Restore game audio after OS events (dictation or siri) use audio

- Dictation reliable raises the handleAudioInterrupt notification, so that
  is used for disabling / enabling audio
- Siri sometimes doesn't raise the handleAudioInterrupt notification, so
  rely on applicationDidBecomeActive / applicationWillResignActive.
- Trial and error showed it is best to destroy and re-create the OS audio
  objects when audio is disabled / enabled.

game/game.cpp

@@ -2165,6 +2165,14 @@ bool Game::FilterEvent(Event *pevt)
     case mpShowObjectivesEvent:
         ShowObjectivesAction::OnMPShowObjectivesEvent(pevt->dw);
         break;
+
+    case disableSoundEvent:
+        gsndm.SaveStateAndClear();
+        break;
+
+    case enableSoundEvent:
+        gsndm.RestoreState();
+        break;
 	}
 
 	return false;
@@ -2201,7 +2209,9 @@ void Game::Suspend()
 	// Call host. This is a modal loop. When it returns, the game isn't
 	// paused anymore
 
+	gsndm.SaveStateAndClear();
 	HostSuspendModalLoop(pbmBack);
+	gsndm.RestoreState();
 
 	// Ok, invalidate everything so it all redraws
 

game/ht.h

@@ -1789,6 +1789,8 @@ struct Event { // evt
 #define checkGameOverEvent 0x6011
 #define connectionCloseEvent 0x6012
 #define showMessageEvent 0x6013
+#define enableSoundEvent 0x6014
+#define disableSoundEvent 0x6015
 
 // gameOverEvent constants (placed in Event::dw)
 

game/iphone/host.cpp

@@ -156,6 +156,16 @@ bool ProcessMessage(base::Message *pmsg, Event *pevt)
         pevt->ff = 0;
         break;
 
+    case kidmDisableSound:
+        pevt->eType = disableSoundEvent;
+        pevt->ff = 0;
+        break;
+
+    case kidmEnableSound:
+        pevt->eType = enableSoundEvent;
+        pevt->ff = 0;
+        break;
+
     default:
         return false;
     }

game/iphone/input.h

@@ -23,6 +23,8 @@ const int kidmAppSetFocus = 17;
 const int kidmAppKillFocus = 18;
 const int kidmAskStringEvent = 19;
 const int kidmKeyDown = 20;
+const int kidmEnableSound = 21;
+const int kidmDisableSound = 22;
 
 extern base::MessageQueue gmq;
 

game/iphone/iphone.mm

@@ -1,5 +1,6 @@
 #import <CoreFoundation/CoreFoundation.h>
 #import <Foundation/Foundation.h>
+#import <AVFoundation/AVFoundation.h>
 #import <UIKit/UIKit.h>
 #import <UIKit/UIWindow.h>
 #import <UIKit/UIApplication.h>
@@ -46,6 +47,27 @@ IPhoneAppDelegate *g_appDelegate;
 {
 }
 
+- (void)handleAudioInterruption:(NSNotification *)notification
+{
+    UInt8 type = [[notification.userInfo valueForKey:AVAudioSessionInterruptionTypeKey] intValue];
+    if (type == AVAudioSessionInterruptionTypeBegan) {
+        if (m_game_thread != NULL) {
+            m_game_thread->Post(kidmDisableSound, NULL);
+        }
+    }
+    if (type == AVAudioSessionInterruptionTypeEnded) {
+        NSError *error = nil;
+        BOOL success = [[AVAudioSession sharedInstance] setActive:YES error:&error];
+        if (success) {
+            if (m_game_thread != NULL) {
+                m_game_thread->Post(kidmEnableSound, NULL);
+            }
+        } else {
+            NSLog(@"AVAudioSession setActive error %@", error);
+        }
+    }
+}
+
 - (void)allocPath:(char **)ppsz baseDir:(const char *)baseDir
         subDir:(const char *)subDir
 {
@@ -171,6 +193,12 @@ IPhoneAppDelegate *g_appDelegate;
     strcpy(m_pszUUID, pszUUID);
     CFRelease(strUUID);
 
+    // Set up a notification to restore sound when interrupted
+    [[NSNotificationCenter defaultCenter] addObserver: self
+            selector: @selector(handleAudioInterruption:)
+            name: AVAudioSessionInterruptionNotification
+            object: nil];
+
     // Spin off a thread to run the game
     m_game_thread = new base::Thread();
     m_game_thread->Start(wi::IPhone::GameThreadStart, NULL);

game/iphone/iphonesounddev.mm

@@ -7,25 +7,6 @@
 #include "criticalsection.h"
 #include "iphone.h"
 
-@interface AudioInterruptionHandler : NSObject
-{
-}
-@end
-
-@implementation AudioInterruptionHandler
-- (void)handleInterruption:(NSNotification *)notification
-{
-    UInt8 type = [[notification.userInfo valueForKey:AVAudioSessionInterruptionTypeKey] intValue];
-    if (type == AVAudioSessionInterruptionTypeEnded) {
-        NSError *error = nil;
-        BOOL success = [[AVAudioSession sharedInstance] setActive:YES error:&error];
-        if (!success) {
-            NSLog(@"AVAudioSession setActive error %@", error);
-        }
-    }
-}
-@end
-
 namespace wi {
 
 #define kcBuffers 4
@@ -91,9 +72,11 @@ IPhoneSoundDevice::IPhoneSoundDevice()
 
 IPhoneSoundDevice::~IPhoneSoundDevice()
 {
+    // This api deletes buffers too
     if (m_haq != NULL) {
         AudioQueueDispose(m_haq, true);
     }
+    SetSoundServiceDevice(NULL);
 }
 
 bool IPhoneSoundDevice::Init()
@@ -118,14 +101,6 @@ bool IPhoneSoundDevice::Init()
         return false;
     }
 
-    // Set up callback for turning on audio when an interruption ends
-    AudioInterruptionHandler *handler = [AudioInterruptionHandler alloc];
-    [[NSNotificationCenter defaultCenter] addObserver: handler
-            selector: @selector(handleInterruption:)
-            name: AVAudioSessionInterruptionNotification
-            object: session];
-    [handler release];
-
     success = [session setActive:YES error:nil];
     if (!success) {
         return false;

game/soundmgr.cpp

@@ -122,9 +122,6 @@ bool SoundMgr::IsEnabled()
 	return false;
 }
 
-// Our game conflicts with OS audio on some devices like Clie. We try to detect these cases and turn audio
-// completely off
-
 void SoundMgr::RestoreState()
 {
 	if (m_fStateSaved) {