Backport PR #4158: generate choices for `--gui` configurable from real mapping

typo prevented `--gui tk` from working, even though it is supported. Should
prevent similar bugs in the future.

closes  #4156

should be backported to 1.1

IPython/core/shellapp.py

@@ -1,406 +1,409
 # encoding: utf-8
 """
 A mixin for :class:`~IPython.core.application.Application` classes that
 launch InteractiveShell instances, load extensions, etc.
 
 Authors
 -------
 
 * Min Ragan-Kelley
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from __future__ import absolute_import
 
 import glob
 import os
 import sys
 
 from IPython.config.application import boolean_flag
 from IPython.config.configurable import Configurable
 from IPython.config.loader import Config
 from IPython.core import pylabtools
 from IPython.utils import py3compat
 from IPython.utils.contexts import preserve_keys
 from IPython.utils.path import filefind
 from IPython.utils.traitlets import (
     Unicode, Instance, List, Bool, CaselessStrEnum, Dict
 )
+from IPython.lib.inputhook import guis
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 
+gui_keys = tuple(sorted([ key for key in guis if key is not None ]))
+
 backend_keys = sorted(pylabtools.backends.keys())
 backend_keys.insert(0, 'auto')
 
 shell_flags = {}
 
 addflag = lambda *args: shell_flags.update(boolean_flag(*args))
 addflag('autoindent', 'InteractiveShell.autoindent',
         'Turn on autoindenting.', 'Turn off autoindenting.'
 )
 addflag('automagic', 'InteractiveShell.automagic',
         """Turn on the auto calling of magic commands. Type %%magic at the
         IPython  prompt  for  more information.""",
         'Turn off the auto calling of magic commands.'
 )
 addflag('pdb', 'InteractiveShell.pdb',
     "Enable auto calling the pdb debugger after every exception.",
     "Disable auto calling the pdb debugger after every exception."
 )
 # pydb flag doesn't do any config, as core.debugger switches on import,
 # which is before parsing.  This just allows the flag to be passed.
 shell_flags.update(dict(
     pydb = ({},
         """Use the third party 'pydb' package as debugger, instead of pdb.
         Requires that pydb is installed."""
     )
 ))
 addflag('pprint', 'PlainTextFormatter.pprint',
     "Enable auto pretty printing of results.",
     "Disable auto pretty printing of results."
 )
 addflag('color-info', 'InteractiveShell.color_info',
     """IPython can display information about objects via a set of func-
     tions, and optionally can use colors for this, syntax highlighting
     source code and various other elements.  However, because this
     information is passed through a pager (like 'less') and many pagers get
     confused with color codes, this option is off by default.  You can test
     it and turn it on permanently in your ipython_config.py file if it
     works for you.  Test it and turn it on permanently if it works with
     your system.  The magic function %%color_info allows you to toggle this
     interactively for testing.""",
     "Disable using colors for info related things."
 )
 addflag('deep-reload', 'InteractiveShell.deep_reload',
     """Enable deep (recursive) reloading by default. IPython can use the
     deep_reload module which reloads changes in modules recursively (it
     replaces the reload() function, so you don't need to change anything to
     use it). deep_reload() forces a full reload of modules whose code may
     have changed, which the default reload() function does not.  When
     deep_reload is off, IPython will use the normal reload(), but
     deep_reload will still be available as dreload(). This feature is off
     by default [which means that you have both normal reload() and
     dreload()].""",
     "Disable deep (recursive) reloading by default."
 )
 nosep_config = Config()
 nosep_config.InteractiveShell.separate_in = ''
 nosep_config.InteractiveShell.separate_out = ''
 nosep_config.InteractiveShell.separate_out2 = ''
 
 shell_flags['nosep']=(nosep_config, "Eliminate all spacing between prompts.")
 shell_flags['pylab'] = (
     {'InteractiveShellApp' : {'pylab' : 'auto'}},
     """Pre-load matplotlib and numpy for interactive use with
     the default matplotlib backend."""
 )
 shell_flags['matplotlib'] = (
     {'InteractiveShellApp' : {'matplotlib' : 'auto'}},
     """Configure matplotlib for interactive use with
     the default matplotlib backend."""
 )
 
 # it's possible we don't want short aliases for *all* of these:
 shell_aliases = dict(
     autocall='InteractiveShell.autocall',
     colors='InteractiveShell.colors',
     logfile='InteractiveShell.logfile',
     logappend='InteractiveShell.logappend',
     c='InteractiveShellApp.code_to_run',
     m='InteractiveShellApp.module_to_run',
     ext='InteractiveShellApp.extra_extension',
     gui='InteractiveShellApp.gui',
     pylab='InteractiveShellApp.pylab',
     matplotlib='InteractiveShellApp.matplotlib',
 )
 shell_aliases['cache-size'] = 'InteractiveShell.cache_size'
 
 #-----------------------------------------------------------------------------
 # Main classes and functions
 #-----------------------------------------------------------------------------
 
 class InteractiveShellApp(Configurable):
     """A Mixin for applications that start InteractiveShell instances.
     
     Provides configurables for loading extensions and executing files
     as part of configuring a Shell environment.
 
     The following methods should be called by the :meth:`initialize` method
     of the subclass:
 
       - :meth:`init_path`
       - :meth:`init_shell` (to be implemented by the subclass)
       - :meth:`init_gui_pylab`
       - :meth:`init_extensions`
       - :meth:`init_code`
     """
     extensions = List(Unicode, config=True,
         help="A list of dotted module names of IPython extensions to load."
     )
     extra_extension = Unicode('', config=True,
         help="dotted module name of an IPython extension to load."
     )
     def _extra_extension_changed(self, name, old, new):
         if new:
             # add to self.extensions
             self.extensions.append(new)
     
     # Extensions that are always loaded (not configurable)
     default_extensions = List(Unicode, [u'storemagic'], config=False)
 
     exec_files = List(Unicode, config=True,
         help="""List of files to run at IPython startup."""
     )
     file_to_run = Unicode('', config=True,
         help="""A file to be run""")
 
     exec_lines = List(Unicode, config=True,
         help="""lines of code to run at IPython startup."""
     )
     code_to_run = Unicode('', config=True,
         help="Execute the given command string."
     )
     module_to_run = Unicode('', config=True,
         help="Run the module as a script."
     )
-    gui = CaselessStrEnum(('qt', 'wx', 'gtk', 'glut', 'pyglet', 'osx'), config=True,
-        help="Enable GUI event loop integration ('qt', 'wx', 'gtk', 'glut', 'pyglet', 'osx')."
+    gui = CaselessStrEnum(gui_keys, config=True,
+        help="Enable GUI event loop integration with any of {0}.".format(gui_keys)
     )
     matplotlib = CaselessStrEnum(backend_keys,
         config=True,
         help="""Configure matplotlib for interactive use with
         the default matplotlib backend."""
     )
     pylab = CaselessStrEnum(backend_keys,
         config=True,
         help="""Pre-load matplotlib and numpy for interactive use,
         selecting a particular matplotlib backend and loop integration.
         """
     )
     pylab_import_all = Bool(True, config=True,
         help="""If true, IPython will populate the user namespace with numpy, pylab, etc.
         and an 'import *' is done from numpy and pylab, when using pylab mode.
         
         When False, pylab mode should not import any names into the user namespace.
         """
     )
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
     
     user_ns = Dict(default_value=None)
     def _user_ns_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_ns = new
             self.shell.init_user_ns()
 
     def init_path(self):
         """Add current working directory, '', to sys.path"""
         if sys.path[0] != '':
             sys.path.insert(0, '')
 
     def init_shell(self):
         raise NotImplementedError("Override in subclasses")
 
     def init_gui_pylab(self):
         """Enable GUI event loop integration, taking pylab into account."""
         enable = False
         shell = self.shell
         if self.pylab:
             enable = lambda key: shell.enable_pylab(key, import_all=self.pylab_import_all)
             key = self.pylab
         elif self.matplotlib:
             enable = shell.enable_matplotlib
             key = self.matplotlib
         elif self.gui:
             enable = shell.enable_gui
             key = self.gui
         
         if not enable:
             return
         
         try:
             r = enable(key)
         except ImportError:
             self.log.warn("Eventloop or matplotlib integration failed. Is matplotlib installed?")
             self.shell.showtraceback()
             return
         except Exception:
             self.log.warn("GUI event loop or pylab initialization failed")
             self.shell.showtraceback()
             return
             
         if isinstance(r, tuple):
             gui, backend = r[:2]
             self.log.info("Enabling GUI event loop integration, "
                       "eventloop=%s, matplotlib=%s", gui, backend)
             if key == "auto":
                 print ("Using matplotlib backend: %s" % backend)
         else:
             gui = r
             self.log.info("Enabling GUI event loop integration, "
                       "eventloop=%s", gui)
 
     def init_extensions(self):
         """Load all IPython extensions in IPythonApp.extensions.
 
         This uses the :meth:`ExtensionManager.load_extensions` to load all
         the extensions listed in ``self.extensions``.
         """
         try:
             self.log.debug("Loading IPython extensions...")
             extensions = self.default_extensions + self.extensions
             for ext in extensions:
                 try:
                     self.log.info("Loading IPython extension: %s" % ext)
                     self.shell.extension_manager.load_extension(ext)
                 except:
                     self.log.warn("Error in loading extension: %s" % ext +
                         "\nCheck your config files in %s" % self.profile_dir.location
                     )
                     self.shell.showtraceback()
         except:
             self.log.warn("Unknown error in loading extensions:")
             self.shell.showtraceback()
 
     def init_code(self):
         """run the pre-flight code, specified via exec_lines"""
         self._run_startup_files()
         self._run_exec_lines()
         self._run_exec_files()
         self._run_cmd_line_code()
         self._run_module()
         
         # flush output, so itwon't be attached to the first cell
         sys.stdout.flush()
         sys.stderr.flush()
         
         # Hide variables defined here from %who etc.
         self.shell.user_ns_hidden.update(self.shell.user_ns)
 
     def _run_exec_lines(self):
         """Run lines of code in IPythonApp.exec_lines in the user's namespace."""
         if not self.exec_lines:
             return
         try:
             self.log.debug("Running code from IPythonApp.exec_lines...")
             for line in self.exec_lines:
                 try:
                     self.log.info("Running code in user namespace: %s" %
                                   line)
                     self.shell.run_cell(line, store_history=False)
                 except:
                     self.log.warn("Error in executing line in user "
                                   "namespace: %s" % line)
                     self.shell.showtraceback()
         except:
             self.log.warn("Unknown error in handling IPythonApp.exec_lines:")
             self.shell.showtraceback()
 
     def _exec_file(self, fname):
         try:
             full_filename = filefind(fname, [u'.', self.ipython_dir])
         except IOError as e:
             self.log.warn("File not found: %r"%fname)
             return
         # Make sure that the running script gets a proper sys.argv as if it
         # were run from a system shell.
         save_argv = sys.argv
         sys.argv = [full_filename] + self.extra_args[1:]
         # protect sys.argv from potential unicode strings on Python 2:
         if not py3compat.PY3:
             sys.argv = [ py3compat.cast_bytes(a) for a in sys.argv ]
         try:
             if os.path.isfile(full_filename):
                 self.log.info("Running file in user namespace: %s" %
                               full_filename)
                 # Ensure that __file__ is always defined to match Python
                 # behavior.
                 with preserve_keys(self.shell.user_ns, '__file__'):
                     self.shell.user_ns['__file__'] = fname
                     if full_filename.endswith('.ipy'):
                         self.shell.safe_execfile_ipy(full_filename)
                     else:
                         # default to python, even without extension
                         self.shell.safe_execfile(full_filename,
                                                  self.shell.user_ns)
         finally:
             sys.argv = save_argv
 
     def _run_startup_files(self):
         """Run files from profile startup directory"""
         startup_dir = self.profile_dir.startup_dir
         startup_files = []
         if os.environ.get('PYTHONSTARTUP', False):
             startup_files.append(os.environ['PYTHONSTARTUP'])
         startup_files += glob.glob(os.path.join(startup_dir, '*.py'))
         startup_files += glob.glob(os.path.join(startup_dir, '*.ipy'))
         if not startup_files:
             return
         
         self.log.debug("Running startup files from %s...", startup_dir)
         try:
             for fname in sorted(startup_files):
                 self._exec_file(fname)
         except:
             self.log.warn("Unknown error in handling startup files:")
             self.shell.showtraceback()
 
     def _run_exec_files(self):
         """Run files from IPythonApp.exec_files"""
         if not self.exec_files:
             return
 
         self.log.debug("Running files in IPythonApp.exec_files...")
         try:
             for fname in self.exec_files:
                 self._exec_file(fname)
         except:
             self.log.warn("Unknown error in handling IPythonApp.exec_files:")
             self.shell.showtraceback()
 
     def _run_cmd_line_code(self):
         """Run code or file specified at the command-line"""
         if self.code_to_run:
             line = self.code_to_run
             try:
                 self.log.info("Running code given at command line (c=): %s" %
                               line)
                 self.shell.run_cell(line, store_history=False)
             except:
                 self.log.warn("Error in executing line in user namespace: %s" %
                               line)
                 self.shell.showtraceback()
 
         # Like Python itself, ignore the second if the first of these is present
         elif self.file_to_run:
             fname = self.file_to_run
             try:
                 self._exec_file(fname)
             except:
                 self.log.warn("Error in executing file in user namespace: %s" %
                               fname)
                 self.shell.showtraceback()
 
     def _run_module(self):
         """Run module specified at the command-line."""
         if self.module_to_run:
             # Make sure that the module gets a proper sys.argv as if it were
             # run using `python -m`.
             save_argv = sys.argv
             sys.argv = [sys.executable] + self.extra_args
             try:
                 self.shell.safe_run_module(self.module_to_run,
                                            self.shell.user_ns)
             finally:
                 sys.argv = save_argv

IPython/lib/inputhook.py

@@ -1,528 +1,529
 # coding: utf-8
 """
 Inputhook management for GUI event loop integration.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 try:
     import ctypes
 except ImportError:
     ctypes = None
 import os
 import sys
 from distutils.version import LooseVersion as V
 
 from IPython.utils.warn import warn
 
 #-----------------------------------------------------------------------------
 # Constants
 #-----------------------------------------------------------------------------
 
 # Constants for identifying the GUI toolkits.
 GUI_WX = 'wx'
 GUI_QT = 'qt'
 GUI_QT4 = 'qt4'
 GUI_GTK = 'gtk'
 GUI_TK = 'tk'
 GUI_OSX = 'osx'
 GUI_GLUT = 'glut'
 GUI_PYGLET = 'pyglet'
 GUI_GTK3 = 'gtk3'
 GUI_NONE = 'none' # i.e. disable
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 def _stdin_ready_posix():
     """Return True if there's something to read on stdin (posix version)."""
     infds, outfds, erfds = select.select([sys.stdin],[],[],0)
     return bool(infds)
 
 def _stdin_ready_nt():
     """Return True if there's something to read on stdin (nt version)."""
     return msvcrt.kbhit()
 
 def _stdin_ready_other():
     """Return True, assuming there's something to read on stdin."""
     return True #
 
 
 def _ignore_CTRL_C_posix():
     """Ignore CTRL+C (SIGINT)."""
     signal.signal(signal.SIGINT, signal.SIG_IGN)
 
 def _allow_CTRL_C_posix():
     """Take CTRL+C into account (SIGINT)."""
     signal.signal(signal.SIGINT, signal.default_int_handler)
 
 def _ignore_CTRL_C_other():
     """Ignore CTRL+C (not implemented)."""
     pass
 
 def _allow_CTRL_C_other():
     """Take CTRL+C into account (not implemented)."""
     pass
 
 if os.name == 'posix':
     import select
     import signal
     stdin_ready = _stdin_ready_posix
     ignore_CTRL_C = _ignore_CTRL_C_posix
     allow_CTRL_C = _allow_CTRL_C_posix
 elif os.name == 'nt':
     import msvcrt
     stdin_ready = _stdin_ready_nt
     ignore_CTRL_C = _ignore_CTRL_C_other
     allow_CTRL_C = _allow_CTRL_C_other
 else:
     stdin_ready = _stdin_ready_other
     ignore_CTRL_C = _ignore_CTRL_C_other
     allow_CTRL_C = _allow_CTRL_C_other
 
 
 #-----------------------------------------------------------------------------
 # Main InputHookManager class
 #-----------------------------------------------------------------------------
 
 
 class InputHookManager(object):
     """Manage PyOS_InputHook for different GUI toolkits.
 
     This class installs various hooks under ``PyOSInputHook`` to handle
     GUI event loop integration.
     """
     
     def __init__(self):
         if ctypes is None:
             warn("IPython GUI event loop requires ctypes, %gui will not be available")
             return
         self.PYFUNC = ctypes.PYFUNCTYPE(ctypes.c_int)
         self._apps = {}
         self._reset()
 
     def _reset(self):
         self._callback_pyfunctype = None
         self._callback = None
         self._installed = False
         self._current_gui = None
 
     def get_pyos_inputhook(self):
         """Return the current PyOS_InputHook as a ctypes.c_void_p."""
         return ctypes.c_void_p.in_dll(ctypes.pythonapi,"PyOS_InputHook")
 
     def get_pyos_inputhook_as_func(self):
         """Return the current PyOS_InputHook as a ctypes.PYFUNCYPE."""
         return self.PYFUNC.in_dll(ctypes.pythonapi,"PyOS_InputHook")
 
     def set_inputhook(self, callback):
         """Set PyOS_InputHook to callback and return the previous one."""
         # On platforms with 'readline' support, it's all too likely to
         # have a KeyboardInterrupt signal delivered *even before* an
         # initial ``try:`` clause in the callback can be executed, so
         # we need to disable CTRL+C in this situation.
         ignore_CTRL_C()
         self._callback = callback
         self._callback_pyfunctype = self.PYFUNC(callback)
         pyos_inputhook_ptr = self.get_pyos_inputhook()
         original = self.get_pyos_inputhook_as_func()
         pyos_inputhook_ptr.value = \
             ctypes.cast(self._callback_pyfunctype, ctypes.c_void_p).value
         self._installed = True
         return original
 
     def clear_inputhook(self, app=None):
         """Set PyOS_InputHook to NULL and return the previous one.
 
         Parameters
         ----------
         app : optional, ignored
           This parameter is allowed only so that clear_inputhook() can be
           called with a similar interface as all the ``enable_*`` methods.  But
           the actual value of the parameter is ignored.  This uniform interface
           makes it easier to have user-level entry points in the main IPython
           app like :meth:`enable_gui`."""
         pyos_inputhook_ptr = self.get_pyos_inputhook()
         original = self.get_pyos_inputhook_as_func()
         pyos_inputhook_ptr.value = ctypes.c_void_p(None).value
         allow_CTRL_C()
         self._reset()
         return original
 
     def clear_app_refs(self, gui=None):
         """Clear IPython's internal reference to an application instance.
 
         Whenever we create an app for a user on qt4 or wx, we hold a
         reference to the app.  This is needed because in some cases bad things
         can happen if a user doesn't hold a reference themselves.  This
         method is provided to clear the references we are holding.
 
         Parameters
         ----------
         gui : None or str
             If None, clear all app references.  If ('wx', 'qt4') clear
             the app for that toolkit.  References are not held for gtk or tk
             as those toolkits don't have the notion of an app.
         """
         if gui is None:
             self._apps = {}
         elif gui in self._apps:
             del self._apps[gui]
 
     def enable_wx(self, app=None):
         """Enable event loop integration with wxPython.
 
         Parameters
         ----------
         app : WX Application, optional.
             Running application to use.  If not given, we probe WX for an
             existing application object, and create a new one if none is found.
 
         Notes
         -----
         This methods sets the ``PyOS_InputHook`` for wxPython, which allows
         the wxPython to integrate with terminal based applications like
         IPython.
 
         If ``app`` is not given we probe for an existing one, and return it if
         found.  If no existing app is found, we create an :class:`wx.App` as
         follows::
 
             import wx
             app = wx.App(redirect=False, clearSigInt=False)
         """
         import wx
         
         wx_version = V(wx.__version__).version
         
         if wx_version < [2, 8]:
             raise ValueError("requires wxPython >= 2.8, but you have %s" % wx.__version__)
         
         from IPython.lib.inputhookwx import inputhook_wx
         self.set_inputhook(inputhook_wx)
         self._current_gui = GUI_WX
         import wx
         if app is None:
             app = wx.GetApp()
         if app is None:
             app = wx.App(redirect=False, clearSigInt=False)
         app._in_event_loop = True
         self._apps[GUI_WX] = app
         return app
 
     def disable_wx(self):
         """Disable event loop integration with wxPython.
 
         This merely sets PyOS_InputHook to NULL.
         """
         if GUI_WX in self._apps:
             self._apps[GUI_WX]._in_event_loop = False
         self.clear_inputhook()
 
     def enable_qt4(self, app=None):
         """Enable event loop integration with PyQt4.
         
         Parameters
         ----------
         app : Qt Application, optional.
             Running application to use.  If not given, we probe Qt for an
             existing application object, and create a new one if none is found.
 
         Notes
         -----
         This methods sets the PyOS_InputHook for PyQt4, which allows
         the PyQt4 to integrate with terminal based applications like
         IPython.
 
         If ``app`` is not given we probe for an existing one, and return it if
         found.  If no existing app is found, we create an :class:`QApplication`
         as follows::
 
             from PyQt4 import QtCore
             app = QtGui.QApplication(sys.argv)
         """
         from IPython.lib.inputhookqt4 import create_inputhook_qt4
         app, inputhook_qt4 = create_inputhook_qt4(self, app)
         self.set_inputhook(inputhook_qt4)
 
         self._current_gui = GUI_QT4
         app._in_event_loop = True
         self._apps[GUI_QT4] = app
         return app
 
     def disable_qt4(self):
         """Disable event loop integration with PyQt4.
 
         This merely sets PyOS_InputHook to NULL.
         """
         if GUI_QT4 in self._apps:
             self._apps[GUI_QT4]._in_event_loop = False
         self.clear_inputhook()
 
     def enable_gtk(self, app=None):
         """Enable event loop integration with PyGTK.
 
         Parameters
         ----------
         app : ignored
            Ignored, it's only a placeholder to keep the call signature of all
            gui activation methods consistent, which simplifies the logic of
            supporting magics.
 
         Notes
         -----
         This methods sets the PyOS_InputHook for PyGTK, which allows
         the PyGTK to integrate with terminal based applications like
         IPython.
         """
         import gtk
         try:
             gtk.set_interactive(True)
             self._current_gui = GUI_GTK
         except AttributeError:
             # For older versions of gtk, use our own ctypes version
             from IPython.lib.inputhookgtk import inputhook_gtk
             self.set_inputhook(inputhook_gtk)
             self._current_gui = GUI_GTK
 
     def disable_gtk(self):
         """Disable event loop integration with PyGTK.
         
         This merely sets PyOS_InputHook to NULL.
         """
         self.clear_inputhook()
 
     def enable_tk(self, app=None):
         """Enable event loop integration with Tk.
 
         Parameters
         ----------
         app : toplevel :class:`Tkinter.Tk` widget, optional.
             Running toplevel widget to use.  If not given, we probe Tk for an
             existing one, and create a new one if none is found.
 
         Notes
         -----
         If you have already created a :class:`Tkinter.Tk` object, the only
         thing done by this method is to register with the
         :class:`InputHookManager`, since creating that object automatically
         sets ``PyOS_InputHook``.
         """
         self._current_gui = GUI_TK
         if app is None:
             import Tkinter
             app = Tkinter.Tk()
             app.withdraw()
             self._apps[GUI_TK] = app
             return app
 
     def disable_tk(self):
         """Disable event loop integration with Tkinter.
         
         This merely sets PyOS_InputHook to NULL.
         """
         self.clear_inputhook()
 
 
     def enable_glut(self, app=None):
         """ Enable event loop integration with GLUT.
 
         Parameters
         ----------
 
         app : ignored
             Ignored, it's only a placeholder to keep the call signature of all
             gui activation methods consistent, which simplifies the logic of
             supporting magics.
 
         Notes
         -----
 
         This methods sets the PyOS_InputHook for GLUT, which allows the GLUT to
         integrate with terminal based applications like IPython. Due to GLUT
         limitations, it is currently not possible to start the event loop
         without first creating a window. You should thus not create another
         window but use instead the created one. See 'gui-glut.py' in the
         docs/examples/lib directory.
         
         The default screen mode is set to:
         glut.GLUT_DOUBLE | glut.GLUT_RGBA | glut.GLUT_DEPTH
         """
 
         import OpenGL.GLUT as glut
         from IPython.lib.inputhookglut import glut_display_mode, \
                                               glut_close, glut_display, \
                                               glut_idle, inputhook_glut
 
         if GUI_GLUT not in self._apps:
             glut.glutInit( sys.argv )
             glut.glutInitDisplayMode( glut_display_mode )
             # This is specific to freeglut
             if bool(glut.glutSetOption):
                 glut.glutSetOption( glut.GLUT_ACTION_ON_WINDOW_CLOSE,
                                     glut.GLUT_ACTION_GLUTMAINLOOP_RETURNS )
             glut.glutCreateWindow( sys.argv[0] )
             glut.glutReshapeWindow( 1, 1 )
             glut.glutHideWindow( )
             glut.glutWMCloseFunc( glut_close )
             glut.glutDisplayFunc( glut_display )
             glut.glutIdleFunc( glut_idle )
         else:
             glut.glutWMCloseFunc( glut_close )
             glut.glutDisplayFunc( glut_display )
             glut.glutIdleFunc( glut_idle)
         self.set_inputhook( inputhook_glut )
         self._current_gui = GUI_GLUT
         self._apps[GUI_GLUT] = True
 
 
     def disable_glut(self):
         """Disable event loop integration with glut.
         
         This sets PyOS_InputHook to NULL and set the display function to a
         dummy one and set the timer to a dummy timer that will be triggered
         very far in the future.
         """
         import OpenGL.GLUT as glut
         from glut_support import glutMainLoopEvent
 
         glut.glutHideWindow() # This is an event to be processed below
         glutMainLoopEvent()
         self.clear_inputhook()
 
     def enable_pyglet(self, app=None):
         """Enable event loop integration with pyglet.
 
         Parameters
         ----------
         app : ignored
            Ignored, it's only a placeholder to keep the call signature of all
            gui activation methods consistent, which simplifies the logic of
            supporting magics.
 
         Notes
         -----
         This methods sets the ``PyOS_InputHook`` for pyglet, which allows
         pyglet to integrate with terminal based applications like
         IPython.
 
         """
         from IPython.lib.inputhookpyglet import inputhook_pyglet
         self.set_inputhook(inputhook_pyglet)
         self._current_gui = GUI_PYGLET
         return app
 
     def disable_pyglet(self):
         """Disable event loop integration with pyglet.
 
         This merely sets PyOS_InputHook to NULL.
         """
         self.clear_inputhook()
 
     def enable_gtk3(self, app=None):
         """Enable event loop integration with Gtk3 (gir bindings).
 
         Parameters
         ----------
         app : ignored
            Ignored, it's only a placeholder to keep the call signature of all
            gui activation methods consistent, which simplifies the logic of
            supporting magics.
 
         Notes
         -----
         This methods sets the PyOS_InputHook for Gtk3, which allows
         the Gtk3 to integrate with terminal based applications like
         IPython.
         """
         from IPython.lib.inputhookgtk3 import inputhook_gtk3
         self.set_inputhook(inputhook_gtk3)
         self._current_gui = GUI_GTK
 
     def disable_gtk3(self):
         """Disable event loop integration with PyGTK.
 
         This merely sets PyOS_InputHook to NULL.
         """
         self.clear_inputhook()
 
     def current_gui(self):
         """Return a string indicating the currently active GUI or None."""
         return self._current_gui
 
 inputhook_manager = InputHookManager()
 
 enable_wx = inputhook_manager.enable_wx
 disable_wx = inputhook_manager.disable_wx
 enable_qt4 = inputhook_manager.enable_qt4
 disable_qt4 = inputhook_manager.disable_qt4
 enable_gtk = inputhook_manager.enable_gtk
 disable_gtk = inputhook_manager.disable_gtk
 enable_tk = inputhook_manager.enable_tk
 disable_tk = inputhook_manager.disable_tk
 enable_glut = inputhook_manager.enable_glut
 disable_glut = inputhook_manager.disable_glut
 enable_pyglet = inputhook_manager.enable_pyglet
 disable_pyglet = inputhook_manager.disable_pyglet
 enable_gtk3 = inputhook_manager.enable_gtk3
 disable_gtk3 = inputhook_manager.disable_gtk3
 clear_inputhook = inputhook_manager.clear_inputhook
 set_inputhook = inputhook_manager.set_inputhook
 current_gui = inputhook_manager.current_gui
 clear_app_refs = inputhook_manager.clear_app_refs
 
+guis = {None: clear_inputhook,
+        GUI_NONE: clear_inputhook,
+        GUI_OSX: lambda app=False: None,
+        GUI_TK: enable_tk,
+        GUI_GTK: enable_gtk,
+        GUI_WX: enable_wx,
+        GUI_QT: enable_qt4, # qt3 not supported
+        GUI_QT4: enable_qt4,
+        GUI_GLUT: enable_glut,
+        GUI_PYGLET: enable_pyglet,
+        GUI_GTK3: enable_gtk3,
+}
+
 
 # Convenience function to switch amongst them
 def enable_gui(gui=None, app=None):
     """Switch amongst GUI input hooks by name.
 
     This is just a utility wrapper around the methods of the InputHookManager
     object.
 
     Parameters
     ----------
     gui : optional, string or None
       If None (or 'none'), clears input hook, otherwise it must be one
       of the recognized GUI names (see ``GUI_*`` constants in module).
 
     app : optional, existing application object.
       For toolkits that have the concept of a global app, you can supply an
       existing one.  If not given, the toolkit will be probed for one, and if
       none is found, a new one will be created.  Note that GTK does not have
       this concept, and passing an app if ``gui=="GTK"`` will raise an error.
 
     Returns
     -------
     The output of the underlying gui switch routine, typically the actual
     PyOS_InputHook wrapper object or the GUI toolkit app created, if there was
     one.
     """
-    guis = {None: clear_inputhook,
-            GUI_NONE: clear_inputhook,
-            GUI_OSX: lambda app=False: None,
-            GUI_TK: enable_tk,
-            GUI_GTK: enable_gtk,
-            GUI_WX: enable_wx,
-            GUI_QT: enable_qt4, # qt3 not supported
-            GUI_QT4: enable_qt4,
-            GUI_GLUT: enable_glut,
-            GUI_PYGLET: enable_pyglet,
-            GUI_GTK3: enable_gtk3,
-            }
     try:
         gui_hook = guis[gui]
     except KeyError:
         e = "Invalid GUI request %r, valid ones are:%s" % (gui, guis.keys())
         raise ValueError(e)
     return gui_hook(app)