launcher

#!/usr/bin/python

import copy
import os
import plistlib
import shlex
import string
import subprocess
import sys
import Tkinter
import tkMessageBox

def show_error(message):
	window = Tkinter.Tk()
	window.wm_withdraw()
	tkMessageBox.showerror(title="Error", message=message, icon=tkMessageBox.ERROR)

def get_java_home(ver=None):
	cmd = ["/usr/libexec/java_home"]
	if ver is not None:
		cmd.extend(["-v", ver])
	p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
	s = p.communicate()
	if 0 != p.returncode:
		raise OSError("Requested version of java was not found")
	return s[0].splitlines()[0]

def get_java_options(plist_root):
	for key in ["Java", "JVMOptions"]:
		plist_java = plist_root.get(key, None)
		if plist_java is not None:
			return plist_java
	raise OSError("Not a java application")

def get_java_properties(plist_props):
	props = []
	for key in plist_props:
		value = os.path.expandvars(plist_props[key])
		props.append("-D%s=%s" % (key, value))
	return props

def expand_path(path):
	return os.path.expandvars(path)

def launch():
	java_env = copy.copy(os.environ)

	package_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), "../.."))
	contents_dir = os.path.join(package_dir, "Contents")
	resources_dir = os.path.join(contents_dir, "Resources")
	bin_dir = os.path.join(package_dir, "bin")
	os.environ["APP_PACKAGE"] = package_dir

	plist_root = plistlib.readPlist(os.path.join(contents_dir, "Info.plist.original"))
	plist_name = plist_root["CFBundleName"]
	plist_icon = plist_root["CFBundleIconFile"]
	plist_java = get_java_options(plist_root)
	plist_ver = plist_java["JVMVersion"]
	plist_classpath = plist_java["ClassPath"]
	plist_workingdir = plist_java["WorkingDirectory"]
	plist_vmoptions = plist_java["VMOptions"]
	plist_properties = plist_java["Properties"]
	plist_mainclass = plist_java["MainClass"]

	java_home = get_java_home(plist_ver)
	java_name = plist_name
	java_icon = os.path.join(resources_dir, plist_icon)
	java_classpath = expand_path(plist_classpath) + ":" + os.path.join(java_home, "lib/*")
	java_workingdir = expand_path(plist_workingdir)
	java_vmoptions = shlex.split(plist_vmoptions)
	java_properties = get_java_properties(plist_properties)
	java_mainclass = plist_mainclass

	java = os.path.join(java_home, "bin/java")
	java_env["JAVA_HOME"] = java_home
	java_args = [java]
	java_args.append("-Xdock:name=" + java_name)
	java_args.append("-Xdock:icon=" + java_icon)
	java_args.extend(java_vmoptions)
	java_args.extend(java_properties)
	java_args.extend(["-classpath", java_classpath])
	java_args.append(java_mainclass)

	os.chdir(java_workingdir)
	os.execve(java, java_args, java_env)
	# must not get here

def main(argv):
	try:
		return launch()
	except Exception, e:
		show_error(str(e))
	return 1

if __name__ == "__main__":
	sys.exit(main(sys.argv))