From 838535ec9c3300da37f91316c086a948c66d021f Mon Sep 17 00:00:00 2001
From: Raph Levien <raph@google.com>
Date: Thu, 19 Dec 2013 13:52:00 -0800
Subject: [PATCH] Only unregister USB receiver if it was registered

This will probably prevent a crash on pre-Honeycomb devices.
---
 .../src/com/levien/synthesizer/android/ui/PianoActivity2.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/android/src/com/levien/synthesizer/android/ui/PianoActivity2.java b/android/src/com/levien/synthesizer/android/ui/PianoActivity2.java
index e8b1da8..9281bf0 100644
--- a/android/src/com/levien/synthesizer/android/ui/PianoActivity2.java
+++ b/android/src/com/levien/synthesizer/android/ui/PianoActivity2.java
@@ -189,7 +189,9 @@ public class PianoActivity2 extends Activity {
   protected void onPause() {
     Log.d("synth", "activity onPause");
     androidGlue_.setPlayState(false);
-    unregisterReceiver(usbReceiver_);
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR1) {
+      unregisterReceiver(usbReceiver_);
+    }
     setMidiInterface(null, null);
     super.onPause();
   }