hooke/ui/commandline.py

   1 """Defines :class:`CommandLine` for driving Hooke from the command
   2 line.
   3 """
   4
   5 import cmd
   6 import readline
   7
   8 from ..command import CommandExit, Command, Argument
   9 from ..ui import UserInterface, CommandMessage
  10
  11 # Define a few helper classes.  The .__call__ methods of these
  12 # functions will provide the do_*, help_*, and complete_* methods of
  13 # HookeCmd.
  14
  15 class CommandMethod (object):
  16     def __init__(self, cmd, command):
  17         self.cmd = cmd
  18         self.command = command
  19
  20     def __call__(self, *args, **kwargs):
  21         raise NotImplementedError
  22
  23 class DoCommand (CommandMethod):
  24     def __call__(self, args):
  25         args = self._parse_args(self.command, args)
  26         self.cmd.inqueue.put(CommandMessage(self.command, args))
  27         while True:
  28             msg = self.cmd.outqueue.get()
  29             if isinstance(msg, CommandExit):
  30                 break
  31             self.cmd.stdout.write(str(msg))
  32
  33     def _parse_args(self, command, args):
  34         print 'ARGS:', args, type(args)
  35         return {}
  36
  37 class HelpCommand (CommandMethod):
  38     def __call__(self):
  39         blocks = [self.command.help(),
  40                   '------',
  41                   'Usage: ' + self._usage_string(),
  42                   '']
  43         self.cmd.stdout.write('\n'.join(blocks))
  44
  45     def _message(self):
  46         return self.command.help()
  47
  48     def _usage_string(self):
  49         return ' '.join([self.command.name, '[args]'])
  50
  51 class CompleteCommand (CommandMethod):
  52     def __call__(self, text, line, begidx, endidx):
  53         pass
  54
  55
  56 # Now onto the main attraction.
  57
  58 class HookeCmd (cmd.Cmd):
  59     def __init__(self, hooke, inqueue, outqueue):
  60         cmd.Cmd.__init__(self)
  61         self.hooke = hooke
  62         self.prompt = 'hooke> '
  63         self._add_command_methods()
  64         self.inqueue = inqueue
  65         self.outqueue = outqueue
  66
  67     def _safe_name(self, name):
  68         return name.lower().replace(' ', '_')
  69
  70     def _add_command_methods(self):
  71         for command in self.hooke.commands:
  72             command.name = self._safe_name(command.name)
  73             command.aliases = [self._safe_name(n) for n in command.aliases]
  74             for name in [command.name] + command.aliases:
  75                 name = self._safe_name(name)
  76                 setattr(self.__class__, 'do_%s' % name,
  77                         DoCommand(self, command))
  78                 setattr(self.__class__, 'help_%s' % name,
  79                         HelpCommand(self, command))
  80                 setattr(self.__class__, 'complete_%s' % name,
  81                         CompleteCommand(self, command))
  82
  83         exit_command = Command(
  84             name='exit', aliases=['quit', 'EOF'],
  85             help='Exit Hooke cleanly.')
  86         exit_command.arguments = [] # remove help argument
  87         for name in [exit_command.name] + exit_command.aliases:
  88             setattr(self.__class__, 'do_%s' % name,
  89                     lambda self, args : True)
  90             # the True return stops .cmdloop execution
  91             setattr(self.__class__, 'help_%s' % name,
  92                     HelpCommand(self, exit_command))
  93
  94         help_command = Command(
  95             name='help',
  96             help="""
  97 Called with an argument, prints that command's documentation.
  98
  99 With no argument, lists all available help topics as well as any
 100 undocumented commands.
 101 """.strip())
 102         help_command.arguments = [ # overwrite help argument
 103             Argument(name='command', type='string', optional=True,
 104                      help='The name of the command you want help with.')
 105             ]
 106         setattr(self.__class__, 'help_help',
 107                 HelpCommand(self, help_command))
 108
 109
 110 class CommandLine (UserInterface):
 111     """Command line interface.  Simple and powerful.
 112     """
 113     def __init__(self):
 114         super(CommandLine, self).__init__(name='command line')
 115
 116     def run(self, hooke, ui_to_command_queue, command_to_ui_queue):
 117         cmd = HookeCmd(hooke,
 118                        inqueue=ui_to_command_queue,
 119                        outqueue=command_to_ui_queue)
 120         cmd.cmdloop(self._splash_text())