Class ICUNotifier
- java.lang.Object
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- com.ibm.icu.impl.ICUNotifier
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- Direct Known Subclasses:
ICUService
public abstract class ICUNotifier extends java.lang.Object
Abstract implementation of a notification facility. Clients add EventListeners with addListener and remove them with removeListener. Notifiers call notifyChanged when they wish to notify listeners. This queues the listener list on the notification thread, which eventually dequeues the list and calls notifyListener on each listener in the list.
Subclasses override acceptsListener and notifyListener to add type-safe notification. AcceptsListener should return true if the listener is of the appropriate type; ICUNotifier itself will ensure the listener is non-null and that the identical listener is not already registered with the Notifier. NotifyListener should cast the listener to the appropriate type and call the appropriate method on the listener.
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Nested Class Summary
Nested Classes Modifier and Type Class Description private static class
ICUNotifier.NotifyThread
The notification thread.
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Field Summary
Fields Modifier and Type Field Description private java.util.List<java.util.EventListener>
listeners
private java.lang.Object
notifyLock
private ICUNotifier.NotifyThread
notifyThread
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Constructor Summary
Constructors Constructor Description ICUNotifier()
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected abstract boolean
acceptsListener(java.util.EventListener l)
Subclasses implement this to return true if the listener is of the appropriate type.void
addListener(java.util.EventListener l)
Add a listener to be notified when notifyChanged is called.void
notifyChanged()
Queue a notification on the notification thread for the current listeners.protected abstract void
notifyListener(java.util.EventListener l)
Subclasses implement this to notify the listener.void
removeListener(java.util.EventListener l)
Stop notifying this listener.
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Field Detail
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notifyLock
private final java.lang.Object notifyLock
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notifyThread
private ICUNotifier.NotifyThread notifyThread
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listeners
private java.util.List<java.util.EventListener> listeners
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Method Detail
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addListener
public void addListener(java.util.EventListener l)
Add a listener to be notified when notifyChanged is called. The listener must not be null. AcceptsListener must return true for the listener. Attempts to concurrently register the identical listener more than once will be silently ignored.
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removeListener
public void removeListener(java.util.EventListener l)
Stop notifying this listener. The listener must not be null. Attempts to remove a listener that is not registered will be silently ignored.
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notifyChanged
public void notifyChanged()
Queue a notification on the notification thread for the current listeners. When the thread unqueues the notification, notifyListener is called on each listener from the notification thread.
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acceptsListener
protected abstract boolean acceptsListener(java.util.EventListener l)
Subclasses implement this to return true if the listener is of the appropriate type.
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notifyListener
protected abstract void notifyListener(java.util.EventListener l)
Subclasses implement this to notify the listener.
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