This interface represents a general event queue.<.
p> Events may be posted to the queue by various sources. Listeners (implementing iEventHandler) can register to receive notification when various events are processed. Typically, one instance of this object is available from the shared-object registry (iObjectRegistry) under the name "crystalspace.event.queue".
Any module which generates events should consider using this interface for posting those events to the queue. The module should implement the iEventPlug interface and register that interface with this method. In return, an iEventOutlet object will be created which can be used to actually post events to the queue. It is the caller's responsibility to send a DecRef() message to the returned event outlet when it is no longer needed.
This is normally called by Process() once for each event in the queue. Events are dispatched to the appropriate listeners (implementors of iEventHandler) which have been registered via RegisterListener().
Get next event from queue; returns NULL if no events are present.
There is rarely any need to manually retrieve events from the queue. Instead, normal event processing via Process() takes care of this responsibility. iEventQueue gives up ownership of the returned iEvent, so it is the caller's responsibility to invoke iEvent::DecRef() when the event is no longer needed.
Get the event cord for a given category and subcategory.<.
p> This allows events to be delivered immediately, bypassing the normal event queue, to a chain of plugins that register with the implementation of iEventCord returned by this function. The category and subcategory are matched against the category and subcategory of each actual iEvent.
Get a public event outlet for posting just an event.
In general most modules should create their own private outlet via CreateEventOutlet() and register as a normal event plug. However, there are cases when you just need to post one event from time to time; in these cases it is easier to post it without the bulk of creating a new iEventPlug interface. In these cases, you can post the event by obtaining the shared event outlet from GetEventOutlet(), and use it to post an event instead.
Note that the returned object is NOT IncRef'd, thus you should NOT DecRef it after usage.
Calls Dispatch() once for each event in the queue in order to actually dispatch the event. Typically, this method is invoked by the host application on a periodic basis (often from the host's own event loop) in order to give Crystal Space modules a chance to run and respond to events.
If the listener is already registered, then this method merely changes the listener's `trigger'. The `trigger' argument is a combination of the CSMASK_XXX event triggers defined in iutil/evdefs.h. Multiple triggers may be specified by combining them with the bitwise "or" operator (`|'). The CSMASK_Nothing event trigger is special. If registered with this trigger, the listener will be called just before Process() iterates over the event queue, and just after it dispatches the last event. In this case, the listener will be sent an csevBroadcast event with the Event.Command.Code equal to cscmdPreProcess before event dispatching, and cscmdPostProcess after event dispatching.