# Electron menu 模块

menu 类可以用来创建原生菜单，它可用作应用菜单和 context（上下文，意为右键）菜单。

这个模块是一个主进程的模块，并且可以通过 remote 模块给渲染进程调用.

每个菜单有一个或几个菜单项 menu items，并且每个菜单项可以有子菜单。

下面这个例子是在网页(渲染进程)中通过 remote 模块动态创建的菜单，并且右键显示：

const remote = require('electron').remote;
const Menu = remote.Menu;
const MenuItem = remote.MenuItem;

var menu = new Menu();
menu.append(new MenuItem({
    label: '右键菜单一',
    click: function(){ 
        console.log('item 1 clicked');
    }   
}));
menu.append(new MenuItem({ type: 'separator' }));
menu.append(new MenuItem({ label: '右键菜单二', type: 'checkbox', checked: true }));

window.addEventListener('contextmenu', function (e) {
e.preventDefault();
menu.popup(remote.getCurrentWindow());
}, false);

例子，在渲染进程中使用模板api创建应用菜单：

const remote = require('electron').remote;
const Menu = remote.Menu;
const MenuItem = remote.MenuItem;

var template = [
  {
    label: '编辑',
    submenu: [
      {
        label: '还原',
        accelerator: 'CmdOrCtrl+Z',
        role: 'undo'
      },
      {
        label: '撤销',
        accelerator: 'Shift+CmdOrCtrl+Z',
        role: 'redo'
      },
      {
        type: 'separator'
      },
      {
        label: '剪切',
        accelerator: 'CmdOrCtrl+X',
        role: 'cut'
      },
      {
        label: '复制',
        accelerator: 'CmdOrCtrl+C',
        role: 'copy'
      },
      {
        label: '粘贴',
        accelerator: 'CmdOrCtrl+V',
        role: 'paste'
      },
      {
        label: '全选',
        accelerator: 'CmdOrCtrl+A',
        role: 'selectall'
      },
    ]
  },
  {
    label: '视图',
    submenu: [
      {
        label: '刷新',
        accelerator: 'CmdOrCtrl+R',
        click: function(item, focusedWindow) {
          if (focusedWindow)
            focusedWindow.reload();
        }
      },
      {
        label: '切换全屏',
        accelerator: (function() {
          if (process.platform == 'darwin')
            return 'Ctrl+Command+F';
          else
            return 'F11';
        })(),
        click: function(item, focusedWindow) {
          if (focusedWindow)
            focusedWindow.setFullScreen(!focusedWindow.isFullScreen());
        }
      },
      {
        label: '开发工具',
        accelerator: (function() {
          if (process.platform == 'darwin')
            return 'Alt+Command+I';
          else
            return 'Ctrl+Shift+I';
        })(),
        click: function(item, focusedWindow) {
          if (focusedWindow)
            focusedWindow.toggleDevTools();
        }
      },
    ]
  },
  {
    label: '窗口',
    role: 'window',
    submenu: [
      {
        label: '最小化',
        accelerator: 'CmdOrCtrl+M',
        role: 'minimize'
      },
      {
        label: '关闭',
        accelerator: 'CmdOrCtrl+W',
        role: 'close'
      },
    ]
  },
  {
    label: '帮助',
    role: 'help',
    submenu: [
      {
        label: '学习更多',
        click: function() { require('electron').shell.openExternal('http://electron.atom.io') }
      },
    ]
  },
];

if (process.platform == 'darwin') {
  var name = require('electron').remote.app.getName();
  template.unshift({
    label: name,
    submenu: [
      {
        label: '关于 ' + name,
        role: 'about'
      },
      {
        type: 'separator'
      },
      {
        label: '服务',
        role: 'services',
        submenu: []
      },
      {
        type: 'separator'
      },
      {
        label: '隐藏 ' + name,
        accelerator: 'Command+H',
        role: 'hide'
      },
      {
        label: '隐藏其他',
        accelerator: 'Command+Alt+H',
        role: 'hideothers'
      },
      {
        label: '显示全部',
        role: 'unhide'
      },
      {
        type: 'separator'
      },
      {
        label: '退出',
        accelerator: 'Command+Q',
        click: function() { app.quit(); }
      },
    ]
  });
  // Window menu.
  template[3].submenu.push(
    {
      type: 'separator'
    },
    {
      label: '切换到前台',
      role: 'front'
    }
  );
}

var menu = Menu.buildFromTemplate(template);
Menu.setApplicationMenu(menu);