Package org.apache.fop.events
Interface EventBroadcaster
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- All Known Implementing Classes:
DefaultEventBroadcaster
,FOUserAgent.FOPEventBroadcaster
public interface EventBroadcaster
The EventBroadcaster is the central relay point for events. It receives events from various parts of the application and forwards them to any registered EventListener.
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
addEventListener(EventListener listener)
Adds an event listener to the broadcaster.void
broadcastEvent(Event event)
Broadcasts an event.<T extends EventProducer>
TgetEventProducerFor(java.lang.Class<T> clazz)
Returns an event producer instance for the given interface class.boolean
hasEventListeners()
Indicates whether any listeners have been registered with the broadcaster.void
removeEventListener(EventListener listener)
Removes an event listener from the broadcaster.
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Method Detail
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addEventListener
void addEventListener(EventListener listener)
Adds an event listener to the broadcaster. It is appended to the list of previously registered listeners (the order of registration defines the calling order).- Parameters:
listener
- the listener to be added
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removeEventListener
void removeEventListener(EventListener listener)
Removes an event listener from the broadcaster. If the event listener is not registered, nothing happens.- Parameters:
listener
- the listener to be removed
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hasEventListeners
boolean hasEventListeners()
Indicates whether any listeners have been registered with the broadcaster.- Returns:
- true if listeners are present, false otherwise
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broadcastEvent
void broadcastEvent(Event event)
Broadcasts an event. This method is usually called from within the observed component.- Parameters:
event
- the event to be broadcast
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getEventProducerFor
<T extends EventProducer> T getEventProducerFor(java.lang.Class<T> clazz)
Returns an event producer instance for the given interface class.- Parameters:
clazz
- the Class object identifying anEventProducer
interface- Returns:
- the event producer instance
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