Basic cocoa application using dock in Python, but not Xcode and all that extras

Question

It seems that if I want to create a very basic Cocoa application with a dock icon and the like, I would have to use Xcode and the GUI builder (w/ PyObjC).

The application I am intending to write is largely concerned with algorithms and basic IO - and thus, not mostly related to Apple specific stuff.

Basically the application is supposed to run periodically (say, every 3 minutes) .. pull some information via AppleScript and write HTML files to a particular directory. I would like to add a Dock icon for this application .. mainly to showing the "status" of the process (for example, if there is an error .. the dock icon would have a red flag on it). Another advantage of the dock icon is that I can make it run on startup.

Additional bonus for defining the dock right-click menu in a simple way (eg: using Python lists of callables).

Can I achieve this without using Xcode or GUI builders but simply using Emacs and Python?

Answer 1

Install the latest py2app, then make a new directory -- cd to it -- in it make a HelloWorld.py file such as:

# generic Python imports
import datetime
import os
import sched
import sys
import tempfile
import threading
import time

# need PyObjC on sys.path...:
for d in sys.path:
  if 'Extras' in d:
    sys.path.append(d + '/PyObjC')
    break

# objc-related imports
import objc
from Foundation import *
from AppKit import *
from PyObjCTools import AppHelper

# all stuff related to the repeating-action
thesched = sched.scheduler(time.time, time.sleep)

def tick(n, writer):
  writer(n)
  thesched.enter(20.0, 10, tick, (n+1, writer))
  fd, name = tempfile.mkstemp('.txt', 'hello', '/tmp');
  print 'writing %r' % name
  f = os.fdopen(fd, 'w')
  f.write(datetime.datetime.now().isoformat())
  f.write('\n')
  f.close()

def schedule(writer):
  pool = NSAutoreleasePool.alloc().init()
  thesched.enter(0.0, 10, tick, (1, writer))
  thesched.run()
  # normally you'd want pool.drain() here, but since this function never
  # ends until end of program (thesched.run never returns since each tick
  # schedules a new one) that pool.drain would never execute here;-).

# objc-related stuff
class TheDelegate(NSObject):

  statusbar = None
  state = 'idle'

  def applicationDidFinishLaunching_(self, notification):
    statusbar = NSStatusBar.systemStatusBar()
    self.statusitem = statusbar.statusItemWithLength_(
        NSVariableStatusItemLength)
    self.statusitem.setHighlightMode_(1)
    self.statusitem.setToolTip_('Example')
    self.statusitem.setTitle_('Example')

    self.menu = NSMenu.alloc().init()
    menuitem = NSMenuItem.alloc().initWithTitle_action_keyEquivalent_(
        'Quit', 'terminate:', '')
    self.menu.addItem_(menuitem)
    self.statusitem.setMenu_(self.menu)

  def writer(self, s):
    self.badge.setBadgeLabel_(str(s))


if __name__ == "__main__":
  # prepare and set our delegate
  app = NSApplication.sharedApplication()
  delegate = TheDelegate.alloc().init()
  app.setDelegate_(delegate)
  delegate.badge = app.dockTile()
  delegate.writer(0)

  # on a separate thread, run the scheduler
  t = threading.Thread(target=schedule, args=(delegate.writer,))
  t.setDaemon(1)
  t.start()

  # let her rip!-)
  AppHelper.runEventLoop()

Of course, in your real code, you'll be performing your own periodic actions every 3 minutes (rather than writing a temp file every 20 seconds as I'm doing here), doing your own status updates (rather than just showing a counter of the number of files written so far), etc, etc, but I hope this example shows you a viable starting point.

Then in Terminal.App cd to the directory containing this source file, py2applet --make-setup HelloWorld.py, python setup.py py2app -A -p PyObjC.

You now have in subdirectory dist a directory HelloWorld.app; open dist and drag the icon to the Dock, and you're all set (on your own machine -- distributing to other machines may not work due to the -A flag, but I had trouble building without it, probably due to mis-installed egg files laying around this machine;-). No doubt you'll want to customize your icon &c.

This doesn't do the "extra credit" thingy you asked for -- it's already a lot of code and I decided to stop here (the extra credit thingy may warrant a new question). Also, I'm not quite sure that all the incantations I'm performing here are actually necessary or useful; the docs are pretty latitant for making a pyobjc .app without Xcode, as you require, so I hacked this together from bits and pieces of example code found on the net plus a substantial amount of trial and error. Still, I hope it helps!-)

Answer 2

PyObjC, which is included with Mac OS X 10.5 and 10.6, is pretty close to what you're looking for.