From fbcb7f717a54d14d3e49d96c1714b53f37a7d34e Mon Sep 17 00:00:00 2001
From: Volker Fischer <corrados@users.noreply.github.com>
Date: Fri, 20 Nov 2015 18:39:28 +0000
Subject: [PATCH] add device notification for a property change (e.g. if the
 number of channels is changed)

---
 mac/sound.cpp | 43 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 37 insertions(+), 6 deletions(-)

diff --git a/mac/sound.cpp b/mac/sound.cpp
index a1a7d7af..161eaa46 100755
--- a/mac/sound.cpp
+++ b/mac/sound.cpp
@@ -533,15 +533,28 @@ void CSound::Start()
     // setup callback for xruns (only for input is enough)
     AudioObjectPropertyAddress stPropertyAddress;
 
-    stPropertyAddress.mSelector = kAudioDeviceProcessorOverload;
     stPropertyAddress.mElement  = kAudioObjectPropertyElementMaster;
     stPropertyAddress.mScope    = kAudioObjectPropertyScopeGlobal;
 
+    stPropertyAddress.mSelector = kAudioDeviceProcessorOverload;
+
     AudioObjectAddPropertyListener ( audioInputDevice[lCurDev],
                                      &stPropertyAddress,
                                      deviceNotification,
                                      this );
 
+    stPropertyAddress.mSelector = kAudioDevicePropertyDeviceHasChanged;
+
+    AudioObjectAddPropertyListener ( audioInputDevice[lCurDev],
+                                     &stPropertyAddress,
+                                     deviceNotification,
+                                     this );
+
+    AudioObjectAddPropertyListener ( audioOutputDevice[lCurDev],
+                                     &stPropertyAddress,
+                                     deviceNotification,
+                                     this );
+
     // register the callback function for input and output
     AudioDeviceCreateIOProcID ( audioInputDevice[lCurDev],
                                 callbackIO,
@@ -574,10 +587,23 @@ void CSound::Stop()
     // unregister the callback function for xruns
     AudioObjectPropertyAddress stPropertyAddress;
 
-    stPropertyAddress.mSelector = kAudioDeviceProcessorOverload;
     stPropertyAddress.mElement  = kAudioObjectPropertyElementMaster;
     stPropertyAddress.mScope    = kAudioObjectPropertyScopeGlobal;
 
+    stPropertyAddress.mSelector = kAudioDevicePropertyDeviceHasChanged;
+
+    AudioObjectRemovePropertyListener( audioOutputDevice[lCurDev],
+                                       &stPropertyAddress,
+                                       deviceNotification,
+                                       this );
+
+    AudioObjectRemovePropertyListener( audioInputDevice[lCurDev],
+                                       &stPropertyAddress,
+                                       deviceNotification,
+                                       this );
+
+    stPropertyAddress.mSelector = kAudioDeviceProcessorOverload;
+
     AudioObjectRemovePropertyListener( audioInputDevice[lCurDev],
                                        &stPropertyAddress,
                                        deviceNotification,
@@ -679,13 +705,18 @@ UInt32 CSound::SetBufferSize ( AudioDeviceID& audioDeviceID,
 
 OSStatus CSound::deviceNotification ( AudioDeviceID,
                                       UInt32,
-                                      const AudioObjectPropertyAddress* /* inAddresses */,
-                                      void*                             /* inRefCon */ )
+                                      const AudioObjectPropertyAddress* inAddresses,
+                                      void*                             inRefCon )
 {
-// TODO: Do we need this anymore? If not, we can completely remove this function...
-/*
     CSound* pSound = static_cast<CSound*> ( inRefCon );
 
+    if ( inAddresses->mSelector == kAudioDevicePropertyDeviceHasChanged )
+    {
+        // if any property of the device has changed, to a full reload
+        pSound->EmitReinitRequestSignal ( RS_RELOAD_RESTART_AND_INIT );
+    }
+
+/*
     if ( inAddresses->mSelector == kAudioDeviceProcessorOverload )
     {
         // xrun handling (it is important to act on xruns under CoreAudio