Class ICUNotifier

java.lang.Object
com.ibm.icu.impl.ICUNotifier
Direct Known Subclasses:
ICUService

public abstract class ICUNotifier extends 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.

  • Field Details

  • Constructor Details

    • ICUNotifier

      public ICUNotifier()
  • Method Details

    • addListener

      public void addListener(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.
    • removeListener

      public void removeListener(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.
    • 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.
    • acceptsListener

      protected abstract boolean acceptsListener(EventListener l)
      Subclasses implement this to return true if the listener is of the appropriate type.
    • notifyListener

      protected abstract void notifyListener(EventListener l)
      Subclasses implement this to notify the listener.