chg: add a FilteredClockListener that trigger an existing ClockListener at times defined by a method

Author: pictavien

lib/jbotsim-core/src/main/java/io/jbotsim/core/event/FilteredClockListener.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2008 - 2020, Arnaud Casteigts and the JBotSim contributors <contact@jbotsim.io>
+ *
+ *
+ * This file is part of JBotSim.
+ *
+ * JBotSim is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JBotSim is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with JBotSim.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package io.jbotsim.core.event;
+
+import io.jbotsim.core.Topology;
+
+public abstract class FilteredClockListener implements ClockListener {
+    private Topology topology;
+    private ClockListener listener;
+
+    public FilteredClockListener(Topology tp, ClockListener listener) {
+        this.topology = tp;
+        this.listener = listener;
+    }
+
+    @Override
+    public void onClock() {
+        if (shouldTriggerListener(topology, topology.getTime()))
+            listener.onClock();
+    }
+
+    protected abstract boolean shouldTriggerListener(Topology tp, int currentTime);
+}