From 1a432197ac62b33d073de2653451b47340a8c133 Mon Sep 17 00:00:00 2001
From: Denny <denny@denny-desktop>
Date: Sat, 20 May 2017 06:51:53 -0400
Subject: [PATCH] Resolves #245 issue with NPE for frequency change event
 listener when using the sound card/mixer as a source.

---
 src/module/ProcessingChain.java | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/module/ProcessingChain.java b/src/module/ProcessingChain.java
index a018e360..7c0bf5cd 100644
--- a/src/module/ProcessingChain.java
+++ b/src/module/ProcessingChain.java
@@ -320,7 +320,13 @@ public class ProcessingChain implements IChannelEventListener
 
         if(module instanceof IFrequencyChangeListener)
         {
-            mFrequencyChangeEventBroadcaster.addListener(((IFrequencyChangeListener) module).getFrequencyChangeListener());
+            Listener<FrequencyChangeEvent> frequencyChangeEventListener =
+                ((IFrequencyChangeListener)module).getFrequencyChangeListener();
+
+            if(frequencyChangeEventListener != null)
+            {
+                mFrequencyChangeEventBroadcaster.addListener(frequencyChangeEventListener);
+            }
         }
 
         if(module instanceof IMessageListener)