A one-file MacRuby app

app.rb

#!/usr/bin/env macruby

framework 'AppKit'

# Inspired by: http://cocoawithlove.com/2010/09/minimalist-cocoa-programming.html

# Inits NSApp
NSApplication.sharedApplication

# Allows an app without an applicaiton bundle or info.plist to still be an app
NSApp.setActivationPolicy NSApplicationActivationPolicyRegular

# The menu bar iteself
NSApp.setMainMenu(NSMenu.new.tap do |menu|
  # The first item on the left of the menu bar
  menu.addItem(NSMenuItem.new.tap do |menu_item|
    # The submenu of the first item
    menu_item.setSubmenu(NSMenu.new.tap do |sub_menu|
      # The only item in the submenu: Quit
      sub_menu.addItem NSMenuItem.alloc.
        initWithTitle "Quit #{NSProcessInfo.processInfo.processName}",
        action: 'terminate:',
        keyEquivalent: 'q'
    end)
  end)
end)

# Create window with dimensions: x,y,w,h
NSWindow.alloc.initWithContentRect(
  [200,300,300,100],
  styleMask:NSTitledWindowMask,
  backing: NSBackingStoreBuffered,
  defer: false
).tap do |win|
  # Minimal window config
  win.title = "imma window, imma imma window"
  win.orderFrontRegardless
end

# Loads this app in front of the terminal (or whatever launched it)
NSApp.activateIgnoringOtherApps true

# Start the run loop
NSApp.run