Delayed listener

lib/jbotsim-core/src/main/java/io/jbotsim/core/ClockManager.java

@@ -21,6 +21,7 @@
 package io.jbotsim.core;
 
 import io.jbotsim.core.event.ClockListener;
+import io.jbotsim.core.event.PeriodicClockListener;
 
 import java.lang.reflect.Constructor;
 import java.util.ArrayList;
@@ -34,8 +35,7 @@ public class ClockManager {
     final static int CLOCK_INITIAL_VALUE = 0;
 
     Topology tp;
-    HashMap<ClockListener, Integer> listeners = new HashMap<>();
-    HashMap<ClockListener, Integer> countdown = new HashMap<>();
+    HashMap<ClockListener, ClockListener> listeners = new HashMap<>();
     Class<? extends Clock> clockModel = null;
     Clock clock = null;
     int time = CLOCK_INITIAL_VALUE;
@@ -65,14 +65,7 @@ private void incrementTime() {
     }
 
     private void callScheduler() {
-        List<ClockListener> expiredListeners = new ArrayList<>();
-        for (ClockListener cl : listeners.keySet()) {
-            countdown.put(cl, countdown.get(cl) - 1);
-            if (countdown.get(cl) == 0) {
-                expiredListeners.add(cl);
-                countdown.put(cl, listeners.get(cl));
-            }
-        }
+        List<ClockListener> expiredListeners = new ArrayList<>(listeners.values());
         tp.getScheduler().onClock(tp, expiredListeners);
     }
 
@@ -109,8 +102,7 @@ public void setClockModel(Class<? extends Clock> clockModel) {
      *                 in time units.
      */
     public void addClockListener(ClockListener listener, int period) {
-        listeners.put(listener, period);
-        countdown.put(listener, period);
+        listeners.put(listener, new PeriodicClockListener(tp, listener, period));
     }
 
     /**
@@ -119,8 +111,7 @@ public void addClockListener(ClockListener listener, int period) {
      * @param listener The listener to register.
      */
     public void addClockListener(ClockListener listener) {
-        listeners.put(listener, 1);
-        countdown.put(listener, 1);
+        listeners.put(listener, listener);
     }
 
     /**
@@ -131,7 +122,6 @@ public void addClockListener(ClockListener listener) {
      */
     public void removeClockListener(ClockListener listener) {
         listeners.remove(listener);
-        countdown.remove(listener);
     }
 
     /**

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);
+}

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

@@ -0,0 +1,38 @@
+/*
+ * 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 class PeriodicClockListener extends FilteredClockListener {
+    private int period;
+
+    public PeriodicClockListener(Topology tp, ClockListener listener, int period) {
+        super(tp, listener);
+        this.period = period;
+    }
+
+    @Override
+    protected boolean shouldTriggerListener(Topology tp, int currentTime) {
+        return ((currentTime + 1) % period == 0);
+    }
+}