2 *******************************************************************************
3 * Copyright (C) 2001-2004, International Business Machines Corporation and *
4 * others. All Rights Reserved. *
5 *******************************************************************************
10 #include "unicode/utypes.h"
12 #if UCONFIG_NO_SERVICE
17 * Allow the declaration of APIs with pointers to BreakIterator
18 * even when break iteration is removed from the build.
26 #include "unicode/uobject.h"
27 #include "unicode/unistr.h"
34 class U_COMMON_API EventListener : public UObject {
36 virtual ~EventListener();
39 static UClassID U_EXPORT2 getStaticClassID();
41 virtual UClassID getDynamicClassID() const;
45 virtual UnicodeString& debug(UnicodeString& result) const {
46 return debugClass(result);
49 virtual UnicodeString& debugClass(UnicodeString& result) const {
50 return result.append("Key");
56 * <p>Abstract implementation of a notification facility. Clients add
57 * EventListeners with addListener and remove them with removeListener.
58 * Notifiers call notifyChanged when they wish to notify listeners.
59 * This queues the listener list on the notification thread, which
60 * eventually dequeues the list and calls notifyListener on each
61 * listener in the list.</p>
63 * <p>Subclasses override acceptsListener and notifyListener
64 * to add type-safe notification. AcceptsListener should return
65 * true if the listener is of the appropriate type; ICUNotifier
66 * itself will ensure the listener is non-null and that the
67 * identical listener is not already registered with the Notifier.
68 * NotifyListener should cast the listener to the appropriate
69 * type and call the appropriate method on the listener.
72 class U_COMMON_API ICUNotifier : public UMemory {
73 private: UMTX notifyLock;
74 private: UVector* listeners;
79 virtual ~ICUNotifier(void);
82 * Add a listener to be notified when notifyChanged is called.
83 * The listener must not be null. AcceptsListener must return
84 * true for the listener. Attempts to concurrently
85 * register the identical listener more than once will be
88 virtual void addListener(const EventListener* l, UErrorCode& status);
91 * Stop notifying this listener. The listener must
92 * not be null. Attemps to remove a listener that is
93 * not registered will be silently ignored.
95 virtual void removeListener(const EventListener* l, UErrorCode& status);
98 * ICU doesn't spawn its own threads. All listeners are notified in
99 * the thread of the caller. Misbehaved listeners can therefore
100 * indefinitely block the calling thread. Callers should beware of
101 * deadlock situations.
103 virtual void notifyChanged(void);
107 * Subclasses implement this to return TRUE if the listener is
108 * of the appropriate type.
110 virtual UBool acceptsListener(const EventListener& l) const = 0;
113 * Subclasses implement this to notify the listener.
115 virtual void notifyListener(EventListener& l) const = 0;
120 /* UCONFIG_NO_SERVICE */