ICUServiceKeys are used to communicate with factories to + * generate an instance of the service. ICUServiceKeys define how + * ids are canonicalized, provide both a current id and a current + * descriptor to use in querying the cache and factories, and + * determine the fallback strategy.
+ * + *ICUServiceKeys provide both a currentDescriptor and a currentID. + * The descriptor contains an optional prefix, followed by '/' + * and the currentID. Factories that handle complex keys, + * for example number format factories that generate multiple + * kinds of formatters for the same locale, use the descriptor + * to provide a fully unique identifier for the service object, + * while using the currentID (in this case, the locale string), + * as the visible IDs that can be localized.
+ * + *The default implementation of ICUServiceKey has no fallbacks and + * has no custom descriptors.
+ */ +class U_COMMON_API ICUServiceKey : public UObject { + private: + const UnicodeString _id; + + protected: + static const UChar PREFIX_DELIMITER; + + public: + + /** + *Construct a key from an id.
+ * + * @param id the ID from which to construct the key. + */ + ICUServiceKey(const UnicodeString& id); + + /** + *Virtual destructor.
+ */ + virtual ~ICUServiceKey(); + + /** + *Return the original ID used to construct this key.
+ * + * @return the ID used to construct this key. + */ + virtual const UnicodeString& getID() const; + + /** + *Return the canonical version of the original ID. This implementation + * appends the original ID to result. Result is returned as a convenience.
+ * + * @param result the output parameter to which the id will be appended. + * @return the modified result. + */ + virtual UnicodeString& canonicalID(UnicodeString& result) const; + + /** + *Return the (canonical) current ID. This implementation appends + * the canonical ID to result. Result is returned as a convenience.
+ * + * @param result the output parameter to which the current id will be appended. + * @return the modified result. + */ + virtual UnicodeString& currentID(UnicodeString& result) const; + + /** + *Return the current descriptor. This implementation appends + * the current descriptor to result. Result is returned as a convenience.
+ * + *The current descriptor is used to fully + * identify an instance of the service in the cache. A + * factory may handle all descriptors for an ID, or just a + * particular descriptor. The factory can either parse the + * descriptor or use custom API on the key in order to + * instantiate the service.
+ * + * @param result the output parameter to which the current id will be appended. + * @return the modified result. + */ + virtual UnicodeString& currentDescriptor(UnicodeString& result) const; + + /** + *If the key has a fallback, modify the key and return true, + * otherwise return false. The current ID will change if there + * is a fallback. No currentIDs should be repeated, and fallback + * must eventually return false. This implementation has no fallbacks + * and always returns false.
+ * + * @return TRUE if the ICUServiceKey changed to a valid fallback value. + */ + virtual UBool fallback(); + + /** + *Return TRUE if a key created from id matches, or would eventually + * fallback to match, the canonical ID of this ICUServiceKey.
+ * + * @param id the id to test. + * @return TRUE if this ICUServiceKey's canonical ID is a fallback of id. + */ + virtual UBool isFallbackOf(const UnicodeString& id) const; + + /** + *Return the prefix. This implementation leaves result unchanged. + * Result is returned as a convenience.
+ * + * @param result the output parameter to which the prefix will be appended. + * @return the modified result. + */ + virtual UnicodeString& prefix(UnicodeString& result) const; + + /** + *A utility to parse the prefix out of a descriptor string. Only + * the (undelimited) prefix, if any, remains in result. Result is returned as a + * convenience.
+ * + * @param result an input/output parameter that on entry is a descriptor, and + * on exit is the prefix of that descriptor. + * @return the modified result. + */ + static UnicodeString& parsePrefix(UnicodeString& result); + + /** + *A utility to parse the suffix out of a descriptor string. Only + * the (undelimited) suffix, if any, remains in result. Result is returned as a + * convenience.
+ * + * @param result an input/output parameter that on entry is a descriptor, and + * on exit is the suffix of that descriptor. + * @return the modified result. + */ + static UnicodeString& parseSuffix(UnicodeString& result); + +public: + /** + * UObject RTTI boilerplate. + */ + static UClassID U_EXPORT2 getStaticClassID(); + + /** + * UObject RTTI boilerplate. + */ + virtual UClassID getDynamicClassID() const; + +#ifdef SERVICE_DEBUG + public: + virtual UnicodeString& debug(UnicodeString& result) const; + virtual UnicodeString& debugClass(UnicodeString& result) const; +#endif + +}; + + /******************************************************************* + * ICUServiceFactory + */ + + /** + *An implementing ICUServiceFactory generates the service objects maintained by the + * service. A factory generates a service object from a key, + * updates id->factory mappings, and returns the display name for + * a supported id.
+ */ +class U_COMMON_API ICUServiceFactory : public UObject { + public: + + /** + *Create a service object from the key, if this factory + * supports the key. Otherwise, return NULL.
+ * + *If the factory supports the key, then it can call + * the service's getKey(ICUServiceKey, String[], ICUServiceFactory) method + * passing itself as the factory to get the object that + * the service would have created prior to the factory's + * registration with the service. This can change the + * key, so any information required from the key should + * be extracted before making such a callback.
+ * + * @param key the service key. + * @param service the service with which this factory is registered. + * @param status the error code status. + * @return the service object, or NULL if the factory does not support the key. + */ + virtual UObject* create(const ICUServiceKey& key, const ICUService* service, UErrorCode& status) const = 0; + + /** + *Update result to reflect the IDs (not descriptors) that this + * factory publicly handles. Result contains mappings from ID to + * factory. On entry it will contain all (visible) mappings from + * previously-registered factories.
+ * + *This function, together with getDisplayName, are used to + * support ICUService::getDisplayNames. The factory determines + * which IDs (of those it supports) it will make visible, and of + * those, which it will provide localized display names for. In + * most cases it will register mappings from all IDs it supports + * to itself.
+ * + * @param result the mapping table to update. + * @param status the error code status. + */ + virtual void updateVisibleIDs(Hashtable& result, UErrorCode& status) const = 0; + + /** + *Return, in result, the display name of the id in the provided locale. + * This is an id, not a descriptor. If the id is + * not visible, sets result to bogus. If the + * incoming result is bogus, it remains bogus. Result is returned as a + * convenience. Results are not defined if id is not one supported by this + * factory.
+ * + * @param id a visible id supported by this factory. + * @param locale the locale for which to generate the corresponding localized display name. + * @param result output parameter to hold the display name. + * @return result. + */ + virtual UnicodeString& getDisplayName(const UnicodeString& id, const Locale& locale, UnicodeString& result) const = 0; +}; + +/* + ****************************************************************** + */ + + /** + *A default implementation of factory. This provides default + * implementations for subclasses, and implements a singleton + * factory that matches a single ID and returns a single + * (possibly deferred-initialized) instance. This implements + * updateVisibleIDs to add a mapping from its ID to itself + * if visible is true, or to remove any existing mapping + * for its ID if visible is false. No localization of display + * names is performed.
+ */ +class U_COMMON_API SimpleFactory : public ICUServiceFactory { + protected: + UObject* _instance; + const UnicodeString _id; + const UBool _visible; + + public: + /** + *Construct a SimpleFactory that maps a single ID to a single + * service instance. If visible is TRUE, the ID will be visible. + * The instance must not be NULL. The SimpleFactory will adopt + * the instance, which must not be changed subsequent to this call.
+ * + * @param instanceToAdopt the service instance to adopt. + * @param id the ID to assign to this service instance. + * @param visible if TRUE, the ID will be visible. + */ + SimpleFactory(UObject* instanceToAdopt, const UnicodeString& id, UBool visible = TRUE); + + /** + *Destructor.
+ */ + virtual ~SimpleFactory(); + + /** + *This implementation returns a clone of the service instance if the factory's ID is equal to + * the key's currentID. Service and prefix are ignored.
+ * + * @param key the service key. + * @param service the service with which this factory is registered. + * @param status the error code status. + * @return the service object, or NULL if the factory does not support the key. + */ + virtual UObject* create(const ICUServiceKey& key, const ICUService* service, UErrorCode& status) const; + + /** + *This implementation adds a mapping from ID -> this to result if visible is TRUE, + * otherwise it removes ID from result.
+ * + * @param result the mapping table to update. + * @param status the error code status. + */ + virtual void updateVisibleIDs(Hashtable& result, UErrorCode& status) const; + + /** + *This implementation returns the factory ID if it equals id and visible is TRUE, + * otherwise it returns the empty string. (This implementation provides + * no localized id information.)
+ * + * @param id a visible id supported by this factory. + * @param locale the locale for which to generate the corresponding localized display name. + * @param result output parameter to hold the display name. + * @return result. + */ + virtual UnicodeString& getDisplayName(const UnicodeString& id, const Locale& locale, UnicodeString& result) const; + +public: + /** + * UObject RTTI boilerplate. + */ + static UClassID U_EXPORT2 getStaticClassID(); + + /** + * UObject RTTI boilerplate. + */ + virtual UClassID getDynamicClassID() const; + +#ifdef SERVICE_DEBUG + public: + virtual UnicodeString& debug(UnicodeString& toAppendTo) const; + virtual UnicodeString& debugClass(UnicodeString& toAppendTo) const; +#endif + +}; + +/* + ****************************************************************** + */ + +/** + *ServiceListener is the listener that ICUService provides by default. + * ICUService will notifiy this listener when factories are added to + * or removed from the service. Subclasses can provide + * different listener interfaces that extend EventListener, and modify + * acceptsListener and notifyListener as appropriate.
+ */ +class U_COMMON_API ServiceListener : public EventListener { +public: + /** + *This method is called when the service changes. At the time of the + * call this listener is registered with the service. It must + * not modify the notifier in the context of this call.
+ * + * @param service the service that changed. + */ + virtual void serviceChanged(const ICUService& service) const = 0; + +public: + /** + * UObject RTTI boilerplate. + */ + static UClassID U_EXPORT2 getStaticClassID(); + + /** + * UObject RTTI boilerplate. + */ + virtual UClassID getDynamicClassID() const; + +}; + +/* + ****************************************************************** + */ + +/** + *A StringPair holds a displayName/ID pair. ICUService uses it + * as the array elements returned by getDisplayNames. + */ +class U_COMMON_API StringPair : public UMemory { +public: + /** + *
The display name of the pair.
+ */ + const UnicodeString displayName; + + /** + *The ID of the pair.
+ */ + const UnicodeString id; + + /** + *Creates a string pair from a displayName and an ID.
+ * + * @param displayName the displayName. + * @param id the ID. + * @param status the error code status. + * @return a StringPair if the creation was successful, otherwise NULL. + */ + static StringPair* create(const UnicodeString& displayName, + const UnicodeString& id, + UErrorCode& status); + + /** + *Return TRUE if either string of the pair is bogus.
+ * @return TRUE if either string of the pair is bogus. + */ + UBool isBogus() const; + +private: + StringPair(const UnicodeString& displayName, const UnicodeString& id); +}; + +/** + * Deleter for StringPairs + */ +U_CAPI void U_EXPORT2 +userv_deleteStringPair(void *obj); + +/** + * Opaque type returned by registerInstance and registerFactory. + */ +typedef const void* URegistryKey; + +/******************************************************************* + * ICUService + */ + + /** + *A Service provides access to service objects that implement a + * particular service, e.g. transliterators. Users provide a String + * id (for example, a locale string) to the service, and get back an + * object for that id. Service objects can be any kind of object. A + * new service object is returned for each query. The caller is + * responsible for deleting it.
+ * + *Services 'canonicalize' the query ID and use the canonical ID to + * query for the service. The service also defines a mechanism to + * 'fallback' the ID multiple times. Clients can optionally request + * the actual ID that was matched by a query when they use an ID to + * retrieve a service object.
+ * + *Service objects are instantiated by ICUServiceFactory objects + * registered with the service. The service queries each + * ICUServiceFactory in turn, from most recently registered to + * earliest registered, until one returns a service object. If none + * responds with a service object, a fallback ID is generated, and the + * process repeats until a service object is returned or until the ID + * has no further fallbacks.
+ * + *In ICU 2.4, UObject (the base class of service instances) does + * not define a polymorphic clone function. ICUService uses clones to + * manage ownership. Thus, for now, ICUService defines an abstract + * method, cloneInstance, that clients must implement to create clones + * of the service instances. This may change in future releases of + * ICU.
+ * + *ICUServiceFactories can be dynamically registered and + * unregistered with the service. When registered, an + * ICUServiceFactory is installed at the head of the factory list, and + * so gets 'first crack' at any keys or fallback keys. When + * unregistered, it is removed from the service and can no longer be + * located through it. Service objects generated by this factory and + * held by the client are unaffected.
+ * + *If a service has variants (e.g., the different variants of + * BreakIterator) an ICUServiceFactory can use the prefix of the + * ICUServiceKey to determine the variant of a service to generate. + * If it does not support all variants, it can request + * previously-registered factories to handle the ones it does not + * support.
+ * + *ICUService uses ICUServiceKeys to query factories and perform + * fallback. The ICUServiceKey defines the canonical form of the ID, + * and implements the fallback strategy. Custom ICUServiceKeys can be + * defined that parse complex IDs into components that + * ICUServiceFactories can more easily use. The ICUServiceKey can + * cache the results of this parsing to save repeated effort. + * ICUService provides convenience APIs that take UnicodeStrings and + * generate default ICUServiceKeys for use in querying.
+ * + *ICUService provides API to get the list of IDs publicly + * supported by the service (although queries aren't restricted to + * this list). This list contains only 'simple' IDs, and not fully + * unique IDs. ICUServiceFactories are associated with each simple ID + * and the responsible factory can also return a human-readable + * localized version of the simple ID, for use in user interfaces. + * ICUService can also provide an array of the all the localized + * visible IDs and their corresponding internal IDs.
+ * + *ICUService implements ICUNotifier, so that clients can register + * to receive notification when factories are added or removed from + * the service. ICUService provides a default EventListener + * subinterface, ServiceListener, which can be registered with the + * service. When the service changes, the ServiceListener's + * serviceChanged method is called with the service as the + * argument.
+ * + *The ICUService API is both rich and generic, and it is expected + * that most implementations will statically 'wrap' ICUService to + * present a more appropriate API-- for example, to declare the type + * of the objects returned from get, to limit the factories that can + * be registered with the service, or to define their own listener + * interface with a custom callback method. They might also customize + * ICUService by overriding it, for example, to customize the + * ICUServiceKey and fallback strategy. ICULocaleService is a + * subclass of ICUService that uses Locale names as IDs and uses + * ICUServiceKeys that implement the standard resource bundle fallback + * strategy. Most clients will wish to subclass it instead of + * ICUService.
+ */ +class U_COMMON_API ICUService : public ICUNotifier { + protected: + /** + * Name useful for debugging. + */ + const UnicodeString name; + + private: + + /** + * single lock used by this service. + */ + UMTX lock; + + /** + * Timestamp so iterators can be fail-fast. + */ + uint32_t timestamp; + + /** + * All the factories registered with this service. + */ + UVector* factories; + + /** + * The service cache. + */ + Hashtable* serviceCache; + + /** + * The ID cache. + */ + Hashtable* idCache; + + /** + * The name cache. + */ + DNCache* dnCache; + + /** + * Constructor. + */ + public: + /** + *Construct a new ICUService.
+ */ + ICUService(); + + /** + *Construct with a name (useful for debugging).
+ * + * @param name a name to use in debugging. + */ + ICUService(const UnicodeString& name); + + /** + *Destructor.
+ */ + virtual ~ICUService(); + + /** + *Return the name of this service. This will be the empty string if none was assigned. + * Returns result as a convenience.
+ * + * @param result an output parameter to contain the name of this service. + * @return the name of this service. + */ + UnicodeString& getName(UnicodeString& result) const; + + /** + *Convenience override for get(ICUServiceKey&, UnicodeString*). This uses + * createKey to create a key for the provided descriptor.
+ * + * @param descriptor the descriptor. + * @param status the error code status. + * @return the service instance, or NULL. + */ + UObject* get(const UnicodeString& descriptor, UErrorCode& status) const; + + /** + *Convenience override for get(ICUServiceKey&, UnicodeString*). This uses + * createKey to create a key from the provided descriptor.
+ * + * @param descriptor the descriptor. + * @param actualReturn a pointer to a UnicodeString to hold the matched descriptor, or NULL. + * @param status the error code status. + * @return the service instance, or NULL. + */ + UObject* get(const UnicodeString& descriptor, UnicodeString* actualReturn, UErrorCode& status) const; + + /** + *Convenience override for get(ICUServiceKey&, UnicodeString*).
+ * + * @param key the key. + * @param status the error code status. + * @return the service instance, or NULL. + */ + UObject* getKey(ICUServiceKey& key, UErrorCode& status) const; + + /** + *Given a key, return a service object, and, if actualReturn + * is not NULL, the descriptor with which it was found in the + * first element of actualReturn. If no service object matches + * this key, returns NULL and leaves actualReturn unchanged.
+ * + *This queries the cache using the key's descriptor, and if no + * object in the cache matches, tries the key on each + * registered factory, in order. If none generates a service + * object for the key, repeats the process with each fallback of + * the key, until either a factory returns a service object, or the key + * has no fallback. If no object is found, the result of handleDefault + * is returned.
+ * + *Subclasses can override this method to further customize the + * result before returning it. + * + * @param key the key. + * @param actualReturn a pointer to a UnicodeString to hold the matched descriptor, or NULL. + * @param status the error code status. + * @return the service instance, or NULL. + */ + virtual UObject* getKey(ICUServiceKey& key, UnicodeString* actualReturn, UErrorCode& status) const; + + /** + *
This version of getKey is only called by ICUServiceFactories within the scope + * of a previous getKey call, to determine what previously-registered factories would + * have returned. For details, see getKey(ICUServiceKey&, UErrorCode&). Subclasses + * should not call it directly, but call through one of the other get functions.
+ * + * @param key the key. + * @param actualReturn a pointer to a UnicodeString to hold the matched descriptor, or NULL. + * @param factory the factory making the recursive call. + * @param status the error code status. + * @return the service instance, or NULL. + */ + UObject* getKey(ICUServiceKey& key, UnicodeString* actualReturn, const ICUServiceFactory* factory, UErrorCode& status) const; + + /** + *Convenience override for getVisibleIDs(String) that passes null + * as the fallback, thus returning all visible IDs.
+ * + * @param result a vector to hold the returned IDs. + * @param status the error code status. + * @return the result vector. + */ + UVector& getVisibleIDs(UVector& result, UErrorCode& status) const; + + /** + *Return a snapshot of the visible IDs for this service. This + * list will not change as ICUServiceFactories are added or removed, but the + * supported IDs will, so there is no guarantee that all and only + * the IDs in the returned list will be visible and supported by the + * service in subsequent calls.
+ * + *The IDs are returned as pointers to UnicodeStrings. The + * caller owns the IDs. Previous contents of result are discarded before + * new elements, if any, are added.
+ * + *matchID is passed to createKey to create a key. If the key + * is not NULL, its isFallbackOf method is used to filter out IDs + * that don't match the key or have it as a fallback.
+ * + * @param result a vector to hold the returned IDs. + * @param matchID an ID used to filter the result, or NULL if all IDs are desired. + * @param status the error code status. + * @return the result vector. + */ + UVector& getVisibleIDs(UVector& result, const UnicodeString* matchID, UErrorCode& status) const; + + /** + *Convenience override for getDisplayName(const UnicodeString&, const Locale&, UnicodeString&) that + * uses the current default locale.
+ * + * @param id the ID for which to retrieve the localized displayName. + * @param result an output parameter to hold the display name. + * @return the modified result. + */ + UnicodeString& getDisplayName(const UnicodeString& id, UnicodeString& result) const; + + /** + *Given a visible ID, return the display name in the requested locale. + * If there is no directly supported ID corresponding to this ID, result is + * set to bogus.
+ * + * @param id the ID for which to retrieve the localized displayName. + * @param result an output parameter to hold the display name. + * @param locale the locale in which to localize the ID. + * @return the modified result. + */ + UnicodeString& getDisplayName(const UnicodeString& id, UnicodeString& result, const Locale& locale) const; + + /** + *Convenience override of getDisplayNames(const Locale&, const UnicodeString*) that + * uses the current default Locale as the locale and NULL for + * the matchID.
+ * + * @param result a vector to hold the returned displayName/id StringPairs. + * @param status the error code status. + * @return the modified result vector. + */ + UVector& getDisplayNames(UVector& result, UErrorCode& status) const; + + /** + *Convenience override of getDisplayNames(const Locale&, const UnicodeString*) that + * uses NULL for the matchID.
+ * + * @param result a vector to hold the returned displayName/id StringPairs. + * @param locale the locale in which to localize the ID. + * @param status the error code status. + * @return the modified result vector. + */ + UVector& getDisplayNames(UVector& result, const Locale& locale, UErrorCode& status) const; + + /** + *Return a snapshot of the mapping from display names to visible + * IDs for this service. This set will not change as factories + * are added or removed, but the supported IDs will, so there is + * no guarantee that all and only the IDs in the returned map will + * be visible and supported by the service in subsequent calls, + * nor is there any guarantee that the current display names match + * those in the result.
+ * + *The names are returned as pointers to StringPairs, which + * contain both the displayName and the corresponding ID. The + * caller owns the StringPairs. Previous contents of result are + * discarded before new elements, if any, are added.
+ * + *matchID is passed to createKey to create a key. If the key + * is not NULL, its isFallbackOf method is used to filter out IDs + * that don't match the key or have it as a fallback.
+ * + * @param result a vector to hold the returned displayName/id StringPairs. + * @param locale the locale in which to localize the ID. + * @param matchID an ID used to filter the result, or NULL if all IDs are desired. + * @param status the error code status. + * @return the result vector. */ + UVector& getDisplayNames(UVector& result, + const Locale& locale, + const UnicodeString* matchID, + UErrorCode& status) const; + + /** + *A convenience override of registerInstance(UObject*, const UnicodeString&, UBool) + * that defaults visible to TRUE.
+ * + * @param objToAdopt the object to register and adopt. + * @param id the ID to assign to this object. + * @param status the error code status. + * @return a registry key that can be passed to unregister to unregister + * (and discard) this instance. + */ + URegistryKey registerInstance(UObject* objToAdopt, const UnicodeString& id, UErrorCode& status); + + /** + *Register a service instance with the provided ID. The ID will be + * canonicalized. The canonicalized ID will be returned by + * getVisibleIDs if visible is TRUE. The service instance will be adopted and + * must not be modified subsequent to this call.
+ * + *This issues a serviceChanged notification to registered listeners.
+ * + *This implementation wraps the object using + * createSimpleFactory, and calls registerFactory.
+ * + * @param objToAdopt the object to register and adopt. + * @param id the ID to assign to this object. + * @param visible TRUE if getVisibleIDs is to return this ID. + * @param status the error code status. + * @return a registry key that can be passed to unregister() to unregister + * (and discard) this instance. + */ + virtual URegistryKey registerInstance(UObject* objToAdopt, const UnicodeString& id, UBool visible, UErrorCode& status); + + /** + *Register an ICUServiceFactory. Returns a registry key that + * can be used to unregister the factory. The factory + * must not be modified subsequent to this call. The service owns + * all registered factories. In case of an error, the factory is + * deleted.
+ * + *This issues a serviceChanged notification to registered listeners.
+ * + *The default implementation accepts all factories.
+ * + * @param factoryToAdopt the factory to register and adopt. + * @param status the error code status. + * @return a registry key that can be passed to unregister to unregister + * (and discard) this factory. + */ + virtual URegistryKey registerFactory(ICUServiceFactory* factoryToAdopt, UErrorCode& status); + + /** + *Unregister a factory using a registry key returned by + * registerInstance or registerFactory. After a successful call, + * the factory will be removed from the service factory list and + * deleted, and the key becomes invalid.
+ * + *This issues a serviceChanged notification to registered + * listeners.
+ * + * @param rkey the registry key. + * @param status the error code status. + * @return TRUE if the call successfully unregistered the factory. + */ + virtual UBool unregister(URegistryKey rkey, UErrorCode& status); + + /** + * Reset the service to the default factories. The factory + * lock is acquired and then reInitializeFactories is called. + * + *This issues a serviceChanged notification to registered listeners.
+ */ + virtual void reset(void); + + /** + *Return TRUE if the service is in its default state.
+ * + *The default implementation returns TRUE if there are no + * factories registered.
+ */ + virtual UBool isDefault(void) const; + + /** + *Create a key from an ID. If ID is NULL, returns NULL.
+ * + *The default implementation creates an ICUServiceKey instance. + * Subclasses can override to define more useful keys appropriate + * to the factories they accept.
+ * + * @param a pointer to the ID for which to create a default ICUServiceKey. + * @param status the error code status. + * @return the ICUServiceKey corresponding to ID, or NULL. + */ + virtual ICUServiceKey* createKey(const UnicodeString* id, UErrorCode& status) const; + + /** + *Clone object so that caller can own the copy. In ICU2.4, UObject doesn't define + * clone, so we need an instance-aware method that knows how to do this. + * This is public so factories can call it, but should really be protected.
+ * + * @param instance the service instance to clone. + * @return a clone of the passed-in instance, or NULL if cloning was unsuccessful. + */ + virtual UObject* cloneInstance(UObject* instance) const = 0; + + + /************************************************************************ + * Subclassing API + */ + + protected: + + /** + *Create a factory that wraps a single service object. Called by registerInstance.
+ * + *The default implementation returns an instance of SimpleFactory.
+ * + * @param instanceToAdopt the service instance to adopt. + * @param id the ID to assign to this service instance. + * @param visible if TRUE, the ID will be visible. + * @param status the error code status. + * @return an instance of ICUServiceFactory that maps this instance to the provided ID. + */ + virtual ICUServiceFactory* createSimpleFactory(UObject* instanceToAdopt, const UnicodeString& id, UBool visible, UErrorCode& status); + + /** + *Reinitialize the factory list to its default state. After this call, isDefault() + * must return TRUE.
+ * + *This issues a serviceChanged notification to registered listeners.
+ * + *The default implementation clears the factory list. + * Subclasses can override to provide other default initialization + * of the factory list. Subclasses must not call this method + * directly, since it must only be called while holding write + * access to the factory list.
+ */ + virtual void reInitializeFactories(void); + + /** + *Default handler for this service if no factory in the factory list + * handled the key passed to getKey.
+ * + *The default implementation returns NULL.
+ * + * @param key the key. + * @param actualReturn a pointer to a UnicodeString to hold the matched descriptor, or NULL. + * @param status the error code status. + * @return the service instance, or NULL. + */ + virtual UObject* handleDefault(const ICUServiceKey& key, UnicodeString* actualReturn, UErrorCode& status) const; + + /** + *Clear caches maintained by this service.
+ * + *Subclasses can override if they implement additional caches + * that need to be cleared when the service changes. Subclasses + * should generally not call this method directly, as it must only + * be called while synchronized on the factory lock.
+ */ + virtual void clearCaches(void); + + /** + *Return true if the listener is accepted.
+ * + *The default implementation accepts the listener if it is + * a ServiceListener. Subclasses can override this to accept + * different listeners.
+ * + * @param l the listener to test. + * @return TRUE if the service accepts the listener. + */ + virtual UBool acceptsListener(const EventListener& l) const; + + /** + *Notify the listener of a service change.
+ * + *The default implementation assumes a ServiceListener. + * If acceptsListener has been overridden to accept different + * listeners, this should be overridden as well.
+ * + * @param l the listener to notify. + */ + virtual void notifyListener(EventListener& l) const; + + /************************************************************************ + * Utilities for subclasses. + */ + + /** + *Clear only the service cache.
+ * + *This can be called by subclasses when a change affects the service + * cache but not the ID caches, e.g., when the default locale changes + * the resolution of IDs also changes, requiring the cache to be + * flushed, but not the visible IDs themselves.
+ */ + void clearServiceCache(void); + + /** + *Return a map from visible IDs to factories. + * This must only be called when the mutex is held.
+ * + * @param status the error code status. + * @return a Hashtable containing mappings from visible + * IDs to factories. + */ + const Hashtable* getVisibleIDMap(UErrorCode& status) const; + + /** + *Allow subclasses to read the time stamp.
+ * + * @return the timestamp. + */ + int32_t getTimestamp(void) const; + + /** + *Return the number of registered factories.
+ * + * @return the number of factories registered at the time of the call. + */ + int32_t countFactories(void) const; + +private: + + friend class ::ICUServiceTest; // give tests access to countFactories. +}; + +U_NAMESPACE_END + + /* UCONFIG_NO_SERVICE */ +#endif + + /* ICUSERV_H */ +#endif +