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);
}
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();
}
}