_per_second, * OutputStream out) throws IOException * { * Gif89Encoder gifenc = new Gif89Encoder(); * for (int i = 0; i < still_images.length; ++i) * gifenc.addFrame(still_images[i]); * gifenc.setComments(annotation); * gifenc.setLoopCount(looped ? 0 : 1); * gifenc.setUniformDelay((int) Math.round(100 / frames_per_second)); * gifenc.encode(out); * } * </pre> * * <strong>Static GIF Example</strong> * <pre> * import net.jmge.gif.Gif89Encoder; * // ... * void writeNormalGIF(Image img, * String annotation, * int transparent_index, // pass -1 for none * boolean interlaced, * OutputStream out) throws IOException * { * Gif89Encoder gifenc = new Gif89Encoder(img); * gifenc.setComments(annotation); * gifenc.setTransparentIndex(transparent_index); * gifenc.getFrameAt(0).setInterlaced(interlaced); * gifenc.encode(out); * } * </pre> * * @version 0.90 beta (15-Jul-2000) * @author J. M. G. Elliott (tep@jmge.net) * @see Gif89Frame * @see DirectGif89Frame * @see IndexGif89Frame */ public class Gif89Encoder { private Dimension dispDim = new Dimension(0, 0); private GifColorTable colorTable; private int bgIndex = 0; private int loopCount = 1; private String theComments; private Vector vFrames = new Vector(); //---------------------------------------------------------------------------- /** Use this default constructor if you'll be adding multiple frames * constructed from RGB data (i.e., AWT Image objects or ARGB-pixel arrays). */ public Gif89Encoder() { // empty color table puts us into "palette autodetect" mode colorTable = new GifColorTable(); } //---------------------------------------------------------------------------- /** Like the default except that it also adds a single frame, for conveniently * encoding a static GIF from an image. * * @param static_image * Any Image object that supports pixel-grabbing. * @exception IOException * See the addFrame() methods. */ public Gif89Encoder(Image static_image) throws IOException { this(); addFrame(static_image); } //---------------------------------------------------------------------------- /** This constructor installs a user color table, overriding the detection of * of a palette from ARBG pixels. * * Use of this constructor imposes a couple of restrictions: * (1) Frame objects can't be of type DirectGif89Frame * (2) Transparency, if desired, must be set explicitly. * * @param colors * Array of color values; no more than 256 colors will be read, since that's * the limit for a GIF. */ public Gif89Encoder(Color[] colors) { colorTable = new GifColorTable(colors); } //---------------------------------------------------------------------------- /** Convenience constructor for encoding a static GIF from index-model data. * Adds a single frame as specified. * * @param colors * Array of color values; no more than 256 colors will be read, since * that's the limit for a GIF. * @param width * Width of the GIF bitmap. * @param height * Height of same. * @param ci_pixels * Array of color-index pixels no less than width * height in length. * @exception IOException * See the addFrame() methods. */ public Gif89Encoder(Color[] colors, int width, int height, byte ci_pixels[]) throws IOException { this(colors); addFrame(width, height, ci_pixels); } //---------------------------------------------------------------------------- /** Get the number of frames that have been added so far. * * @return * Number of frame items. */ public int getFrameCount() { return vFrames.size(); } //---------------------------------------------------------------------------- /** Get a reference back to a Gif89Frame object by position. * * @param index * Zero-based index of the frame in the sequence. * @return * Gif89Frame object at the specified position (or null if no such frame). */ public Gif89Frame getFrameAt(int index) { return isOk(index) ? (Gif89Frame) vFrames.elementAt(index) : null; } //---------------------------------------------------------------------------- /** Add a Gif89Frame frame to the end of the internal sequence. Note that * there are restrictions on the Gif89Frame type: if the encoder object was * constructed with an explicit color table, an attempt to add a * DirectGif89Frame will throw an exception. * * @param gf * An externally constructed Gif89Frame. * @exception IOException * If Gif89Frame can't be accommodated. This could happen if either (1) the *