findrox.py

# Most of the common code needed by ROX applications is in ROX-Lib2.
# Except this code, which is needed to find ROX-Lib2 in the first place!

# Just make sure you run findrox.version() before importing anything inside
# ROX-Lib2...

import os, sys
from os.path import exists
import string

def version(major, minor, micro):
	"""Find ROX-Lib2, with a version >= (major, minor, micro), and
	add it to sys.path. If version is missing or too old, either
	prompt the user, or (if possible) upgrade it automatically.
	If 'rox' is already in PYTHONPATH, just use that (assume the injector
	is being used)."""
	try:
		import rox
	except ImportError:
		pass
	else:
		#print "Using ROX-Lib in PYTHONPATH"
		if (major, minor, micro) > rox.roxlib_version:
			print >>sys.stderr, "WARNING: ROX-Lib version " \
				"%d.%d.%d requested, but using version " \
				"%d.%d.%d from %s" % \
				(major, minor, micro,
				 rox.roxlib_version[0],
				 rox.roxlib_version[1],
				 rox.roxlib_version[2],
				 rox.__file__)
		return

	if not os.getenv('ROXLIB_DISABLE_ZEROINSTALL') and os.path.exists('/uri/0install/rox.sourceforge.net'):
		# We're using ZeroInstall. Good :-)
		zpath = '/uri/0install/rox.sourceforge.net/lib/ROX-Lib2/' \
			'latest-2'
		if not os.path.exists(zpath):
			os.system('0refresh rox.sourceforge.net')
			assert os.path.exists(zpath)
		vs = os.readlink(zpath).split('-')[-1]
		v = tuple(map(int, vs.split('.')))
		if v < (major, minor, micro):
			if os.system('0refresh rox.sourceforge.net'):
				report_error('Using ROX-Lib in Zero Install, but cached version (%s) is too old (need %d.%d.%d) and updating failed (is zero-install running?)' % (vs, major, minor, micro))
		sys.path.append(zpath + '/python')
		return
	try:
		path = os.environ['LIBDIRPATH']
		paths = string.split(path, ':')
	except KeyError:
		paths = [os.environ['HOME'] + '/lib',
			 '/usr/local/lib', '/usr/lib' ]

	for p in paths:
		p = os.path.join(p, 'ROX-Lib2')
		if exists(p):
			# TODO: check version is new enough
			sys.path.append(os.path.join(p, 'python'))
			import rox
			if major == 1 and minor == 9 and micro < 10:
				return	# Can't check version
			if not hasattr(rox, 'roxlib_version'):
				break
			if (major, minor, micro) <= rox.roxlib_version:
				return	# OK
	report_error("This program needs ROX-Lib2 (version %d.%d.%d) " % \
		(major, minor, micro) + "to run.\n" + \
		"I tried all of these places:\n\n" + \
		string.join(paths, '\n') + '\n\n' + \
		"ROX-Lib2 is available from:\n" + \
		"http://rox.sourceforge.net")

def report_error(err):
	"Write 'error' to stderr and, if possible, display a dialog box too."
	try:
		sys.stderr.write('*** ' + err + '\n')
	except:
		pass
	try:
		import pygtk; pygtk.require('2.0')
		import gtk; g = gtk
	except:
		import gtk
		win = gtk.GtkDialog()
		message = gtk.GtkLabel(err + 
				'\n\nAlso, pygtk2 needs to be present')
		win.set_title('Missing ROX-Lib2')
		win.set_position(gtk.WIN_POS_CENTER)
		message.set_padding(20, 20)
		win.vbox.pack_start(message)

		ok = gtk.GtkButton("OK")
		ok.set_flags(gtk.CAN_DEFAULT)
		win.action_area.pack_start(ok)
		ok.connect('clicked', gtk.mainquit)
		ok.grab_default()
		
		win.connect('destroy', gtk.mainquit)
		win.show_all()
		gtk.mainloop()
	else:
		box = g.MessageDialog(None, g.MESSAGE_ERROR, 0,
					g.BUTTONS_OK, err)
		box.set_title('Missing ROX-Lib2')
		box.set_position(g.WIN_POS_CENTER)
		box.set_default_response(g.RESPONSE_OK)
		box.run()
	sys.exit(1)