--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/fschmidt/db/ListenerList.java	Sun Oct 05 17:24:15 2025 -0600
@@ -0,0 +1,56 @@
+/*
+Copyright (c) 2008  Franklin Schmidt <fschmidt@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+package fschmidt.db;
+
+import java.util.List;
+import java.util.ArrayList;
+
+
+public final class ListenerList<T> implements Listener<T> {
+	private List<Listener<? super T>> listeners = new ArrayList<Listener<? super T>>();
+	private Exception firstFired = null;
+
+	public synchronized void add(Listener<? super T> listener) {
+		if( firstFired != null )
+			throw new IllegalStateException("adding to ListenerList after already in use",firstFired);
+		listeners.add(listener);
+	}
+/*
+	public synchronized void remove(Listener<? super T> listener) {
+		listeners.remove(listener);
+	}
+*/
+	public void event(T obj) {
+		synchronized(this) {
+			if( firstFired == null )
+				firstFired = new Exception("first fired");
+		}
+		for( Listener<? super T> listener : listeners ) {
+			listener.event(obj);
+		}
+	}
+
+	public boolean isEmpty() {
+		return listeners.isEmpty();
+	}
+}