cocos2dx js自定义js-binding

今天药忘吃喽~ 2022-06-04 10:10 283阅读 0赞

**一、环境**

mac 10.12.2

编译、编辑环境Xcode9.1

CocosCreator版本1.5.1

**二、绑定js-binding前的准备**

本文和[前文lua-binding][lua-binding]有些不同，写这个绑定的例子前，我自己也没有学习过jsb的文档或者api，就直接把这个例子给做好了，之所以这么顺利,要归功于像前文一样借鉴其他js-binding的例子。

所以不管对cocos2dx原代码了解多少，都是可以做完写自己的s-binding这个功能的。当然，如果能对原码有比较好的了解的话，肯定会事半功倍。

其实lua-binding和js-binding大体的步骤都是一样的，为了防止部分同学只做lua和js中的一种，所以两个语言都写一篇比较保险。

还有一点要说明一下，我这个jsb是在CocosCreator中的jsb，可能和cocos2dx-js中的有点出入。而cocos2dx-js的jsb我并没有实验过，所以大家绑定cocos2dx-js的时候出现的一些问题，可能我力不能及了。

**三、绑定自己的js-binding**

像前文一样，我们要借鉴一个已经写好的js-binding实例，这次我们借鉴的是jsb\_cocos2dx\_ui\_auto。

jsb\_cocos2dx\_ui\_auto文件的真实目录是cocos/scripting/js-bindings/auto。

1.写自己的Node类

写一个类，继承自Node类或者Sprite类，好让这个类能在js代码中新建起来。

2.仿照jsb\_cocos2dx\_ui\_auto中的代码

查看jsb\_cocos2dx\_ui\_auto.cpp中的代码，并写出一个jsb\_cocos2dx\_liveVideo\_auto.cpp文件的代码。

![Center][]

jsb\_cocos2dx\_liveVideo\_auto.cpp代码如：

#include "scripting/js-bindings/auto/jsb_cocos2dx_ui_liveVideo.hpp"
    #include "scripting/js-bindings/manual/cocos2d_specifics.hpp"
    #include "ui/CocosGUI.h"
    #include "ui/UIScrollViewBar.h"
    #include "editor-support/cocostudio/CocosStudioExtension.h"
    #include "liveVideo/LiveVideo.h"
    
    JSClass  *jsb_cocos2d_ui_LiveVideo_class;
    JSObject *jsb_cocos2d_ui_LiveVideo_prototype;
    
    
    bool js_cocos2dx_ui_LiveVideo_create(JSContext *cx, uint32_t argc, jsval *vp)
    {
        JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
        bool ok = true;
        if (argc == 1) {
            std::string arg0;
            ok &= jsval_to_std_string(cx, args.get(0), &arg0);
            JSB_PRECONDITION2(ok, cx, false, "js_cocos2dx_ui_Slider_loadSlidBallTextureNormal : Error processing arguments");
            LiveVideo* ret = LiveVideo::create(arg0);
            jsval jsret = JSVAL_NULL;
            if (ret) {
                jsret = OBJECT_TO_JSVAL(js_get_or_create_jsobject<LiveVideo>(cx, (LiveVideo*)ret));
            } else {
                jsret = JSVAL_NULL;
            };
            args.rval().set(jsret);
            return true;
        }
        
        if (argc == 5) {
            std::string arg0;
            double arg1 = 0, arg2 = 0, arg3 = 0, arg4 = 0;
            ok &= jsval_to_std_string(cx, args.get(0), &arg0);
            ok &= JS::ToNumber( cx, args.get(1), &arg1) && !std::isnan(arg1);
            ok &= JS::ToNumber( cx, args.get(2), &arg2) && !std::isnan(arg2);
            ok &= JS::ToNumber( cx, args.get(3), &arg3) && !std::isnan(arg3);
            ok &= JS::ToNumber( cx, args.get(4), &arg4) && !std::isnan(arg4);
            JSB_PRECONDITION2(ok, cx, false, "js_cocos2dx_ui_Slider_loadSlidBallTextureNormal : Error processing arguments");
            LiveVideo* ret = LiveVideo::create(arg0, arg1, arg2, arg3, arg4);
            jsval jsret = JSVAL_NULL;
            if (ret) {
                jsret = OBJECT_TO_JSVAL(js_get_or_create_jsobject<LiveVideo>(cx, (LiveVideo*)ret));
            } else {
                jsret = JSVAL_NULL;
            };
            args.rval().set(jsret);
            return true;
        }
        JS_ReportError(cx, "js_cocos2dx_ui_LiveVideo_create : wrong number of arguments");
        return false;
    }
    
    bool js_cocos2dx_ui_LiveVideo_close(JSContext *cx, uint32_t argc, jsval *vp)
    {
        
        JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
        JS::RootedObject obj(cx, args.thisv().toObjectOrNull());
        js_proxy_t *proxy = jsb_get_js_proxy(obj);
        LiveVideo* cobj = (LiveVideo *)(proxy ? proxy->ptr : NULL);
        JSB_PRECONDITION2( cobj, cx, false, "js_cocos2dx_ui_LiveVideo_close : Invalid Native Object");
        cobj->close();
        args.rval().setUndefined();
        return true;
    }
    
    bool js_cocos2dx_ui_LiveVideo_constructor(JSContext *cx, uint32_t argc, jsval *vp)
    {
        JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
        bool ok = true;
        LiveVideo* cobj = new (std::nothrow) LiveVideo();
        
        js_type_class_t *typeClass = js_get_type_from_native<LiveVideo>(cobj);
        
        // link the native object with the javascript object
        JS::RootedObject jsobj(cx, jsb_ref_create_jsobject(cx, cobj, typeClass, "LiveVideo"));
        args.rval().set(OBJECT_TO_JSVAL(jsobj));
        //    if (JS_HasProperty(cx, jsobj, "_ctor", &ok) && ok)
        //        ScriptingCore::getInstance()->executeFunctionWithOwner(OBJECT_TO_JSVAL(jsobj), "_ctor", args);
        return true;
    }
    
    extern JSObject *jsb_cocos2d_Node_prototype;
    
    
    void js_register_cocos2dx_ui_LiveVideo(JSContext *cx, JS::HandleObject global) {
        jsb_cocos2d_ui_LiveVideo_class = (JSClass *)calloc(1, sizeof(JSClass));
        jsb_cocos2d_ui_LiveVideo_class->name = "LiveVideo";
        jsb_cocos2d_ui_LiveVideo_class->addProperty = JS_PropertyStub;
        jsb_cocos2d_ui_LiveVideo_class->delProperty = JS_DeletePropertyStub;
        jsb_cocos2d_ui_LiveVideo_class->getProperty = JS_PropertyStub;
        jsb_cocos2d_ui_LiveVideo_class->setProperty = JS_StrictPropertyStub;
        jsb_cocos2d_ui_LiveVideo_class->enumerate = JS_EnumerateStub;
        jsb_cocos2d_ui_LiveVideo_class->resolve = JS_ResolveStub;
        jsb_cocos2d_ui_LiveVideo_class->convert = JS_ConvertStub;
        jsb_cocos2d_ui_LiveVideo_class->flags = JSCLASS_HAS_RESERVED_SLOTS(2);
        
        static JSPropertySpec properties[] = {
            JS_PS_END
        };
        
        static JSFunctionSpec funcs[] = {
            JS_FN("close", js_cocos2dx_ui_LiveVideo_close, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),
            JS_FS_END
        };
        
        static JSFunctionSpec st_funcs[] = {
            JS_FN("create", js_cocos2dx_ui_LiveVideo_create, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),
            
            JS_FS_END
        };
        
        JS::RootedObject parent_proto(cx, jsb_cocos2d_Node_prototype);
        jsb_cocos2d_ui_LiveVideo_prototype = JS_InitClass(
                                                          cx, global,
                                                          parent_proto,
                                                          jsb_cocos2d_ui_LiveVideo_class,
                                                          js_cocos2dx_ui_LiveVideo_constructor, 0, // constructor
                                                          properties,
                                                          funcs,
                                                          NULL, // no static properties
                                                          st_funcs);
        
        JS::RootedObject proto(cx, jsb_cocos2d_ui_LiveVideo_prototype);
        JS::RootedValue className(cx, std_string_to_jsval(cx, "LiveVideo"));
        JS_SetProperty(cx, proto, "_className", className);
        JS_SetProperty(cx, proto, "__nativeObj", JS::TrueHandleValue);
        JS_SetProperty(cx, proto, "__is_ref", JS::TrueHandleValue);
        // add the proto and JSClass to the type->js info hash table
        jsb_register_class<LiveVideo>(cx, jsb_cocos2d_ui_LiveVideo_class, proto, parent_proto);
        anonEvaluate(cx, global, "(function () { cc.LiveVideo.extend = cc.Class.extend; })()");
    }
    
    void register_all_cocos2dx_liveVideo(JSContext* cx, JS::HandleObject obj) {
        // Get the ns
        CCLOG("vvv");
        JS::RootedObject ns(cx);
        get_or_create_js_obj(cx, obj, "cc", &ns);
        js_register_cocos2dx_ui_LiveVideo(cx, ns);
    }

查看jsb\_cocos2dx\_ui\_auto.hpp中的代码，并写出一个jsb\_cocos2dx\_liveVideo\_auto.hpp文件的代码。

//
    //  jsb_cocos2dx_livevideo.hpp
    //  cocos2d_js_bindings
    //
    //  Created by  on 2017/10/20.
    //
    #include "base/ccConfig.h"
    #ifndef jsb_cocos2dx_livevideo_hpp
    #define jsb_cocos2dx_livevideo_hpp
    
    #include "jsapi.h"
    #include "jsfriendapi.h"
    
    extern JSClass  *jsb_cocos2d_LiveVideo_class;
    extern JSObject *jsb_cocos2d_LiveVideo_prototype;
    
    bool js_cocos2dx_LiveVideo_constructor(JSContext *cx, uint32_t argc, jsval *vp);
    
    bool js_cocos2dx_LiveVideo_create(JSContext *cx, uint32_t argc, jsval *vp);
    bool js_cocos2dx_LiveVideo_close(JSContext *cx, uint32_t argc, jsval *vp);
    
    void js_cocos2dx_liveVideo_finalize(JSContext *cx, JSObject *obj);
    void js_register_cocos2dx_LiveVideo(JSContext *cx, JS::HandleObject global);
    void register_all_cocos2dx_liveVideo(JSContext* cx, JS::HandleObject obj);
    
    #endif /* jsb_cocos2dx_livevideo_hpp */

最后，找到js\_module\_register.cpp文件。

![Center 1][]

编辑js\_module\_register.cpp文件：

![Center 2][]

和：

![Center 3][]

最最后，CocosCreator中的调用代码应该这样写：

initLiveVideo : function() {
        var url = "rtmp://live.hkstv.hk.lxdns.com/live/hks";
        this.liveVideo = ccui.LiveVideo.create(url, 0, 0 , 1136, 640);
        this.node._sgNode.addChild(this.liveVideo);
    },

[lua-binding]: http://blog.csdn.net/u013654125/article/details/78758205
[Center]: /images/20220604/935bb346f0914b3cb78e0fedae05f45f.png
[Center 1]: /images/20220604/5d900be28a38404493fd554a80302d4e.png
[Center 2]: /images/20220604/98a25b7d635548af9e756f08d5b9f5f8.png
[Center 3]: /images/20220604/d151f74eb9ee409c8da57d190799a24a.png