svn commit: r1610289 - in /commons/proper/configuration/trunk/src: main/java/org/apache/commons/configuration/event/EventListenerList.java test/java/org/apache/commons/configuration/event/TestEventListenerList.java

[oh...@apache.org]

Author: oheger
Date: Sun Jul 13 20:01:47 2014
New Revision: 1610289

URL: http://svn.apache.org/r1610289
Log:
EventListenerList now provides a method for querying registrations of a super type.

With this method it is possible to find all event listeners derived from a
given type.

Modified:
    commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/event/EventListenerList.java
    commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/event/TestEventListenerList.java

Modified: commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/event/EventListenerList.java
URL: http://svn.apache.org/viewvc/commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/event/EventListenerList.java?rev=1610289&r1=1610288&r2=1610289&view=diff
==============================================================================
--- commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/event/EventListenerList.java (original)
+++ commons/proper/configuration/trunk/src/main/java/org/apache/commons/configuration/event/EventListenerList.java Sun Jul 13 20:01:47 2014
@@ -17,9 +17,12 @@
 package org.apache.commons.configuration.event;
 
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArrayList;
@@ -206,6 +209,48 @@ public class EventListenerList
     }
 
     /**
+     * Returns a list with {@code EventListenerRegistrationData} objects for all
+     * event listener registrations of the specified event type or an event type
+     * having this type as super type (directly or indirectly). Note that this
+     * is the opposite direction than querying event types for firing events: in
+     * this case event listener registrations are searched which are super event
+     * types from a given type. This method in contrast returns event listener
+     * registrations for listeners that extend a given super type.
+     *
+     * @param eventType the event type object
+     * @param <T> the event type
+     * @return a list with the matching event listener registration objects
+     */
+    public <T extends Event> List<EventListenerRegistrationData<? extends T>> getRegistrationsForSuperType(
+            EventType<T> eventType)
+    {
+        Map<EventType<?>, Set<EventType<?>>> superTypes =
+                new HashMap<EventType<?>, Set<EventType<?>>>();
+        List<EventListenerRegistrationData<? extends T>> results =
+                new LinkedList<EventListenerRegistrationData<? extends T>>();
+
+        for (EventListenerRegistrationData<?> reg : listeners)
+        {
+            Set<EventType<?>> base = superTypes.get(reg.getEventType());
+            if (base == null)
+            {
+                base = fetchSuperEventTypes(reg.getEventType());
+                superTypes.put(reg.getEventType(), base);
+            }
+            if (base.contains(eventType))
+            {
+                @SuppressWarnings("unchecked")
+                // This is safe because we just did a check
+                EventListenerRegistrationData<? extends T> result =
+                        (EventListenerRegistrationData<? extends T>) reg;
+                results.add(result);
+            }
+        }
+
+        return results;
+    }
+
+    /**
      * Removes all event listeners registered at this object.
      */
     public void clear()

Modified: commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/event/TestEventListenerList.java
URL: http://svn.apache.org/viewvc/commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/event/TestEventListenerList.java?rev=1610289&r1=1610288&r2=1610289&view=diff
==============================================================================
--- commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/event/TestEventListenerList.java (original)
+++ commons/proper/configuration/trunk/src/test/java/org/apache/commons/configuration/event/TestEventListenerList.java Sun Jul 13 20:01:47 2014
@@ -28,6 +28,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.NoSuchElementException;
 
+import org.easymock.EasyMock;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -509,6 +510,30 @@ public class TestEventListenerList
     }
 
     /**
+     * Tests whether event listener registrations derived from a super type can
+     * be queried.
+     */
+    @Test
+    public void testGetEventListenerRegistrationsForSuperType()
+    {
+        ListenerTestImpl l1 = new ListenerTestImpl();
+        ListenerTestImpl l2 = new ListenerTestImpl();
+        @SuppressWarnings("unchecked")
+        EventListener<Event> l3 = EasyMock.createMock(EventListener.class);
+        list.addEventListener(typeSub1, l1);
+        list.addEventListener(Event.ANY, l3);
+        list.addEventListener(typeBase, l2);
+
+        List<EventListenerRegistrationData<? extends EventBase>> regs =
+                list.getRegistrationsForSuperType(typeBase);
+        Iterator<EventListenerRegistrationData<? extends EventBase>> iterator =
+                regs.iterator();
+        assertEquals("Wrong listener 1", l1, iterator.next().getListener());
+        assertEquals("Wrong listener 2", l2, iterator.next().getListener());
+        assertFalse("Too many elements", iterator.hasNext());
+    }
+
+    /**
      * Test event class. For testing purposes, a small hierarchy of test event
      * class is created. This way it can be checked whether event types are
      * correctly evaluated and take the event hierarchy into account.