code updates per review of PR #454

IPython/config/loader.py

@@ -1,514 +1,524 b''
 """A simple configuration system.
 
 Authors
 -------
 * Brian Granger
 * Fernando Perez
 * Min RK
 """
 
 #-----------------------------------------------------------------------------
 #  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
 #-----------------------------------------------------------------------------
 
 import __builtin__
 import re
 import sys
 
 from IPython.external import argparse
 from IPython.utils.path import filefind
 
 #-----------------------------------------------------------------------------
 # Exceptions
 #-----------------------------------------------------------------------------
 
 
 class ConfigError(Exception):
     pass
 
 
 class ConfigLoaderError(ConfigError):
     pass
 
 class ArgumentError(ConfigLoaderError):
     pass
 
 #-----------------------------------------------------------------------------
 # Argparse fix
 #-----------------------------------------------------------------------------
 
 # Unfortunately argparse by default prints help messages to stderr instead of
 # stdout.  This makes it annoying to capture long help screens at the command
 # line, since one must know how to pipe stderr, which many users don't know how
 # to do.  So we override the print_help method with one that defaults to
 # stdout and use our class instead.
 
 class ArgumentParser(argparse.ArgumentParser):
     """Simple argparse subclass that prints help to stdout by default."""
     
     def print_help(self, file=None):
         if file is None:
             file = sys.stdout
         return super(ArgumentParser, self).print_help(file)
     
     print_help.__doc__ = argparse.ArgumentParser.print_help.__doc__
     
 #-----------------------------------------------------------------------------
 # Config class for holding config information
 #-----------------------------------------------------------------------------
 
 
 class Config(dict):
     """An attribute based dict that can do smart merges."""
 
     def __init__(self, *args, **kwds):
         dict.__init__(self, *args, **kwds)
         # This sets self.__dict__ = self, but it has to be done this way
         # because we are also overriding __setattr__.
         dict.__setattr__(self, '__dict__', self)
 
     def _merge(self, other):
         to_update = {}
         for k, v in other.iteritems():
             if not self.has_key(k):
                 to_update[k] = v
             else: # I have this key
                 if isinstance(v, Config):
                     # Recursively merge common sub Configs
                     self[k]._merge(v)
                 else:
                     # Plain updates for non-Configs
                     to_update[k] = v
 
         self.update(to_update)
 
     def _is_section_key(self, key):
         if key[0].upper()==key[0] and not key.startswith('_'):
             return True
         else:
             return False
 
     def __contains__(self, key):
         if self._is_section_key(key):
             return True
         else:
             return super(Config, self).__contains__(key)
     # .has_key is deprecated for dictionaries.
     has_key = __contains__
 
     def _has_section(self, key):
         if self._is_section_key(key):
             if super(Config, self).__contains__(key):
                 return True
         return False
 
     def copy(self):
         return type(self)(dict.copy(self))
 
     def __copy__(self):
         return self.copy()
 
     def __deepcopy__(self, memo):
         import copy
         return type(self)(copy.deepcopy(self.items()))
 
     def __getitem__(self, key):
         # We cannot use directly self._is_section_key, because it triggers
         # infinite recursion on top of PyPy. Instead, we manually fish the
         # bound method.
         is_section_key = self.__class__._is_section_key.__get__(self)
         
         # Because we use this for an exec namespace, we need to delegate
         # the lookup of names in __builtin__ to itself.  This means
         # that you can't have section or attribute names that are 
         # builtins.
         try:
             return getattr(__builtin__, key)
         except AttributeError:
             pass
         if is_section_key(key):
             try:
                 return dict.__getitem__(self, key)
             except KeyError:
                 c = Config()
                 dict.__setitem__(self, key, c)
                 return c
         else:
             return dict.__getitem__(self, key)
 
     def __setitem__(self, key, value):
         # Don't allow names in __builtin__ to be modified.
         if hasattr(__builtin__, key):
             raise ConfigError('Config variable names cannot have the same name '
                               'as a Python builtin: %s' % key)
         if self._is_section_key(key):
             if not isinstance(value, Config):
                 raise ValueError('values whose keys begin with an uppercase '
                                  'char must be Config instances: %r, %r' % (key, value))
         else:
             dict.__setitem__(self, key, value)
 
     def __getattr__(self, key):
         try:
             return self.__getitem__(key)
         except KeyError, e:
             raise AttributeError(e)
 
     def __setattr__(self, key, value):
         try:
             self.__setitem__(key, value)
         except KeyError, e:
             raise AttributeError(e)
 
     def __delattr__(self, key):
         try:
             dict.__delitem__(self, key)
         except KeyError, e:
             raise AttributeError(e)
 
 
 #-----------------------------------------------------------------------------
 # Config loading classes
 #-----------------------------------------------------------------------------
 
 
 class ConfigLoader(object):
     """A object for loading configurations from just about anywhere.
     
     The resulting configuration is packaged as a :class:`Struct`.
     
     Notes
     -----
     A :class:`ConfigLoader` does one thing: load a config from a source 
     (file, command line arguments) and returns the data as a :class:`Struct`.
     There are lots of things that :class:`ConfigLoader` does not do.  It does
     not implement complex logic for finding config files.  It does not handle
     default values or merge multiple configs.  These things need to be 
     handled elsewhere.
     """
 
     def __init__(self):
         """A base class for config loaders.
         
         Examples
         --------
         
         >>> cl = ConfigLoader()
         >>> config = cl.load_config()
         >>> config
         {}
         """
         self.clear()
 
     def clear(self):
         self.config = Config()
 
     def load_config(self):
         """Load a config from somewhere, return a :class:`Config` instance.
         
         Usually, this will cause self.config to be set and then returned.
         However, in most cases, :meth:`ConfigLoader.clear` should be called
         to erase any previous state.
         """
         self.clear()
         return self.config
 
 
 class FileConfigLoader(ConfigLoader):
     """A base class for file based configurations.
 
     As we add more file based config loaders, the common logic should go
     here.
     """
     pass
 
 
 class PyFileConfigLoader(FileConfigLoader):
     """A config loader for pure python files.
     
     This calls execfile on a plain python file and looks for attributes
     that are all caps.  These attribute are added to the config Struct.
     """
 
     def __init__(self, filename, path=None):
         """Build a config loader for a filename and path.
 
         Parameters
         ----------
         filename : str
             The file name of the config file.
         path : str, list, tuple
             The path to search for the config file on, or a sequence of
             paths to try in order.
         """
         super(PyFileConfigLoader, self).__init__()
         self.filename = filename
         self.path = path
         self.full_filename = ''
         self.data = None
 
     def load_config(self):
         """Load the config from a file and return it as a Struct."""
         self.clear()
         self._find_file()
         self._read_file_as_dict()
         self._convert_to_config()
         return self.config
 
     def _find_file(self):
         """Try to find the file by searching the paths."""
         self.full_filename = filefind(self.filename, self.path)
 
     def _read_file_as_dict(self):
         """Load the config file into self.config, with recursive loading."""
         # This closure is made available in the namespace that is used
         # to exec the config file.  This allows users to call
         # load_subconfig('myconfig.py') to load config files recursively.
         # It needs to be a closure because it has references to self.path
         # and self.config.  The sub-config is loaded with the same path
         # as the parent, but it uses an empty config which is then merged
         # with the parents.
         def load_subconfig(fname):
             loader = PyFileConfigLoader(fname, self.path)
             try:
                 sub_config = loader.load_config()
             except IOError:
                 # Pass silently if the sub config is not there. This happens
                 # when a user us using a profile, but not the default config.
                 pass
             else:
                 self.config._merge(sub_config)
 
         # Again, this needs to be a closure and should be used in config
         # files to get the config being loaded.
         def get_config():
             return self.config
 
         namespace = dict(load_subconfig=load_subconfig, get_config=get_config)
         fs_encoding = sys.getfilesystemencoding() or 'ascii'
         conf_filename = self.full_filename.encode(fs_encoding)
         execfile(conf_filename, namespace)
 
     def _convert_to_config(self):
         if self.data is None:
             ConfigLoaderError('self.data does not exist')
 
 
 class CommandLineConfigLoader(ConfigLoader):
     """A config loader for command line arguments.
 
     As we add more command line based loaders, the common logic should go
     here.
     """
 
 kv_pattern = re.compile(r'[A-Za-z]\w*(\.\w+)*\=.*')
 flag_pattern = re.compile(r'\-\-\w+(\-\w)*')
 
 class KeyValueConfigLoader(CommandLineConfigLoader):
     """A config loader that loads key value pairs from the command line.
 
     This allows command line options to be gives in the following form::
     
         ipython Global.profile="foo" InteractiveShell.autocall=False
     """
 
     def __init__(self, argv=None, aliases=None, flags=None):
         """Create a key value pair config loader.
 
         Parameters
         ----------
         argv : list
             A list that has the form of sys.argv[1:] which has unicode
             elements of the form u"key=value". If this is None (default),
             then sys.argv[1:] will be used.
         aliases : dict
             A dict of aliases for configurable traits.
             Keys are the short aliases, Values are the resolved trait.
             Of the form: `{'alias' : 'Configurable.trait'}`
         flags : dict
             A dict of flags, keyed by str name. Vaues can be Config objects,
             dicts, or "key=value" strings.  If Config or dict, when the flag
             is triggered, The flag is loaded as `self.config.update(m)`.
 
         Returns
         -------
         config : Config
             The resulting Config object.
 
         Examples
         --------
 
             >>> from IPython.config.loader import KeyValueConfigLoader
             >>> cl = KeyValueConfigLoader()
             >>> cl.load_config(["foo='bar'","A.name='brian'","B.number=0"])
             {'A': {'name': 'brian'}, 'B': {'number': 0}, 'foo': 'bar'}
         """
+        self.clear()
         if argv is None:
             argv = sys.argv[1:]
         self.argv = argv
         self.aliases = aliases or {}
         self.flags = flags or {}
+        
+    
+    def clear(self):
+        super(KeyValueConfigLoader, self).clear()
+        self.extra_args = []
+        
 
     def load_config(self, argv=None, aliases=None, flags=None):
         """Parse the configuration and generate the Config object.
-
+        
+        After loading, any arguments that are not key-value or
+        flags will be stored in self.extra_args - a list of
+        unparsed command-line arguments.  This is used for
+        arguments such as input files or subcommands.
+        
         Parameters
         ----------
         argv : list, optional
             A list that has the form of sys.argv[1:] which has unicode
             elements of the form u"key=value". If this is None (default),
             then self.argv will be used.
         aliases : dict
             A dict of aliases for configurable traits.
             Keys are the short aliases, Values are the resolved trait.
             Of the form: `{'alias' : 'Configurable.trait'}`
         flags : dict
             A dict of flags, keyed by str name. Values can be Config objects
             or dicts.  When the flag is triggered, The config is loaded as 
             `self.config.update(cfg)`.
         """
         from IPython.config.configurable import Configurable
 
         self.clear()
         if argv is None:
             argv = self.argv
         if aliases is None:
             aliases = self.aliases
         if flags is None:
             flags = self.flags
         
-        self.extra_args = []
-        
         for item in argv:
             if kv_pattern.match(item):
                 lhs,rhs = item.split('=',1)
                 # Substitute longnames for aliases.
                 if lhs in aliases:
                     lhs = aliases[lhs]
                 exec_str = 'self.config.' + lhs + '=' + rhs
                 try:
                     # Try to see if regular Python syntax will work. This
                     # won't handle strings as the quote marks are removed
                     # by the system shell.
                     exec exec_str in locals(), globals()
                 except (NameError, SyntaxError):
                     # This case happens if the rhs is a string but without
                     # the quote marks.  We add the quote marks and see if
                     # it succeeds. If it still fails, we let it raise.
                     exec_str = 'self.config.' + lhs + '="' + rhs + '"'
                     exec exec_str in locals(), globals()
             elif flag_pattern.match(item):
                 # trim leading '--'
                 m = item[2:]
                 cfg,_ = flags.get(m, (None,None))
                 if cfg is None:
                     raise ArgumentError("Unrecognized flag: %r"%item)
                 elif isinstance(cfg, (dict, Config)):
                     # don't clobber whole config sections, update
                     # each section from config:
                     for sec,c in cfg.iteritems():
                         self.config[sec].update(c)
                 else:
                     raise ValueError("Invalid flag: %r"%flag)
             elif item.startswith('-'):
                 # this shouldn't ever be valid
                 raise ArgumentError("Invalid argument: %r"%item)
             else:
                 # keep all args that aren't valid in a list, 
                 # in case our parent knows what to do with them.
                 self.extra_args.append(item)
         return self.config
 
 class ArgParseConfigLoader(CommandLineConfigLoader):
     """A loader that uses the argparse module to load from the command line."""
 
     def __init__(self, argv=None, *parser_args, **parser_kw):
         """Create a config loader for use with argparse.
 
         Parameters
         ----------
 
         argv : optional, list
           If given, used to read command-line arguments from, otherwise
           sys.argv[1:] is used.
 
         parser_args : tuple
           A tuple of positional arguments that will be passed to the
           constructor of :class:`argparse.ArgumentParser`.
 
         parser_kw : dict
           A tuple of keyword arguments that will be passed to the
           constructor of :class:`argparse.ArgumentParser`.
 
         Returns
         -------
         config : Config
             The resulting Config object.
         """
         super(CommandLineConfigLoader, self).__init__()
         if argv == None:
             argv = sys.argv[1:]
         self.argv = argv
         self.parser_args = parser_args
         self.version = parser_kw.pop("version", None)
         kwargs = dict(argument_default=argparse.SUPPRESS)
         kwargs.update(parser_kw)
         self.parser_kw = kwargs
 
     def load_config(self, argv=None):
         """Parse command line arguments and return as a Config object.
 
         Parameters
         ----------
 
         args : optional, list
           If given, a list with the structure of sys.argv[1:] to parse
           arguments from. If not given, the instance's self.argv attribute
           (given at construction time) is used."""
         self.clear()
         if argv is None:
             argv = self.argv
         self._create_parser()
         self._parse_args(argv)
         self._convert_to_config()
         return self.config
 
     def get_extra_args(self):
         if hasattr(self, 'extra_args'):
             return self.extra_args
         else:
             return []
 
     def _create_parser(self):
         self.parser = ArgumentParser(*self.parser_args, **self.parser_kw)
         self._add_arguments()
 
     def _add_arguments(self):
         raise NotImplementedError("subclasses must implement _add_arguments")
 
     def _parse_args(self, args):
         """self.parser->self.parsed_data"""
         # decode sys.argv to support unicode command-line options
         uargs = []
         for a in args:
             if isinstance(a, str):
                 # don't decode if we already got unicode
                 a = a.decode(sys.stdin.encoding or 
                                             sys.getdefaultencoding())
             uargs.append(a)
         self.parsed_data, self.extra_args = self.parser.parse_known_args(uargs)
 
     def _convert_to_config(self):
         """self.parsed_data->self.config"""
         for k, v in vars(self.parsed_data).iteritems():
             exec_str = 'self.config.' + k + '= v'
             exec exec_str in locals(), globals()
 
 

IPython/core/shellapp.py

@@ -1,243 +1,244 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 A mixin for :class:`~IPython.core.newapplication.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 os
 import sys
 
 from IPython.config.application import boolean_flag
 from IPython.config.configurable import Configurable
+from IPython.config.loader import Config
 from IPython.utils.path import filefind
 from IPython.utils.traitlets import Unicode, Instance, List
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 
 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."
 )
 addflag('pprint', 'PlainTextFormatter.pprint',
     "Enable auto pretty printing of results.",
     "Disable auto 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
-    inter- actively for testing.""",
+    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.")
+
 
 # it's possible we don't want short aliases for *all* of these:
 shell_aliases = dict(
     autocall='InteractiveShell.autocall',
     cache_size='InteractiveShell.cache_size',
     colors='InteractiveShell.colors',
     logfile='InteractiveShell.logfile',
     log_append='InteractiveShell.logappend',
-    pi1='InteractiveShell.prompt_in1',
-    pi2='InteractiveShell.prompt_in1',
-    po='InteractiveShell.prompt_out',
-    si='InteractiveShell.separate_in',
-    so='InteractiveShell.separate_out',
-    so2='InteractiveShell.separate_out2',
-    xmode='InteractiveShell.xmode',
     c='InteractiveShellApp.code_to_run',
     ext='InteractiveShellApp.extra_extension',
 )
 
 #-----------------------------------------------------------------------------
 # 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.
     
     Provides init_extensions() and init_code() methods, to be called
     after init_shell(), which must be implemented by subclasses.
     """
     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)
 
     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."
     )
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
 
     def init_shell(self):
         raise NotImplementedError("Override in subclasses")
     
     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``.
         """
         if not self.extensions:
             return
         try:
             self.log.debug("Loading IPython extensions...")
             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)
                     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_exec_lines()
         self._run_exec_files()
         self._run_cmd_line_code()
 
     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):
         full_filename = filefind(fname, [u'.', self.ipython_dir])
         if os.path.isfile(full_filename):
             if full_filename.endswith(u'.py'):
                 self.log.info("Running file in user namespace: %s" %
                               full_filename)
                 # Ensure that __file__ is always defined to match Python behavior
                 self.shell.user_ns['__file__'] = fname
                 try:
                     self.shell.safe_execfile(full_filename, self.shell.user_ns)
                 finally:
                     del self.shell.user_ns['__file__']
             elif full_filename.endswith('.ipy'):
                 self.log.info("Running file in user namespace: %s" %
                               full_filename)
                 self.shell.safe_execfile_ipy(full_filename)
             else:
                 self.log.warn("File does not have a .py or .ipy extension: <%s>"
                                % full_filename)
 
     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()
 

IPython/frontend/qt/console/console_widget.py

@@ -1,1796 +1,1797 b''
 """ An abstract base class for console-type widgets.
 """
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports
 import os
 from os.path import commonprefix
 import re
 import sys
 from textwrap import dedent
 from unicodedata import category
 
 # System library imports
 from IPython.external.qt import QtCore, QtGui
 
 # Local imports
 from IPython.config.configurable import Configurable
 from IPython.frontend.qt.rich_text import HtmlExporter
 from IPython.frontend.qt.util import MetaQObjectHasTraits, get_font
 from IPython.utils.traitlets import Bool, Enum, Int, Unicode
 from ansi_code_processor import QtAnsiCodeProcessor
 from completion_widget import CompletionWidget
 from kill_ring import QtKillRing
 
 #-----------------------------------------------------------------------------
 # Functions
 #-----------------------------------------------------------------------------
 
 def is_letter_or_number(char):
     """ Returns whether the specified unicode character is a letter or a number.
     """
     cat = category(char)
     return cat.startswith('L') or cat.startswith('N')
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class ConsoleWidget(Configurable, QtGui.QWidget):
     """ An abstract base class for console-type widgets. This class has 
         functionality for:
 
             * Maintaining a prompt and editing region
             * Providing the traditional Unix-style console keyboard shortcuts 
             * Performing tab completion
             * Paging text
             * Handling ANSI escape codes
 
         ConsoleWidget also provides a number of utility methods that will be
         convenient to implementors of a console-style widget.
     """
     __metaclass__ = MetaQObjectHasTraits
 
     #------ Configuration ------------------------------------------------------
 
     ansi_codes = Bool(True, config=True,
         help="Whether to process ANSI escape codes."
     )
     buffer_size = Int(500, config=True,
         help="""
         The maximum number of lines of text before truncation. Specifying a
         non-positive number disables text truncation (not recommended).
         """
     )
     gui_completion = Bool(False, config=True,
         help="Use a list widget instead of plain text output for tab completion."
     )
     # NOTE: this value can only be specified during initialization.
     kind = Enum(['plain', 'rich'], default_value='plain', config=True,
         help="""
         The type of underlying text widget to use. Valid values are 'plain', which
         specifies a QPlainTextEdit, and 'rich', which specifies a QTextEdit.
         """
     )
     # NOTE: this value can only be specified during initialization.
     paging = Enum(['inside', 'hsplit', 'vsplit', 'custom', 'none'], 
                   default_value='inside', config=True,
         help="""
         The type of paging to use. Valid values are:
+        
             'inside' : The widget pages like a traditional terminal.
             'hsplit' : When paging is requested, the widget is split
-            :          horizontally. The top pane contains the console, and the
-            :          bottom pane contains the paged text.
+                       horizontally. The top pane contains the console, and the
+                       bottom pane contains the paged text.
             'vsplit' : Similar to 'hsplit', except that a vertical splitter used.
             'custom' : No action is taken by the widget beyond emitting a
-            :          'custom_page_requested(str)' signal.
+                       'custom_page_requested(str)' signal.
             'none'   : The text is written directly to the console.
         """)
 
     font_family = Unicode(config=True,
         help="""The font family to use for the console.
         On OSX this defaults to Monaco, on Windows the default is
         Consolas with fallback of Courier, and on other platforms
         the default is Monospace.
         """)
     def _font_family_default(self):
         if sys.platform == 'win32':
             # Consolas ships with Vista/Win7, fallback to Courier if needed
             return 'Consolas'
         elif sys.platform == 'darwin':
             # OSX always has Monaco, no need for a fallback
             return 'Monaco'
         else:
             # Monospace should always exist, no need for a fallback
             return 'Monospace'
 
     font_size = Int(config=True,
         help="""The font size. If unconfigured, Qt will be entrusted
         with the size of the font.
         """)
 
     # Whether to override ShortcutEvents for the keybindings defined by this
     # widget (Ctrl+n, Ctrl+a, etc). Enable this if you want this widget to take
     # priority (when it has focus) over, e.g., window-level menu shortcuts.
     override_shortcuts = Bool(False)
 
     #------ Signals ------------------------------------------------------------
 
     # Signals that indicate ConsoleWidget state.
     copy_available = QtCore.Signal(bool)
     redo_available = QtCore.Signal(bool)
     undo_available = QtCore.Signal(bool)
 
     # Signal emitted when paging is needed and the paging style has been
     # specified as 'custom'.
     custom_page_requested = QtCore.Signal(object)
 
     # Signal emitted when the font is changed.
     font_changed = QtCore.Signal(QtGui.QFont)
 
     #------ Protected class variables ------------------------------------------
 
     # When the control key is down, these keys are mapped.
     _ctrl_down_remap = { QtCore.Qt.Key_B : QtCore.Qt.Key_Left,
                          QtCore.Qt.Key_F : QtCore.Qt.Key_Right,
                          QtCore.Qt.Key_A : QtCore.Qt.Key_Home,
                          QtCore.Qt.Key_P : QtCore.Qt.Key_Up,
                          QtCore.Qt.Key_N : QtCore.Qt.Key_Down,
                          QtCore.Qt.Key_H : QtCore.Qt.Key_Backspace,
                          QtCore.Qt.Key_D : QtCore.Qt.Key_Delete, }
     if not sys.platform == 'darwin':
         # On OS X, Ctrl-E already does the right thing, whereas End moves the
         # cursor to the bottom of the buffer.
         _ctrl_down_remap[QtCore.Qt.Key_E] = QtCore.Qt.Key_End
 
     # The shortcuts defined by this widget. We need to keep track of these to
     # support 'override_shortcuts' above.
     _shortcuts = set(_ctrl_down_remap.keys() +
                      [ QtCore.Qt.Key_C, QtCore.Qt.Key_G, QtCore.Qt.Key_O,
                        QtCore.Qt.Key_V ])
 
     #---------------------------------------------------------------------------
     # 'QObject' interface
     #---------------------------------------------------------------------------
 
     def __init__(self, parent=None, **kw):
         """ Create a ConsoleWidget.
 
         Parameters:
         -----------
         parent : QWidget, optional [default None]
             The parent for this widget.
         """
         QtGui.QWidget.__init__(self, parent)
         Configurable.__init__(self, **kw)
 
         # Create the layout and underlying text widget.
         layout = QtGui.QStackedLayout(self)
         layout.setContentsMargins(0, 0, 0, 0)
         self._control = self._create_control()
         self._page_control = None
         self._splitter = None
         if self.paging in ('hsplit', 'vsplit'):
             self._splitter = QtGui.QSplitter()
             if self.paging == 'hsplit':
                 self._splitter.setOrientation(QtCore.Qt.Horizontal)
             else:
                 self._splitter.setOrientation(QtCore.Qt.Vertical)
             self._splitter.addWidget(self._control)
             layout.addWidget(self._splitter)
         else:
             layout.addWidget(self._control)
 
         # Create the paging widget, if necessary.
         if self.paging in ('inside', 'hsplit', 'vsplit'):
             self._page_control = self._create_page_control()
             if self._splitter:
                 self._page_control.hide()
                 self._splitter.addWidget(self._page_control)
             else:
                 layout.addWidget(self._page_control)
 
         # Initialize protected variables. Some variables contain useful state
         # information for subclasses; they should be considered read-only.
         self._ansi_processor = QtAnsiCodeProcessor()
         self._completion_widget = CompletionWidget(self._control)
         self._continuation_prompt = '> '
         self._continuation_prompt_html = None
         self._executing = False
         self._filter_drag = False
         self._filter_resize = False
         self._html_exporter = HtmlExporter(self._control)
         self._input_buffer_executing = ''
         self._input_buffer_pending = ''
         self._kill_ring = QtKillRing(self._control)
         self._prompt = ''
         self._prompt_html = None
         self._prompt_pos = 0
         self._prompt_sep = ''
         self._reading = False
         self._reading_callback = None
         self._tab_width = 8
         self._text_completing_pos = 0
 
         # Set a monospaced font.
         self.reset_font()
 
         # Configure actions.
         action = QtGui.QAction('Print', None)
         action.setEnabled(True)
         printkey = QtGui.QKeySequence(QtGui.QKeySequence.Print)
         if printkey.matches("Ctrl+P") and sys.platform != 'darwin':
             # Only override the default if there is a collision.
             # Qt ctrl = cmd on OSX, so the match gets a false positive on OSX.
             printkey = "Ctrl+Shift+P"
         action.setShortcut(printkey)
         action.triggered.connect(self.print_)
         self.addAction(action)
         self._print_action = action
 
         action = QtGui.QAction('Save as HTML/XML', None)
         action.setShortcut(QtGui.QKeySequence.Save)
         action.triggered.connect(self.export_html)
         self.addAction(action)
         self._export_action = action
         
         action = QtGui.QAction('Select All', None)
         action.setEnabled(True)
         action.setShortcut(QtGui.QKeySequence.SelectAll)
         action.triggered.connect(self.select_all)
         self.addAction(action)
         self._select_all_action = action
 
     def eventFilter(self, obj, event):
         """ Reimplemented to ensure a console-like behavior in the underlying
             text widgets.
         """
         etype = event.type()
         if etype == QtCore.QEvent.KeyPress:
 
             # Re-map keys for all filtered widgets.
             key = event.key()
             if self._control_key_down(event.modifiers()) and \
                     key in self._ctrl_down_remap:
                 new_event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress, 
                                             self._ctrl_down_remap[key],
                                             QtCore.Qt.NoModifier)
                 QtGui.qApp.sendEvent(obj, new_event)
                 return True
 
             elif obj == self._control:
                 return self._event_filter_console_keypress(event)
 
             elif obj == self._page_control:
                 return self._event_filter_page_keypress(event)
 
         # Make middle-click paste safe.
         elif etype == QtCore.QEvent.MouseButtonRelease and \
                 event.button() == QtCore.Qt.MidButton and \
                 obj == self._control.viewport():
             cursor = self._control.cursorForPosition(event.pos())
             self._control.setTextCursor(cursor)
             self.paste(QtGui.QClipboard.Selection)
             return True
 
         # Manually adjust the scrollbars *after* a resize event is dispatched.
         elif etype == QtCore.QEvent.Resize and not self._filter_resize:
             self._filter_resize = True
             QtGui.qApp.sendEvent(obj, event)
             self._adjust_scrollbars()
             self._filter_resize = False
             return True
 
         # Override shortcuts for all filtered widgets.
         elif etype == QtCore.QEvent.ShortcutOverride and \
                 self.override_shortcuts and \
                 self._control_key_down(event.modifiers()) and \
                 event.key() in self._shortcuts:
             event.accept()
 
         # Ensure that drags are safe. The problem is that the drag starting
         # logic, which determines whether the drag is a Copy or Move, is locked
         # down in QTextControl. If the widget is editable, which it must be if
         # we're not executing, the drag will be a Move. The following hack
         # prevents QTextControl from deleting the text by clearing the selection
         # when a drag leave event originating from this widget is dispatched.
         # The fact that we have to clear the user's selection is unfortunate,
         # but the alternative--trying to prevent Qt from using its hardwired
         # drag logic and writing our own--is worse.
         elif etype == QtCore.QEvent.DragEnter and \
                 obj == self._control.viewport() and \
                 event.source() == self._control.viewport():
             self._filter_drag = True
         elif etype == QtCore.QEvent.DragLeave and \
                 obj == self._control.viewport() and \
                 self._filter_drag:
             cursor = self._control.textCursor()
             cursor.clearSelection()
             self._control.setTextCursor(cursor)
             self._filter_drag = False
 
         # Ensure that drops are safe.
         elif etype == QtCore.QEvent.Drop and obj == self._control.viewport():
             cursor = self._control.cursorForPosition(event.pos())
             if self._in_buffer(cursor.position()):
                 text = event.mimeData().text()
                 self._insert_plain_text_into_buffer(cursor, text)
 
             # Qt is expecting to get something here--drag and drop occurs in its
             # own event loop. Send a DragLeave event to end it.
             QtGui.qApp.sendEvent(obj, QtGui.QDragLeaveEvent())
             return True
 
         return super(ConsoleWidget, self).eventFilter(obj, event)
 
     #---------------------------------------------------------------------------
     # 'QWidget' interface
     #---------------------------------------------------------------------------
 
     def sizeHint(self):
         """ Reimplemented to suggest a size that is 80 characters wide and
             25 lines high.
         """
         font_metrics = QtGui.QFontMetrics(self.font)
         margin = (self._control.frameWidth() +
                   self._control.document().documentMargin()) * 2
         style = self.style()
         splitwidth = style.pixelMetric(QtGui.QStyle.PM_SplitterWidth)
 
         # Note 1: Despite my best efforts to take the various margins into
         # account, the width is still coming out a bit too small, so we include
         # a fudge factor of one character here.
         # Note 2: QFontMetrics.maxWidth is not used here or anywhere else due
         # to a Qt bug on certain Mac OS systems where it returns 0.
         width = font_metrics.width(' ') * 81 + margin
         width += style.pixelMetric(QtGui.QStyle.PM_ScrollBarExtent)
         if self.paging == 'hsplit':
             width = width * 2 + splitwidth
 
         height = font_metrics.height() * 25 + margin
         if self.paging == 'vsplit':
             height = height * 2 + splitwidth
 
         return QtCore.QSize(width, height)
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     def can_copy(self):
         """ Returns whether text can be copied to the clipboard.
         """
         return self._control.textCursor().hasSelection()
 
     def can_cut(self):
         """ Returns whether text can be cut to the clipboard.
         """
         cursor = self._control.textCursor()
         return (cursor.hasSelection() and 
                 self._in_buffer(cursor.anchor()) and 
                 self._in_buffer(cursor.position()))
         
     def can_paste(self):
         """ Returns whether text can be pasted from the clipboard.
         """
         if self._control.textInteractionFlags() & QtCore.Qt.TextEditable:
             return bool(QtGui.QApplication.clipboard().text())
         return False
 
     def clear(self, keep_input=True):
         """ Clear the console. 
 
         Parameters:
         -----------
         keep_input : bool, optional (default True)
             If set, restores the old input buffer if a new prompt is written.
         """
         if self._executing:
             self._control.clear()
         else:
             if keep_input:
                 input_buffer = self.input_buffer
             self._control.clear()
             self._show_prompt()
             if keep_input:
                 self.input_buffer = input_buffer
 
     def copy(self):
         """ Copy the currently selected text to the clipboard.
         """
         self._control.copy()
 
     def cut(self):
         """ Copy the currently selected text to the clipboard and delete it
             if it's inside the input buffer.
         """
         self.copy()
         if self.can_cut():
             self._control.textCursor().removeSelectedText()
 
     def execute(self, source=None, hidden=False, interactive=False):
         """ Executes source or the input buffer, possibly prompting for more
         input.
 
         Parameters:
         -----------     
         source : str, optional
 
             The source to execute. If not specified, the input buffer will be
             used. If specified and 'hidden' is False, the input buffer will be
             replaced with the source before execution.
 
         hidden : bool, optional (default False)
 
             If set, no output will be shown and the prompt will not be modified.
             In other words, it will be completely invisible to the user that
             an execution has occurred.
 
         interactive : bool, optional (default False)
 
             Whether the console is to treat the source as having been manually
             entered by the user. The effect of this parameter depends on the
             subclass implementation.
 
         Raises:
         -------
         RuntimeError
             If incomplete input is given and 'hidden' is True. In this case,
             it is not possible to prompt for more input.
 
         Returns:
         --------
         A boolean indicating whether the source was executed.
         """
         # WARNING: The order in which things happen here is very particular, in
         # large part because our syntax highlighting is fragile. If you change
         # something, test carefully!
 
         # Decide what to execute.
         if source is None:
             source = self.input_buffer
             if not hidden:
                 # A newline is appended later, but it should be considered part
                 # of the input buffer.
                 source += '\n'
         elif not hidden:
             self.input_buffer = source
             
         # Execute the source or show a continuation prompt if it is incomplete.
         complete = self._is_complete(source, interactive)
         if hidden:
             if complete:
                 self._execute(source, hidden)
             else:
                 error = 'Incomplete noninteractive input: "%s"'
                 raise RuntimeError(error % source)                
         else:
             if complete:
                 self._append_plain_text('\n')
                 self._input_buffer_executing = self.input_buffer
                 self._executing = True
                 self._prompt_finished()
 
                 # The maximum block count is only in effect during execution.
                 # This ensures that _prompt_pos does not become invalid due to
                 # text truncation.
                 self._control.document().setMaximumBlockCount(self.buffer_size)
 
                 # Setting a positive maximum block count will automatically
                 # disable the undo/redo history, but just to be safe:
                 self._control.setUndoRedoEnabled(False)
 
                 # Perform actual execution.
                 self._execute(source, hidden)
             
             else:
                 # Do this inside an edit block so continuation prompts are
                 # removed seamlessly via undo/redo.
                 cursor = self._get_end_cursor()
                 cursor.beginEditBlock()
                 cursor.insertText('\n')
                 self._insert_continuation_prompt(cursor)
                 cursor.endEditBlock()
 
                 # Do not do this inside the edit block. It works as expected
                 # when using a QPlainTextEdit control, but does not have an 
                 # effect when using a QTextEdit. I believe this is a Qt bug.
                 self._control.moveCursor(QtGui.QTextCursor.End)
 
         return complete
 
     def export_html(self):
         """ Shows a dialog to export HTML/XML in various formats.
         """
         self._html_exporter.export()
 
     def _get_input_buffer(self):
         """ The text that the user has entered entered at the current prompt.
 
         If the console is currently executing, the text that is executing will
         always be returned.
         """
         # If we're executing, the input buffer may not even exist anymore due to
         # the limit imposed by 'buffer_size'. Therefore, we store it.
         if self._executing:
             return self._input_buffer_executing
 
         cursor = self._get_end_cursor()
         cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
         input_buffer = cursor.selection().toPlainText()
 
         # Strip out continuation prompts.
         return input_buffer.replace('\n' + self._continuation_prompt, '\n')
 
     def _set_input_buffer(self, string):
         """ Sets the text in the input buffer.
 
         If the console is currently executing, this call has no *immediate*
         effect. When the execution is finished, the input buffer will be updated
         appropriately.
         """
         # If we're executing, store the text for later.
         if self._executing:
             self._input_buffer_pending = string
             return
 
         # Remove old text.
         cursor = self._get_end_cursor()
         cursor.beginEditBlock()
         cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
         cursor.removeSelectedText()
 
         # Insert new text with continuation prompts.
         self._insert_plain_text_into_buffer(self._get_prompt_cursor(), string)
         cursor.endEditBlock()
         self._control.moveCursor(QtGui.QTextCursor.End)
 
     input_buffer = property(_get_input_buffer, _set_input_buffer)
 
     def _get_font(self):
         """ The base font being used by the ConsoleWidget.
         """
         return self._control.document().defaultFont()
 
     def _set_font(self, font):
         """ Sets the base font for the ConsoleWidget to the specified QFont.
         """
         font_metrics = QtGui.QFontMetrics(font)
         self._control.setTabStopWidth(self.tab_width * font_metrics.width(' '))
 
         self._completion_widget.setFont(font)
         self._control.document().setDefaultFont(font)
         if self._page_control:
             self._page_control.document().setDefaultFont(font)
 
         self.font_changed.emit(font)
 
     font = property(_get_font, _set_font)
 
     def paste(self, mode=QtGui.QClipboard.Clipboard):
         """ Paste the contents of the clipboard into the input region.
 
         Parameters:
         -----------
         mode : QClipboard::Mode, optional [default QClipboard::Clipboard]
 
             Controls which part of the system clipboard is used. This can be
             used to access the selection clipboard in X11 and the Find buffer
             in Mac OS. By default, the regular clipboard is used.
         """
         if self._control.textInteractionFlags() & QtCore.Qt.TextEditable:
             # Make sure the paste is safe.
             self._keep_cursor_in_buffer()
             cursor = self._control.textCursor()
 
             # Remove any trailing newline, which confuses the GUI and forces the
             # user to backspace.
             text = QtGui.QApplication.clipboard().text(mode).rstrip()
             self._insert_plain_text_into_buffer(cursor, dedent(text))
 
     def print_(self, printer = None):
         """ Print the contents of the ConsoleWidget to the specified QPrinter.
         """
         if (not printer):
             printer = QtGui.QPrinter()
             if(QtGui.QPrintDialog(printer).exec_() != QtGui.QDialog.Accepted):
                 return
         self._control.print_(printer)
 
     def prompt_to_top(self):
         """ Moves the prompt to the top of the viewport.
         """
         if not self._executing:
             prompt_cursor = self._get_prompt_cursor()
             if self._get_cursor().blockNumber() < prompt_cursor.blockNumber():
                 self._set_cursor(prompt_cursor)
             self._set_top_cursor(prompt_cursor)
             
     def redo(self):
         """ Redo the last operation. If there is no operation to redo, nothing
             happens.
         """
         self._control.redo()
 
     def reset_font(self):
         """ Sets the font to the default fixed-width font for this platform.
         """
         if sys.platform == 'win32':
             # Consolas ships with Vista/Win7, fallback to Courier if needed
             fallback = 'Courier'
         elif sys.platform == 'darwin':
             # OSX always has Monaco
             fallback = 'Monaco'
         else:
             # Monospace should always exist
             fallback = 'Monospace'
         font = get_font(self.font_family, fallback)
         if self.font_size:
             font.setPointSize(self.font_size)
         else:
             font.setPointSize(QtGui.qApp.font().pointSize())
         font.setStyleHint(QtGui.QFont.TypeWriter)
         self._set_font(font)
 
     def change_font_size(self, delta):
         """Change the font size by the specified amount (in points).
         """
         font = self.font
         size = max(font.pointSize() + delta, 1) # minimum 1 point
         font.setPointSize(size)
         self._set_font(font)
 
     def select_all(self):
         """ Selects all the text in the buffer.
         """
         self._control.selectAll()
 
     def _get_tab_width(self):
         """ The width (in terms of space characters) for tab characters.
         """
         return self._tab_width
 
     def _set_tab_width(self, tab_width):
         """ Sets the width (in terms of space characters) for tab characters.
         """
         font_metrics = QtGui.QFontMetrics(self.font)
         self._control.setTabStopWidth(tab_width * font_metrics.width(' '))
 
         self._tab_width = tab_width
 
     tab_width = property(_get_tab_width, _set_tab_width)
 
     def undo(self):
         """ Undo the last operation. If there is no operation to undo, nothing
             happens.
         """
         self._control.undo()
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' abstract interface
     #---------------------------------------------------------------------------
 
     def _is_complete(self, source, interactive):
         """ Returns whether 'source' can be executed. When triggered by an
             Enter/Return key press, 'interactive' is True; otherwise, it is
             False.
         """
         raise NotImplementedError
 
     def _execute(self, source, hidden):
         """ Execute 'source'. If 'hidden', do not show any output.
         """
         raise NotImplementedError
 
     def _prompt_started_hook(self):
         """ Called immediately after a new prompt is displayed.
         """
         pass
 
     def _prompt_finished_hook(self):
         """ Called immediately after a prompt is finished, i.e. when some input
             will be processed and a new prompt displayed.
         """
         pass
 
     def _up_pressed(self, shift_modifier):
         """ Called when the up key is pressed. Returns whether to continue
             processing the event.
         """
         return True
 
     def _down_pressed(self, shift_modifier):
         """ Called when the down key is pressed. Returns whether to continue
             processing the event.
         """
         return True
 
     def _tab_pressed(self):
         """ Called when the tab key is pressed. Returns whether to continue
             processing the event.
         """
         return False
 
     #--------------------------------------------------------------------------
     # 'ConsoleWidget' protected interface
     #--------------------------------------------------------------------------
 
     def _append_html(self, html):
         """ Appends html at the end of the console buffer.
         """
         cursor = self._get_end_cursor()
         self._insert_html(cursor, html)
 
     def _append_html_fetching_plain_text(self, html):
         """ Appends 'html', then returns the plain text version of it.
         """
         cursor = self._get_end_cursor()
         return self._insert_html_fetching_plain_text(cursor, html)
 
     def _append_plain_text(self, text):
         """ Appends plain text at the end of the console buffer, processing
             ANSI codes if enabled.
         """
         cursor = self._get_end_cursor()
         self._insert_plain_text(cursor, text)
 
     def _append_plain_text_keeping_prompt(self, text):
         """ Writes 'text' after the current prompt, then restores the old prompt
             with its old input buffer.
         """
         input_buffer = self.input_buffer
         self._append_plain_text('\n')
         self._prompt_finished()
 
         self._append_plain_text(text)
         self._show_prompt()
         self.input_buffer = input_buffer
 
     def _cancel_text_completion(self):
         """ If text completion is progress, cancel it.
         """
         if self._text_completing_pos:
             self._clear_temporary_buffer()
             self._text_completing_pos = 0
 
     def _clear_temporary_buffer(self):
         """ Clears the "temporary text" buffer, i.e. all the text following
             the prompt region.
         """
         # Select and remove all text below the input buffer.
         cursor = self._get_prompt_cursor()
         prompt = self._continuation_prompt.lstrip()
         while cursor.movePosition(QtGui.QTextCursor.NextBlock):
             temp_cursor = QtGui.QTextCursor(cursor)
             temp_cursor.select(QtGui.QTextCursor.BlockUnderCursor)
             text = temp_cursor.selection().toPlainText().lstrip()
             if not text.startswith(prompt):
                 break
         else:
             # We've reached the end of the input buffer and no text follows.
             return
         cursor.movePosition(QtGui.QTextCursor.Left) # Grab the newline.
         cursor.movePosition(QtGui.QTextCursor.End,
                             QtGui.QTextCursor.KeepAnchor)
         cursor.removeSelectedText()
 
         # After doing this, we have no choice but to clear the undo/redo
         # history. Otherwise, the text is not "temporary" at all, because it
         # can be recalled with undo/redo. Unfortunately, Qt does not expose
         # fine-grained control to the undo/redo system.
         if self._control.isUndoRedoEnabled():
             self._control.setUndoRedoEnabled(False)
             self._control.setUndoRedoEnabled(True)
 
     def _complete_with_items(self, cursor, items):
         """ Performs completion with 'items' at the specified cursor location.
         """
         self._cancel_text_completion()
 
         if len(items) == 1:
             cursor.setPosition(self._control.textCursor().position(), 
                                QtGui.QTextCursor.KeepAnchor)
             cursor.insertText(items[0])
 
         elif len(items) > 1:
             current_pos = self._control.textCursor().position()
             prefix = commonprefix(items)
             if prefix:
                 cursor.setPosition(current_pos, QtGui.QTextCursor.KeepAnchor)
                 cursor.insertText(prefix)
                 current_pos = cursor.position()
 
             if self.gui_completion:
                 cursor.movePosition(QtGui.QTextCursor.Left, n=len(prefix))
                 self._completion_widget.show_items(cursor, items) 
             else:
                 cursor.beginEditBlock()
                 self._append_plain_text('\n')
                 self._page(self._format_as_columns(items))
                 cursor.endEditBlock()
 
                 cursor.setPosition(current_pos)
                 self._control.moveCursor(QtGui.QTextCursor.End)
                 self._control.setTextCursor(cursor)
                 self._text_completing_pos = current_pos
 
     def _context_menu_make(self, pos):
         """ Creates a context menu for the given QPoint (in widget coordinates).
         """
         menu = QtGui.QMenu(self)
 
         cut_action = menu.addAction('Cut', self.cut)
         cut_action.setEnabled(self.can_cut())
         cut_action.setShortcut(QtGui.QKeySequence.Cut)
 
         copy_action = menu.addAction('Copy', self.copy)
         copy_action.setEnabled(self.can_copy())
         copy_action.setShortcut(QtGui.QKeySequence.Copy)
 
         paste_action = menu.addAction('Paste', self.paste)
         paste_action.setEnabled(self.can_paste())
         paste_action.setShortcut(QtGui.QKeySequence.Paste)
 
         menu.addSeparator()
         menu.addAction(self._select_all_action)
 
         menu.addSeparator()
         menu.addAction(self._export_action)
         menu.addAction(self._print_action)
 
         return menu
 
     def _control_key_down(self, modifiers, include_command=False):
         """ Given a KeyboardModifiers flags object, return whether the Control
         key is down.
 
         Parameters:
         -----------
         include_command : bool, optional (default True)
             Whether to treat the Command key as a (mutually exclusive) synonym
             for Control when in Mac OS.
         """
         # Note that on Mac OS, ControlModifier corresponds to the Command key
         # while MetaModifier corresponds to the Control key.
         if sys.platform == 'darwin':
             down = include_command and (modifiers & QtCore.Qt.ControlModifier)
             return bool(down) ^ bool(modifiers & QtCore.Qt.MetaModifier)
         else:
             return bool(modifiers & QtCore.Qt.ControlModifier)
 
     def _create_control(self):
         """ Creates and connects the underlying text widget.
         """
         # Create the underlying control.
         if self.kind == 'plain':
             control = QtGui.QPlainTextEdit()
         elif self.kind == 'rich':
             control = QtGui.QTextEdit()
             control.setAcceptRichText(False)
 
         # Install event filters. The filter on the viewport is needed for
         # mouse events and drag events.
         control.installEventFilter(self)
         control.viewport().installEventFilter(self)
 
         # Connect signals.
         control.cursorPositionChanged.connect(self._cursor_position_changed)
         control.customContextMenuRequested.connect(
             self._custom_context_menu_requested)
         control.copyAvailable.connect(self.copy_available)
         control.redoAvailable.connect(self.redo_available)
         control.undoAvailable.connect(self.undo_available)
 
         # Hijack the document size change signal to prevent Qt from adjusting
         # the viewport's scrollbar. We are relying on an implementation detail
         # of Q(Plain)TextEdit here, which is potentially dangerous, but without
         # this functionality we cannot create a nice terminal interface.
         layout = control.document().documentLayout()
         layout.documentSizeChanged.disconnect()
         layout.documentSizeChanged.connect(self._adjust_scrollbars)
 
         # Configure the control.
         control.setAttribute(QtCore.Qt.WA_InputMethodEnabled, True)
         control.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
         control.setReadOnly(True)
         control.setUndoRedoEnabled(False)
         control.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOn)
         return control
 
     def _create_page_control(self):
         """ Creates and connects the underlying paging widget.
         """
         if self.kind == 'plain':
             control = QtGui.QPlainTextEdit()
         elif self.kind == 'rich':
             control = QtGui.QTextEdit()
         control.installEventFilter(self)
         control.setReadOnly(True)
         control.setUndoRedoEnabled(False)
         control.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOn)
         return control
 
     def _event_filter_console_keypress(self, event):
         """ Filter key events for the underlying text widget to create a
             console-like interface.
         """
         intercepted = False
         cursor = self._control.textCursor()
         position = cursor.position()
         key = event.key()
         ctrl_down = self._control_key_down(event.modifiers())
         alt_down = event.modifiers() & QtCore.Qt.AltModifier
         shift_down = event.modifiers() & QtCore.Qt.ShiftModifier
 
         #------ Special sequences ----------------------------------------------
 
         if event.matches(QtGui.QKeySequence.Copy):
             self.copy()
             intercepted = True
 
         elif event.matches(QtGui.QKeySequence.Cut):
             self.cut()
             intercepted = True
 
         elif event.matches(QtGui.QKeySequence.Paste):
             self.paste()
             intercepted = True
 
         #------ Special modifier logic -----------------------------------------
 
         elif key in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
             intercepted = True
                 
             # Special handling when tab completing in text mode.
             self._cancel_text_completion()
 
             if self._in_buffer(position):
                 if self._reading:
                     self._append_plain_text('\n')
                     self._reading = False
                     if self._reading_callback:
                         self._reading_callback()
 
                 # If the input buffer is a single line or there is only
                 # whitespace after the cursor, execute. Otherwise, split the
                 # line with a continuation prompt.
                 elif not self._executing:
                     cursor.movePosition(QtGui.QTextCursor.End,
                                         QtGui.QTextCursor.KeepAnchor)
                     at_end = len(cursor.selectedText().strip()) == 0
                     single_line = (self._get_end_cursor().blockNumber() ==
                                    self._get_prompt_cursor().blockNumber())
                     if (at_end or shift_down or single_line) and not ctrl_down:
                         self.execute(interactive = not shift_down)
                     else:
                         # Do this inside an edit block for clean undo/redo.
                         cursor.beginEditBlock()
                         cursor.setPosition(position)
                         cursor.insertText('\n')
                         self._insert_continuation_prompt(cursor)
                         cursor.endEditBlock()
 
                         # Ensure that the whole input buffer is visible.
                         # FIXME: This will not be usable if the input buffer is
                         # taller than the console widget.
                         self._control.moveCursor(QtGui.QTextCursor.End)
                         self._control.setTextCursor(cursor)
 
         #------ Control/Cmd modifier -------------------------------------------
 
         elif ctrl_down:
             if key == QtCore.Qt.Key_G:
                 self._keyboard_quit()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_K:
                 if self._in_buffer(position):
                     cursor.movePosition(QtGui.QTextCursor.EndOfLine,
                                         QtGui.QTextCursor.KeepAnchor)
                     if not cursor.hasSelection():
                         # Line deletion (remove continuation prompt)
                         cursor.movePosition(QtGui.QTextCursor.NextBlock,
                                             QtGui.QTextCursor.KeepAnchor)
                         cursor.movePosition(QtGui.QTextCursor.Right,
                                             QtGui.QTextCursor.KeepAnchor,
                                             len(self._continuation_prompt))
                     self._kill_ring.kill_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_L:
                 self.prompt_to_top()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_O:
                 if self._page_control and self._page_control.isVisible():
                     self._page_control.setFocus()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_U:
                 if self._in_buffer(position):
                     start_line = cursor.blockNumber()
                     if start_line == self._get_prompt_cursor().blockNumber():
                         offset = len(self._prompt)
                     else:
                         offset = len(self._continuation_prompt)
                     cursor.movePosition(QtGui.QTextCursor.StartOfBlock,
                                         QtGui.QTextCursor.KeepAnchor)
                     cursor.movePosition(QtGui.QTextCursor.Right,
                                         QtGui.QTextCursor.KeepAnchor, offset)
                     self._kill_ring.kill_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Y:
                 self._keep_cursor_in_buffer()
                 self._kill_ring.yank()
                 intercepted = True
 
             elif key in (QtCore.Qt.Key_Backspace, QtCore.Qt.Key_Delete):
                 intercepted = True
 
             elif key in (QtCore.Qt.Key_Plus, QtCore.Qt.Key_Equal):
                 self.change_font_size(1)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Minus:
                 self.change_font_size(-1)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_0:
                 self.reset_font()
                 intercepted = True
 
         #------ Alt modifier ---------------------------------------------------
 
         elif alt_down:
             if key == QtCore.Qt.Key_B:
                 self._set_cursor(self._get_word_start_cursor(position))
                 intercepted = True
                 
             elif key == QtCore.Qt.Key_F:
                 self._set_cursor(self._get_word_end_cursor(position))
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Y:
                 self._kill_ring.rotate()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Backspace:
                 cursor = self._get_word_start_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 self._kill_ring.kill_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_D:
                 cursor = self._get_word_end_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 self._kill_ring.kill_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Delete:
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Greater:
                 self._control.moveCursor(QtGui.QTextCursor.End)
                 intercepted = True
                 
             elif key == QtCore.Qt.Key_Less:
                 self._control.setTextCursor(self._get_prompt_cursor())
                 intercepted = True
 
         #------ No modifiers ---------------------------------------------------
 
         else:
             if shift_down:
                 anchormode = QtGui.QTextCursor.KeepAnchor
             else:
                 anchormode = QtGui.QTextCursor.MoveAnchor
             
             if key == QtCore.Qt.Key_Escape:
                 self._keyboard_quit()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Up:
                 if self._reading or not self._up_pressed(shift_down):
                     intercepted = True
                 else:
                     prompt_line = self._get_prompt_cursor().blockNumber()
                     intercepted = cursor.blockNumber() <= prompt_line
 
             elif key == QtCore.Qt.Key_Down:
                 if self._reading or not self._down_pressed(shift_down):
                     intercepted = True
                 else:
                     end_line = self._get_end_cursor().blockNumber()
                     intercepted = cursor.blockNumber() == end_line
 
             elif key == QtCore.Qt.Key_Tab:
                 if not self._reading:
                     intercepted = not self._tab_pressed()
 
             elif key == QtCore.Qt.Key_Left:
 
                 # Move to the previous line
                 line, col = cursor.blockNumber(), cursor.columnNumber()
                 if line > self._get_prompt_cursor().blockNumber() and \
                         col == len(self._continuation_prompt):
                     self._control.moveCursor(QtGui.QTextCursor.PreviousBlock, 
                                              mode=anchormode)
                     self._control.moveCursor(QtGui.QTextCursor.EndOfBlock, 
                                              mode=anchormode)
                     intercepted = True
 
                 # Regular left movement
                 else:
                     intercepted = not self._in_buffer(position - 1)
                     
             elif key == QtCore.Qt.Key_Right:
                 original_block_number = cursor.blockNumber()
                 cursor.movePosition(QtGui.QTextCursor.Right, 
                                 mode=anchormode)
                 if cursor.blockNumber() != original_block_number:
                     cursor.movePosition(QtGui.QTextCursor.Right,
                                         n=len(self._continuation_prompt),
                                         mode=anchormode)
                 self._set_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Home:
                 start_line = cursor.blockNumber()
                 if start_line == self._get_prompt_cursor().blockNumber():
                     start_pos = self._prompt_pos
                 else:
                     cursor.movePosition(QtGui.QTextCursor.StartOfBlock,
                                         QtGui.QTextCursor.KeepAnchor)
                     start_pos = cursor.position()
                     start_pos += len(self._continuation_prompt)
                     cursor.setPosition(position)
                 if shift_down and self._in_buffer(position):
                     cursor.setPosition(start_pos, QtGui.QTextCursor.KeepAnchor)
                 else:
                     cursor.setPosition(start_pos)
                 self._set_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Backspace:
 
                 # Line deletion (remove continuation prompt)
                 line, col = cursor.blockNumber(), cursor.columnNumber()
                 if not self._reading and \
                         col == len(self._continuation_prompt) and \
                         line > self._get_prompt_cursor().blockNumber():
                     cursor.beginEditBlock()
                     cursor.movePosition(QtGui.QTextCursor.StartOfBlock,
                                         QtGui.QTextCursor.KeepAnchor)
                     cursor.removeSelectedText()
                     cursor.deletePreviousChar()
                     cursor.endEditBlock()
                     intercepted = True
 
                 # Regular backwards deletion
                 else:
                     anchor = cursor.anchor()
                     if anchor == position:
                         intercepted = not self._in_buffer(position - 1)
                     else:
                         intercepted = not self._in_buffer(min(anchor, position))
 
             elif key == QtCore.Qt.Key_Delete:
 
                 # Line deletion (remove continuation prompt)
                 if not self._reading and self._in_buffer(position) and \
                         cursor.atBlockEnd() and not cursor.hasSelection():
                     cursor.movePosition(QtGui.QTextCursor.NextBlock,
                                         QtGui.QTextCursor.KeepAnchor)
                     cursor.movePosition(QtGui.QTextCursor.Right,
                                         QtGui.QTextCursor.KeepAnchor,
                                         len(self._continuation_prompt))
                     cursor.removeSelectedText()
                     intercepted = True
 
                 # Regular forwards deletion:
                 else:
                     anchor = cursor.anchor()
                     intercepted = (not self._in_buffer(anchor) or
                                    not self._in_buffer(position))
 
         # Don't move the cursor if Control/Cmd is pressed to allow copy-paste
         # using the keyboard in any part of the buffer.
         if not self._control_key_down(event.modifiers(), include_command=True):
             self._keep_cursor_in_buffer()
 
         return intercepted
 
     def _event_filter_page_keypress(self, event):
         """ Filter key events for the paging widget to create console-like 
             interface.
         """
         key = event.key()
         ctrl_down = self._control_key_down(event.modifiers())
         alt_down = event.modifiers() & QtCore.Qt.AltModifier
 
         if ctrl_down:
             if key == QtCore.Qt.Key_O:
                 self._control.setFocus()
                 intercept = True
 
         elif alt_down:
             if key == QtCore.Qt.Key_Greater:
                 self._page_control.moveCursor(QtGui.QTextCursor.End)
                 intercepted = True
                 
             elif key == QtCore.Qt.Key_Less:
                 self._page_control.moveCursor(QtGui.QTextCursor.Start)
                 intercepted = True
 
         elif key in (QtCore.Qt.Key_Q, QtCore.Qt.Key_Escape):
             if self._splitter:
                 self._page_control.hide()
             else:
                 self.layout().setCurrentWidget(self._control)
             return True
 
         elif key in (QtCore.Qt.Key_Enter, QtCore.Qt.Key_Return):
             new_event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress, 
                                         QtCore.Qt.Key_PageDown, 
                                         QtCore.Qt.NoModifier)
             QtGui.qApp.sendEvent(self._page_control, new_event)
             return True
 
         elif key == QtCore.Qt.Key_Backspace:
             new_event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress,
                                         QtCore.Qt.Key_PageUp, 
                                         QtCore.Qt.NoModifier)
             QtGui.qApp.sendEvent(self._page_control, new_event)
             return True
 
         return False
 
     def _format_as_columns(self, items, separator='  '):
         """ Transform a list of strings into a single string with columns.
 
         Parameters
         ----------
         items : sequence of strings
             The strings to process.
 
         separator : str, optional [default is two spaces]
             The string that separates columns.
 
         Returns
         -------
         The formatted string.
         """
         # Note: this code is adapted from columnize 0.3.2.
         # See http://code.google.com/p/pycolumnize/
 
         # Calculate the number of characters available.
         width = self._control.viewport().width()
         char_width = QtGui.QFontMetrics(self.font).width(' ')
         displaywidth = max(10, (width / char_width) - 1)
 
         # Some degenerate cases.
         size = len(items)
         if size == 0: 
             return '\n'
         elif size == 1:
             return '%s\n' % items[0]
 
         # Try every row count from 1 upwards
         array_index = lambda nrows, row, col: nrows*col + row
         for nrows in range(1, size):
             ncols = (size + nrows - 1) // nrows
             colwidths = []
             totwidth = -len(separator)
             for col in range(ncols):
                 # Get max column width for this column
                 colwidth = 0
                 for row in range(nrows):
                     i = array_index(nrows, row, col)
                     if i >= size: break
                     x = items[i]
                     colwidth = max(colwidth, len(x))
                 colwidths.append(colwidth)
                 totwidth += colwidth + len(separator)
                 if totwidth > displaywidth: 
                     break
             if totwidth <= displaywidth: 
                 break
 
         # The smallest number of rows computed and the max widths for each
         # column has been obtained. Now we just have to format each of the rows.
         string = ''
         for row in range(nrows):
             texts = []
             for col in range(ncols):
                 i = row + nrows*col
                 if i >= size:
                     texts.append('')
                 else:
                     texts.append(items[i])
             while texts and not texts[-1]:
                 del texts[-1]
             for col in range(len(texts)):
                 texts[col] = texts[col].ljust(colwidths[col])
             string += '%s\n' % separator.join(texts)
         return string
 
     def _get_block_plain_text(self, block):
         """ Given a QTextBlock, return its unformatted text.
         """
         cursor = QtGui.QTextCursor(block)
         cursor.movePosition(QtGui.QTextCursor.StartOfBlock)
         cursor.movePosition(QtGui.QTextCursor.EndOfBlock, 
                             QtGui.QTextCursor.KeepAnchor)
         return cursor.selection().toPlainText()
 
     def _get_cursor(self):
         """ Convenience method that returns a cursor for the current position.
         """
         return self._control.textCursor()
                 
     def _get_end_cursor(self):
         """ Convenience method that returns a cursor for the last character.
         """
         cursor = self._control.textCursor()
         cursor.movePosition(QtGui.QTextCursor.End)
         return cursor
 
     def _get_input_buffer_cursor_column(self):
         """ Returns the column of the cursor in the input buffer, excluding the
             contribution by the prompt, or -1 if there is no such column.
         """
         prompt = self._get_input_buffer_cursor_prompt()
         if prompt is None:
             return -1
         else:
             cursor = self._control.textCursor()
             return cursor.columnNumber() - len(prompt)
 
     def _get_input_buffer_cursor_line(self):
         """ Returns the text of the line of the input buffer that contains the
             cursor, or None if there is no such line.
         """
         prompt = self._get_input_buffer_cursor_prompt()
         if prompt is None:
             return None
         else:
             cursor = self._control.textCursor()
             text = self._get_block_plain_text(cursor.block())
             return text[len(prompt):]
 
     def _get_input_buffer_cursor_prompt(self):
         """ Returns the (plain text) prompt for line of the input buffer that
             contains the cursor, or None if there is no such line.
         """
         if self._executing:
             return None
         cursor = self._control.textCursor()
         if cursor.position() >= self._prompt_pos:
             if cursor.blockNumber() == self._get_prompt_cursor().blockNumber():
                 return self._prompt
             else:
                 return self._continuation_prompt
         else:
             return None
 
     def _get_prompt_cursor(self):
         """ Convenience method that returns a cursor for the prompt position.
         """
         cursor = self._control.textCursor()
         cursor.setPosition(self._prompt_pos)
         return cursor
 
     def _get_selection_cursor(self, start, end):
         """ Convenience method that returns a cursor with text selected between
             the positions 'start' and 'end'.
         """
         cursor = self._control.textCursor()
         cursor.setPosition(start)
         cursor.setPosition(end, QtGui.QTextCursor.KeepAnchor)
         return cursor
 
     def _get_word_start_cursor(self, position):
         """ Find the start of the word to the left the given position. If a
             sequence of non-word characters precedes the first word, skip over
             them. (This emulates the behavior of bash, emacs, etc.)
         """
         document = self._control.document()
         position -= 1
         while position >= self._prompt_pos and \
                   not is_letter_or_number(document.characterAt(position)):
             position -= 1
         while position >= self._prompt_pos and \
                   is_letter_or_number(document.characterAt(position)):
             position -= 1
         cursor = self._control.textCursor()
         cursor.setPosition(position + 1)
         return cursor
 
     def _get_word_end_cursor(self, position):
         """ Find the end of the word to the right the given position. If a
             sequence of non-word characters precedes the first word, skip over
             them. (This emulates the behavior of bash, emacs, etc.)
         """
         document = self._control.document()
         end = self._get_end_cursor().position()
         while position < end and \
                   not is_letter_or_number(document.characterAt(position)):
             position += 1
         while position < end and \
                   is_letter_or_number(document.characterAt(position)):
             position += 1
         cursor = self._control.textCursor()
         cursor.setPosition(position)
         return cursor
 
     def _insert_continuation_prompt(self, cursor):
         """ Inserts new continuation prompt using the specified cursor.
         """
         if self._continuation_prompt_html is None:
             self._insert_plain_text(cursor, self._continuation_prompt)
         else:
             self._continuation_prompt = self._insert_html_fetching_plain_text(
                 cursor, self._continuation_prompt_html)
 
     def _insert_html(self, cursor, html):
         """ Inserts HTML using the specified cursor in such a way that future
             formatting is unaffected.
         """
         cursor.beginEditBlock()
         cursor.insertHtml(html)
 
         # After inserting HTML, the text document "remembers" it's in "html
         # mode", which means that subsequent calls adding plain text will result
         # in unwanted formatting, lost tab characters, etc. The following code
         # hacks around this behavior, which I consider to be a bug in Qt, by
         # (crudely) resetting the document's style state.
         cursor.movePosition(QtGui.QTextCursor.Left,
                             QtGui.QTextCursor.KeepAnchor)
         if cursor.selection().toPlainText() == ' ':
             cursor.removeSelectedText()
         else:
             cursor.movePosition(QtGui.QTextCursor.Right)
         cursor.insertText(' ', QtGui.QTextCharFormat())
         cursor.endEditBlock()
 
     def _insert_html_fetching_plain_text(self, cursor, html):
         """ Inserts HTML using the specified cursor, then returns its plain text
             version.
         """
         cursor.beginEditBlock()
         cursor.removeSelectedText()
 
         start = cursor.position()
         self._insert_html(cursor, html)
         end = cursor.position()
         cursor.setPosition(start, QtGui.QTextCursor.KeepAnchor)
         text = cursor.selection().toPlainText()
 
         cursor.setPosition(end)
         cursor.endEditBlock()
         return text
 
     def _insert_plain_text(self, cursor, text):
         """ Inserts plain text using the specified cursor, processing ANSI codes
             if enabled.
         """
         cursor.beginEditBlock()
         if self.ansi_codes:
             for substring in self._ansi_processor.split_string(text):
                 for act in self._ansi_processor.actions:
 
                     # Unlike real terminal emulators, we don't distinguish
                     # between the screen and the scrollback buffer. A screen
                     # erase request clears everything.
                     if act.action == 'erase' and act.area == 'screen':
                         cursor.select(QtGui.QTextCursor.Document)
                         cursor.removeSelectedText()
 
                     # Simulate a form feed by scrolling just past the last line.
                     elif act.action == 'scroll' and act.unit == 'page':
                         cursor.insertText('\n')
                         cursor.endEditBlock()
                         self._set_top_cursor(cursor)
                         cursor.joinPreviousEditBlock()
                         cursor.deletePreviousChar()
                         
                 format = self._ansi_processor.get_format()
                 cursor.insertText(substring, format)
         else:
             cursor.insertText(text)
         cursor.endEditBlock()
 
     def _insert_plain_text_into_buffer(self, cursor, text):
         """ Inserts text into the input buffer using the specified cursor (which
             must be in the input buffer), ensuring that continuation prompts are
             inserted as necessary.
         """
         lines = text.splitlines(True)
         if lines:
             cursor.beginEditBlock()
             cursor.insertText(lines[0])
             for line in lines[1:]:
                 if self._continuation_prompt_html is None:
                     cursor.insertText(self._continuation_prompt)
                 else:
                     self._continuation_prompt = \
                         self._insert_html_fetching_plain_text(
                             cursor, self._continuation_prompt_html)
                 cursor.insertText(line)
             cursor.endEditBlock()
 
     def _in_buffer(self, position=None):
         """ Returns whether the current cursor (or, if specified, a position) is
             inside the editing region.
         """
         cursor = self._control.textCursor()
         if position is None:
             position = cursor.position()
         else:
             cursor.setPosition(position)
         line = cursor.blockNumber()
         prompt_line = self._get_prompt_cursor().blockNumber()
         if line == prompt_line:
             return position >= self._prompt_pos
         elif line > prompt_line:
             cursor.movePosition(QtGui.QTextCursor.StartOfBlock)
             prompt_pos = cursor.position() + len(self._continuation_prompt)
             return position >= prompt_pos
         return False
 
     def _keep_cursor_in_buffer(self):
         """ Ensures that the cursor is inside the editing region. Returns
             whether the cursor was moved.
         """
         moved = not self._in_buffer()
         if moved:
             cursor = self._control.textCursor()
             cursor.movePosition(QtGui.QTextCursor.End)
             self._control.setTextCursor(cursor)
         return moved
 
     def _keyboard_quit(self):
         """ Cancels the current editing task ala Ctrl-G in Emacs.
         """
         if self._text_completing_pos:
             self._cancel_text_completion()
         else:
             self.input_buffer = ''
         
     def _page(self, text, html=False):
         """ Displays text using the pager if it exceeds the height of the
         viewport.
 
         Parameters:
         -----------
         html : bool, optional (default False)
             If set, the text will be interpreted as HTML instead of plain text.
         """
         line_height = QtGui.QFontMetrics(self.font).height()
         minlines = self._control.viewport().height() / line_height
         if self.paging != 'none' and \
                 re.match("(?:[^\n]*\n){%i}" % minlines, text):
             if self.paging == 'custom':
                 self.custom_page_requested.emit(text)
             else:
                 self._page_control.clear()
                 cursor = self._page_control.textCursor()
                 if html:
                     self._insert_html(cursor, text)
                 else:
                     self._insert_plain_text(cursor, text)
                 self._page_control.moveCursor(QtGui.QTextCursor.Start)
 
                 self._page_control.viewport().resize(self._control.size())
                 if self._splitter:
                     self._page_control.show()
                     self._page_control.setFocus()
                 else:
                     self.layout().setCurrentWidget(self._page_control)
         elif html:
             self._append_plain_html(text)
         else:
             self._append_plain_text(text)
 
     def _prompt_finished(self):
         """ Called immediately after a prompt is finished, i.e. when some input
             will be processed and a new prompt displayed.
         """
         self._control.setReadOnly(True)
         self._prompt_finished_hook()
 
     def _prompt_started(self):
         """ Called immediately after a new prompt is displayed.
         """
         # Temporarily disable the maximum block count to permit undo/redo and 
         # to ensure that the prompt position does not change due to truncation.
         self._control.document().setMaximumBlockCount(0)
         self._control.setUndoRedoEnabled(True)
 
         # Work around bug in QPlainTextEdit: input method is not re-enabled
         # when read-only is disabled.
         self._control.setReadOnly(False)
         self._control.setAttribute(QtCore.Qt.WA_InputMethodEnabled, True)
 
         self._executing = False
         self._prompt_started_hook()
 
         # If the input buffer has changed while executing, load it.
         if self._input_buffer_pending:
             self.input_buffer = self._input_buffer_pending
             self._input_buffer_pending = ''
 
         self._control.moveCursor(QtGui.QTextCursor.End)
 
     def _readline(self, prompt='', callback=None):
         """ Reads one line of input from the user. 
 
         Parameters
         ----------
         prompt : str, optional
             The prompt to print before reading the line.
 
         callback : callable, optional
             A callback to execute with the read line. If not specified, input is
             read *synchronously* and this method does not return until it has
             been read.
 
         Returns
         -------
         If a callback is specified, returns nothing. Otherwise, returns the
         input string with the trailing newline stripped.
         """
         if self._reading:
             raise RuntimeError('Cannot read a line. Widget is already reading.')
 
         if not callback and not self.isVisible():
             # If the user cannot see the widget, this function cannot return.
             raise RuntimeError('Cannot synchronously read a line if the widget '
                                'is not visible!')
 
         self._reading = True
         self._show_prompt(prompt, newline=False)
 
         if callback is None:
             self._reading_callback = None
             while self._reading:
                 QtCore.QCoreApplication.processEvents()
             return self.input_buffer.rstrip('\n')
 
         else:
             self._reading_callback = lambda: \
                 callback(self.input_buffer.rstrip('\n'))
 
     def _set_continuation_prompt(self, prompt, html=False):
         """ Sets the continuation prompt.
 
         Parameters
         ----------
         prompt : str
             The prompt to show when more input is needed.
 
         html : bool, optional (default False)
             If set, the prompt will be inserted as formatted HTML. Otherwise,
             the prompt will be treated as plain text, though ANSI color codes
             will be handled.
         """
         if html:
             self._continuation_prompt_html = prompt
         else:
             self._continuation_prompt = prompt
             self._continuation_prompt_html = None
             
     def _set_cursor(self, cursor):
         """ Convenience method to set the current cursor.
         """
         self._control.setTextCursor(cursor)
 
     def _set_top_cursor(self, cursor):
         """ Scrolls the viewport so that the specified cursor is at the top.
         """
         scrollbar = self._control.verticalScrollBar()
         scrollbar.setValue(scrollbar.maximum())
         original_cursor = self._control.textCursor()
         self._control.setTextCursor(cursor)
         self._control.ensureCursorVisible()
         self._control.setTextCursor(original_cursor)
 
     def _show_prompt(self, prompt=None, html=False, newline=True):
         """ Writes a new prompt at the end of the buffer.
 
         Parameters
         ----------
         prompt : str, optional
             The prompt to show. If not specified, the previous prompt is used.
 
         html : bool, optional (default False)
             Only relevant when a prompt is specified. If set, the prompt will
             be inserted as formatted HTML. Otherwise, the prompt will be treated
             as plain text, though ANSI color codes will be handled.
 
         newline : bool, optional (default True)
             If set, a new line will be written before showing the prompt if 
             there is not already a newline at the end of the buffer.
         """
         # Insert a preliminary newline, if necessary.
         if newline:
             cursor = self._get_end_cursor()
             if cursor.position() > 0:
                 cursor.movePosition(QtGui.QTextCursor.Left, 
                                     QtGui.QTextCursor.KeepAnchor)
                 if cursor.selection().toPlainText() != '\n':
                     self._append_plain_text('\n')
 
         # Write the prompt.
         self._append_plain_text(self._prompt_sep)
         if prompt is None:
             if self._prompt_html is None:
                 self._append_plain_text(self._prompt)
             else:
                 self._append_html(self._prompt_html)
         else:
             if html:
                 self._prompt = self._append_html_fetching_plain_text(prompt)
                 self._prompt_html = prompt
             else:
                 self._append_plain_text(prompt)
                 self._prompt = prompt
                 self._prompt_html = None
 
         self._prompt_pos = self._get_end_cursor().position()
         self._prompt_started()
 
     #------ Signal handlers ----------------------------------------------------
 
     def _adjust_scrollbars(self):
         """ Expands the vertical scrollbar beyond the range set by Qt.
         """
         # This code is adapted from _q_adjustScrollbars in qplaintextedit.cpp
         # and qtextedit.cpp.
         document = self._control.document()
         scrollbar = self._control.verticalScrollBar()
         viewport_height = self._control.viewport().height()
         if isinstance(self._control, QtGui.QPlainTextEdit):
             maximum = max(0, document.lineCount() - 1)
             step = viewport_height / self._control.fontMetrics().lineSpacing()
         else:
             # QTextEdit does not do line-based layout and blocks will not in
             # general have the same height. Therefore it does not make sense to
             # attempt to scroll in line height increments.
             maximum = document.size().height()
             step = viewport_height
         diff = maximum - scrollbar.maximum()
         scrollbar.setRange(0, maximum)
         scrollbar.setPageStep(step)
 
         # Compensate for undesirable scrolling that occurs automatically due to
         # maximumBlockCount() text truncation.
         if diff < 0 and document.blockCount() == document.maximumBlockCount():
             scrollbar.setValue(scrollbar.value() + diff)
 
     def _cursor_position_changed(self):
         """ Clears the temporary buffer based on the cursor position.
         """
         if self._text_completing_pos:
             document = self._control.document()
             if self._text_completing_pos < document.characterCount():
                 cursor = self._control.textCursor()
                 pos = cursor.position()
                 text_cursor = self._control.textCursor()
                 text_cursor.setPosition(self._text_completing_pos)
                 if pos < self._text_completing_pos or \
                         cursor.blockNumber() > text_cursor.blockNumber():
                     self._clear_temporary_buffer()
                     self._text_completing_pos = 0
             else:
                 self._clear_temporary_buffer()
                 self._text_completing_pos = 0
 
     def _custom_context_menu_requested(self, pos):
         """ Shows a context menu at the given QPoint (in widget coordinates).
         """
         menu = self._context_menu_make(pos)
         menu.exec_(self._control.mapToGlobal(pos))

IPython/frontend/qt/console/ipythonqt.py

@@ -1,404 +1,420 b''
 """ A minimal application using the Qt console-style IPython frontend.
+
+This is not a complete console app, as subprocess will not be able to receive
+input, there is no real readline support, among other limitations.
+
+Authors:
+
+* Evan Patterson
+* Min RK
+* Erik Tollerud
+* Fernando Perez
+
 """
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # stdlib imports
 import os
 import signal
 import sys
 
 # System library imports
 from IPython.external.qt import QtGui
 from pygments.styles import get_all_styles
 
 # Local imports
 from IPython.config.application import boolean_flag
 from IPython.core.newapplication import ProfileDir, BaseIPythonApplication
 from IPython.frontend.qt.console.frontend_widget import FrontendWidget
 from IPython.frontend.qt.console.ipython_widget import IPythonWidget
 from IPython.frontend.qt.console.rich_ipython_widget import RichIPythonWidget
 from IPython.frontend.qt.console import styles
 from IPython.frontend.qt.kernelmanager import QtKernelManager
 from IPython.utils.traitlets import (
     Dict, List, Unicode, Int, CaselessStrEnum, CBool, Any
 )
 from IPython.zmq.ipkernel import (
     flags as ipkernel_flags,
     aliases as ipkernel_aliases,
     IPKernelApp
 )
 from IPython.zmq.session import Session
 from IPython.zmq.zmqshell import ZMQInteractiveShell
 
 
 #-----------------------------------------------------------------------------
 # Network Constants
 #-----------------------------------------------------------------------------
 
 from IPython.utils.localinterfaces import LOCALHOST, LOCAL_IPS
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class MainWindow(QtGui.QMainWindow):
 
     #---------------------------------------------------------------------------
     # 'object' interface
     #---------------------------------------------------------------------------
     
     def __init__(self, app, frontend, existing=False, may_close=True,
                     confirm_exit=True):
         """ Create a MainWindow for the specified FrontendWidget.
         
         The app is passed as an argument to allow for different
         closing behavior depending on whether we are the Kernel's parent.
         
         If existing is True, then this Console does not own the Kernel.
         
         If may_close is True, then this Console is permitted to close the kernel
         """
         super(MainWindow, self).__init__()
         self._app = app
         self._frontend = frontend
         self._existing = existing
         if existing:
             self._may_close = may_close
         else:
             self._may_close = True
         self._frontend.exit_requested.connect(self.close)
         self._confirm_exit = confirm_exit
         self.setCentralWidget(frontend)
     
     #---------------------------------------------------------------------------
     # QWidget interface
     #---------------------------------------------------------------------------
     
     def closeEvent(self, event):
         """ Close the window and the kernel (if necessary).
         
         This will prompt the user if they are finished with the kernel, and if
         so, closes the kernel cleanly. Alternatively, if the exit magic is used,
         it closes without prompt.
         """
         keepkernel = None #Use the prompt by default
         if hasattr(self._frontend,'_keep_kernel_on_exit'): #set by exit magic
             keepkernel = self._frontend._keep_kernel_on_exit
         
         kernel_manager = self._frontend.kernel_manager
         
         if keepkernel is None and not self._confirm_exit:
             # don't prompt, just terminate the kernel if we own it
             # or leave it alone if we don't
             keepkernel = not self._existing
         
         if keepkernel is None: #show prompt
             if kernel_manager and kernel_manager.channels_running:
                 title = self.window().windowTitle()
                 cancel = QtGui.QMessageBox.Cancel
                 okay = QtGui.QMessageBox.Ok
                 if self._may_close:
                     msg = "You are closing this Console window."
                     info = "Would you like to quit the Kernel and all attached Consoles as well?"
                     justthis = QtGui.QPushButton("&No, just this Console", self)
                     justthis.setShortcut('N')
                     closeall = QtGui.QPushButton("&Yes, quit everything", self)
                     closeall.setShortcut('Y')
                     box = QtGui.QMessageBox(QtGui.QMessageBox.Question,
                                             title, msg)
                     box.setInformativeText(info)
                     box.addButton(cancel)
                     box.addButton(justthis, QtGui.QMessageBox.NoRole)
                     box.addButton(closeall, QtGui.QMessageBox.YesRole)
                     box.setDefaultButton(closeall)
                     box.setEscapeButton(cancel)
                     reply = box.exec_()
                     if reply == 1: # close All
                         kernel_manager.shutdown_kernel()
                         #kernel_manager.stop_channels()
                         event.accept()
                     elif reply == 0: # close Console
                         if not self._existing:
                             # Have kernel: don't quit, just close the window
                             self._app.setQuitOnLastWindowClosed(False)
                             self.deleteLater()
                         event.accept()
                     else:
                         event.ignore()
                 else:
                     reply = QtGui.QMessageBox.question(self, title,
                         "Are you sure you want to close this Console?"+
                         "\nThe Kernel and other Consoles will remain active.",
                         okay|cancel,
                         defaultButton=okay
                         )
                     if reply == okay:
                         event.accept()
                     else:
                         event.ignore()
         elif keepkernel: #close console but leave kernel running (no prompt)
             if kernel_manager and kernel_manager.channels_running:
                 if not self._existing:
                     # I have the kernel: don't quit, just close the window
                     self._app.setQuitOnLastWindowClosed(False)
                 event.accept()
         else: #close console and kernel (no prompt)
             if kernel_manager and kernel_manager.channels_running:
                 kernel_manager.shutdown_kernel()
                 event.accept()
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 
 flags = dict(ipkernel_flags)
 
 flags.update({
     'existing' : ({'IPythonQtConsoleApp' : {'existing' : True}},
             "Connect to an existing kernel."),
     'pure' : ({'IPythonQtConsoleApp' : {'pure' : True}},
             "Use a pure Python kernel instead of an IPython kernel."),
     'plain' : ({'ConsoleWidget' : {'kind' : 'plain'}},
             "Disable rich text support."),
 })
 flags.update(boolean_flag(
     'gui-completion', 'ConsoleWidget.gui_completion',
     "use a GUI widget for tab completion",
     "use plaintext output for completion"
 ))
 flags.update(boolean_flag(
     'confirm-exit', 'IPythonQtConsoleApp.confirm_exit',
     """Set to display confirmation dialog on exit. You can always use 'exit' or 'quit',
        to force a direct exit without any confirmation.
     """,
     """Don't prompt the user when exiting. This will terminate the kernel
        if it is owned by the frontend, and leave it alive if it is external.
     """
 ))
 # the flags that are specific to the frontend
 # these must be scrubbed before being passed to the kernel,
 # or it will raise an error on unrecognized flags
 qt_flags = ['existing', 'pure', 'plain', 'gui-completion', 'no-gui-completion',
             'confirm-exit', 'no-confirm-exit']
 
 aliases = dict(ipkernel_aliases)
 
 aliases.update(dict(
     hb = 'IPythonQtConsoleApp.hb_port',
     shell = 'IPythonQtConsoleApp.shell_port',
     iopub = 'IPythonQtConsoleApp.iopub_port',
     stdin = 'IPythonQtConsoleApp.stdin_port',
     ip = 'IPythonQtConsoleApp.ip',
 
     plain = 'IPythonQtConsoleApp.plain',
     pure = 'IPythonQtConsoleApp.pure',
     gui_completion = 'ConsoleWidget.gui_completion',
     style = 'IPythonWidget.syntax_style',
     stylesheet = 'IPythonQtConsoleApp.stylesheet',
     colors = 'ZMQInteractiveShell.colors',
 
     editor = 'IPythonWidget.editor',
-    pi = 'IPythonWidget.in_prompt',
-    po = 'IPythonWidget.out_prompt',
-    si = 'IPythonWidget.input_sep',
-    so = 'IPythonWidget.output_sep',
-    so2 = 'IPythonWidget.output_sep2',
 ))
 
 #-----------------------------------------------------------------------------
 # IPythonQtConsole
 #-----------------------------------------------------------------------------
-
 class IPythonQtConsoleApp(BaseIPythonApplication):
     name = 'ipython-qtconsole'
     default_config_file_name='ipython_config.py'
+    
+    description = """
+        The IPython QtConsole.
+        
+        This launches a Console-style application using Qt.  It is not a full
+        console, in that launched terminal subprocesses will not.
+        
+        The QtConsole supports various extra features beyond the
+        
+    """
+    
     classes = [IPKernelApp, IPythonWidget, ZMQInteractiveShell, ProfileDir, Session]
     flags = Dict(flags)
     aliases = Dict(aliases)
 
     kernel_argv = List(Unicode)
 
     # connection info:
     ip = Unicode(LOCALHOST, config=True,
         help="""Set the kernel\'s IP address [default localhost].
         If the IP address is something other than localhost, then
         Consoles on other machines will be able to connect
         to the Kernel, so be careful!"""
     )
     hb_port = Int(0, config=True,
         help="set the heartbeat port [default: random]")
     shell_port = Int(0, config=True,
         help="set the shell (XREP) port [default: random]")
     iopub_port = Int(0, config=True,
         help="set the iopub (PUB) port [default: random]")
     stdin_port = Int(0, config=True,
         help="set the stdin (XREQ) port [default: random]")
 
     existing = CBool(False, config=True,
         help="Whether to connect to an already running Kernel.")
 
     stylesheet = Unicode('', config=True,
         help="path to a custom CSS stylesheet")
 
     pure = CBool(False, config=True,
         help="Use a pure Python kernel instead of an IPython kernel.")
     plain = CBool(False, config=True,
         help="Use a plaintext widget instead of rich text (plain can't print/save).")
 
     def _pure_changed(self, name, old, new):
         kind = 'plain' if self.plain else 'rich'
         self.config.ConsoleWidget.kind = kind
         if self.pure:
             self.widget_factory = FrontendWidget
         elif self.plain:
             self.widget_factory = IPythonWidget
         else:
             self.widget_factory = RichIPythonWidget
 
     _plain_changed = _pure_changed
 
     confirm_exit = CBool(True, config=True,
         help="""
         Set to display confirmation dialog on exit. You can always use 'exit' or 'quit',
         to force a direct exit without any confirmation.""",
     )
     
     # the factory for creating a widget
     widget_factory = Any(RichIPythonWidget)
 
     def parse_command_line(self, argv=None):
         super(IPythonQtConsoleApp, self).parse_command_line(argv)
         if argv is None:
             argv = sys.argv[1:]
 
         self.kernel_argv = list(argv) # copy
 
         # scrub frontend-specific flags
         for a in argv:
             if a.startswith('--') and a[2:] in qt_flags:
                 self.kernel_argv.remove(a)
 
     def init_kernel_manager(self):
         # Don't let Qt or ZMQ swallow KeyboardInterupts.
         signal.signal(signal.SIGINT, signal.SIG_DFL)
 
         # Create a KernelManager and start a kernel.
         self.kernel_manager = QtKernelManager(
                                 shell_address=(self.ip, self.shell_port),
                                 sub_address=(self.ip, self.iopub_port),
                                 stdin_address=(self.ip, self.stdin_port),
                                 hb_address=(self.ip, self.hb_port),
                                 config=self.config
         )
         # start the kernel
         if not self.existing:
             kwargs = dict(ip=self.ip, ipython=not self.pure)
             kwargs['extra_arguments'] = self.kernel_argv
             self.kernel_manager.start_kernel(**kwargs)
         self.kernel_manager.start_channels()
 
 
     def init_qt_elements(self):
         # Create the widget.
         self.app = QtGui.QApplication([])
         local_kernel = (not self.existing) or self.ip in LOCAL_IPS
         self.widget = self.widget_factory(config=self.config,
                                         local_kernel=local_kernel)
         self.widget.kernel_manager = self.kernel_manager
         self.window = MainWindow(self.app, self.widget, self.existing,
                                 may_close=local_kernel,
                                 confirm_exit=self.confirm_exit)
         self.window.setWindowTitle('Python' if self.pure else 'IPython')
 
     def init_colors(self):
         """Configure the coloring of the widget"""
         # Note: This will be dramatically simplified when colors
         # are removed from the backend.
 
         if self.pure:
             # only IPythonWidget supports styling
             return
 
         # parse the colors arg down to current known labels
         try:
             colors = self.config.ZMQInteractiveShell.colors
         except AttributeError:
             colors = None
         try:
             style = self.config.IPythonWidget.colors
         except AttributeError:
             style = None
 
         # find the value for colors:
         if colors:
             colors=colors.lower()
             if colors in ('lightbg', 'light'):
                 colors='lightbg'
             elif colors in ('dark', 'linux'):
                 colors='linux'
             else:
                 colors='nocolor'
         elif style:
             if style=='bw':
                 colors='nocolor'
             elif styles.dark_style(style):
                 colors='linux'
             else:
                 colors='lightbg'
         else:
             colors=None
 
         # Configure the style.
         widget = self.widget
         if style:
             widget.style_sheet = styles.sheet_from_template(style, colors)
             widget.syntax_style = style
             widget._syntax_style_changed()
             widget._style_sheet_changed()
         elif colors:
             # use a default style
             widget.set_default_style(colors=colors)
         else:
             # this is redundant for now, but allows the widget's
             # defaults to change
             widget.set_default_style()
 
         if self.stylesheet:
             # we got an expicit stylesheet
             if os.path.isfile(self.stylesheet):
                 with open(self.stylesheet) as f:
                     sheet = f.read()
                 widget.style_sheet = sheet
                 widget._style_sheet_changed()
             else:
                 raise IOError("Stylesheet %r not found."%self.stylesheet)
 
     def initialize(self, argv=None):
         super(IPythonQtConsoleApp, self).initialize(argv)
         self.init_kernel_manager()
         self.init_qt_elements()
         self.init_colors()
 
     def start(self):
 
         # draw the window
         self.window.show()
 
         # Start the application main loop.
         self.app.exec_()
 
 #-----------------------------------------------------------------------------
 # Main entry point
 #-----------------------------------------------------------------------------
 
 def main():
     app = IPythonQtConsoleApp()
     app.initialize()
     app.start()
 
 
 if __name__ == '__main__':
     main()

IPython/frontend/terminal/ipapp.py

@@ -1,365 +1,357 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 The :class:`~IPython.core.newapplication.Application` object for the command
 line :command:`ipython` program.
 
 Authors
 -------
 
 * Brian Granger
 * Fernando Perez
 * Min Ragan-Kelley
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2010  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 logging
 import os
 import sys
 
 from IPython.config.loader import (
     Config, PyFileConfigLoader
 )
 from IPython.config.application import boolean_flag
 from IPython.core import release
 from IPython.core import usage
 from IPython.core.crashhandler import CrashHandler
 from IPython.core.formatters import PlainTextFormatter
 from IPython.core.newapplication import (
     ProfileDir, BaseIPythonApplication, base_flags, base_aliases
 )
 from IPython.core.shellapp import (
     InteractiveShellApp, shell_flags, shell_aliases
 )
 from IPython.frontend.terminal.interactiveshell import TerminalInteractiveShell
 from IPython.lib import inputhook
 from IPython.utils.path import get_ipython_dir, check_for_old_config
 from IPython.utils.traitlets import (
     Bool, Dict, CaselessStrEnum
 )
 
 #-----------------------------------------------------------------------------
 # Globals, utilities and helpers
 #-----------------------------------------------------------------------------
 
 #: The default config file name for this application.
 default_config_file_name = u'ipython_config.py'
 
 
 #-----------------------------------------------------------------------------
 # Crash handler for this application
 #-----------------------------------------------------------------------------
 
 _message_template = """\
 Oops, $self.app_name crashed. We do our best to make it stable, but...
 
 A crash report was automatically generated with the following information:
   - A verbatim copy of the crash traceback.
   - A copy of your input history during this session.
   - Data on your current $self.app_name configuration.
 
 It was left in the file named:
 \t'$self.crash_report_fname'
 If you can email this file to the developers, the information in it will help
 them in understanding and correcting the problem.
 
 You can mail it to: $self.contact_name at $self.contact_email
 with the subject '$self.app_name Crash Report'.
 
 If you want to do it now, the following command will work (under Unix):
 mail -s '$self.app_name Crash Report' $self.contact_email < $self.crash_report_fname
 
 To ensure accurate tracking of this issue, please file a report about it at:
 $self.bug_tracker
 """
 
 class IPAppCrashHandler(CrashHandler):
     """sys.excepthook for IPython itself, leaves a detailed report on disk."""
 
     message_template = _message_template
 
     def __init__(self, app):
         contact_name = release.authors['Fernando'][0]
         contact_email = release.authors['Fernando'][1]
         bug_tracker = 'http://github.com/ipython/ipython/issues'
         super(IPAppCrashHandler,self).__init__(
             app, contact_name, contact_email, bug_tracker
         )
 
     def make_report(self,traceback):
         """Return a string containing a crash report."""
 
         sec_sep = self.section_sep
         # Start with parent report
         report = [super(IPAppCrashHandler, self).make_report(traceback)]
         # Add interactive-specific info we may have
         rpt_add = report.append
         try:
             rpt_add(sec_sep+"History of session input:")
             for line in self.app.shell.user_ns['_ih']:
                 rpt_add(line)
             rpt_add('\n*** Last line of input (may not be in above history):\n')
             rpt_add(self.app.shell._last_input_line+'\n')
         except:
             pass
 
         return ''.join(report)
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 flags = dict(base_flags)
 flags.update(shell_flags)
 addflag = lambda *args: flags.update(boolean_flag(*args))
 addflag('autoedit-syntax', 'TerminalInteractiveShell.autoedit_syntax',
         'Turn on auto editing of files with syntax errors.',
         'Turn off auto editing of files with syntax errors.'
 )
 addflag('banner', 'TerminalIPythonApp.display_banner',
         "Display a banner upon starting IPython.",
         "Don't display a banner upon starting IPython."
 )
 addflag('confirm-exit', 'TerminalInteractiveShell.confirm_exit',
     """Set to confirm when you try to exit IPython with an EOF (Control-D
     in Unix, Control-Z/Enter in Windows). By typing 'exit' or 'quit',
     you can force a direct exit without any confirmation.""",
     "Don't prompt the user when exiting."
 )
 addflag('term-title', 'TerminalInteractiveShell.term_title',
     "Enable auto setting the terminal title.",
     "Disable auto setting the terminal title."
 )
 classic_config = Config()
 classic_config.InteractiveShell.cache_size = 0
 classic_config.PlainTextFormatter.pprint = False
 classic_config.InteractiveShell.prompt_in1 = '>>> '
 classic_config.InteractiveShell.prompt_in2 = '... '
 classic_config.InteractiveShell.prompt_out = ''
 classic_config.InteractiveShell.separate_in = ''
 classic_config.InteractiveShell.separate_out = ''
 classic_config.InteractiveShell.separate_out2 = ''
 classic_config.InteractiveShell.colors = 'NoColor'
 classic_config.InteractiveShell.xmode = 'Plain'
 
 flags['classic']=(
     classic_config,
     "Gives IPython a similar feel to the classic Python prompt."
 )
 # # log doesn't make so much sense this way anymore
 # paa('--log','-l',
 #     action='store_true', dest='InteractiveShell.logstart',
 #     help="Start logging to the default log file (./ipython_log.py).")
 #
 # # quick is harder to implement
 flags['quick']=(
     {'TerminalIPythonApp' : {'quick' : True}},
     "Enable quick startup with no config files."
 )
 
-nosep_config = Config()
-nosep_config.InteractiveShell.separate_in = ''
-nosep_config.InteractiveShell.separate_out = ''
-nosep_config.InteractiveShell.separate_out2 = ''
-
-flags['nosep']=(nosep_config, "Eliminate all spacing between prompts.")
-
 flags['i'] = (
     {'TerminalIPythonApp' : {'force_interact' : True}},
     "If running code from the command line, become interactive afterwards."
 )
 flags['pylab'] = (
     {'TerminalIPythonApp' : {'pylab' : 'auto'}},
     """Pre-load matplotlib and numpy for interactive use with
     the default matplotlib backend."""
 )
 
 aliases = dict(base_aliases)
 aliases.update(shell_aliases)
 
 # it's possible we don't want short aliases for *all* of these:
 aliases.update(dict(
-    editor='TerminalInteractiveShell.editor',
-    sl='TerminalInteractiveShell.screen_length',
     gui='TerminalIPythonApp.gui',
     pylab='TerminalIPythonApp.pylab',
 ))
 
 #-----------------------------------------------------------------------------
 # Main classes and functions
 #-----------------------------------------------------------------------------
 
 class TerminalIPythonApp(BaseIPythonApplication, InteractiveShellApp):
     name = u'ipython'
     description = usage.cl_usage
     # command_line_loader = IPAppConfigLoader
     default_config_file_name = default_config_file_name
     crash_handler_class = IPAppCrashHandler
     
     flags = Dict(flags)
     aliases = Dict(aliases)
     classes = [InteractiveShellApp, TerminalInteractiveShell, ProfileDir, PlainTextFormatter]
     subcommands = Dict(dict(
         qtconsole=('IPython.frontend.qt.console.ipythonqt.IPythonQtConsoleApp',
             """Launch the IPython QtConsole.  Also launched as ipython-qtconsole"""
         )
     ))
     
     # *do* autocreate requested profile
     auto_create=Bool(True)
     copy_config_files=Bool(True)
     # configurables
     ignore_old_config=Bool(False, config=True,
         help="Suppress warning messages about legacy config files"
     )
     quick = Bool(False, config=True,
         help="""Start IPython quickly by skipping the loading of config files."""
     )
     def _quick_changed(self, name, old, new):
         if new:
             self.load_config_file = lambda *a, **kw: None
             self.ignore_old_config=True
 
     gui = CaselessStrEnum(('qt','wx','gtk'), config=True,
         help="Enable GUI event loop integration ('qt', 'wx', 'gtk')."
     )
     pylab = CaselessStrEnum(['tk', 'qt', 'wx', 'gtk', 'osx', 'auto'],
         config=True,
         help="""Pre-load matplotlib and numpy for interactive use,
         selecting a particular matplotlib backend and loop integration.
         """
     )
     display_banner = Bool(True, config=True,
         help="Whether to display a banner upon starting IPython."
     )
 
     # if there is code of files to run from the cmd line, don't interact
     # unless the --i flag (App.force_interact) is true.
     force_interact = Bool(False, config=True,
         help="""If a command or file is given via the command-line,
         e.g. 'ipython foo.py"""
     )
     def _force_interact_changed(self, name, old, new):
         if new:
             self.interact = True
     
     def _file_to_run_changed(self, name, old, new):
         if new and not self.force_interact:
                 self.interact = False
     _code_to_run_changed = _file_to_run_changed
 
     # internal, not-configurable
     interact=Bool(True)
 
 
     def initialize(self, argv=None):
         """Do actions after construct, but before starting the app."""
         super(TerminalIPythonApp, self).initialize(argv)
         if self.subapp is not None:
             # don't bother initializing further, starting subapp
             return
         if not self.ignore_old_config:
             check_for_old_config(self.ipython_dir)
         # print self.extra_args
         if self.extra_args:
             self.file_to_run = self.extra_args[0]
         # create the shell
         self.init_shell()
         # and draw the banner
         self.init_banner()
         # Now a variety of things that happen after the banner is printed.
         self.init_gui_pylab()
         self.init_extensions()
         self.init_code()
 
     def init_shell(self):
         """initialize the InteractiveShell instance"""
         # I am a little hesitant to put these into InteractiveShell itself.
         # But that might be the place for them
         sys.path.insert(0, '')
 
         # Create an InteractiveShell instance.
         # shell.display_banner should always be False for the terminal 
         # based app, because we call shell.show_banner() by hand below
         # so the banner shows *before* all extension loading stuff.
         self.shell = TerminalInteractiveShell.instance(config=self.config,
                         display_banner=False, profile_dir=self.profile_dir,
                         ipython_dir=self.ipython_dir)
 
     def init_banner(self):
         """optionally display the banner"""
         if self.display_banner and self.interact:
             self.shell.show_banner()
         # Make sure there is a space below the banner.
         if self.log_level <= logging.INFO: print
 
 
     def init_gui_pylab(self):
         """Enable GUI event loop integration, taking pylab into account."""
         gui = self.gui
 
         # Using `pylab` will also require gui activation, though which toolkit
         # to use may be chosen automatically based on mpl configuration.
         if self.pylab:
             activate = self.shell.enable_pylab
             if self.pylab == 'auto':
                 gui = None
             else:
                 gui = self.pylab
         else:
             # Enable only GUI integration, no pylab
             activate = inputhook.enable_gui
 
         if gui or self.pylab:
             try:
                 self.log.info("Enabling GUI event loop integration, "
                               "toolkit=%s, pylab=%s" % (gui, self.pylab) )
                 activate(gui)
             except:
                 self.log.warn("Error in enabling GUI event loop integration:")
                 self.shell.showtraceback()
 
     def start(self):
         if self.subapp is not None:
             return self.subapp.start()
         # perform any prexec steps:
         if self.interact:
             self.log.debug("Starting IPython's mainloop...")
             self.shell.mainloop()
         else:
             self.log.debug("IPython not interactive...")
 
 
 def load_default_config(ipython_dir=None):
     """Load the default config file from the default ipython_dir.
 
     This is useful for embedded shells.
     """
     if ipython_dir is None:
         ipython_dir = get_ipython_dir()
     profile_dir = os.path.join(ipython_dir, 'profile_default')
     cl = PyFileConfigLoader(default_config_file_name, profile_dir)
     config = cl.load_config()
     return config
 
 
 def launch_new_instance():
     """Create and run a full blown IPython instance"""
     app = TerminalIPythonApp.instance()
     app.initialize()
     app.start()
 
 
 if __name__ == '__main__':
     launch_new_instance()
+

IPython/parallel/apps/win32support.py

@@ -1,73 +1,73 b''
 #!/usr/bin/env python
 """Utility for forwarding file read events over a zmq socket.
 
-This is necessary because select on Windows only supports
+This is necessary because select on Windows only supports sockets, not FDs.
 
 Authors:
 
 * MinRK
 
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 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
 #-----------------------------------------------------------------------------
 
 import uuid
 import zmq
 
 from threading import Thread
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 class ForwarderThread(Thread):
     def __init__(self, sock, fd):
         Thread.__init__(self)
         self.daemon=True
         self.sock = sock
         self.fd = fd
 
     def run(self):
-        """loop through lines in self.fd, and send them over self.sock"""
+        """Loop through lines in self.fd, and send them over self.sock."""
         line = self.fd.readline()
         # allow for files opened in unicode mode
         if isinstance(line, unicode):
             send = self.sock.send_unicode
         else:
             send = self.sock.send
         while line:
             send(line)
             line = self.fd.readline()
         # line == '' means EOF
         self.fd.close()
         self.sock.close()
 
 def forward_read_events(fd, context=None):
-    """forward read events from an FD over a socket.
+    """Forward read events from an FD over a socket.
 
     This method wraps a file in a socket pair, so it can
     be polled for read events by select (specifically zmq.eventloop.ioloop)
     """
     if context is None:
         context = zmq.Context.instance()
     push = context.socket(zmq.PUSH)
     push.setsockopt(zmq.LINGER, -1)
     pull = context.socket(zmq.PULL)
     addr='inproc://%s'%uuid.uuid4()
     push.bind(addr)
     pull.connect(addr)
     forwarder = ForwarderThread(push, fd)
     forwarder.start()
     return pull
 
 
-__all__ = ['forward_read_events']
  No newline at end of file
+__all__ = ['forward_read_events']

IPython/zmq/kernelapp.py

@@ -1,214 +1,215 b''
 #!/usr/bin/env python
 """An Application for launching a kernel
 
 Authors
 -------
 * MinRK
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING.txt, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports.
 import os
 import sys
 
 # System library imports.
 import zmq
 
 # IPython imports.
 from IPython.core.ultratb import FormattedTB
 from IPython.core.newapplication import (
     BaseIPythonApplication, base_flags, base_aliases
 )
 from IPython.utils import io
 from IPython.utils.localinterfaces import LOCALHOST
 from IPython.utils.traitlets import Any, Instance, Dict, Unicode, Int, Bool
 from IPython.utils.importstring import import_item
 # local imports
 from IPython.zmq.heartbeat import Heartbeat
 from IPython.zmq.parentpoller import ParentPollerUnix, ParentPollerWindows
 from IPython.zmq.session import Session
 
 
 #-----------------------------------------------------------------------------
 # Flags and Aliases
 #-----------------------------------------------------------------------------
 
 kernel_aliases = dict(base_aliases)
 kernel_aliases.update({
     'ip' : 'KernelApp.ip',
     'hb' : 'KernelApp.hb_port',
     'shell' : 'KernelApp.shell_port',
     'iopub' : 'KernelApp.iopub_port',
     'stdin' : 'KernelApp.stdin_port',
     'parent': 'KernelApp.parent',
 })
 if sys.platform.startswith('win'):
     kernel_aliases['interrupt'] = 'KernelApp.interrupt'
 
 kernel_flags = dict(base_flags)
 kernel_flags.update({
     'no-stdout' : (
             {'KernelApp' : {'no_stdout' : True}},
             "redirect stdout to the null device"),
     'no-stderr' : (
             {'KernelApp' : {'no_stderr' : True}},
             "redirect stderr to the null device"),
 })
 
 
 #-----------------------------------------------------------------------------
 # Application class for starting a Kernel
 #-----------------------------------------------------------------------------
 
 class KernelApp(BaseIPythonApplication):
     name='pykernel'
     aliases = Dict(kernel_aliases)
     flags = Dict(kernel_flags)
     classes = [Session]
     # the kernel class, as an importstring
     kernel_class = Unicode('IPython.zmq.pykernel.Kernel')
     kernel = Any()
     poller = Any() # don't restrict this even though current pollers are all Threads
     heartbeat = Instance(Heartbeat)
     session = Instance('IPython.zmq.session.Session')
     ports = Dict()
 
     # connection info:
     ip = Unicode(LOCALHOST, config=True,
         help="Set the IP or interface on which the kernel will listen.")
     hb_port = Int(0, config=True, help="set the heartbeat port [default: random]")
     shell_port = Int(0, config=True, help="set the shell (XREP) port [default: random]")
     iopub_port = Int(0, config=True, help="set the iopub (PUB) port [default: random]")
     stdin_port = Int(0, config=True, help="set the stdin (XREQ) port [default: random]")
 
     # streams, etc.
     no_stdout = Bool(False, config=True, help="redirect stdout to the null device")
     no_stderr = Bool(False, config=True, help="redirect stderr to the null device")
     outstream_class = Unicode('IPython.zmq.iostream.OutStream', config=True,
         help="The importstring for the OutStream factory")
     displayhook_class = Unicode('IPython.zmq.displayhook.DisplayHook', config=True,
         help="The importstring for the DisplayHook factory")
 
     # polling
     parent = Int(0, config=True,
         help="""kill this process if its parent dies.  On Windows, the argument
         specifies the HANDLE of the parent process, otherwise it is simply boolean.
         """)
     interrupt = Int(0, config=True,
         help="""ONLY USED ON WINDOWS
         Interrupt this process when the parent is signalled.
         """)
 
     def init_crash_handler(self):
         # Install minimal exception handling
         sys.excepthook = FormattedTB(mode='Verbose', color_scheme='NoColor',
                                      ostream=sys.__stdout__)
 
     def init_poller(self):
         if sys.platform == 'win32':
             if self.interrupt or self.parent:
                 self.poller = ParentPollerWindows(self.interrupt, self.parent)
         elif self.parent:
             self.poller = ParentPollerUnix()
 
     def _bind_socket(self, s, port):
         iface = 'tcp://%s' % self.ip
         if port <= 0:
             port = s.bind_to_random_port(iface)
         else:
             s.bind(iface + ':%i'%port)
         return port
 
     def init_sockets(self):
         # Create a context, a session, and the kernel sockets.
         io.raw_print("Starting the kernel at pid:", os.getpid())
         context = zmq.Context.instance()
         # Uncomment this to try closing the context.
         # atexit.register(context.term)
 
         self.shell_socket = context.socket(zmq.XREP)
         self.shell_port = self._bind_socket(self.shell_socket, self.shell_port)
         self.log.debug("shell XREP Channel on port: %i"%self.shell_port)
 
         self.iopub_socket = context.socket(zmq.PUB)
         self.iopub_port = self._bind_socket(self.iopub_socket, self.iopub_port)
         self.log.debug("iopub PUB Channel on port: %i"%self.iopub_port)
 
         self.stdin_socket = context.socket(zmq.XREQ)
         self.stdin_port = self._bind_socket(self.stdin_socket, self.stdin_port)
         self.log.debug("stdin XREQ Channel on port: %i"%self.stdin_port)
 
         self.heartbeat = Heartbeat(context, (self.ip, self.hb_port))
         self.hb_port = self.heartbeat.port
         self.log.debug("Heartbeat REP Channel on port: %i"%self.hb_port)
 
         # Helper to make it easier to connect to an existing kernel, until we have
         # single-port connection negotiation fully implemented.
         self.log.info("To connect another client to this kernel, use:")
         self.log.info("--external shell={0} iopub={1} stdin={2} hb={3}".format(
             self.shell_port, self.iopub_port, self.stdin_port, self.hb_port))
 
 
         self.ports = dict(shell=self.shell_port, iopub=self.iopub_port,
                                 stdin=self.stdin_port, hb=self.hb_port)
 
     def init_session(self):
         """create our session object"""
         self.session = Session(config=self.config, username=u'kernel')
 
     def init_io(self):
         """redirects stdout/stderr, and installs a display hook"""
         # Re-direct stdout/stderr, if necessary.
         if self.no_stdout or self.no_stderr:
             blackhole = file(os.devnull, 'w')
             if self.no_stdout:
                 sys.stdout = sys.__stdout__ = blackhole
             if self.no_stderr:
                 sys.stderr = sys.__stderr__ = blackhole
 
         # Redirect input streams and set a display hook.
 
         if self.outstream_class:
             outstream_factory = import_item(str(self.outstream_class))
             sys.stdout = outstream_factory(self.session, self.iopub_socket, u'stdout')
             sys.stderr = outstream_factory(self.session, self.iopub_socket, u'stderr')
         if self.displayhook_class:
             displayhook_factory = import_item(str(self.displayhook_class))
             sys.displayhook = displayhook_factory(self.session, self.iopub_socket)
 
     def init_kernel(self):
         """Create the Kernel object itself"""
         kernel_factory = import_item(str(self.kernel_class))
         self.kernel = kernel_factory(config=self.config, session=self.session,
                                 shell_socket=self.shell_socket,
                                 iopub_socket=self.iopub_socket,
                                 stdin_socket=self.stdin_socket,
                                 log=self.log
         )
         self.kernel.record_ports(self.ports)
 
     def initialize(self, argv=None):
         super(KernelApp, self).initialize(argv)
         self.init_session()
         self.init_poller()
         self.init_sockets()
         self.init_io()
         self.init_kernel()
 
     def start(self):
         self.heartbeat.start()
         if self.poller is not None:
             self.poller.start()
         try:
             self.kernel.start()
         except KeyboardInterrupt:
             pass
+