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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/**
*******************************************************************************
* Copyright (C) 2001-2014, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
#ifndef ICUNOTIF_H
#define ICUNOTIF_H
#include "unicode/utypes.h"
#if UCONFIG_NO_SERVICE
U_NAMESPACE_BEGIN
/*
* Allow the declaration of APIs with pointers to BreakIterator
* even when break iteration is removed from the build.
*/
class ICUNotifier;
U_NAMESPACE_END
#else
#include "unicode/uobject.h"
#include "unicode/unistr.h"
#include "mutex.h"
#include "uvector.h"
U_NAMESPACE_BEGIN
class U_COMMON_API EventListener : public UObject {
public:
virtual ~EventListener();
public:
static UClassID U_EXPORT2 getStaticClassID();
virtual UClassID getDynamicClassID() const;
public:
#ifdef SERVICE_DEBUG
virtual UnicodeString& debug(UnicodeString& result) const {
return debugClass(result);
}
virtual UnicodeString& debugClass(UnicodeString& result) const {
return result.append((UnicodeString)"Key");
}
#endif
};
/**
* <p>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.</p>
*
* <p>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.
*/
class U_COMMON_API ICUNotifier : public UMemory {
private: UVector* listeners;
public:
ICUNotifier(void);
virtual ~ICUNotifier(void);
/**
* 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.
*/
virtual void addListener(const EventListener* l, UErrorCode& status);
/**
* Stop notifying this listener. The listener must
* not be null. Attemps to remove a listener that is
* not registered will be silently ignored.
*/
virtual void removeListener(const EventListener* l, UErrorCode& status);
/**
* ICU doesn't spawn its own threads. All listeners are notified in
* the thread of the caller. Misbehaved listeners can therefore
* indefinitely block the calling thread. Callers should beware of
* deadlock situations.
*/
virtual void notifyChanged(void);
protected:
/**
* Subclasses implement this to return true if the listener is
* of the appropriate type.
*/
virtual UBool acceptsListener(const EventListener& l) const = 0;
/**
* Subclasses implement this to notify the listener.
*/
virtual void notifyListener(EventListener& l) const = 0;
};
U_NAMESPACE_END
/* UCONFIG_NO_SERVICE */
#endif
/* ICUNOTIF_H */
#endif