Mac OS X DialogDriver was lacking OKCancel, I also added YesNo Dialog to every platform.

src/arch/Dialog/Dialog.cpp

@@ -234,6 +234,30 @@ Dialog::Result Dialog::AbortRetry( RString sMessage, RString sID )
 	return ret;
 }
 
+Dialog::Result Dialog::YesNo( RString sMessage, RString sID )
+{
+	Dialog::Init();
+
+	if( LOG )
+		LOG->Trace( "Dialog: \"%s\" [%s]", sMessage.c_str(), sID.c_str() );
+
+	if( sID != "" && MessageIsIgnored(sID) )
+		return g_NullDriver.YesNo( sMessage, sID );
+
+	RageThread::SetIsShowingDialog( true );
+
+	// only show Dialog if windowed
+	Dialog::Result ret;
+	if( DialogsEnabled() )
+		ret = g_pImpl->YesNo( sMessage, sID );	// call derived version
+	else
+		ret = g_NullDriver.YesNo( sMessage, sID );
+	
+	RageThread::SetIsShowingDialog( false );
+
+	return ret;
+}
+
 /*
  * (c) 2003-2004 Glenn Maynard, Chris Danford
  * All rights reserved.

src/arch/Dialog/Dialog.h

@@ -10,12 +10,13 @@ namespace Dialog
 
 	void SetWindowed( bool bWindowed );
 
-	enum Result { ok, cancel, abort, retry, ignore };
+	enum Result { ok, cancel, abort, retry, ignore, yes, no };
 	void Error( RString sError, RString sID = "" );
 	void OK( RString sMessage, RString sID = "" );
 	Result OKCancel( RString sMessage, RString sID = "" );
 	Result AbortRetryIgnore( RString sMessage, RString sID = "" );
 	Result AbortRetry( RString sMessage, RString sID = "" );
+	Result YesNo( RString sMessage, RString sID = "" );
 
 	/* for DialogDrivers */
 	void IgnoreMessage( RString sID );

src/arch/Dialog/DialogDriver.h

@@ -14,6 +14,7 @@ public:
 	virtual Dialog::Result OKCancel( RString sMessage, RString sID ) { return Dialog::ok; }
 	virtual Dialog::Result AbortRetryIgnore( RString sMessage, RString sID ) { return Dialog::ignore; }
 	virtual Dialog::Result AbortRetry( RString sMessage, RString sID ) { return Dialog::abort; }
+	virtual Dialog::Result YesNo( RString sMessage, RString sID ) { return Dialog::no; }
 
 	virtual RString Init() { return RString(); }
 	virtual ~DialogDriver() { }

src/arch/Dialog/DialogDriver_MacOSX.cpp

@@ -54,6 +54,27 @@ void DialogDriver_MacOSX::Error( RString sError, RString sID )
 	ShowAlert( kCFUserNotificationStopAlertLevel, sError, CFSTR("OK") );
 }
 
+Dialog::Result DialogDriver_MacOSX::OKCancel( RString sMessage, RString sID )
+{
+	CFBundleRef bundle = CFBundleGetMainBundle();
+	CFStringRef sOK = LSTRING( bundle, "OK" );
+	CFStringRef sCancel = LSTRING( bundle, "Cancel" );
+	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage, sOK, sCancel );
+
+	CFRelease( sOK );
+	CFRelease( sCancel );
+	switch( result )
+	{
+	case kCFUserNotificationDefaultResponse:
+	case kCFUserNotificationCancelResponse:
+		return Dialog::cancel;
+	case kCFUserNotificationAlternateResponse:
+		return Dialog::ok;
+	default:
+		FAIL_M( ssprintf("Invalid response: %d.", int(result)) );
+	}
+}
+
 Dialog::Result DialogDriver_MacOSX::AbortRetryIgnore( RString sMessage, RString sID )
 {
 	CFBundleRef bundle = CFBundleGetMainBundle();
@@ -101,6 +122,27 @@ Dialog::Result DialogDriver_MacOSX::AbortRetry( RString sMessage, RString sID )
 	}
 }
 
+Dialog::Result DialogDriver_MacOSX::YesNo( RString sMessage, RString sID )
+{
+	CFBundleRef bundle = CFBundleGetMainBundle();
+	CFStringRef sYes = LSTRING( bundle, "Yes" );
+	CFStringRef sNo = LSTRING( bundle, "No" );
+	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage, sYes, sNo );
+
+	CFRelease( sYes );
+	CFRelease( sNo );
+	switch( result )
+	{
+	case kCFUserNotificationDefaultResponse:
+	case kCFUserNotificationCancelResponse:
+		return Dialog::no;
+	case kCFUserNotificationAlternateResponse:
+		return Dialog::yes;
+	default:
+		FAIL_M( ssprintf("Invalid response: %d.", int(result)) );
+	}
+}
+
 /*
  * (c) 2003-2006 Steve Checkoway
  * All rights reserved.

src/arch/Dialog/DialogDriver_MacOSX.h

@@ -8,8 +8,10 @@ class DialogDriver_MacOSX: public DialogDriver
 public:
 	void Error( RString sError, RString sID );
 	void OK( RString sMessage, RString sID );
+	Dialog::Result OKCancel( RString sMessage, RString sID );
 	Dialog::Result AbortRetryIgnore( RString sMessage, RString sID );
 	Dialog::Result AbortRetry( RString sMessage, RString sID );
+	Dialog::Result YesNo( RString sMessage, RString sID );
 };
 #define USE_DIALOG_DRIVER_COCOA
     

src/arch/Dialog/DialogDriver_Win32.cpp

@@ -263,6 +263,22 @@ Dialog::Result DialogDriver_Win32::AbortRetry( RString sMessage, RString sID )
 	}
 } 
 
+Dialog::Result DialogDriver_Win32::YesNo( RString sMessage, RString sID )
+{
+	int iRet = 0;
+#if !defined(SMPACKAGE)
+	iRet = ::MessageBox(::GetHwnd(), ConvertUTF8ToACP(sMessage).c_str(), ConvertUTF8ToACP(::GetWindowTitle()).c_str(), MB_YESNO);
+#else
+	iRet = ::AfxMessageBox( ConvertUTF8ToACP(sMessage).c_str(), MB_RETRYCANCEL, 0 );
+#endif
+	switch( iRet )
+	{
+	case IDYES:	return Dialog::yes;
+	default:	ASSERT(0);
+	case IDNO:	return Dialog::no;
+	}
+}
+
 /*
  * (c) 2003-2004 Glenn Maynard, Chris Danford
  * All rights reserved.

src/arch/Dialog/DialogDriver_Win32.h

@@ -11,6 +11,7 @@ public:
 	Dialog::Result OKCancel( RString sMessage, RString sID );
 	Dialog::Result AbortRetryIgnore( RString sMessage, RString sID );
 	Dialog::Result AbortRetry( RString sMessage, RString sID );
+	Dialog::Result YesNo( RString sMessage, RString sID );
 };
 
 #endif