This interface provides the observer with hooks to implement a layered
event queue. For example, it is possible to overlay processing events
for a GUI toolkit on top of the events for a thread:
var NativeQueue;
Observer = {
onDispatchedEvent(thread) {
NativeQueue.signal();
}
onProcessNextEvent(thread, mayWait, recursionDepth) {
if (NativeQueue.hasNextEvent())
NativeQueue.processNextEvent();
while (mayWait && !thread.hasPendingEvent()) {
NativeQueue.wait();
NativeQueue.processNextEvent();
}
}
};
NOTE: The implementation of this interface must be threadsafe.
NOTE: It is valid to change the thread’s observer during a call to an
observer method.
NOTE: Will be split into two interfaces soon: one for onProcessNextEvent and
afterProcessNextEvent, then another that inherits the first and adds
onDispatchedEvent.
This method is called after an event has been dispatched to the thread.
This method may be called from any thread.
| thread | The thread where the event is being dispatched. |
This method is called when nsIThread::ProcessNextEvent is called. It does
not guarantee that an event is actually going to be processed. This method
is only called on the target thread.
| thread | The thread being asked to process another event. |
| mayWait | Indicates whether or not the method is allowed to block the calling thread. For example, this parameter is false during thread shutdown. |
| recursionDepth | Indicates the number of calls to ProcessNextEvent on the call stack in addition to the current call. |
This method is called (from nsIThread::ProcessNextEvent) after an event
is processed. It does not guarantee that an event was actually processed
(depends on the value of |eventWasProcessed|. This method is only called
on the target thread.
| thread | The thread that processed another event. |
| recursionDepth | Indicates the number of calls to ProcessNextEvent on the call stack in addition to the current call. |
| eventWasProcessed | Indicates whether an event was actually processed. May be false if the |mayWait| flag was false when calling nsIThread::ProcessNextEvent(). |