public void doFetch() {
synchronized (this) {
if (consumers == null) {
awaitingFetch = false;
return;
}
}
ImageDecoder imgd = getDecoder();
if (imgd == null) {
badDecoder();
} else {
setDecoder(imgd);
try {
imgd.produceImage();
} catch (IOException e) {
e.printStackTrace();
// the finally clause will send an error.
} catch (ImageFormatException e) {
e.printStackTrace();
// the finally clause will send an error.
} finally {
removeDecoder(imgd);
if (Thread.currentThread().isInterrupted() || !Thread.currentThread().isAlive()) {
errorAllConsumers(imgd.queue, true);
} else {
errorAllConsumers(imgd.queue, false);
}
}
}
}
public synchronized boolean isConsumer(ImageConsumer ic) {
for (ImageDecoder id = decoders; id != null; id = id.next) {
if (id.isConsumer(ic)) {
return true;
}
}
return ImageConsumerQueue.isConsumer(consumers, ic);
}
private synchronized void removeDecoder(ImageDecoder mydecoder) {
doneDecoding(mydecoder);
ImageDecoder idprev = null;
for (ImageDecoder id = decoders; id != null; id = id.next) {
if (id == mydecoder) {
if (idprev == null) {
decoders = id.next;
} else {
idprev.next = id.next;
}
break;
}
idprev = id;
}
}
synchronized void addConsumer(ImageConsumer ic, boolean produce) {
checkSecurity(null, false);
for (ImageDecoder id = decoders; id != null; id = id.next) {
if (id.isConsumer(ic)) {
// This consumer is already being fed.
return;
}
}
ImageConsumerQueue cq = consumers;
while (cq != null && cq.consumer != ic) {
cq = cq.next;
}
if (cq == null) {
cq = new ImageConsumerQueue(this, ic);
cq.next = consumers;
consumers = cq;
} else {
if (!cq.secure) {
Object context = null;
SecurityManager security = System.getSecurityManager();
if (security != null) {
context = security.getSecurityContext();
}
if (cq.securityContext == null) {
cq.securityContext = context;
} else if (!cq.securityContext.equals(context)) {
// If there are two different security contexts that both
// have a handle on the same ImageConsumer, then there has
// been a security breach and whether or not they trade
// image data is small fish compared to what they could be
// trading. Throw a Security exception anyway...
errorConsumer(cq, false);
throw new SecurityException("Applets are trading image data!");
}
}
cq.interested = true;
}
if (produce && decoder == null) {
startProduction();
}
}
private void setDecoder(ImageDecoder mydecoder) {
ImageConsumerQueue cq;
synchronized (this) {
mydecoder.next = decoders;
decoders = mydecoder;
decoder = mydecoder;
cq = consumers;
mydecoder.queue = cq;
consumers = null;
awaitingFetch = false;
}
while (cq != null) {
if (cq.interested) {
// Now that there is a decoder, security may have changed
// so reverify it here, just in case.
if (!checkSecurity(cq.securityContext, true)) {
errorConsumer(cq, false);
}
}
cq = cq.next;
}
}
public synchronized void removeConsumer(ImageConsumer ic) {
for (ImageDecoder id = decoders; id != null; id = id.next) {
id.removeConsumer(ic);
}
consumers = ImageConsumerQueue.removeConsumer(consumers, ic, false);
}