split unity_console.h to unity_console.cc and unity_console.h and make the details of native console logging invisible to users

com.unity.uiwidgets/Runtime/engine2/UIWidgetsPanel.cs

                 _width, _height, _devicePixelRatio, Application.streamingAssetsPath);
 
             Input_OnEnable();
-            NativeConsole.InitNativeConsoleDelegate(NativeConsole.LogMessageFromCpp);
+            NativeConsole.OnEnable();
         }
 
         protected virtual void main() {

com.unity.uiwidgets/Runtime/engine2/native_console.cs

 using NativeBindings = Unity.UIWidgets.ui.NativeBindings;
 
 public static class NativeConsole {
-    public delegate void LogDelegate(IntPtr message, int iSize);
+    internal delegate void LogDelegate(IntPtr message, int iSize);
-    public static extern void InitNativeConsoleDelegate(LogDelegate log);
+    internal static extern void InitNativeConsoleDelegate(LogDelegate log);
-    public static void LogMessageFromCpp(IntPtr message, int iSize) {
+    internal static void LogMessageFromCpp(IntPtr message, int iSize) {
+    public static void OnEnable()
+    {
+        InitNativeConsoleDelegate(LogMessageFromCpp);
+    }
 }

engine/Build.bee.cs

                 "src/shell/platform/unity/unity_surface_manager.h",
                 "src/shell/platform/unity/win32_task_runner.cc",
                 "src/shell/platform/unity/win32_task_runner.h",
+                "src/shell/platform/unity/unity_console.cc",
+                "src/shell/platform/unity/unity_console.h",
 
                 "src/shell/version/version.cc",
                 "src/shell/version/version.h",

engine/src/shell/platform/unity/uiwidgets_panel.cc

 #include "shell/common/switches.h"
 #include "uiwidgets_system.h"
 #include "unity_external_texture_gl.h"
-#include "unity_console.h"
 
 namespace uiwidgets {
 
 UIWidgetsPanel_onMouseDown(UIWidgetsPanel* panel, float x, float y,
                            int button) {
   panel->OnMouseDown(x, y, button);
-  UnityConsole::WriteLine("OnMouseDown");
-  UnityConsole::WriteLine("OnMouseUp");
 }
 
 UIWIDGETS_API(void)

engine/src/shell/platform/unity/unity_console.h

+#pragma once
 #include "runtime/mono_api.h"
 
 namespace uiwidgets {
-extern "C"{
+
-   static void (*Log)(char* message,int iSize);
-   /*
+  static LogDelegate _log;
+
+   /**
+    @param fmt   log format
+    @param ...   log args
+    @return      null
+
+    example: 
+      UnityConsole::WriteLine("output log without fmt param");
+      UnityConsole::WriteLine("%s: %d + %d = %d","output log with param", 1, 2, 3);
-   static void WriteLine(const char* fmt, ...){ 
-   char log_str[512] = { 0 };
-   va_list ap;
-   va_start(ap, fmt);
-   sprintf_s(log_str, fmt, ap);
-   Log(log_str, strlen(log_str));
-   va_end(ap);
-  }
+  static void WriteLine(const char* fmt, ...);
-  void (*UnityConsole::Log)(char* message, int iSize);
-  UIWIDGETS_API(void) 
-  InitNativeConsoleDelegate(LogDelegate Log){ UnityConsole::Log = Log; }
-}
+
 } // namespace uiwidgets

engine/src/shell/platform/unity/unity_console.cc

+#include "unity_console.h"
+#include <stdarg.h>
+
+namespace uiwidgets {
+
+ void UnityConsole::WriteLine(const char* fmt, ...) {
+  char log_str[512] = { 0 };
+  va_list ap;
+  va_start(ap, fmt);
+  vsprintf(log_str, fmt, ap);
+  _log(log_str, strlen(log_str));
+  va_end(ap);
+}
+
+LogDelegate UnityConsole::_log;
+
+UIWIDGETS_API(void) 
+InitNativeConsoleDelegate(LogDelegate Log) { 
+  UnityConsole::_log = Log; 
+}
+
+}