Capture errors in user's input lines and raises meaningfull exceptions.

IPython/frontend/linefrontendbase.py

@@ -1,311 +1,320 b''
 """
 Base front end class for all line-oriented frontends, rather than
 block-oriented.
 
 Currently this focuses on synchronous frontends.
 """
 __docformat__ = "restructuredtext en"
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2008  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 re
 
 import IPython
 import sys
 import codeop
+import traceback
 
 from frontendbase import FrontEndBase
 from IPython.kernel.core.interpreter import Interpreter
 
 def common_prefix(strings):
     """ Given a list of strings, return the common prefix between all
         these strings.
     """
     ref = strings[0]
     prefix = ''
     for size in range(len(ref)):
         test_prefix = ref[:size+1]
         for string in strings[1:]:
             if not string.startswith(test_prefix):
                 return prefix
         prefix = test_prefix
 
     return prefix
 
 #-------------------------------------------------------------------------------
 # Base class for the line-oriented front ends
 #-------------------------------------------------------------------------------
 class LineFrontEndBase(FrontEndBase):
     """ Concrete implementation of the FrontEndBase class. This is meant
     to be the base class behind all the frontend that are line-oriented,
     rather than block-oriented.
     """
     
     # We need to keep the prompt number, to be able to increment
     # it when there is an exception.
     prompt_number = 1
 
     # We keep a reference to the last result: it helps testing and
     # programatic control of the frontend. 
     last_result = dict(number=0)
 
     # The input buffer being edited
     input_buffer = ''
 
     # Set to true for debug output
     debug = False
 
     # A banner to print at startup
     banner = None
 
     #--------------------------------------------------------------------------
     # FrontEndBase interface
     #--------------------------------------------------------------------------
 
     def __init__(self, shell=None, history=None, banner=None, *args, **kwargs):
         if shell is None:
             shell = Interpreter()
         FrontEndBase.__init__(self, shell=shell, history=history)
 
         if banner is not None:
             self.banner = banner
 
     def start(self):
         """ Put the frontend in a state where it is ready for user
             interaction.
         """
         if self.banner is not None:
             self.write(self.banner, refresh=False)
 
         self.new_prompt(self.input_prompt_template.substitute(number=1))
 
 
     def complete(self, line):
         """Complete line in engine's user_ns
         
         Parameters
         ----------
         line : string
         
         Result
         ------
         The replacement for the line and the list of possible completions.
         """
         completions = self.shell.complete(line)
         complete_sep =  re.compile('[\s\{\}\[\]\(\)\=]')
         if completions:
             prefix = common_prefix(completions) 
             residual = complete_sep.split(line)[:-1]
             line = line[:-len(residual)] + prefix
         return line, completions 
  
 
     def render_result(self, result):
         """ Frontend-specific rendering of the result of a calculation
         that has been sent to an engine.
         """
         if 'stdout' in result and result['stdout']:
             self.write('\n' + result['stdout'])
         if 'display' in result and result['display']:
             self.write("%s%s\n" % ( 
                             self.output_prompt_template.substitute(
                                     number=result['number']),
                             result['display']['pprint']
                             ) )
        
 
     def render_error(self, failure):
         """ Frontend-specific rendering of error. 
         """
         self.write('\n\n'+str(failure)+'\n\n')
         return failure
 
 
     def is_complete(self, string):
         """ Check if a string forms a complete, executable set of
         commands.
 
         For the line-oriented frontend, multi-line code is not executed
         as soon as it is complete: the users has to enter two line
         returns.
         """
         if string in ('', '\n'):
             # Prefiltering, eg through ipython0, may return an empty
             # string although some operations have been accomplished. We
             # thus want to consider an empty string as a complete
             # statement.
             return True
         elif ( len(self.input_buffer.split('\n'))>2 
                         and not re.findall(r"\n[\t ]*\n[\t ]*$", string)):
             return False
         else:
+            self.capture_output()
+            try:
             # Add line returns here, to make sure that the statement is
             # complete.
-            return codeop.compile_command(string.rstrip() + '\n\n',
+                is_complete = codeop.compile_command(string.rstrip() + '\n\n',
                         "<string>", "exec")
+                self.release_output()
+            except Exception, e:
+                # XXX: Hack: return True so that the
+                # code gets executed and the error captured.
+                is_complete = True
+            return is_complete
 
 
     def write(self, string, refresh=True):
         """ Write some characters to the display.
 
             Subclass should overide this method.
 
             The refresh keyword argument is used in frontends with an
             event loop, to choose whether the write should trigget an UI
             refresh, and thus be syncrhonous, or not.
         """
         print >>sys.__stderr__, string
 
 
     def execute(self, python_string, raw_string=None):
         """ Stores the raw_string in the history, and sends the
         python string to the interpreter.
         """
         if raw_string is None:
             raw_string = python_string
         # Create a false result, in case there is an exception
         self.last_result = dict(number=self.prompt_number)
         try:
             self.history.input_cache[-1] = raw_string.rstrip()
             result = self.shell.execute(python_string)
             self.last_result = result
             self.render_result(result)
         except:
             self.show_traceback()
         finally:
             self.after_execute()
 
     #--------------------------------------------------------------------------
     # LineFrontEndBase interface
     #--------------------------------------------------------------------------
 
     def prefilter_input(self, string):
         """ Prefilter the input to turn it in valid python.
         """
         string = string.replace('\r\n', '\n')
         string = string.replace('\t', 4*' ')
         # Clean the trailing whitespace
         string = '\n'.join(l.rstrip()  for l in string.split('\n'))
         return string
 
 
     def after_execute(self):
         """ All the operations required after an execution to put the
             terminal back in a shape where it is usable.
         """
         self.prompt_number += 1
         self.new_prompt(self.input_prompt_template.substitute(
                             number=(self.last_result['number'] + 1)))
         # Start a new empty history entry
         self._add_history(None, '')
         self.history_cursor = len(self.history.input_cache) - 1
 
 
     def complete_current_input(self):
         """ Do code completion on current line. 
         """
         if self.debug:
             print >>sys.__stdout__, "complete_current_input", 
         line = self.input_buffer
         new_line, completions = self.complete(line)
         if len(completions)>1:
             self.write_completion(completions, new_line=new_line)
         elif not line == new_line:
             self.input_buffer = new_line
         if self.debug:
             print >>sys.__stdout__, 'line', line
             print >>sys.__stdout__, 'new_line', new_line
             print >>sys.__stdout__, completions 
 
 
     def get_line_width(self):
         """ Return the width of the line in characters.
         """
         return 80
 
 
     def write_completion(self, possibilities, new_line=None):
         """ Write the list of possible completions.
 
             new_line is the completed input line that should be displayed
             after the completion are writen. If None, the input_buffer
             before the completion is used.
         """
         if new_line is None:
             new_line = self.input_buffer
         
         self.write('\n')
         max_len = len(max(possibilities, key=len)) + 1
         
         # Now we check how much symbol we can put on a line...
         chars_per_line = self.get_line_width()
         symbols_per_line = max(1, chars_per_line/max_len)
 
         pos = 1
         buf = []
         for symbol in possibilities:
             if pos < symbols_per_line:
                 buf.append(symbol.ljust(max_len))
                 pos += 1
             else:
                 buf.append(symbol.rstrip() + '\n')
                 pos = 1
         self.write(''.join(buf))
         self.new_prompt(self.input_prompt_template.substitute(
                             number=self.last_result['number'] + 1))
         self.input_buffer = new_line
 
 
     def new_prompt(self, prompt):
         """ Prints a prompt and starts a new editing buffer. 
 
             Subclasses should use this method to make sure that the
             terminal is put in a state favorable for a new line
             input.
         """
         self.input_buffer = ''
         self.write(prompt)
 
 
     #--------------------------------------------------------------------------
     # Private API
     #--------------------------------------------------------------------------
  
     def _on_enter(self):
         """ Called when the return key is pressed in a line editing
             buffer.
         """
         current_buffer = self.input_buffer
         cleaned_buffer = self.prefilter_input(current_buffer)
         if self.is_complete(cleaned_buffer):
             self.execute(cleaned_buffer, raw_string=current_buffer)
         else:
             self.input_buffer += self._get_indent_string(
                                                 current_buffer[:-1])
             if len(current_buffer.split('\n')) == 2:
                 self.input_buffer += '\t\t'
             if current_buffer[:-1].split('\n')[-1].rstrip().endswith(':'):
                 self.input_buffer += '\t'
 
 
     def _get_indent_string(self, string):
         """ Return the string of whitespace that prefixes a line. Used to
         add the right amount of indendation when creating a new line.
         """
         string = string.replace('\t', ' '*4)
         string = string.split('\n')[-1]
         indent_chars = len(string) - len(string.lstrip())
         indent_string = '\t'*(indent_chars // 4) + \
                             ' '*(indent_chars % 4)
 
         return indent_string
  
     

IPython/frontend/wx/wx_frontend.py

@@ -1,512 +1,523 b''
 # encoding: utf-8 -*- test-case-name:
 # FIXME: Need to add tests.
 # ipython1.frontend.wx.tests.test_wx_frontend -*-
 
 """Classes to provide a Wx frontend to the
 IPython.kernel.core.interpreter.
 
 This class inherits from ConsoleWidget, that provides a console-like
 widget to provide a text-rendering widget suitable for a terminal.
 """
 
 __docformat__ = "restructuredtext en"
 
 #-------------------------------------------------------------------------------
 #       Copyright (C) 2008  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
 #-------------------------------------------------------------------------------
 
 # Major library imports
 import re
 import __builtin__
 from time import sleep
 import sys
 from threading import Lock
 import string
 
 import wx
 from wx import stc
 
 # Ipython-specific imports.
 from IPython.frontend._process import PipedProcess
 from console_widget import ConsoleWidget
 from IPython.frontend.prefilterfrontend import PrefilterFrontEnd
 
 #-------------------------------------------------------------------------------
 # Constants 
 #-------------------------------------------------------------------------------
 
 _COMPLETE_BUFFER_BG = '#FAFAF1' # Nice green
 _INPUT_BUFFER_BG = '#FDFFD3' # Nice yellow
 _ERROR_BG = '#FFF1F1' # Nice red
 
 _COMPLETE_BUFFER_MARKER = 31
 _ERROR_MARKER = 30
 _INPUT_MARKER = 29
 
 prompt_in1 = \
         '\n\x01\x1b[0;34m\x02In [\x01\x1b[1;34m\x02$number\x01\x1b[0;34m\x02]: \x01\x1b[0m\x02'
 
 prompt_out = \
     '\x01\x1b[0;31m\x02Out[\x01\x1b[1;31m\x02$number\x01\x1b[0;31m\x02]: \x01\x1b[0m\x02'
 
 #-------------------------------------------------------------------------------
 # Classes to implement the Wx frontend
 #-------------------------------------------------------------------------------
 class WxController(ConsoleWidget, PrefilterFrontEnd):
     """Classes to provide a Wx frontend to the
     IPython.kernel.core.interpreter.
 
     This class inherits from ConsoleWidget, that provides a console-like
     widget to provide a text-rendering widget suitable for a terminal.
     """
 
     output_prompt_template = string.Template(prompt_out)
 
     input_prompt_template = string.Template(prompt_in1)
 
     # Print debug info on what is happening to the console.
     debug = False
 
     # The title of the terminal, as captured through the ANSI escape
     # sequences.
     def _set_title(self, title):
             return self.Parent.SetTitle(title)
 
     def _get_title(self):
             return self.Parent.GetTitle()
 
     title = property(_get_title, _set_title)
 
 
     # The buffer being edited.
     # We are duplicating the definition here because of multiple
     # inheritence
     def _set_input_buffer(self, string):
         ConsoleWidget._set_input_buffer(self, string)
         self._colorize_input_buffer()
 
     def _get_input_buffer(self):
         """ Returns the text in current edit buffer.
         """
         return ConsoleWidget._get_input_buffer(self)
 
     input_buffer = property(_get_input_buffer, _set_input_buffer)
 
 
     #--------------------------------------------------------------------------
     # Private Attributes
     #--------------------------------------------------------------------------
 
     # A flag governing the behavior of the input. Can be:
     #
     #       'readline' for readline-like behavior with a prompt 
     #            and an edit buffer.
     #       'raw_input' similar to readline, but triggered by a raw-input
     #           call. Can be used by subclasses to act differently.
     #       'subprocess' for sending the raw input directly to a
     #           subprocess.
     #       'buffering' for buffering of the input, that will be used
     #           when the input state switches back to another state.
     _input_state = 'readline'
 
     # Attribute to store reference to the pipes of a subprocess, if we
     # are running any.
     _running_process = False
 
     # A queue for writing fast streams to the screen without flooding the
     # event loop
     _out_buffer = []
 
     # A lock to lock the _out_buffer to make sure we don't empty it
     # while it is being swapped
     _out_buffer_lock = Lock()
 
     # The different line markers used to higlight the prompts.
     _markers = dict()
 
     #--------------------------------------------------------------------------
     # Public API
     #--------------------------------------------------------------------------
  
     def __init__(self, parent, id=wx.ID_ANY, pos=wx.DefaultPosition,
                  size=wx.DefaultSize,
                  style=wx.CLIP_CHILDREN|wx.WANTS_CHARS,
                  *args, **kwds):
         """ Create Shell instance.
         """
         ConsoleWidget.__init__(self, parent, id, pos, size, style)
         PrefilterFrontEnd.__init__(self, **kwds)
 
         # Marker for complete buffer.
         self.MarkerDefine(_COMPLETE_BUFFER_MARKER, stc.STC_MARK_BACKGROUND,
                                 background=_COMPLETE_BUFFER_BG)
         # Marker for current input buffer.
         self.MarkerDefine(_INPUT_MARKER, stc.STC_MARK_BACKGROUND,
                                 background=_INPUT_BUFFER_BG)
         # Marker for tracebacks.
         self.MarkerDefine(_ERROR_MARKER, stc.STC_MARK_BACKGROUND,
                                 background=_ERROR_BG)
 
         # A time for flushing the write buffer
         BUFFER_FLUSH_TIMER_ID = 100
         self._buffer_flush_timer = wx.Timer(self, BUFFER_FLUSH_TIMER_ID)
         wx.EVT_TIMER(self, BUFFER_FLUSH_TIMER_ID, self._buffer_flush)
 
         if 'debug' in kwds:
             self.debug = kwds['debug']
             kwds.pop('debug')
 
         # Inject self in namespace, for debug
         if self.debug:
             self.shell.user_ns['self'] = self
 
 
     def raw_input(self, prompt):
         """ A replacement from python's raw_input.
         """
         self.new_prompt(prompt)
         self._input_state = 'raw_input'
         if hasattr(self, '_cursor'):
             del self._cursor 
         self.SetCursor(wx.StockCursor(wx.CURSOR_CROSS))
         self.waiting = True
         self.__old_on_enter = self._on_enter
         def my_on_enter():
             self.waiting = False
         self._on_enter = my_on_enter
         # XXX: Busy waiting, ugly.
         while self.waiting:
             wx.Yield()
             sleep(0.1)
         self._on_enter = self.__old_on_enter
         self._input_state = 'buffering'
         self._cursor = wx.BusyCursor()
         return self.input_buffer.rstrip('\n')
 
 
     def system_call(self, command_string):
         self._input_state = 'subprocess'
         self._running_process = PipedProcess(command_string, 
                     out_callback=self.buffered_write,
                     end_callback = self._end_system_call)
         self._running_process.start()
         # XXX: another one of these polling loops to have a blocking
         # call
         wx.Yield()
         while self._running_process:
             wx.Yield()
             sleep(0.1)
         # Be sure to flush the buffer.
         self._buffer_flush(event=None)
 
 
     def do_calltip(self):
         """ Analyse current and displays useful calltip for it.
         """
         if self.debug:
             print >>sys.__stdout__, "do_calltip" 
         separators =  re.compile('[\s\{\}\[\]\(\)\= ,:]')
         symbol = self.input_buffer
         symbol_string = separators.split(symbol)[-1]
         base_symbol_string = symbol_string.split('.')[0]
         if base_symbol_string in self.shell.user_ns:
             symbol = self.shell.user_ns[base_symbol_string]
         elif base_symbol_string in self.shell.user_global_ns:
             symbol = self.shell.user_global_ns[base_symbol_string]
         elif base_symbol_string in __builtin__.__dict__:
             symbol = __builtin__.__dict__[base_symbol_string]
         else:
             return False
         try:
             for name in symbol_string.split('.')[1:] + ['__doc__']:
                 symbol = getattr(symbol, name)
             self.AutoCompCancel()
             wx.Yield()
             self.CallTipShow(self.GetCurrentPos(), symbol)
         except:
             # The retrieve symbol couldn't be converted to a string
             pass
 
 
     def _popup_completion(self, create=False):
         """ Updates the popup completion menu if it exists. If create is 
             true, open the menu.
         """
         if self.debug:
             print >>sys.__stdout__, "_popup_completion" 
         line = self.input_buffer
         if (self.AutoCompActive() and line and not line[-1] == '.') \
                     or create==True:
             suggestion, completions = self.complete(line)
             offset=0
             if completions:
                 complete_sep =  re.compile('[\s\{\}\[\]\(\)\= ,:]')
                 residual = complete_sep.split(line)[-1]
                 offset = len(residual)
                 self.pop_completion(completions, offset=offset)
                 if self.debug:
                     print >>sys.__stdout__, completions 
 
 
     def buffered_write(self, text):
         """ A write method for streams, that caches the stream in order
             to avoid flooding the event loop.
 
             This can be called outside of the main loop, in separate
             threads.
         """
         self._out_buffer_lock.acquire()
         self._out_buffer.append(text)
         self._out_buffer_lock.release()
         if not self._buffer_flush_timer.IsRunning():
             wx.CallAfter(self._buffer_flush_timer.Start, 
                                         milliseconds=100, oneShot=True)
 
 
     #--------------------------------------------------------------------------
     # LineFrontEnd interface 
     #--------------------------------------------------------------------------
  
     def execute(self, python_string, raw_string=None):
         self._input_state = 'buffering'
         self.CallTipCancel()
         self._cursor = wx.BusyCursor()
         if raw_string is None:
             raw_string = python_string
         end_line = self.current_prompt_line \
                         + max(1,  len(raw_string.split('\n'))-1)
         for i in range(self.current_prompt_line, end_line):
             if i in self._markers:
                 self.MarkerDeleteHandle(self._markers[i])
             self._markers[i] = self.MarkerAdd(i, _COMPLETE_BUFFER_MARKER)
         # Update the display:
         wx.Yield()
         self.GotoPos(self.GetLength())
         PrefilterFrontEnd.execute(self, python_string, raw_string=raw_string)
 
     def save_output_hooks(self):    
         self.__old_raw_input = __builtin__.raw_input
         PrefilterFrontEnd.save_output_hooks(self)
 
     def capture_output(self):
         __builtin__.raw_input = self.raw_input
         self.SetLexer(stc.STC_LEX_NULL)
         PrefilterFrontEnd.capture_output(self)
         
     
     def release_output(self):
         __builtin__.raw_input = self.__old_raw_input
         PrefilterFrontEnd.release_output(self)
         self.SetLexer(stc.STC_LEX_PYTHON)
 
 
     def after_execute(self):
         PrefilterFrontEnd.after_execute(self)
         # Clear the wait cursor
         if hasattr(self, '_cursor'):
             del self._cursor
         self.SetCursor(wx.StockCursor(wx.CURSOR_CHAR))
 
 
     def show_traceback(self):
         start_line = self.GetCurrentLine()
         PrefilterFrontEnd.show_traceback(self)
         wx.Yield()
         for i in range(start_line, self.GetCurrentLine()):
             self._markers[i] = self.MarkerAdd(i, _ERROR_MARKER)
 
     
     #--------------------------------------------------------------------------
+    # FrontEndBase interface 
+    #--------------------------------------------------------------------------
+    
+    def render_error(self, e):
+        start_line = self.GetCurrentLine()
+        self.write('\n' + e + '\n')
+        for i in range(start_line, self.GetCurrentLine()):
+            self._markers[i] = self.MarkerAdd(i, _ERROR_MARKER)
+
+
+    #--------------------------------------------------------------------------
     # ConsoleWidget interface 
     #--------------------------------------------------------------------------
 
     def new_prompt(self, prompt):
         """ Display a new prompt, and start a new input buffer.
         """
         self._input_state = 'readline'
         ConsoleWidget.new_prompt(self, prompt)
         i = self.current_prompt_line
         self._markers[i] = self.MarkerAdd(i, _INPUT_MARKER)
 
 
     def write(self, *args, **kwargs):
         # Avoid multiple inheritence, be explicit about which
         # parent method class gets called
         ConsoleWidget.write(self, *args, **kwargs)
 
 
     def _on_key_down(self, event, skip=True):
         """ Capture the character events, let the parent
             widget handle them, and put our logic afterward.
         """
         # FIXME: This method needs to be broken down in smaller ones.
         current_line_number = self.GetCurrentLine()
         if event.KeyCode in (ord('c'), ord('C')) and event.ControlDown():
             # Capture Control-C
             if self._input_state == 'subprocess':
                 if self.debug:
                     print >>sys.__stderr__, 'Killing running process'
                 self._running_process.process.kill()
             elif self._input_state == 'buffering':
                 if self.debug:
                     print >>sys.__stderr__, 'Raising KeyboardInterrupt'
                 raise KeyboardInterrupt
                 # XXX: We need to make really sure we
                 # get back to a prompt.
         elif self._input_state == 'subprocess' and (
                 ( event.KeyCode<256 and
                         not event.ControlDown() )
                     or 
                 ( event.KeyCode in (ord('d'), ord('D')) and
                   event.ControlDown())):
             #  We are running a process, we redirect keys.
             ConsoleWidget._on_key_down(self, event, skip=skip)
             char = chr(event.KeyCode)
             # Deal with some inconsistency in wx keycodes:
             if char == '\r':
                 char = '\n'
             elif not event.ShiftDown():
                 char = char.lower()
             if event.ControlDown() and event.KeyCode in (ord('d'), ord('D')):
                 char = '\04'
             self._running_process.process.stdin.write(char)
             self._running_process.process.stdin.flush()
         elif event.KeyCode in (ord('('), 57):
             # Calltips
             event.Skip()
             self.do_calltip()
         elif self.AutoCompActive() and not event.KeyCode == ord('\t'):
             event.Skip()
             if event.KeyCode in (wx.WXK_BACK, wx.WXK_DELETE): 
                 wx.CallAfter(self._popup_completion, create=True)
             elif not event.KeyCode in (wx.WXK_UP, wx.WXK_DOWN, wx.WXK_LEFT,
                             wx.WXK_RIGHT, wx.WXK_ESCAPE):
                 wx.CallAfter(self._popup_completion)
         else:
             # Up history
             if event.KeyCode == wx.WXK_UP and (
                     ( current_line_number == self.current_prompt_line and
                         event.Modifiers in (wx.MOD_NONE, wx.MOD_WIN) ) 
                     or event.ControlDown() ):
                 new_buffer = self.get_history_previous(
                                             self.input_buffer)
                 if new_buffer is not None:
                     self.input_buffer = new_buffer
                     if self.GetCurrentLine() > self.current_prompt_line:
                         # Go to first line, for seemless history up.
                         self.GotoPos(self.current_prompt_pos)
             # Down history
             elif event.KeyCode == wx.WXK_DOWN and (
                     ( current_line_number == self.LineCount -1 and
                         event.Modifiers in (wx.MOD_NONE, wx.MOD_WIN) ) 
                     or event.ControlDown() ):
                 new_buffer = self.get_history_next()
                 if new_buffer is not None:
                     self.input_buffer = new_buffer
             # Tab-completion
             elif event.KeyCode == ord('\t'):
                 last_line = self.input_buffer.split('\n')[-1]
                 if not re.match(r'^\s*$', last_line):
                     self.complete_current_input()
                     if self.AutoCompActive():
                         wx.CallAfter(self._popup_completion, create=True)
                 else:
                     event.Skip()
             else:
                 ConsoleWidget._on_key_down(self, event, skip=skip)
 
 
     def _on_key_up(self, event, skip=True):
         """ Called when any key is released.
         """
         if event.KeyCode in (59, ord('.')):
             # Intercepting '.'
             event.Skip()
             wx.CallAfter(self._popup_completion, create=True)
         else:
             ConsoleWidget._on_key_up(self, event, skip=skip)
 
 
     def _on_enter(self):
         """ Called on return key down, in readline input_state.
         """
         if self.debug:
             print >>sys.__stdout__, repr(self.input_buffer)
         PrefilterFrontEnd._on_enter(self)
 
 
     #--------------------------------------------------------------------------
     # EditWindow API
     #--------------------------------------------------------------------------
 
     def OnUpdateUI(self, event):
         """ Override the OnUpdateUI of the EditWindow class, to prevent 
             syntax highlighting both for faster redraw, and for more
             consistent look and feel.
         """
         if not self._input_state == 'readline':
             ConsoleWidget.OnUpdateUI(self, event)
 
     #--------------------------------------------------------------------------
     # Private API
     #--------------------------------------------------------------------------
  
     def _end_system_call(self):
         """ Called at the end of a system call.
         """
         self._input_state = 'buffering'
         self._running_process = False
 
 
     def _buffer_flush(self, event):
         """ Called by the timer to flush the write buffer.
             
             This is always called in the mainloop, by the wx timer.
         """
         self._out_buffer_lock.acquire()
         _out_buffer = self._out_buffer
         self._out_buffer = []
         self._out_buffer_lock.release()
         self.write(''.join(_out_buffer), refresh=False)
 
 
     def _colorize_input_buffer(self):
         """ Keep the input buffer lines at a bright color.
         """
         if not self._input_state in ('readline', 'raw_input'):
             return
         end_line = self.GetCurrentLine()
         if not sys.platform == 'win32':
             end_line += 1
         for i in range(self.current_prompt_line, end_line):
             if i in self._markers:
                 self.MarkerDeleteHandle(self._markers[i])
             self._markers[i] = self.MarkerAdd(i, _INPUT_MARKER)
 
 
 if __name__ == '__main__':
     class MainWindow(wx.Frame):
         def __init__(self, parent, id, title):
             wx.Frame.__init__(self, parent, id, title, size=(300,250))
             self._sizer = wx.BoxSizer(wx.VERTICAL)
             self.shell = WxController(self)
             self._sizer.Add(self.shell, 1, wx.EXPAND)
             self.SetSizer(self._sizer)
             self.SetAutoLayout(1)
             self.Show(True)
 
     app = wx.PySimpleApp()
     frame = MainWindow(None, wx.ID_ANY, 'Ipython')
     frame.shell.SetFocus()
     frame.SetSize((680, 460))
     self = frame.shell
 
     app.MainLoop()