Construct a sys.argv from the initial AppleEvent sent by the finder

during startup of a program. This module will replace the C code in
macgetargv.c so we can get rid of the special macmain.c for OSX
Python.app.

Mac/Lib/argvemulator.py

+"""argvemulator - create sys.argv from OSA events. Used by applets that
+want unix-style arguments.
+"""
+
+import sys
+import traceback
+from Carbon import AE
+from Carbon.AppleEvents import *
+from Carbon import Evt
+from Carbon.Events import *
+import aetools
+
+class ArgvCollector:
+	
+	"""A minimal FrameWork.Application-like class"""
+	
+	def __init__(self):
+		self.quitting = 0
+		self.ae_handlers = {}
+		self.installaehandler('aevt', 'oapp', self.open_app)
+		self.installaehandler('aevt', 'open', self.open_file)
+	
+	def installaehandler(self, classe, type, callback):
+		AE.AEInstallEventHandler(classe, type, self.callback_wrapper)
+		self.ae_handlers[(classe, type)] = callback
+	
+	def close(self):
+		for classe, type in self.ae_handlers.keys():
+			AE.AERemoveEventHandler(classe, type)
+	
+	def mainloop(self, mask = highLevelEventMask, timeout = 1*60):
+		stoptime = Evt.TickCount() + timeout
+		while not self.quitting and Evt.TickCount() < stoptime:
+			self.dooneevent(mask, timeout)
+		self.close()
+	
+	def _quit(self):
+		self.quitting = 1
+	
+	def dooneevent(self, mask = highLevelEventMask, timeout = 1*60):
+		got, event = Evt.WaitNextEvent(mask, timeout)
+		if got:
+			self.lowlevelhandler(event)
+	
+	def lowlevelhandler(self, event):
+		what, message, when, where, modifiers = event
+		h, v = where
+		if what == kHighLevelEvent:
+			try:
+				AE.AEProcessAppleEvent(event)
+			except AE.Error, err:
+				msg = "High Level Event: %s %s" % \
+					(`hex(message)`, `hex(h | (v<<16))`)
+				print 'AE error: ', err
+				print 'in', msg
+				traceback.print_exc()
+			return
+		else:
+			print "Unhandled event:", event
+
+	def callback_wrapper(self, _request, _reply):
+		_parameters, _attributes = aetools.unpackevent(_request)
+		_class = _attributes['evcl'].type
+		_type = _attributes['evid'].type
+		
+		if self.ae_handlers.has_key((_class, _type)):
+			_function = self.ae_handlers[(_class, _type)]
+		elif self.ae_handlers.has_key((_class, '****')):
+			_function = self.ae_handlers[(_class, '****')]
+		elif self.ae_handlers.has_key(('****', '****')):
+			_function = self.ae_handlers[('****', '****')]
+		else:
+			raise 'Cannot happen: AE callback without handler', (_class, _type)
+		
+		# XXXX Do key-to-name mapping here
+		
+		_parameters['_attributes'] = _attributes
+		_parameters['_class'] = _class
+		_parameters['_type'] = _type
+		if _parameters.has_key('----'):
+			_object = _parameters['----']
+			del _parameters['----']
+			# The try/except that used to be here can mask programmer errors.
+			# Let the program crash, the programmer can always add a **args
+			# to the formal parameter list.
+			rv = apply(_function, (_object,), _parameters)
+		else:
+			#Same try/except comment as above
+			rv = apply(_function, (), _parameters)
+		
+		if rv == None:
+			aetools.packevent(_reply, {})
+		else:
+			aetools.packevent(_reply, {'----':rv})
+
+	def open_app(self, **args):
+		self._quit()
+		
+	def open_file(self, _object=None, **args):
+		for alias in _object:
+			fss = alias.Resolve()[0]
+			pathname = fss.as_pathname()
+			sys.argv.append(pathname)
+		self._quit()
+		
+	def other(self, _object=None, _class=None, _type=None, **args):
+		print 'Ignore AppleEvent', (_class, _type), 'for', _object, 'Other args:', args
+
+if __name__ == '__main__':
+	ArgvCollector().mainloop()
+	print "sys.argv=", sys.argv