ICU-8.11.tar.gz

[apple/icu.git] / icuSources / common / servnotf.h

diff --git a/icuSources/common/servnotf.h b/icuSources/common/servnotf.h
new file mode 100644 (file)
index 0000000..19c2d69
--- /dev/null
+++ b/icuSources/common/servnotf.h
@@ -0,0 +1,124 @@
+/**
+ *******************************************************************************
+ * Copyright (C) 2001-2004, 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("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: UMTX notifyLock;
+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