[{"_1":2,"_3":-5,"_4":-5},"loaderData",{"_5":6,"_7":8},"actionData","errors","root",{"_11":-5},"routes/user.$name.replies",{"_9":10,"_11":12,"_13":14,"_15":16,"_17":18,"_19":16},"replies",[35],"user",{"_20":21,"_13":14,"_22":23,"_24":25,"_26":27,"_28":29,"_30":31,"_32":16,"_33":34},"loginname","chrisak","page",1,"limit",50,"total","id","1129","avatar_url","http://www.gravatar.com/avatar/ef54afa584c043fdfd947c802b922506?s=48","githubUsername","","create_at","2011-11-03 00:38:00","score",5,"topic_count",0,"reply_count","is_star",false,{"_20":36,"_37":38,"_39":-5,"_40":41,"_42":43,"_44":45,"_46":34,"_47":34,"_32":48,"_49":50,"_26":51,"_52":53},"53","author_id","277","tab","content","node的定位是，server-side javascript。\r\n
\r\n
但程序员最爱做的事，就是把一个东西用在不该用的地方。那么，可以把node用在桌面开发上吗？当然可以。\r\n
\r\n
把Javascript用在桌面开发上，早有先例，比如GTK+的gjs，还有Qt的QML（顺带一提，QML代表着桌面开发的另一个方向，a promising way），GNOME3中，也用javascript作为桌面插件的开发语言。\r\n
\r\n
那么为何要多此一举，把node引入到桌面开发上？因为node的网络编程能力。使用node，你可以十几分钟就写出一个微博客户端来，而且代码简单明了，这种内在的网络能力，是其他所有语言欠缺的。\r\n

第一个例子

\r\n
那么，单刀直入，让我们先看一个hello world：\r\n

var gui = require('../lib/gui');\r\n
\r\n
var window = new gui.Window ({\r\n
    'title': 'node-gui',\r\n
    'window-position': 1,\r\n
    'opacity': 0.5\r\n
});\r\n
\r\n
window.show ();\r\n
\r\n
window.on ('delete-event', function () {\r\n
    gui.quit ();\r\n
});

\r\n
代码很简单，就像其他所有module一样。\r\n
\r\n
首先，我们使用new Window建立了一个新窗口，参数是窗口property的列表，分别代表标题、位置、透明度，其它属性可以在GTK+文档里查到。然后，我们调用了show方法。接着，使窗口响应'delete-event'消息，在窗口关闭时退出。\r\n

node-gui

\r\n
代码中引用的module在这里： https://github.com/zcbenz/node-gui/ ，内有详细说明。\r\n
\r\n
可以直接用npm安装：npm install gui\r\n
\r\n
编译时需要注意，你需要GTK+开发库支持。而且因为耍了很多C++11的花枪，你还需要很新的GCC4.6。\r\n
\r\n
为node编写界面库的难点，在于把两种格格不入的事件循环融合起来。我采用的方案，是将GTK+主循环放在新线程中进行，一来简化了逻辑，二来GUI操作向来费时，把GUI操作放在新线程中操作符合异步的要义。\r\n

Windows

\r\n
提到桌面开发，Windows从来是不得不支持的平台。node已经部分支持了Windows，那么使用node-gui的程序能在Windows下跑起来吗？可以，但是需要艰苦卓绝的努力。\r\n
\r\n
node Windows porting尚未实现功能之一，就是native C++ module的支持（如果你想知道原因，是因为模板类成员函数无法导出到额外加载的DLL中），这几乎堵死了我的路。不过经过一番努力，我把node-gui作为node的一部分编译入了node，成功运转了起来。（另外，如果你想亲自尝试的话，为了获得更好的用户体验，最好在编译选项中把Console Window取消掉。）\r\n
\r\n
但是坦言说来，这样没有太大意义，Windows下的GTK+运行库大约有18mb，而且GTK+3也暂时没有Windows的二进制库（原来的贡献者退出了）。为几kb的脚本付出二十来mb的运行时代价，用户不会买账的（也是为何鲜有民用桌面软件采用.NET开发）。\r\n

复杂的例子

\r\n
那么，让我们再接着看一个复杂些的例子，这次我们用上了网络：\r\n

var gui = require ('../lib/gui');\r\n
var http = require ('http');\r\n
\r\n
new gui.Builder (__dirname + '/download.glade', function (builder) {\r\n
    var window   = builder.get ('window'   , gui.Window   ) ;\r\n
    var download = builder.get ('download' , gui.Button   ) ;\r\n
    var url      = builder.get ('url'      , gui.Entry    ) ;\r\n
    var text     = builder.get ('text'     , gui.TextView ) ;\r\n
\r\n
    window.setBorderWidth (10);\r\n
    window.show ();\r\n
\r\n
    window.on ('delete-event', function () {\r\n
        gui.quit ();\r\n
        process.exit (0);\r\n
    });\r\n
\r\n
    var onDownload = function () {\r\n
        var sUrl  = url.getText ();\r\n
\r\n
        var options = require ('url').parse (sUrl);\r\n
        var data = \"\";\r\n
        var req = http.request (options, function (res) {\r\n
            res.on ('data', function (chunk) {\r\n
                var buffer = text.getBuffer ();\r\n
                var str = String (chunk);\r\n
                buffer.insertAtCursor (str, str.length);\r\n
            });\r\n
\r\n
            res.on ('end', function () {\r\n
                download.setLabel ('Download');\r\n
                download.setSensitive (true);\r\n
            });\r\n
        });\r\n
\r\n
        req.on ('error', function (e) {\r\n
            var message = new gui.MessageDialog ({\r\n
                'buttons': 1,\r\n
                'text': 'Networking Error',\r\n
                'secondary-text': e.message\r\n
            });\r\n
            message.show ();\r\n
            message.on ('response', function () {\r\n
                message.destroy ();\r\n
            });\r\n
\r\n
            download.setLabel ('Download');\r\n
            download.setSensitive (true);\r\n
        });\r\n
\r\n
        req.on ('response', function () {\r\n
            text.getBuffer ().setProperty ('text', '');\r\n
        });\r\n
\r\n
        req.end ();\r\n
\r\n
        download.setLabel ('Downloading...');\r\n
        download.setSensitive (false);\r\n
    };\r\n
\r\n
    download.on ('clicked', onDownload);\r\n
    url.on ('activate', onDownload);\r\n
});

\r\n
代码我不再详述，github页面有（不太）详细的文档。简单说来，Builder可以从XML文件里直接构造界面，而GUI事件循环也可以和node的网络事件完美融合起来。\r\n
\r\n
界面截图：\r\n
\r\n
$\"\"$ \r\n

未来

\r\n
这只是一个玩具，开发的唯一目的，就是试试一个idea是否能成（另一个目的是想骗一只阿里云手机来玩，<(￣︶￣)>，可惜不能如愿）。所以，请不要把它用来生产项目中。\r\n
\r\n
而且，因为对GTK+和C++11的依赖，大部分同学到这里，应该都还没编译成功吧…… ╮(￣▽￣)╭\r\n
\r\n
严肃地看来，作为真正的跨平台GUI库，Qt应该是个更好的选择。更严肃地看来，为每个平台单独开发界面库，更符合用户的需求。更更严肃地看来，拿C++写桌面程序，用户才会买账。那都是后话了。","title","用node作桌面开发","last_reply_at","2016-03-10 08:01:52.659","good","top",17,"visit_count",32402,"2011-10-29 04:17:57","author",{"_13":54,"_22":55},"fool","http://www.gravatar.com/avatar/dc13d329db98a4ff44d52013b80e3bf4?s=48"]