Cocoa Rectangle Drawing Example (with Lua objc FFI)

main.lua

-- This gist uses http://luapower.com/objc.html as an FFI. I think it works on it's own, but I would recommend
-- getting the whole LuaPower project, because all the libraries rock.
--
-- This script will open a window that displays two rectangles. One red and one blue.

local glue = require'glue'
local objc = require'objc'
local ffi = require'ffi'
local pp = require'pp'

io.stdout:setvbuf'no'
io.stderr:setvbuf'no'

setmetatable(_G, {__index = objc})

objc.load'AppKit'
objc.load'Foundation'

local NSApp = class('NSApp', 'NSApplication <NSApplicationDelegate>')

function NSApp:applicationShouldTerminateAfterLastWindowClosed()
  print'last window closed...'
  collectgarbage()
  return true
end

function NSApp:applicationShouldTerminate()
  print'terminating...'
  return true
end

local app = NSApp:sharedApplication()
app:setDelegate(app)
app:setActivationPolicy(NSApplicationActivationPolicyRegular)

local NSWin = class('NSWin', 'NSWindow <NSWindowDelegate>')

function NSWin:windowWillClose()
  print'window will close...'
end

local style = bit.bor(NSTitledWindowMask, NSClosableWindowMask, NSMiniaturizableWindowMask, NSResizableWindowMask)
local win_rect = NSMakeRect(300, 300, 500, 300)
local win = NSWin:alloc():initWithContentRect_styleMask_backing_defer(win_rect, style, NSBackingStoreBuffered, false)
local view = NSView:alloc():initWithFrame(win_rect)

x = 10
function view:drawRect()
  local myRect = NSMakeRect(x, 10, 100, 100)
  local myRect2 = NSMakeRect(60, 60, 100, 100)
  NSColor:blueColor():set()
  NSRectFill(myRect)
  NSColor:redColor():set()
  NSRectFill(myRect2)
  x = x + 1
  print(x)
end

view:setNeedsDisplay(true)

win:setContentView(view)

win:setDelegate(win)
win:setTitle"Lua Rocks"

app:activateIgnoringOtherApps(true)
win:makeKeyAndOrderFront(nil)

app:run()