@SuppressWarnings("unchecked")
private <E extends Event> void doPost(E e) {
ListenerBucket<E> b;
Listener<? super E>[] ls = null;
Lock l = locks.get(e);
l.lock();
try {
if (retained) {
if ((b = (ListenerBucket<E>) handlers.get(e)) == null)
handlers.put(e, b = (ListenerBucket<E>) bucketSupplier.get());
ls = b.post(e);
} else {
if ((b = (ListenerBucket<E>) handlers.get(e)) != null) {
ls = b.post(e);
if (b.isEmpty()) handlers.remove(e);
}
}
} finally {
l.unlock();
}
if (ls != null) {
for (Listener<? super E> li : ls) {
try {
li.execute(e);
} catch (RejectedExecutionException ex) {
Log.get().postSevere("Event listener rejected! Did the executor shut down?", ex);
}
}
}
}
/**
* Registers the specified event listener.
*
* @param e The event to listen for.
* @param l The event listener.
* @throws NullPointerException if either argument is null.
*/
protected final <E extends Event> void doAddListener(E e, Listener<? super E> li) {
Objects.requireNonNull(li);
Lock l = locks.get(e);
l.lock();
try {
if (handlers.computeIfAbsent(e, k -> bucketSupplier.get()).addListener(li)) return;
} finally {
l.unlock();
}
// No return = listener rejected = we should execute it now
li.execute(e);
}
/**
* Removes an event listener, if it exists.
*
* <p>Note that this method generally does not interact nicely with lambdas as they aren't
* designed for equality testing. As such, when using this method, ensure you're properly
* unregistering a listener!
*
* @param e The event being listened for.
* @param handler The handler to remove.
* @throws NullPointerException if either argument is null.
*/
public <E extends Event> void removeListener(E e, EventHandler<? super E> handler) {
Objects.requireNonNull(handler);
Lock l = locks.get(e);
l.lock();
try {
ListenerBucket<?> b = handlers.get(e);
if (b != null) {
b.removeListener(li -> li.handler.equals(handler));
if (b.isEmpty()) handlers.remove(e);
}
} finally {
l.unlock();
}
}
/**
* Clears any listeners satisfying the specified predicate. This is exposed for subclasses to
* utilise if they wish; however it is not a part of the public API for obvious reasons.
*
* @throws NullPointerException if {@code pred} is {@code null}.
*/
public final void clearListeners(Predicate<Listener<?>> pred) {
Objects.requireNonNull(pred);
handlers
.entrySet()
.removeIf(
e -> {
Lock l = locks.get(e.getKey());
l.lock();
try {
ListenerBucket<?> b = e.getValue();
b.removeListeners(pred);
return b.isEmpty();
} finally {
l.unlock();
}
});
}
