From f7caba5295680e713c45849a7b97654ac3123281 Mon Sep 17 00:00:00 2001
From: Bruce Brown <1st-BrainStormer@users.noreply.github.com>
Date: Sat, 20 Jan 2018 11:17:47 -0800
Subject: [PATCH] de-bounce Midi::USBchanged signal.

Debounced USBchanged signal to prevent pauses.
---
 interface/src/Application.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 4b96bc2f2e..3cfa5338ba 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -503,7 +503,13 @@ public:
             }
 
             if (message->message == WM_DEVICECHANGE) {
-                Midi::USBchanged();                // re-scan the MIDI bus
+                const float MIN_DELTA_SECONDS = 2.0f; // de-bounce signal
+                static float lastTriggerTime = 0.0f;
+                const float deltaSeconds = secTimestampNow() - lastTriggerTime;
+                lastTriggerTime = secTimestampNow();
+                if (deltaSeconds > MIN_DELTA_SECONDS) {
+                    Midi::USBchanged();                // re-scan the MIDI bus
+                }
             }
         }
         return false;