add default log handler for xamarin IOS

coreapi/CMakeLists.txt

@@ -128,6 +128,7 @@ endif()
 set(LINPHONE_SOURCE_FILES_OBJC)
 if (IOS)
 	list(APPEND LINPHONE_SOURCE_FILES_OBJC ringtoneplayer_ios.m ringtoneplayer_ios.h)
+	list(APPEND LINPHONE_SOURCE_FILES_CXX linphonecore_ios.cc)
 endif()
 
 

coreapi/linphonecore_ios.cc

+#include <stdio.h>
+#include "linphone/core.h"
+
+#ifdef __APPLE__
+#include "TargetConditionals.h"
+#endif
+
+#if TARGET_OS_IPHONE
+static void linphone_iphone_log_handler(const char *domain, OrtpLogLevel lev, const char *fmt, va_list args) {
+	char* str = bctbx_strdup_vprintf(fmt, args);
+    const char *levname = "undef";
+
+	if (!domain)
+		domain = "lib";
+
+	switch (lev) {
+		case ORTP_FATAL:
+			levname = "Fatal";
+			break;
+		case ORTP_ERROR:
+			levname = "Error";
+			break;
+		case ORTP_WARNING:
+			levname = "Warning";
+			break;
+		case ORTP_MESSAGE:
+			levname = "Message";
+			break;
+		case ORTP_DEBUG:
+			levname = "Debug";
+			break;
+		case ORTP_TRACE:
+			levname = "Trace";
+			break;
+		case ORTP_LOGLEV_END:
+			return;
+	}
+	fprintf(stdout,"[%s] %s", levname, str);
+}
+
+extern "C" void linphone_iphone_enable_logs() {
+	linphone_core_enable_logs_with_cb(linphone_iphone_log_handler);
+}
+#endif
\ No newline at end of file