From d39f803459e5c993617367e2343c2efb6116fecf Mon Sep 17 00:00:00 2001
From: halx99 <halx99@live.com>
Date: Tue, 25 Aug 2020 13:49:45 +0800
Subject: [PATCH] Add utils::createInstance to instead macro CREATE_FUNC

---
 cocos/base/ccUtils.h                          | 42 +++++++++++++++++--
 .../Classes/AppDelegate.cpp                   |  2 +-
 .../Classes/HelloWorldScene.cpp               |  5 ---
 .../Classes/HelloWorldScene.h                 |  5 ---
 4 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/cocos/base/ccUtils.h b/cocos/base/ccUtils.h
index a6c31136a4..708c8866a6 100644
--- a/cocos/base/ccUtils.h
+++ b/cocos/base/ccUtils.h
@@ -153,8 +153,8 @@ namespace utils
 
      * @return  Returns found node or nullptr with specified type 'T'
      */
-    template<typename T> inline
-    T findChild(Node* levelRoot, const std::string& name)
+    template<typename T>
+    inline T findChild(Node* levelRoot, const std::string& name)
     {
         return dynamic_cast<T>(findChild(levelRoot, name));
     }
@@ -164,12 +164,46 @@ namespace utils
 
      * @return  Returns found node or nullptr with specified type 'T'
      */
-    template<typename T> inline
-    T findChild(Node* levelRoot, int tag)
+    template<typename T>
+    inline T findChild(Node* levelRoot, int tag)
     {
         return dynamic_cast<T>(findChild(levelRoot, tag));
     }
 
+    /**
+     * Create a Game Object instance, like CREATE_FUNC, but more powerful
+
+     * @return  Returns a autorelease game object
+     * @limition: the init function finit must be public
+     */
+    template<typename T, typename F, typename...Ts>
+    inline T* createInstance(F&& finit, Ts&&... args)
+    {
+        T* pRet = new(std::nothrow) T();
+        if (pRet && std::mem_fn(finit)(pRet, std::forward<_Types>(args)...)) {
+            pRet->autorelease();
+            return pRet;
+        }
+        else
+        {
+            delete pRet;
+            pRet = nullptr;
+            return nullptr;
+        }
+    }
+
+    /**
+     * Create a Game Object instance with 'bool T::init()' function, like CREATE_FUNC, but more powerful
+
+     * @return  Returns a autorelease game object
+     * @limition: the init function finit must be public
+     */
+    template<typename T>
+    inline T* createInstance()
+    {
+        return ::cocos2d::utils::createInstance<T>(&T::init);
+    }
+
     /**
      *  Gets the md5 hash for the given file.
      *  @param filename The file to calculate md5 hash.
diff --git a/templates/cpp-template-default/Classes/AppDelegate.cpp b/templates/cpp-template-default/Classes/AppDelegate.cpp
index 8f9a485057..00d169397c 100644
--- a/templates/cpp-template-default/Classes/AppDelegate.cpp
+++ b/templates/cpp-template-default/Classes/AppDelegate.cpp
@@ -108,7 +108,7 @@ bool AppDelegate::applicationDidFinishLaunching() {
     register_all_packages();
 
     // create a scene. it's an autorelease object
-    auto scene = HelloWorld::createScene();
+    auto scene = utils::createInstance<HelloWorld>();
 
     // run
     director->runWithScene(scene);
diff --git a/templates/cpp-template-default/Classes/HelloWorldScene.cpp b/templates/cpp-template-default/Classes/HelloWorldScene.cpp
index 6da19024a3..0169bf96f6 100644
--- a/templates/cpp-template-default/Classes/HelloWorldScene.cpp
+++ b/templates/cpp-template-default/Classes/HelloWorldScene.cpp
@@ -26,11 +26,6 @@
 
 USING_NS_CC;
 
-Scene* HelloWorld::createScene()
-{
-    return HelloWorld::create();
-}
-
 // Print useful error message instead of segfaulting when files are not there.
 static void problemLoading(const char* filename)
 {
diff --git a/templates/cpp-template-default/Classes/HelloWorldScene.h b/templates/cpp-template-default/Classes/HelloWorldScene.h
index 00170938aa..2a0c4b6e80 100644
--- a/templates/cpp-template-default/Classes/HelloWorldScene.h
+++ b/templates/cpp-template-default/Classes/HelloWorldScene.h
@@ -30,15 +30,10 @@
 class HelloWorld : public cocos2d::Scene
 {
 public:
-    static cocos2d::Scene* createScene();
-
     virtual bool init();
     
     // a selector callback
     void menuCloseCallback(cocos2d::Ref* pSender);
-    
-    // implement the "static create()" method manually
-    CREATE_FUNC(HelloWorld);
 };
 
 #endif // __HELLOWORLD_SCENE_H__