/** Read Image data */
private boolean readImage(boolean first, int disposal_method, int delay) throws IOException {
if (curframe != null && !curframe.dispose()) {
abort();
return false;
}
long tm = 0;
if (verbose) {
tm = System.currentTimeMillis();
}
// Allocate the buffer
byte block[] = new byte[256 + 3];
// Read the image descriptor
if (readBytes(block, 0, 10) != 0) {
throw new IOException();
}
int x = ExtractWord(block, 0);
int y = ExtractWord(block, 2);
int width = ExtractWord(block, 4);
int height = ExtractWord(block, 6);
boolean interlace = (block[8] & INTERLACEMASK) != 0;
IndexColorModel model = global_model;
if ((block[8] & COLORMAPMASK) != 0) {
// We read one extra byte above so now when we must
// transfer that byte as the first colormap byte
// and manually read the code size when we are done
int num_local_colors = 1 << ((block[8] & 0x7) + 1);
// Read local colors
byte[] local_colormap = new byte[num_local_colors * 3];
local_colormap[0] = block[9];
if (readBytes(local_colormap, 1, num_local_colors * 3 - 1) != 0) {
throw new IOException();
}
// Now read the "real" code size byte which follows
// the local color table
if (readBytes(block, 9, 1) != 0) {
throw new IOException();
}
model = new IndexColorModel(8, num_local_colors, local_colormap, 0, false, trans_pixel);
} else if (model == null || trans_pixel != model.getTransparentPixel()) {
model = new IndexColorModel(8, num_global_colors, global_colormap, 0, false, trans_pixel);
global_model = model;
}
// Notify the consumers
if (first) {
if (global_width == 0) global_width = width;
if (global_height == 0) global_height = height;
setDimensions(global_width, global_height);
setProperties(props);
setColorModel(model);
headerComplete();
}
if (disposal_method == GifFrame.DISPOSAL_SAVE && saved_image == null) {
saved_image = new byte[global_width * global_height];
}
int hints = (interlace ? interlaceflags : normalflags);
setHints(hints);
curframe =
new GifFrame(this, disposal_method, delay, (curframe == null), model, x, y, width, height);
// allocate the raster data
byte rasline[] = new byte[width];
if (verbose) {
System.out.print(
"Reading a "
+ width
+ " by "
+ height
+ " "
+ (interlace ? "" : "non-")
+ "interlaced image...");
}
boolean ret =
parseImage(x, y, width, height, interlace, ExtractByte(block, 9), block, rasline, model);
if (!ret) {
abort();
}
if (verbose) {
System.out.println("done in " + (System.currentTimeMillis() - tm) + "ms");
}
return ret;
}
/** produce an image from the stream. */
public void produceImage() throws IOException, ImageFormatException {
try {
readHeader();
int totalframes = 0;
int frameno = 0;
int nloops = -1;
int disposal_method = 0;
int delay = -1;
boolean loopsRead = false;
boolean isAnimation = false;
while (!aborted) {
int code;
if (!ImageProductionMonitor.allowsProduction()) {
abort();
break;
}
switch (code = input.read()) {
case EXBLOCK:
switch (code = input.read()) {
case EX_GRAPHICS_CONTROL:
{
byte buf[] = new byte[6];
if (readBytes(buf, 0, 6) != 0) {
return; // error("corrupt GIF file");
}
if ((buf[0] != 4) || (buf[5] != 0)) {
return; // error("corrupt GIF file (GCE size)");
}
// Get the index of the transparent color
delay = ExtractWord(buf, 2) * 10;
if (delay > 0 && !isAnimation) {
isAnimation = true;
ImageFetcher.startingAnimation();
}
disposal_method = (buf[1] >> 2) & 7;
if ((buf[1] & TRANSPARENCYMASK) != 0) {
trans_pixel = ExtractByte(buf, 4);
} else {
trans_pixel = -1;
}
break;
}
case EX_COMMENT:
case EX_APPLICATION:
default:
boolean loop_tag = false;
String comment = "";
while (true) {
int n = input.read();
if (n <= 0) {
break;
}
byte buf[] = new byte[n];
if (readBytes(buf, 0, n) != 0) {
return; // error("corrupt GIF file");
}
if (code == EX_COMMENT) {
comment += new String(buf);
} else if (code == EX_APPLICATION) {
if (loop_tag) {
if (n == 3 && buf[0] == 1) {
if (loopsRead) {
ExtractWord(buf, 1);
} else {
nloops = ExtractWord(buf, 1);
loopsRead = true;
}
} else {
loop_tag = false;
}
}
if ("NETSCAPE2.0".equals(new String(buf))) {
loop_tag = true;
}
}
}
if (code == EX_COMMENT) {
props.put("comment", comment);
}
if (loop_tag && !isAnimation) {
isAnimation = true;
ImageFetcher.startingAnimation();
}
break;
case -1:
return; // error("corrupt GIF file");
}
break;
case IMAGESEP:
if (!isAnimation) {
input.mark(0); // we don't need the mark buffer
}
try {
if (!readImage(totalframes == 0, disposal_method, delay)) {
return;
}
} catch (Exception e) {
if (verbose) {
e.printStackTrace();
}
return;
}
frameno++;
totalframes++;
break;
default:
case -1:
if (verbose) {
if (code == -1) {
System.err.println("Premature EOF in GIF file," + " frame " + frameno);
} else {
System.err.println("corrupt GIF file (parse) [" + code + "].");
}
}
if (frameno == 0) {
return;
}
// NOBREAK
case TERMINATOR:
if (nloops == 0 || nloops-- >= 0) {
try {
if (curframe != null) {
curframe.dispose();
curframe = null;
}
input.reset();
saved_image = null;
saved_model = null;
frameno = 0;
break;
} catch (IOException e) {
return; // Unable to reset input buffer
}
}
if (verbose && frameno != 1) {
System.out.println(
"processing GIF terminator," + " frames: " + frameno + " total: " + totalframes);
}
imageComplete(ImageConsumer.STATICIMAGEDONE, true);
return;
}
}
} finally {
close();
}
}