Initial version. JM-807

git-svn-id: http://svn.igniterealtime.org/svn/repos/wildfire/trunk@4964 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/wildfire/roster/RosterEventDispatcher.java

+/**
+ * $RCSfile$
+ * $Revision: $
+ * $Date: $
+ *
+ * Copyright (C) 2006 Jive Software. All rights reserved.
+ *
+ * This software is published under the terms of the GNU Public License (GPL),
+ * a copy of which is included in this distribution.
+ */
+
+package org.jivesoftware.wildfire.roster;
+
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * Dispatches roster events. The following events are supported:
+ * <ul>
+ * <li><b>rosterLoaded</b> --> A roster has just been loaded.</li>
+ * <li><b>contactAdded</b> --> A contact has been added to a roster.</li>
+ * <li><b>contactUpdated</b> --> A contact has been updated of a roster.</li>
+ * <li><b>contactDeleted</b> --> A contact has been deleted from a roster.</li>
+ * </ul>
+ * Use {@link #addListener(RosterEventListener)} and {@link #removeListener(RosterEventListener)}
+ * to add or remove {@link RosterEventListener}.
+ *
+ * @author Gaston Dombiak
+ */
+public class RosterEventDispatcher {
+
+    private static List<RosterEventListener> listeners =
+            new CopyOnWriteArrayList<RosterEventListener>();
+
+    /**
+     * Registers a listener to receive events.
+     *
+     * @param listener the listener.
+     */
+    public static void addListener(RosterEventListener listener) {
+        if (listener == null) {
+            throw new NullPointerException();
+        }
+        listeners.add(listener);
+    }
+
+    /**
+     * Unregisters a listener to receive events.
+     *
+     * @param listener the listener.
+     */
+    public static void removeListener(RosterEventListener listener) {
+        listeners.remove(listener);
+    }
+
+    /**
+     * Notifies the listeners that a roster has just been loaded.
+     *
+     * @param roster the loaded roster.
+     */
+    public static void rosterLoaded(Roster roster) {
+        if (!listeners.isEmpty()) {
+            for (RosterEventListener listener : listeners) {
+                listener.rosterLoaded(roster);
+            }
+        }
+    }
+
+    /**
+     * Notifies the listeners that a contact has been added to a roster.
+     *
+     * @param roster the roster that was updated.
+     * @param item   the new roster item.
+     */
+    public static void contactAdded(Roster roster, RosterItem item) {
+        if (!listeners.isEmpty()) {
+            for (RosterEventListener listener : listeners) {
+                listener.contactAdded(roster, item);
+            }
+        }
+    }
+
+    /**
+     * Notifies the listeners that a contact has been updated.
+     *
+     * @param roster the roster that was updated.
+     * @param item   the updated roster item.
+     */
+    public static void contactUpdated(Roster roster, RosterItem item) {
+        if (!listeners.isEmpty()) {
+            for (RosterEventListener listener : listeners) {
+                listener.contactUpdated(roster, item);
+            }
+        }
+    }
+
+    /**
+     * Notifies the listeners that a contact has been deleted from a roster.
+     *
+     * @param roster the roster that was updated.
+     * @param item   the roster item that was deleted.
+     */
+    public static void contactDeleted(Roster roster, RosterItem item) {
+        if (!listeners.isEmpty()) {
+            for (RosterEventListener listener : listeners) {
+                listener.contactDeleted(roster, item);
+            }
+        }
+    }
+}

src/java/org/jivesoftware/wildfire/roster/RosterEventListener.java

+/**
+ * $RCSfile$
+ * $Revision: $
+ * $Date: $
+ *
+ * Copyright (C) 2006 Jive Software. All rights reserved.
+ *
+ * This software is published under the terms of the GNU Public License (GPL),
+ * a copy of which is included in this distribution.
+ */
+
+package org.jivesoftware.wildfire.roster;
+
+/**
+ * Interface to listen for roster events. Use the
+ * {@link RosterEventDispatcher#addListener(RosterEventListener)}
+ * method to register for events.
+ *
+ * @author Gaston Dombiak
+ */
+public interface RosterEventListener {
+
+    /**
+     * Notification message indicating that a roster has just been loaded.
+     *
+     * @param roster the loaded roster.
+     */
+    public void rosterLoaded(Roster roster);
+
+    /**
+     * Notification message indicating that a contact has been added to a roster.
+     *
+     * @param roster the roster that was updated.
+     * @param item the new roster item.
+     */
+    public void contactAdded(Roster roster, RosterItem item);
+
+    /**
+     * Notification message indicating that a contact has been updated.
+     *
+     * @param roster the roster that was updated.
+     * @param item the updated roster item.
+     */
+    public void contactUpdated(Roster roster, RosterItem item);
+
+    /**
+     * Notification message indicating that a contact has been deleted from a roster.
+     *
+     * @param roster the roster that was updated.
+     * @param item the roster item that was deleted.
+     */
+    public void contactDeleted(Roster roster, RosterItem item);
+}