Paved the way for PySide support.

Created a Qt API switcher that imports PyQt4 or PySide as appropriate. If PyQt4 is loaded, the new-style QString API is used. This facillates both Python 3 and PySide compatibility.

IPython/external/qt.py

@@ -0,0 +1,22 b''
+""" A Qt API selector that can be used to switch between PyQt and PySide.
+"""
+
+import os
+
+# Use PyQt by default until PySide is stable.
+qt_api = os.environ.get('QT_API', 'pyqt')
+
+if qt_api == 'pyqt':
+    # For PySide compatibility, use the new string API that automatically
+    # converts QStrings to unicode Python strings.
+    import sip
+    sip.setapi('QString', 2)
+
+    from PyQt4 import QtCore, QtGui, QtSvg
+
+    # Alias PyQt-specific functions for PySide compatibility.
+    QtCore.Signal = QtCore.pyqtSignal
+    QtCore.Slot = QtCore.pyqtSlot
+
+else:
+    from PySide import QtCore, QtGui, QtSvg

IPython/frontend/qt/console/ansi_code_processor.py

@@ -1,233 +1,233 b''
 """ Utilities for processing ANSI escape codes and special ASCII characters.
 """
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports
 from collections import namedtuple
 import re
 
 # System library imports
-from PyQt4 import QtCore, QtGui
+from IPython.external.qt import QtCore, QtGui
 
 #-----------------------------------------------------------------------------
 # Constants and datatypes
 #-----------------------------------------------------------------------------
 
 # An action for erase requests (ED and EL commands).
 EraseAction = namedtuple('EraseAction', ['action', 'area', 'erase_to'])
 
 # An action for cursor move requests (CUU, CUD, CUF, CUB, CNL, CPL, CHA, CUP,
 # and HVP commands).
 # FIXME: Not implemented in AnsiCodeProcessor.
 MoveAction = namedtuple('MoveAction', ['action', 'dir', 'unit', 'count'])
 
 # An action for scroll requests (SU and ST) and form feeds.
 ScrollAction = namedtuple('ScrollAction', ['action', 'dir', 'unit', 'count'])
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class AnsiCodeProcessor(object):
     """ Translates special ASCII characters and ANSI escape codes into readable
         attributes.
     """
 
     # Whether to increase intensity or set boldness for SGR code 1.
     # (Different terminals handle this in different ways.)
     bold_text_enabled = False    
 
     # Protected class variables.
     _ansi_commands = 'ABCDEFGHJKSTfmnsu'
     _ansi_pattern = re.compile('\x01?\x1b\[(.*?)([%s])\x02?' % _ansi_commands)
     _special_pattern = re.compile('([\f])')
 
     #---------------------------------------------------------------------------
     # AnsiCodeProcessor interface
     #---------------------------------------------------------------------------
 
     def __init__(self):
         self.actions = []
         self.reset_sgr()
 
     def reset_sgr(self):
         """ Reset graphics attributs to their default values.
         """
         self.intensity = 0
         self.italic = False
         self.bold = False
         self.underline = False
         self.foreground_color = None
         self.background_color = None
 
     def split_string(self, string):
         """ Yields substrings for which the same escape code applies.
         """
         self.actions = []
         start = 0
 
         for match in self._ansi_pattern.finditer(string):
             raw = string[start:match.start()]
             substring = self._special_pattern.sub(self._replace_special, raw)
             if substring or self.actions:
                 yield substring
             start = match.end()
 
             self.actions = []
             try:
                 params = []
                 for param in match.group(1).split(';'):
                     if param:
                         params.append(int(param))
             except ValueError:
                 # Silently discard badly formed escape codes.
                 pass
             else:
                 self.set_csi_code(match.group(2), params)
 
         raw = string[start:]
         substring = self._special_pattern.sub(self._replace_special, raw)
         if substring or self.actions:
             yield substring
 
     def set_csi_code(self, command, params=[]):
         """ Set attributes based on CSI (Control Sequence Introducer) code.
 
         Parameters
         ----------
         command : str
             The code identifier, i.e. the final character in the sequence.
         
         params : sequence of integers, optional
             The parameter codes for the command.
         """
         if command == 'm':   # SGR - Select Graphic Rendition
             if params:
                 for code in params:
                     self.set_sgr_code(code)
             else:
                 self.set_sgr_code(0)
 
         elif (command == 'J' or # ED - Erase Data
               command == 'K'):  # EL - Erase in Line
             code = params[0] if params else 0
             if 0 <= code <= 2:
                 area = 'screen' if command == 'J' else 'line'
                 if code == 0:
                     erase_to = 'end'
                 elif code == 1:
                     erase_to = 'start'
                 elif code == 2:
                     erase_to = 'all'
                 self.actions.append(EraseAction('erase', area, erase_to))
 
         elif (command == 'S' or # SU - Scroll Up
               command == 'T'):  # SD - Scroll Down
             dir = 'up' if command == 'S' else 'down'
             count = params[0] if params else 1
             self.actions.append(ScrollAction('scroll', dir, 'line', count))
         
     def set_sgr_code(self, code):
         """ Set attributes based on SGR (Select Graphic Rendition) code.
         """
         if code == 0:
             self.reset_sgr()
         elif code == 1:
             if self.bold_text_enabled:
                 self.bold = True
             else:
                 self.intensity = 1
         elif code == 2:
             self.intensity = 0
         elif code == 3:
             self.italic = True
         elif code == 4:
             self.underline = True
         elif code == 22:
             self.intensity = 0
             self.bold = False
         elif code == 23:
             self.italic = False
         elif code == 24:
             self.underline = False
         elif code >= 30 and code <= 37:
             self.foreground_color = code - 30
         elif code == 39:
             self.foreground_color = None
         elif code >= 40 and code <= 47:
             self.background_color = code - 40
         elif code == 49:
             self.background_color = None
 
     #---------------------------------------------------------------------------
     # Protected interface
     #---------------------------------------------------------------------------
 
     def _replace_special(self, match):
         special = match.group(1)
         if special == '\f':
             self.actions.append(ScrollAction('scroll', 'down', 'page', 1))
         return ''
         
 
 class QtAnsiCodeProcessor(AnsiCodeProcessor):
     """ Translates ANSI escape codes into QTextCharFormats.
     """
 
     # A map from color codes to RGB colors.
     default_map = (# Normal,      Bright/Light    ANSI color code
                    ('black',      'grey'),        # 0: black
                    ('darkred',    'red'),         # 1: red
                    ('darkgreen',  'lime'),        # 2: green
                    ('brown',      'yellow'),      # 3: yellow
                    ('darkblue',   'deepskyblue'), # 4: blue
                    ('darkviolet', 'magenta'),     # 5: magenta
                    ('steelblue',  'cyan'),        # 6: cyan
                    ('grey',       'white'))       # 7: white
 
     def __init__(self):
         super(QtAnsiCodeProcessor, self).__init__()
         self.color_map = self.default_map
     
     def get_format(self):
         """ Returns a QTextCharFormat that encodes the current style attributes.
         """
         format = QtGui.QTextCharFormat()
 
         # Set foreground color
         if self.foreground_color is not None:
             color = self.color_map[self.foreground_color][self.intensity]
             format.setForeground(QtGui.QColor(color))
 
         # Set background color
         if self.background_color is not None:
             color = self.color_map[self.background_color][self.intensity]
             format.setBackground(QtGui.QColor(color))
 
         # Set font weight/style options
         if self.bold:
             format.setFontWeight(QtGui.QFont.Bold)
         else:
             format.setFontWeight(QtGui.QFont.Normal)
         format.setFontItalic(self.italic)
         format.setFontUnderline(self.underline)
 
         return format
 
     def set_background_color(self, color):
         """ Given a background color (a QColor), attempt to set a color map
             that will be aesthetically pleasing.
         """
         if color.value() < 127:
             # Colors appropriate for a terminal with a dark background.
             self.color_map = self.default_map
 
         else:
             # Colors appropriate for a terminal with a light background. For 
             # now, only use non-bright colors...
             self.color_map = [ (pair[0], pair[0]) for pair in self.default_map ]
 
             # ...and replace white with black.
             self.color_map[7] = ('black', 'black')

IPython/frontend/qt/console/bracket_matcher.py

@@ -1,101 +1,100 b''
 """ Provides bracket matching for Q[Plain]TextEdit widgets.
 """
 
 # System library imports
-from PyQt4 import QtCore, QtGui
+from IPython.external.qt import QtCore, QtGui
 
 
 class BracketMatcher(QtCore.QObject):
     """ Matches square brackets, braces, and parentheses based on cursor
         position.
     """
     
     # Protected class variables.
     _opening_map = { '(':')', '{':'}', '[':']' }
     _closing_map = { ')':'(', '}':'{', ']':'[' }
 
     #--------------------------------------------------------------------------
     # 'QObject' interface
     #--------------------------------------------------------------------------
 
     def __init__(self, text_edit):
         """ Create a call tip manager that is attached to the specified Qt
             text edit widget.
         """
         assert isinstance(text_edit, (QtGui.QTextEdit, QtGui.QPlainTextEdit))
         super(BracketMatcher, self).__init__()
 
         # The format to apply to matching brackets.
         self.format = QtGui.QTextCharFormat()
         self.format.setBackground(QtGui.QColor('silver'))
 
         self._text_edit = text_edit
         text_edit.cursorPositionChanged.connect(self._cursor_position_changed)
 
     #--------------------------------------------------------------------------
     # Protected interface
     #--------------------------------------------------------------------------
 
     def _find_match(self, position):
         """ Given a valid position in the text document, try to find the
             position of the matching bracket. Returns -1 if unsuccessful.
         """
         # Decide what character to search for and what direction to search in.
         document = self._text_edit.document()
-        qchar = document.characterAt(position)
-        start_char = qchar.toAscii()
+        start_char = document.characterAt(position)
         search_char = self._opening_map.get(start_char)
         if search_char:
             increment = 1
         else:
             search_char = self._closing_map.get(start_char)
             if search_char:
                 increment = -1
             else:
                 return -1
 
         # Search for the character.
+        char = start_char
         depth = 0
         while position >= 0 and position < document.characterCount():
-            char = qchar.toAscii()
             if char == start_char:
                 depth += 1
             elif char == search_char:
                 depth -= 1
             if depth == 0:
                 break
             position += increment
-            qchar = document.characterAt(position)
+            char = document.characterAt(position)
         else:
             position = -1
         return position
 
     def _selection_for_character(self, position):
         """ Convenience method for selecting a character.
         """
         selection = QtGui.QTextEdit.ExtraSelection()
         cursor = self._text_edit.textCursor()
         cursor.setPosition(position)
         cursor.movePosition(QtGui.QTextCursor.NextCharacter, 
                             QtGui.QTextCursor.KeepAnchor)
         selection.cursor = cursor
         selection.format = self.format
         return selection
 
     #------ Signal handlers ----------------------------------------------------
 
     def _cursor_position_changed(self):
         """ Updates the document formatting based on the new cursor position.
         """
         # Clear out the old formatting.
         self._text_edit.setExtraSelections([])
 
         # Attempt to match a bracket for the new cursor position.
         cursor = self._text_edit.textCursor()
         if not cursor.hasSelection():
             position = cursor.position() - 1
             match_position = self._find_match(position)
             if match_position != -1:
                 extra_selections = [ self._selection_for_character(pos)
                                      for pos in (position, match_position) ]
                 self._text_edit.setExtraSelections(extra_selections)

IPython/frontend/qt/console/call_tip_widget.py

@@ -1,225 +1,225 b''
 # Standard library imports
 import re
 from textwrap import dedent
+from unicodedata import category
 
 # System library imports
-from PyQt4 import QtCore, QtGui
+from IPython.external.qt import QtCore, QtGui
 
 
 class CallTipWidget(QtGui.QLabel):
     """ Shows call tips by parsing the current text of Q[Plain]TextEdit.
     """
 
     #--------------------------------------------------------------------------
     # 'QObject' interface
     #--------------------------------------------------------------------------
 
     def __init__(self, text_edit):
         """ Create a call tip manager that is attached to the specified Qt
             text edit widget.
         """
         assert isinstance(text_edit, (QtGui.QTextEdit, QtGui.QPlainTextEdit))
         super(CallTipWidget, self).__init__(None, QtCore.Qt.ToolTip)
 
         self._hide_timer = QtCore.QBasicTimer()
         self._text_edit = text_edit
 
         self.setFont(text_edit.document().defaultFont())
         self.setForegroundRole(QtGui.QPalette.ToolTipText)
         self.setBackgroundRole(QtGui.QPalette.ToolTipBase)
         self.setPalette(QtGui.QToolTip.palette())
 
         self.setAlignment(QtCore.Qt.AlignLeft)
         self.setIndent(1)
         self.setFrameStyle(QtGui.QFrame.NoFrame)
         self.setMargin(1 + self.style().pixelMetric(
                 QtGui.QStyle.PM_ToolTipLabelFrameWidth, None, self))
         self.setWindowOpacity(self.style().styleHint(
                 QtGui.QStyle.SH_ToolTipLabel_Opacity, None, self) / 255.0)
 
     def eventFilter(self, obj, event):
         """ Reimplemented to hide on certain key presses and on text edit focus
             changes.
         """
         if obj == self._text_edit:
             etype = event.type()
 
             if etype == QtCore.QEvent.KeyPress:
                 key = event.key()
                 if key in (QtCore.Qt.Key_Enter, QtCore.Qt.Key_Return):
                     self.hide()
                 elif key == QtCore.Qt.Key_Escape:
                     self.hide()
                     return True
 
             elif etype == QtCore.QEvent.FocusOut:
                 self.hide()
 
             elif etype == QtCore.QEvent.Enter:
                 self._hide_timer.stop()
 
             elif etype == QtCore.QEvent.Leave:
                 self._hide_later()
 
         return super(CallTipWidget, self).eventFilter(obj, event)
 
     def timerEvent(self, event):
         """ Reimplemented to hide the widget when the hide timer fires.
         """
         if event.timerId() == self._hide_timer.timerId():
             self._hide_timer.stop()
             self.hide()
 
     #--------------------------------------------------------------------------
     # 'QWidget' interface
     #--------------------------------------------------------------------------
 
     def enterEvent(self, event):
         """ Reimplemented to cancel the hide timer.
         """
         super(CallTipWidget, self).enterEvent(event)
         self._hide_timer.stop()
 
     def hideEvent(self, event):
         """ Reimplemented to disconnect signal handlers and event filter.
         """
         super(CallTipWidget, self).hideEvent(event)
         self._text_edit.cursorPositionChanged.disconnect(
             self._cursor_position_changed)
         self._text_edit.removeEventFilter(self)
 
     def leaveEvent(self, event):
         """ Reimplemented to start the hide timer.
         """
         super(CallTipWidget, self).leaveEvent(event)
         self._hide_later()
 
     def paintEvent(self, event):
         """ Reimplemented to paint the background panel.
         """
         painter = QtGui.QStylePainter(self)
         option = QtGui.QStyleOptionFrame()
         option.init(self)
         painter.drawPrimitive(QtGui.QStyle.PE_PanelTipLabel, option)
         painter.end()
 
         super(CallTipWidget, self).paintEvent(event)
 
     def setFont(self, font):
         """ Reimplemented to allow use of this method as a slot.
         """
         super(CallTipWidget, self).setFont(font)
 
     def showEvent(self, event):
         """ Reimplemented to connect signal handlers and event filter.
         """
         super(CallTipWidget, self).showEvent(event)
         self._text_edit.cursorPositionChanged.connect(
             self._cursor_position_changed)
         self._text_edit.installEventFilter(self)
 
     #--------------------------------------------------------------------------
     # 'CallTipWidget' interface
     #--------------------------------------------------------------------------
 
     def show_call_info(self, call_line=None, doc=None, maxlines=20):
         """ Attempts to show the specified call line and docstring at the
             current cursor location. The docstring is possibly truncated for
             length.
         """
         if doc:
             match = re.match("(?:[^\n]*\n){%i}" % maxlines, doc)
             if match:
                 doc = doc[:match.end()] + '\n[Documentation continues...]'
         else:
             doc = ''
             
         if call_line:
             doc = '\n\n'.join([call_line, doc])
         return self.show_tip(doc)
 
     def show_tip(self, tip):
         """ Attempts to show the specified tip at the current cursor location.
         """
         # Attempt to find the cursor position at which to show the call tip.
         text_edit = self._text_edit
         document = text_edit.document()
         cursor = text_edit.textCursor()
         search_pos = cursor.position() - 1
         self._start_position, _ = self._find_parenthesis(search_pos, 
                                                          forward=False)
         if self._start_position == -1:
             return False
 
         # Set the text and resize the widget accordingly.
         self.setText(tip)
         self.resize(self.sizeHint())
     
         # Locate and show the widget. Place the tip below the current line
         # unless it would be off the screen. In that case, place it above
         # the current line.
         padding = 3 # Distance in pixels between cursor bounds and tip box.
         cursor_rect = text_edit.cursorRect(cursor)
         screen_rect = QtGui.qApp.desktop().screenGeometry(text_edit)
         point = text_edit.mapToGlobal(cursor_rect.bottomRight())
         point.setY(point.y() + padding)
         tip_height = self.size().height()
         if point.y() + tip_height > screen_rect.height():
             point = text_edit.mapToGlobal(cursor_rect.topRight())
             point.setY(point.y() - tip_height - padding)
         self.move(point)
         self.show()
         return True
             
     #--------------------------------------------------------------------------
     # Protected interface
     #--------------------------------------------------------------------------
 
     def _find_parenthesis(self, position, forward=True):
         """ If 'forward' is True (resp. False), proceed forwards
             (resp. backwards) through the line that contains 'position' until an
             unmatched closing (resp. opening) parenthesis is found. Returns a
             tuple containing the position of this parenthesis (or -1 if it is
             not found) and the number commas (at depth 0) found along the way.
         """
         commas = depth = 0
         document = self._text_edit.document()
-        qchar = document.characterAt(position)
-        while (position > 0 and qchar.isPrint() and 
-               # Need to check explicitly for line/paragraph separators:
-               qchar.unicode() not in (0x2028, 0x2029)):
-            char = qchar.toAscii()
+        char = document.characterAt(position)
+        # Search until a match is found or a non-printable character is
+        # encountered.
+        while category(char) != 'Cc' and position > 0:
             if char == ',' and depth == 0:
                 commas += 1
             elif char == ')':
                 if forward and depth == 0:
                     break
                 depth += 1
             elif char == '(':
                 if not forward and depth == 0:
                     break
                 depth -= 1
             position += 1 if forward else -1
-            qchar = document.characterAt(position)
+            char = document.characterAt(position)
         else:
             position = -1
         return position, commas
 
     def _hide_later(self):
         """ Hides the tooltip after some time has passed.
         """
         if not self._hide_timer.isActive():
             self._hide_timer.start(300, self)
 
     #------ Signal handlers ----------------------------------------------------
 
     def _cursor_position_changed(self):
         """ Updates the tip based on user cursor movement.
         """
         cursor = self._text_edit.textCursor()
         if cursor.position() <= self._start_position:
             self.hide()
         else:
             position, commas = self._find_parenthesis(self._start_position + 1)
             if position != -1:
                 self.hide()

IPython/frontend/qt/console/completion_widget.py

@@ -1,133 +1,133 b''
 # System library imports
-from PyQt4 import QtCore, QtGui
+from IPython.external.qt import QtCore, QtGui
 
 
 class CompletionWidget(QtGui.QListWidget):
     """ A widget for GUI tab completion.
     """
 
     #--------------------------------------------------------------------------
     # 'QObject' interface
     #--------------------------------------------------------------------------
 
     def __init__(self, text_edit):
         """ Create a completion widget that is attached to the specified Qt
             text edit widget.
         """
         assert isinstance(text_edit, (QtGui.QTextEdit, QtGui.QPlainTextEdit))
         super(CompletionWidget, self).__init__()
 
         self._text_edit = text_edit
 
         self.setAttribute(QtCore.Qt.WA_StaticContents)
         self.setWindowFlags(QtCore.Qt.ToolTip | QtCore.Qt.WindowStaysOnTopHint)
 
         # Ensure that the text edit keeps focus when widget is displayed.
         self.setFocusProxy(self._text_edit)
 
         self.setFrameShadow(QtGui.QFrame.Plain)
         self.setFrameShape(QtGui.QFrame.StyledPanel)
 
         self.itemActivated.connect(self._complete_current)
 
     def eventFilter(self, obj, event):
         """ Reimplemented to handle keyboard input and to auto-hide when the
             text edit loses focus.
         """
         if obj == self._text_edit:
             etype = event.type()
 
             if etype == QtCore.QEvent.KeyPress:
                 key, text = event.key(), event.text()
                 if key in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter, 
                            QtCore.Qt.Key_Tab):
                     self._complete_current()
                     return True
                 elif key == QtCore.Qt.Key_Escape:
                     self.hide()
                     return True
                 elif key in (QtCore.Qt.Key_Up, QtCore.Qt.Key_Down, 
                              QtCore.Qt.Key_PageUp, QtCore.Qt.Key_PageDown, 
                              QtCore.Qt.Key_Home, QtCore.Qt.Key_End):
                     self.keyPressEvent(event)
                     return True
 
             elif etype == QtCore.QEvent.FocusOut:
                 self.hide()
 
         return super(CompletionWidget, self).eventFilter(obj, event)
 
     #--------------------------------------------------------------------------
     # 'QWidget' interface
     #--------------------------------------------------------------------------
 
     def hideEvent(self, event):
         """ Reimplemented to disconnect signal handlers and event filter.
         """
         super(CompletionWidget, self).hideEvent(event)
         self._text_edit.cursorPositionChanged.disconnect(self._update_current)
         self._text_edit.removeEventFilter(self)
 
     def showEvent(self, event):
         """ Reimplemented to connect signal handlers and event filter.
         """
         super(CompletionWidget, self).showEvent(event)
         self._text_edit.cursorPositionChanged.connect(self._update_current)
         self._text_edit.installEventFilter(self)
 
     #--------------------------------------------------------------------------
     # 'CompletionWidget' interface
     #--------------------------------------------------------------------------
 
     def show_items(self, cursor, items):
         """ Shows the completion widget with 'items' at the position specified
             by 'cursor'.
         """
         text_edit = self._text_edit
         point = text_edit.cursorRect(cursor).bottomRight()
         point = text_edit.mapToGlobal(point)
         screen_rect = QtGui.QApplication.desktop().availableGeometry(self)
         if screen_rect.size().height() - point.y() - self.height() < 0:
             point = text_edit.mapToGlobal(text_edit.cursorRect().topRight())
             point.setY(point.y() - self.height())
         self.move(point)
 
         self._start_position = cursor.position()
         self.clear()
         self.addItems(items)
         self.setCurrentRow(0)
         self.show()
 
     #--------------------------------------------------------------------------
     # Protected interface
     #--------------------------------------------------------------------------
 
     def _complete_current(self):
         """ Perform the completion with the currently selected item.
         """
         self._current_text_cursor().insertText(self.currentItem().text())
         self.hide()
 
     def _current_text_cursor(self):
         """ Returns a cursor with text between the start position and the
             current position selected.
         """
         cursor = self._text_edit.textCursor()
         if cursor.position() >= self._start_position:
             cursor.setPosition(self._start_position, 
                                QtGui.QTextCursor.KeepAnchor)
         return cursor
         
     def _update_current(self):
         """ Updates the current item based on the current text.
         """
         prefix = self._current_text_cursor().selection().toPlainText()
         if prefix:
             items = self.findItems(prefix, (QtCore.Qt.MatchStartsWith | 
                                             QtCore.Qt.MatchCaseSensitive))
             if items:
                 self.setCurrentItem(items[0])
             else:
                 self.hide()
         else:
             self.hide()

IPython/frontend/qt/console/console_widget.py

@@ -1,1895 +1,1906 b''
 """ An abstract base class for console-type widgets.
 """
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports
+import os
 from os.path import commonprefix
 import re
-import os
 import sys
 from textwrap import dedent
+from unicodedata import category
 
 # System library imports
-from PyQt4 import QtCore, QtGui
+from IPython.external.qt import QtCore, QtGui
 
 # Local imports
 from IPython.config.configurable import Configurable
 from IPython.frontend.qt.util import MetaQObjectHasTraits, get_font
 from IPython.utils.traitlets import Bool, Enum, Int
 from ansi_code_processor import QtAnsiCodeProcessor
 from completion_widget import CompletionWidget
 
 #-----------------------------------------------------------------------------
+# 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 ------------------------------------------------------
 
     # Whether to process ANSI escape codes.
     ansi_codes = Bool(True, config=True)
 
     # The maximum number of lines of text before truncation. Specifying a
     # non-positive number disables text truncation (not recommended).
     buffer_size = Int(500, config=True)
 
     # Whether to use a list widget or plain text output for tab completion.
     gui_completion = Bool(False, config=True)
 
     # 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.
     kind = Enum(['plain', 'rich'], default_value='plain', config=True)
 
     # 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.
     #     '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.
     #     'none'   : The text is written directly to the console.
     # NOTE: this value can only be specified during initialization.
     paging = Enum(['inside', 'hsplit', 'vsplit', 'custom', 'none'], 
                   default_value='inside', config=True)
 
     # 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.pyqtSignal(bool)
-    redo_available = QtCore.pyqtSignal(bool)
-    undo_available = QtCore.pyqtSignal(bool)
+    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.pyqtSignal(object)
+    custom_page_requested = QtCore.Signal(object)
 
     # Signal emitted when the font is changed.
-    font_changed = QtCore.pyqtSignal(QtGui.QFont)
+    font_changed = QtCore.Signal(QtGui.QFont)
 
     #------ Protected class variables ------------------------------------------
 
     _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_E : QtCore.Qt.Key_End,
                          QtCore.Qt.Key_P : QtCore.Qt.Key_Up,
                          QtCore.Qt.Key_N : QtCore.Qt.Key_Down,
                          QtCore.Qt.Key_D : QtCore.Qt.Key_Delete, }
 
     _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._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
         self._filename = 'ipython.html'
         self._png_mode=None
 
         # 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 if there is a collision
             # Qt ctrl = cmd on OSX, so the match gets a false positive on darwin
             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.setEnabled(self.can_export())
         action.setShortcut(QtGui.QKeySequence.Save)
         action.triggered.connect(self.export)
         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 = unicode(event.mimeData().text())
+                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 not QtGui.QApplication.clipboard().text().isEmpty()
+            return bool(QtGui.QApplication.clipboard().text())
         return False
 
     def can_export(self):
         """Returns whether we can export. Currently only rich widgets
         can export html.
         """
         return self.kind == "rich"
 
     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._executing_input_buffer = 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 _get_input_buffer(self):
         """ The text that the user has entered entered at the current prompt.
         """
         # 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._executing_input_buffer
 
         cursor = self._get_end_cursor()
         cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
-        input_buffer = unicode(cursor.selection().toPlainText())
+        input_buffer = cursor.selection().toPlainText()
 
         # Strip out continuation prompts.
         return input_buffer.replace('\n' + self._continuation_prompt, '\n')
 
     def _set_input_buffer(self, string):
         """ Replaces the text in the input buffer with 'string'.
         """
         # For now, it is an error to modify the input buffer during execution.
         if self._executing:
             raise RuntimeError("Cannot change input buffer during execution.")
 
         # 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 = unicode(QtGui.QApplication.clipboard().text(mode)).rstrip()
+            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 export(self, parent = None):
         """Export HTML/XML in various modes from one Dialog."""
         parent = parent or None # sometimes parent is False
         dialog = QtGui.QFileDialog(parent, 'Save Console as...')
         dialog.setAcceptMode(QtGui.QFileDialog.AcceptSave)
         filters = [
             'HTML with PNG figures (*.html *.htm)',
             'XHTML with inline SVG figures (*.xhtml *.xml)'
         ]
         dialog.setNameFilters(filters)
         if self._filename:
             dialog.selectFile(self._filename)
             root,ext = os.path.splitext(self._filename)
             if ext.lower() in ('.xml', '.xhtml'):
                 dialog.selectNameFilter(filters[-1])
         if dialog.exec_():
             filename = str(dialog.selectedFiles()[0])
             self._filename = filename
             choice = str(dialog.selectedNameFilter())
 
             if choice.startswith('XHTML'):
                 exporter = self.export_xhtml
             else:
                 exporter = self.export_html
 
             try:
                 return exporter(filename)
             except Exception, e:
                 title = self.window().windowTitle()
                 msg = "Error while saving to: %s\n"%filename+str(e)
                 reply = QtGui.QMessageBox.warning(self, title, msg,
                     QtGui.QMessageBox.Ok, QtGui.QMessageBox.Ok)
         return None
 
     def export_html(self, filename):
         """ Export the contents of the ConsoleWidget as HTML.
 
         Parameters:
         -----------
         filename : str
             The file to be saved.
         inline : bool, optional [default True]
             If True, include images as inline PNGs.  Otherwise,
             include them as links to external PNG files, mimicking
             web browsers' "Web Page, Complete" behavior.
         """
         # N.B. this is overly restrictive, but Qt's output is
         # predictable...
         img_re = re.compile(r'<img src="(?P<name>[\d]+)" />')
         html = self.fix_html_encoding(
             str(self._control.toHtml().toUtf8()))
         if self._png_mode:
             # preference saved, don't ask again
             if img_re.search(html):
                 inline = (self._png_mode == 'inline')
             else:
                 inline = True
         elif img_re.search(html):
             # there are images
             widget = QtGui.QWidget()
             layout = QtGui.QVBoxLayout(widget)
             title = self.window().windowTitle()
             msg = "Exporting HTML with PNGs"
             info = "Would you like inline PNGs (single large html file) or "+\
             "external image files?"
             checkbox = QtGui.QCheckBox("&Don't ask again")
             checkbox.setShortcut('D')
             ib = QtGui.QPushButton("&Inline", self)
             ib.setShortcut('I')
             eb = QtGui.QPushButton("&External", self)
             eb.setShortcut('E')
             box = QtGui.QMessageBox(QtGui.QMessageBox.Question, title, msg)
             box.setInformativeText(info)
             box.addButton(ib,QtGui.QMessageBox.NoRole)
             box.addButton(eb,QtGui.QMessageBox.YesRole)
             box.setDefaultButton(ib)
             layout.setSpacing(0)
             layout.addWidget(box)
             layout.addWidget(checkbox)
             widget.setLayout(layout)
             widget.show()
             reply = box.exec_()
             inline = (reply == 0)
             if checkbox.checkState():
                 # don't ask anymore, always use this choice
                 if inline:
                     self._png_mode='inline'
                 else:
                     self._png_mode='external'
         else:
             # no images
             inline = True
 
         if inline:
             path = None
         else:
             root,ext = os.path.splitext(filename)
             path = root+"_files"
             if os.path.isfile(path):
                 raise OSError("%s exists, but is not a directory."%path)
 
         f = open(filename, 'w')
         try:
             f.write(img_re.sub(
                 lambda x: self.image_tag(x, path = path, format = "png"),
                 html))
         except Exception, e:
             f.close()
             raise e
         else:
             f.close()
         return filename
 
 
     def export_xhtml(self, filename):
         """ Export the contents of the ConsoleWidget as XHTML with inline SVGs.
         """
         f = open(filename, 'w')
         try:
             # N.B. this is overly restrictive, but Qt's output is
             # predictable...
             img_re = re.compile(r'<img src="(?P<name>[\d]+)" />')
             html = str(self._control.toHtml().toUtf8())
             # Hack to make xhtml header -- note that we are not doing
             # any check for valid xml
             offset = html.find("<html>")
             assert(offset > -1)
             html = ('<html xmlns="http://www.w3.org/1999/xhtml">\n'+
                     html[offset+6:])
             # And now declare UTF-8 encoding
             html = self.fix_html_encoding(html)
             f.write(img_re.sub(
                 lambda x: self.image_tag(x, path = None, format = "svg"),
                 html))
         except Exception, e:
             f.close()
             raise e
         else:
             f.close()
         return filename
 
     def fix_html_encoding(self, html):
         """ Return html string, with a UTF-8 declaration added to <HEAD>.
 
         Assumes that html is Qt generated and has already been UTF-8 encoded
         and coerced to a python string.  If the expected head element is
         not found, the given object is returned unmodified.
 
         This patching is needed for proper rendering of some characters
         (e.g., indented commands) when viewing exported HTML on a local
         system (i.e., without seeing an encoding declaration in an HTTP
         header).
 
         C.f. http://www.w3.org/International/O-charset for details.
         """
         offset = html.find("<head>")
         if(offset > -1):
             html = (html[:offset+6]+
                     '\n<meta http-equiv="Content-Type" '+
                     'content="text/html; charset=utf-8" />\n'+
                     html[offset+6:])
 
         return html
 
     def image_tag(self, match, path = None, format = "png"):
         """ Return (X)HTML mark-up for the image-tag given by match.
 
         Parameters
         ----------
         match : re.SRE_Match 
             A match to an HTML image tag as exported by Qt, with
             match.group("Name") containing the matched image ID.
 
         path : string|None, optional [default None]
             If not None, specifies a path to which supporting files
             may be written (e.g., for linked images).
             If None, all images are to be included inline.
 
         format : "png"|"svg", optional [default "png"]
             Format for returned or referenced images.
 
         Subclasses supporting image display should override this
         method.
         """
 
         # Default case -- not enough information to generate tag
         return ""
 
     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
             family, fallback = 'Consolas', 'Courier'
         elif sys.platform == 'darwin':
             # OSX always has Monaco, no need for a fallback
             family, fallback = 'Monaco', None
         else:
             # FIXME: remove Consolas as a default on Linux once our font
             # selections are configurable by the user.
             family, fallback = 'Consolas', 'Monospace'
         font = get_font(family, fallback)
         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
         font.setPointSize(font.pointSize() + delta)
         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):
         """ Called when the up key is pressed. Returns whether to continue
             processing the event.
         """
         return True
 
     def _down_pressed(self):
         """ 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 = unicode(temp_cursor.selection().toPlainText()).lstrip()
+            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.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 = cursor.selectedText().trimmed().isEmpty() 
+                    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))
                     cursor.removeSelectedText()
                 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_Y:
                 self.paste()
                 intercepted = True
 
             elif key in (QtCore.Qt.Key_Backspace, QtCore.Qt.Key_Delete):
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Plus:
                 self.change_font_size(1)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Minus:
                 self.change_font_size(-1)
                 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_Backspace:
                 cursor = self._get_word_start_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 cursor.removeSelectedText()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_D:
                 cursor = self._get_word_end_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 cursor.removeSelectedText()
                 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():
                     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():
                     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 is down to allow copy-paste using
         # the keyboard in any part of the buffer.
         if not ctrl_down:
             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 unicode(cursor.selection().toPlainText())
+        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 document.characterAt(position).isLetterOrNumber():
+                  not is_letter_or_number(document.characterAt(position)):
             position -= 1
         while position >= self._prompt_pos and \
-                document.characterAt(position).isLetterOrNumber():
+                  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 document.characterAt(position).isLetterOrNumber():
+                  not is_letter_or_number(document.characterAt(position)):
             position += 1
         while position < end and \
-                document.characterAt(position).isLetterOrNumber():
+                  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 = unicode(cursor.selection().toPlainText())
+        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 = unicode(text).splitlines(True)
+        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.
         """
         # Flush all state from the input splitter so the next round of
         # reading input starts with a clean buffer.
         self._input_splitter.reset()
 
         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)
 
         self._control.setReadOnly(False)
         self._control.moveCursor(QtGui.QTextCursor.End)
         self._executing = False
         self._prompt_started_hook()
 
     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 unicode(cursor.selection().toPlainText()) != '\n':
+                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/frontend_widget.py

@@ -1,598 +1,598 b''
 from __future__ import print_function
 
 # Standard library imports
 from collections import namedtuple
 import sys
 import time
 
 # System library imports
 from pygments.lexers import PythonLexer
-from PyQt4 import QtCore, QtGui
+from IPython.external.qt import QtCore, QtGui
 
 # Local imports
 from IPython.core.inputsplitter import InputSplitter, transform_classic_prompt
 from IPython.core.oinspect import call_tip
 from IPython.frontend.qt.base_frontend_mixin import BaseFrontendMixin
 from IPython.utils.traitlets import Bool
 from bracket_matcher import BracketMatcher
 from call_tip_widget import CallTipWidget
 from completion_lexer import CompletionLexer
 from history_console_widget import HistoryConsoleWidget
 from pygments_highlighter import PygmentsHighlighter
 
 
 class FrontendHighlighter(PygmentsHighlighter):
     """ A PygmentsHighlighter that can be turned on and off and that ignores
         prompts.
     """
 
     def __init__(self, frontend):
         super(FrontendHighlighter, self).__init__(frontend._control.document())
         self._current_offset = 0
         self._frontend = frontend
         self.highlighting_on = False
 
-    def highlightBlock(self, qstring):
+    def highlightBlock(self, string):
         """ Highlight a block of text. Reimplemented to highlight selectively.
         """
         if not self.highlighting_on:
             return
 
-        # The input to this function is unicode string that may contain
+        # The input to this function is a unicode string that may contain
         # paragraph break characters, non-breaking spaces, etc. Here we acquire
         # the string as plain text so we can compare it.
         current_block = self.currentBlock()
         string = self._frontend._get_block_plain_text(current_block)
 
         # Decide whether to check for the regular or continuation prompt.
         if current_block.contains(self._frontend._prompt_pos):
             prompt = self._frontend._prompt
         else:
             prompt = self._frontend._continuation_prompt
 
         # Don't highlight the part of the string that contains the prompt.
         if string.startswith(prompt):
             self._current_offset = len(prompt)
-            qstring.remove(0, len(prompt))
+            string = string[len(prompt):]
         else:
             self._current_offset = 0
 
-        PygmentsHighlighter.highlightBlock(self, qstring)
+        PygmentsHighlighter.highlightBlock(self, string)
 
     def rehighlightBlock(self, block):
         """ Reimplemented to temporarily enable highlighting if disabled.
         """
         old = self.highlighting_on
         self.highlighting_on = True
         super(FrontendHighlighter, self).rehighlightBlock(block)
         self.highlighting_on = old
 
     def setFormat(self, start, count, format):
         """ Reimplemented to highlight selectively.
         """
         start += self._current_offset
         PygmentsHighlighter.setFormat(self, start, count, format)
 
 
 class FrontendWidget(HistoryConsoleWidget, BaseFrontendMixin):
     """ A Qt frontend for a generic Python kernel.
     """
 
     # An option and corresponding signal for overriding the default kernel
     # interrupt behavior.
     custom_interrupt = Bool(False)
-    custom_interrupt_requested = QtCore.pyqtSignal()
+    custom_interrupt_requested = QtCore.Signal()
 
     # An option and corresponding signals for overriding the default kernel
     # restart behavior.
     custom_restart = Bool(False)
-    custom_restart_kernel_died = QtCore.pyqtSignal(float)
-    custom_restart_requested = QtCore.pyqtSignal()
+    custom_restart_kernel_died = QtCore.Signal(float)
+    custom_restart_requested = QtCore.Signal()
    
     # Emitted when an 'execute_reply' has been received from the kernel and
     # processed by the FrontendWidget.
-    executed = QtCore.pyqtSignal(object)
+    executed = QtCore.Signal(object)
 
     # Emitted when an exit request has been received from the kernel.
-    exit_requested = QtCore.pyqtSignal()
+    exit_requested = QtCore.Signal()
     
     # Protected class variables.
     _CallTipRequest = namedtuple('_CallTipRequest', ['id', 'pos'])
     _CompletionRequest = namedtuple('_CompletionRequest', ['id', 'pos'])
     _ExecutionRequest = namedtuple('_ExecutionRequest', ['id', 'kind'])
     _input_splitter_class = InputSplitter
     _local_kernel = False
 
     #---------------------------------------------------------------------------
     # 'object' interface
     #---------------------------------------------------------------------------
     
     def __init__(self, *args, **kw):
         super(FrontendWidget, self).__init__(*args, **kw)
 
         # FrontendWidget protected variables.
         self._bracket_matcher = BracketMatcher(self._control)
         self._call_tip_widget = CallTipWidget(self._control)
         self._completion_lexer = CompletionLexer(PythonLexer())
         self._copy_raw_action = QtGui.QAction('Copy (Raw Text)', None)
         self._hidden = False
         self._highlighter = FrontendHighlighter(self)
         self._input_splitter = self._input_splitter_class(input_mode='cell')
         self._kernel_manager = None
         self._request_info = {}
 
         # Configure the ConsoleWidget.
         self.tab_width = 4
         self._set_continuation_prompt('... ')
 
         # Configure the CallTipWidget.
         self._call_tip_widget.setFont(self.font)
         self.font_changed.connect(self._call_tip_widget.setFont)
 
         # Configure actions.
         action = self._copy_raw_action
         key = QtCore.Qt.CTRL | QtCore.Qt.SHIFT | QtCore.Qt.Key_C
         action.setEnabled(False)
         action.setShortcut(QtGui.QKeySequence(key))
         action.setShortcutContext(QtCore.Qt.WidgetWithChildrenShortcut)
         action.triggered.connect(self.copy_raw)
         self.copy_available.connect(action.setEnabled)
         self.addAction(action)
 
         # Connect signal handlers.
         document = self._control.document()
         document.contentsChange.connect(self._document_contents_change)
         
         # set flag for whether we are connected via localhost
         self._local_kernel = kw.get('local_kernel', FrontendWidget._local_kernel)
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     def copy(self):
         """ Copy the currently selected text to the clipboard, removing prompts.
         """
-        text = unicode(self._control.textCursor().selection().toPlainText())
+        text = self._control.textCursor().selection().toPlainText()
         if text:
             lines = map(transform_classic_prompt, text.splitlines())
             text = '\n'.join(lines)
             QtGui.QApplication.clipboard().setText(text)
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' abstract interface
     #---------------------------------------------------------------------------
 
     def _is_complete(self, source, interactive):
         """ Returns whether 'source' can be completely processed and a new
             prompt created. When triggered by an Enter/Return key press,
             'interactive' is True; otherwise, it is False.
         """
         complete = self._input_splitter.push(source)
         if interactive:
             complete = not self._input_splitter.push_accepts_more()
         return complete
 
     def _execute(self, source, hidden):
         """ Execute 'source'. If 'hidden', do not show any output.
 
         See parent class :meth:`execute` docstring for full details.
         """
         msg_id = self.kernel_manager.xreq_channel.execute(source, hidden)
         self._request_info['execute'] = self._ExecutionRequest(msg_id, 'user')
         self._hidden = hidden
         
     def _prompt_started_hook(self):
         """ Called immediately after a new prompt is displayed.
         """
         if not self._reading:
             self._highlighter.highlighting_on = True
 
     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.
         """
         if not self._reading:
             self._highlighter.highlighting_on = False
 
     def _tab_pressed(self):
         """ Called when the tab key is pressed. Returns whether to continue
             processing the event.
         """
         # Perform tab completion if:
         # 1) The cursor is in the input buffer.
         # 2) There is a non-whitespace character before the cursor.
         text = self._get_input_buffer_cursor_line()
         if text is None:
             return False
         complete = bool(text[:self._get_input_buffer_cursor_column()].strip())
         if complete:
             self._complete()
         return not complete
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _context_menu_make(self, pos):
         """ Reimplemented to add an action for raw copy.
         """
         menu = super(FrontendWidget, self)._context_menu_make(pos)
         for before_action in menu.actions():
             if before_action.shortcut().matches(QtGui.QKeySequence.Paste) == \
                     QtGui.QKeySequence.ExactMatch:
                 menu.insertAction(before_action, self._copy_raw_action)
                 break
         return menu
 
     def _event_filter_console_keypress(self, event):
         """ Reimplemented for execution interruption and smart backspace.
         """
         key = event.key()
         if self._control_key_down(event.modifiers(), include_command=False):
 
             if key == QtCore.Qt.Key_C and self._executing:
                 self.interrupt_kernel()
                 return True
 
             elif key == QtCore.Qt.Key_Period:
                 message = 'Are you sure you want to restart the kernel?'
                 self.restart_kernel(message, now=False)
                 return True
 
         elif not event.modifiers() & QtCore.Qt.AltModifier:
 
             # Smart backspace: remove four characters in one backspace if:
             # 1) everything left of the cursor is whitespace
             # 2) the four characters immediately left of the cursor are spaces
             if key == QtCore.Qt.Key_Backspace:
                 col = self._get_input_buffer_cursor_column()
                 cursor = self._control.textCursor()
                 if col > 3 and not cursor.hasSelection():
                     text = self._get_input_buffer_cursor_line()[:col]
                     if text.endswith('    ') and not text.strip():
                         cursor.movePosition(QtGui.QTextCursor.Left,
                                             QtGui.QTextCursor.KeepAnchor, 4)
                         cursor.removeSelectedText()
                         return True
 
         return super(FrontendWidget, self)._event_filter_console_keypress(event)
 
     def _insert_continuation_prompt(self, cursor):
         """ Reimplemented for auto-indentation.
         """
         super(FrontendWidget, self)._insert_continuation_prompt(cursor)
         cursor.insertText(' ' * self._input_splitter.indent_spaces)
 
     #---------------------------------------------------------------------------
     # 'BaseFrontendMixin' abstract interface
     #---------------------------------------------------------------------------
 
     def _handle_complete_reply(self, rep):
         """ Handle replies for tab completion.
         """
         cursor = self._get_cursor()
         info = self._request_info.get('complete')
         if info and info.id == rep['parent_header']['msg_id'] and \
                 info.pos == cursor.position():
             text = '.'.join(self._get_context())
             cursor.movePosition(QtGui.QTextCursor.Left, n=len(text))
             self._complete_with_items(cursor, rep['content']['matches'])
 
     def _handle_execute_reply(self, msg):
         """ Handles replies for code execution.
         """
         info = self._request_info.get('execute')
         if info and info.id == msg['parent_header']['msg_id'] and \
                 info.kind == 'user' and not self._hidden:
             # Make sure that all output from the SUB channel has been processed
             # before writing a new prompt.
             self.kernel_manager.sub_channel.flush()
 
             # Reset the ANSI style information to prevent bad text in stdout
             # from messing up our colors. We're not a true terminal so we're
             # allowed to do this.
             if self.ansi_codes:
                 self._ansi_processor.reset_sgr()
 
             content = msg['content']
             status = content['status']
             if status == 'ok':
                 self._process_execute_ok(msg)
             elif status == 'error':
                 self._process_execute_error(msg)
             elif status == 'abort':
                 self._process_execute_abort(msg)
 
             self._show_interpreter_prompt_for_reply(msg)
             self.executed.emit(msg)
 
     def _handle_input_request(self, msg):
         """ Handle requests for raw_input.
         """
         if self._hidden:
             raise RuntimeError('Request for raw input during hidden execution.')
 
         # Make sure that all output from the SUB channel has been processed
         # before entering readline mode.
         self.kernel_manager.sub_channel.flush()
 
         def callback(line):
             self.kernel_manager.rep_channel.input(line)
         self._readline(msg['content']['prompt'], callback=callback)
 
     def _handle_kernel_died(self, since_last_heartbeat):
         """ Handle the kernel's death by asking if the user wants to restart.
         """
         if self.custom_restart:
             self.custom_restart_kernel_died.emit(since_last_heartbeat)
         else:
             message = 'The kernel heartbeat has been inactive for %.2f ' \
                 'seconds. Do you want to restart the kernel? You may ' \
                 'first want to check the network connection.' % \
                 since_last_heartbeat
             self.restart_kernel(message, now=True)
 
     def _handle_object_info_reply(self, rep):
         """ Handle replies for call tips.
         """
         cursor = self._get_cursor()
         info = self._request_info.get('call_tip')
         if info and info.id == rep['parent_header']['msg_id'] and \
                 info.pos == cursor.position():
             # Get the information for a call tip.  For now we format the call
             # line as string, later we can pass False to format_call and
             # syntax-highlight it ourselves for nicer formatting in the
             # calltip.
             call_info, doc = call_tip(rep['content'], format_call=True)
             if call_info or doc:
                 self._call_tip_widget.show_call_info(call_info, doc)
 
     def _handle_pyout(self, msg):
         """ Handle display hook output.
         """
         if not self._hidden and self._is_from_this_session(msg):
             self._append_plain_text(msg['content']['data']['text/plain'] + '\n')
 
     def _handle_stream(self, msg):
         """ Handle stdout, stderr, and stdin.
         """
         if not self._hidden and self._is_from_this_session(msg):
             # Most consoles treat tabs as being 8 space characters. Convert tabs
             # to spaces so that output looks as expected regardless of this
             # widget's tab width.
             text = msg['content']['data'].expandtabs(8)
             
             self._append_plain_text(text)
             self._control.moveCursor(QtGui.QTextCursor.End)
 
     def _handle_shutdown_reply(self, msg):
         """ Handle shutdown signal, only if from other console.
         """
         if not self._hidden and not self._is_from_this_session(msg):
             if self._local_kernel:
                 if not msg['content']['restart']:
                     sys.exit(0)
                 else:
                     # we just got notified of a restart!
                     time.sleep(0.25) # wait 1/4 sec to reset
                                      # lest the request for a new prompt
                                      # goes to the old kernel
                     self.reset()
             else: # remote kernel, prompt on Kernel shutdown/reset
                 title = self.window().windowTitle()
                 if not msg['content']['restart']:
                     reply = QtGui.QMessageBox.question(self, title,
                         "Kernel has been shutdown permanently. Close the Console?",
                         QtGui.QMessageBox.Yes,QtGui.QMessageBox.No)
                     if reply == QtGui.QMessageBox.Yes:
                         sys.exit(0)
                 else:
                     reply = QtGui.QMessageBox.question(self, title,
                         "Kernel has been reset. Clear the Console?",
                         QtGui.QMessageBox.Yes,QtGui.QMessageBox.No)
                     if reply == QtGui.QMessageBox.Yes:
                         time.sleep(0.25) # wait 1/4 sec to reset
                                          # lest the request for a new prompt
                                          # goes to the old kernel
                         self.reset()
 
     def _started_channels(self):
         """ Called when the KernelManager channels have started listening or 
             when the frontend is assigned an already listening KernelManager.
         """
         self.reset()
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' public interface
     #---------------------------------------------------------------------------
 
     def copy_raw(self):
         """ Copy the currently selected text to the clipboard without attempting
             to remove prompts or otherwise alter the text.
         """
         self._control.copy()
 
     def execute_file(self, path, hidden=False):
         """ Attempts to execute file with 'path'. If 'hidden', no output is
             shown.
         """
         self.execute('execfile("%s")' % path, hidden=hidden)
 
     def interrupt_kernel(self):
         """ Attempts to interrupt the running kernel.
         """
         if self.custom_interrupt:
             self.custom_interrupt_requested.emit()
         elif self.kernel_manager.has_kernel:
             self.kernel_manager.interrupt_kernel()
         else:
             self._append_plain_text('Kernel process is either remote or '
                                     'unspecified. Cannot interrupt.\n')
 
     def reset(self):
         """ Resets the widget to its initial state. Similar to ``clear``, but
             also re-writes the banner and aborts execution if necessary.
         """ 
         if self._executing:
             self._executing = False
             self._request_info['execute'] = None
         self._reading = False
         self._highlighter.highlighting_on = False
 
         self._control.clear()
         self._append_plain_text(self._get_banner())
         self._show_interpreter_prompt()
 
     def restart_kernel(self, message, now=False):
         """ Attempts to restart the running kernel.
         """
         # FIXME: now should be configurable via a checkbox in the dialog.  Right
         # now at least the heartbeat path sets it to True and the manual restart
         # to False.  But those should just be the pre-selected states of a
         # checkbox that the user could override if so desired.  But I don't know
         # enough Qt to go implementing the checkbox now.
 
         if self.custom_restart:
             self.custom_restart_requested.emit()
 
         elif self.kernel_manager.has_kernel:
             # Pause the heart beat channel to prevent further warnings.
             self.kernel_manager.hb_channel.pause()
 
             # Prompt the user to restart the kernel. Un-pause the heartbeat if
             # they decline. (If they accept, the heartbeat will be un-paused
             # automatically when the kernel is restarted.)
             buttons = QtGui.QMessageBox.Yes | QtGui.QMessageBox.No
             result = QtGui.QMessageBox.question(self, 'Restart kernel?',
                                                 message, buttons)
             if result == QtGui.QMessageBox.Yes:
                 try:
                     self.kernel_manager.restart_kernel(now=now)
                 except RuntimeError:
                     self._append_plain_text('Kernel started externally. '
                                             'Cannot restart.\n')
                 else:
                     self.reset()
             else:
                 self.kernel_manager.hb_channel.unpause()
 
         else:
             self._append_plain_text('Kernel process is either remote or '
                                     'unspecified. Cannot restart.\n')
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _call_tip(self):
         """ Shows a call tip, if appropriate, at the current cursor location.
         """
         # Decide if it makes sense to show a call tip
         cursor = self._get_cursor()
         cursor.movePosition(QtGui.QTextCursor.Left)
-        if cursor.document().characterAt(cursor.position()).toAscii() != '(':
+        if cursor.document().characterAt(cursor.position()) != '(':
             return False
         context = self._get_context(cursor)
         if not context:
             return False
 
         # Send the metadata request to the kernel
         name = '.'.join(context)
         msg_id = self.kernel_manager.xreq_channel.object_info(name)
         pos = self._get_cursor().position()
         self._request_info['call_tip'] = self._CallTipRequest(msg_id, pos)
         return True
 
     def _complete(self):
         """ Performs completion at the current cursor location.
         """
         context = self._get_context()
         if context:
             # Send the completion request to the kernel
             msg_id = self.kernel_manager.xreq_channel.complete(
                 '.'.join(context),                       # text
                 self._get_input_buffer_cursor_line(),    # line
                 self._get_input_buffer_cursor_column(),  # cursor_pos
                 self.input_buffer)                       # block 
             pos = self._get_cursor().position()
             info = self._CompletionRequest(msg_id, pos)
             self._request_info['complete'] = info
 
     def _get_banner(self):
         """ Gets a banner to display at the beginning of a session.
         """
         banner = 'Python %s on %s\nType "help", "copyright", "credits" or ' \
             '"license" for more information.'
         return banner % (sys.version, sys.platform)
 
     def _get_context(self, cursor=None):
         """ Gets the context for the specified cursor (or the current cursor
             if none is specified).
         """
         if cursor is None:
             cursor = self._get_cursor()
         cursor.movePosition(QtGui.QTextCursor.StartOfBlock, 
                             QtGui.QTextCursor.KeepAnchor)
-        text = unicode(cursor.selection().toPlainText())
+        text = cursor.selection().toPlainText()
         return self._completion_lexer.get_context(text)
 
     def _process_execute_abort(self, msg):
         """ Process a reply for an aborted execution request.
         """
         self._append_plain_text("ERROR: execution aborted\n")
 
     def _process_execute_error(self, msg):
         """ Process a reply for an execution request that resulted in an error.
         """
         content = msg['content']
         # If a SystemExit is passed along, this means exit() was called - also
         # all the ipython %exit magic syntax of '-k' to be used to keep
         # the kernel running
         if content['ename']=='SystemExit':
             keepkernel = content['evalue']=='-k' or content['evalue']=='True'
             self._keep_kernel_on_exit = keepkernel
             self.exit_requested.emit()
         else:
             traceback = ''.join(content['traceback'])
             self._append_plain_text(traceback)
 
     def _process_execute_ok(self, msg):
         """ Process a reply for a successful execution equest.
         """
         payload = msg['content']['payload']
         for item in payload:
             if not self._process_execute_payload(item):
                 warning = 'Warning: received unknown payload of type %s'
                 print(warning % repr(item['source']))
 
     def _process_execute_payload(self, item):
         """ Process a single payload item from the list of payload items in an
             execution reply. Returns whether the payload was handled.
         """
         # The basic FrontendWidget doesn't handle payloads, as they are a
         # mechanism for going beyond the standard Python interpreter model.
         return False
 
     def _show_interpreter_prompt(self):
         """ Shows a prompt for the interpreter.
         """
         self._show_prompt('>>> ')
 
     def _show_interpreter_prompt_for_reply(self, msg):
         """ Shows a prompt for the interpreter given an 'execute_reply' message.
         """
         self._show_interpreter_prompt()
 
     #------ Signal handlers ----------------------------------------------------
 
     def _document_contents_change(self, position, removed, added):
         """ Called whenever the document's content changes. Display a call tip
             if appropriate.
         """
         # Calculate where the cursor should be *after* the change:
         position += added
 
         document = self._control.document()
         if position == self._get_cursor().position():
             self._call_tip()

IPython/frontend/qt/console/history_console_widget.py

@@ -1,163 +1,163 b''
 # System library imports
-from PyQt4 import QtGui
+from IPython.external.qt import QtGui
 
 # Local imports
 from console_widget import ConsoleWidget
 
 
 class HistoryConsoleWidget(ConsoleWidget):
     """ A ConsoleWidget that keeps a history of the commands that have been
         executed and provides a readline-esque interface to this history.
     """
     
     #---------------------------------------------------------------------------
     # 'object' interface
     #---------------------------------------------------------------------------
 
     def __init__(self, *args, **kw):
         super(HistoryConsoleWidget, self).__init__(*args, **kw)
 
         # HistoryConsoleWidget protected variables.
         self._history = []
         self._history_index = 0
         self._history_prefix = ''
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     def execute(self, source=None, hidden=False, interactive=False):
         """ Reimplemented to the store history.
         """
         if not hidden:
             history = self.input_buffer if source is None else source
 
         executed = super(HistoryConsoleWidget, self).execute(
             source, hidden, interactive)
 
         if executed and not hidden:
             # Save the command unless it was an empty string or was identical 
             # to the previous command.
             history = history.rstrip()
             if history and (not self._history or self._history[-1] != history):
                 self._history.append(history)
 
             # Move the history index to the most recent item.
             self._history_index = len(self._history)
 
         return executed
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' abstract interface
     #---------------------------------------------------------------------------
 
     def _up_pressed(self):
         """ Called when the up key is pressed. Returns whether to continue
             processing the event.
         """
         prompt_cursor = self._get_prompt_cursor()
         if self._get_cursor().blockNumber() == prompt_cursor.blockNumber():
 
             # Set a search prefix based on the cursor position.
             col = self._get_input_buffer_cursor_column()
             input_buffer = self.input_buffer
             if self._history_index == len(self._history) or \
                     (self._history_prefix and col != len(self._history_prefix)):
                 self._history_index = len(self._history)
                 self._history_prefix = input_buffer[:col]
 
             # Perform the search.
             self.history_previous(self._history_prefix)
 
             # Go to the first line of the prompt for seemless history scrolling.
             # Emulate readline: keep the cursor position fixed for a prefix
             # search.
             cursor = self._get_prompt_cursor()
             if self._history_prefix:
                 cursor.movePosition(QtGui.QTextCursor.Right, 
                                     n=len(self._history_prefix))
             else:
                 cursor.movePosition(QtGui.QTextCursor.EndOfLine)
             self._set_cursor(cursor)
 
             return False
 
         return True
 
     def _down_pressed(self):
         """ Called when the down key is pressed. Returns whether to continue
             processing the event.
         """
         end_cursor = self._get_end_cursor()
         if self._get_cursor().blockNumber() == end_cursor.blockNumber():
 
             # Perform the search.
             self.history_next(self._history_prefix)
 
             # Emulate readline: keep the cursor position fixed for a prefix
             # search. (We don't need to move the cursor to the end of the buffer
             # in the other case because this happens automatically when the
             # input buffer is set.)
             if self._history_prefix:
                 cursor = self._get_prompt_cursor()
                 cursor.movePosition(QtGui.QTextCursor.Right, 
                                     n=len(self._history_prefix))
                 self._set_cursor(cursor)
 
             return False
 
         return True
 
     #---------------------------------------------------------------------------
     # 'HistoryConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     def history_previous(self, prefix=''):
         """ If possible, set the input buffer to a previous item in the history.
 
         Parameters:
         -----------
         prefix : str, optional
             If specified, search for an item with this prefix.
         """
         index = self._history_index
         while index > 0:
             index -= 1
             history = self._history[index]
             if history.startswith(prefix):
                 break
         else:
             history = None
         
         if history is not None:
             self._history_index = index
             self.input_buffer = history
 
     def history_next(self, prefix=''):
         """ Set the input buffer to a subsequent item in the history, or to the
         original search prefix if there is no such item.
 
         Parameters:
         -----------
         prefix : str, optional
             If specified, search for an item with this prefix.
         """
         while self._history_index < len(self._history) - 1:
             self._history_index += 1
             history = self._history[self._history_index]
             if history.startswith(prefix):
                 break
         else:
             self._history_index = len(self._history)
             history = prefix
         self.input_buffer = history
 
     #---------------------------------------------------------------------------
     # 'HistoryConsoleWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _set_history(self, history):
         """ Replace the current history with a sequence of history items.
         """
         self._history = list(history)
         self._history_index = len(self._history)

IPython/frontend/qt/console/ipython_widget.py

@@ -1,497 +1,497 b''
 """ A FrontendWidget that emulates the interface of the console IPython and
     supports the additional functionality provided by the IPython kernel.
 
     TODO: Add support for retrieving the system default editor. Requires code
           paths for Windows (use the registry), Mac OS (use LaunchServices), and
           Linux (use the xdg system).
 """
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports
 from collections import namedtuple
 import re
 from subprocess import Popen
 from textwrap import dedent
 
 # System library imports
-from PyQt4 import QtCore, QtGui
+from IPython.external.qt import QtCore, QtGui
 
 # Local imports
 from IPython.core.inputsplitter import IPythonInputSplitter, \
     transform_ipy_prompt
 from IPython.core.usage import default_gui_banner
 from IPython.utils.traitlets import Bool, Str
 from frontend_widget import FrontendWidget
 from styles import (default_light_style_sheet,  default_light_syntax_style,
                     default_dark_style_sheet, default_dark_syntax_style,
                     default_bw_style_sheet, default_bw_syntax_style)
 
 #-----------------------------------------------------------------------------
 # Constants
 #-----------------------------------------------------------------------------
 
 # Default strings to build and display input and output prompts (and separators
 # in between)
 default_in_prompt = 'In [<span class="in-prompt-number">%i</span>]: '
 default_out_prompt = 'Out[<span class="out-prompt-number">%i</span>]: '
 default_input_sep = '\n'
 default_output_sep = ''
 default_output_sep2 = ''
 
 # Base path for most payload sources.
 zmq_shell_source = 'IPython.zmq.zmqshell.ZMQInteractiveShell'
 
 #-----------------------------------------------------------------------------
 # IPythonWidget class
 #-----------------------------------------------------------------------------
 
 class IPythonWidget(FrontendWidget):
     """ A FrontendWidget for an IPython kernel.
     """
 
     # If set, the 'custom_edit_requested(str, int)' signal will be emitted when
     # an editor is needed for a file. This overrides 'editor' and 'editor_line'
     # settings.
     custom_edit = Bool(False)
-    custom_edit_requested = QtCore.pyqtSignal(object, object)
+    custom_edit_requested = QtCore.Signal(object, object)
 
     # A command for invoking a system text editor. If the string contains a
     # {filename} format specifier, it will be used. Otherwise, the filename will
     # be appended to the end the command.
     editor = Str('default', config=True)
 
     # The editor command to use when a specific line number is requested. The
     # string should contain two format specifiers: {line} and {filename}. If
     # this parameter is not specified, the line number option to the %edit magic
     # will be ignored.
     editor_line = Str(config=True)
 
     # A CSS stylesheet. The stylesheet can contain classes for:
     #     1. Qt: QPlainTextEdit, QFrame, QWidget, etc
     #     2. Pygments: .c, .k, .o, etc (see PygmentsHighlighter)
     #     3. IPython: .error, .in-prompt, .out-prompt, etc
     style_sheet = Str(config=True)
     
     # If not empty, use this Pygments style for syntax highlighting. Otherwise,
     # the style sheet is queried for Pygments style information.
     syntax_style = Str(config=True)
 
     # Prompts.
     in_prompt = Str(default_in_prompt, config=True)
     out_prompt = Str(default_out_prompt, config=True)
     input_sep = Str(default_input_sep, config=True)
     output_sep = Str(default_output_sep, config=True)
     output_sep2 = Str(default_output_sep2, config=True)
 
     # FrontendWidget protected class variables.
     _input_splitter_class = IPythonInputSplitter
 
     # IPythonWidget protected class variables.
     _PromptBlock = namedtuple('_PromptBlock', ['block', 'length', 'number'])
     _payload_source_edit = zmq_shell_source + '.edit_magic'
     _payload_source_exit = zmq_shell_source + '.ask_exit'
     _payload_source_loadpy = zmq_shell_source + '.magic_loadpy'
     _payload_source_page = 'IPython.zmq.page.page'
 
     #---------------------------------------------------------------------------
     # 'object' interface
     #---------------------------------------------------------------------------
     
     def __init__(self, *args, **kw):
         super(IPythonWidget, self).__init__(*args, **kw)
 
         # IPythonWidget protected variables.
         self._code_to_load = None
         self._payload_handlers = { 
             self._payload_source_edit : self._handle_payload_edit,
             self._payload_source_exit : self._handle_payload_exit,
             self._payload_source_page : self._handle_payload_page,
             self._payload_source_loadpy : self._handle_payload_loadpy }
         self._previous_prompt_obj = None
         self._keep_kernel_on_exit = None
 
         # Initialize widget styling.
         if self.style_sheet:
             self._style_sheet_changed()
             self._syntax_style_changed()
         else:
             self.set_default_style()
 
     #---------------------------------------------------------------------------
     # 'BaseFrontendMixin' abstract interface
     #---------------------------------------------------------------------------
 
     def _handle_complete_reply(self, rep):
         """ Reimplemented to support IPython's improved completion machinery.
         """
         cursor = self._get_cursor()
         info = self._request_info.get('complete')
         if info and info.id == rep['parent_header']['msg_id'] and \
                 info.pos == cursor.position():
             matches = rep['content']['matches']
             text = rep['content']['matched_text']
             offset = len(text)
 
             # Clean up matches with period and path separators if the matched
             # text has not been transformed. This is done by truncating all
             # but the last component and then suitably decreasing the offset
             # between the current cursor position and the start of completion.
             if len(matches) > 1 and matches[0][:offset] == text:
                 parts = re.split(r'[./\\]', text) 
                 sep_count = len(parts) - 1
                 if sep_count:
                     chop_length = sum(map(len, parts[:sep_count])) + sep_count
                     matches = [ match[chop_length:] for match in matches ]
                     offset -= chop_length
 
             # Move the cursor to the start of the match and complete.
             cursor.movePosition(QtGui.QTextCursor.Left, n=offset)
             self._complete_with_items(cursor, matches)
 
     def _handle_execute_reply(self, msg):
         """ Reimplemented to support prompt requests.
         """
         info = self._request_info.get('execute')
         if info and info.id == msg['parent_header']['msg_id']:
             if info.kind == 'prompt':
                 number = msg['content']['execution_count'] + 1
                 self._show_interpreter_prompt(number)
             else:
                 super(IPythonWidget, self)._handle_execute_reply(msg)
 
     def _handle_history_reply(self, msg):
         """ Implemented to handle history replies, which are only supported by
             the IPython kernel.
         """
         history_dict = msg['content']['history']
         input_history_dict = {}
         for key,val in history_dict.items():
             input_history_dict[int(key)] = val
         items = [ val.rstrip() for _, val in sorted(input_history_dict.items()) ]
         self._set_history(items)
 
     def _handle_pyout(self, msg):
         """ Reimplemented for IPython-style "display hook".
         """
         if not self._hidden and self._is_from_this_session(msg):
             content = msg['content']
             prompt_number = content['execution_count']
             data = content['data']
             if data.has_key('text/html'):
                 self._append_plain_text(self.output_sep)
                 self._append_html(self._make_out_prompt(prompt_number))
                 html = data['text/html']
                 self._append_plain_text('\n')
                 self._append_html(html + self.output_sep2)
             elif data.has_key('text/plain'):
                 self._append_plain_text(self.output_sep)
                 self._append_html(self._make_out_prompt(prompt_number))
                 text = data['text/plain']
                 self._append_plain_text(text + self.output_sep2)
 
     def _handle_display_data(self, msg):
         """ The base handler for the ``display_data`` message.
         """
         # For now, we don't display data from other frontends, but we 
         # eventually will as this allows all frontends to monitor the display
         # data. But we need to figure out how to handle this in the GUI.
         if not self._hidden and self._is_from_this_session(msg):
             source = msg['content']['source']
             data = msg['content']['data']
             metadata = msg['content']['metadata']
             # In the regular IPythonWidget, we simply print the plain text
             # representation.
             if data.has_key('text/html'):
                 html = data['text/html']
                 self._append_html(html)
             elif data.has_key('text/plain'):
                 text = data['text/plain']
                 self._append_plain_text(text)
             # This newline seems to be needed for text and html output.
             self._append_plain_text(u'\n')
 
     def _started_channels(self):
         """ Reimplemented to make a history request.
         """
         super(IPythonWidget, self)._started_channels()
         self.kernel_manager.xreq_channel.history(raw=True, output=False)
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     def copy(self):
         """ Copy the currently selected text to the clipboard, removing prompts
             if possible.
         """
-        text = unicode(self._control.textCursor().selection().toPlainText())
+        text = self._control.textCursor().selection().toPlainText()
         if text:
             lines = map(transform_ipy_prompt, text.splitlines())
             text = '\n'.join(lines)
             QtGui.QApplication.clipboard().setText(text)
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' public interface
     #---------------------------------------------------------------------------
 
     def execute_file(self, path, hidden=False):
         """ Reimplemented to use the 'run' magic.
         """
         self.execute('%%run %s' % path, hidden=hidden)
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _complete(self):
         """ Reimplemented to support IPython's improved completion machinery.
         """
         # We let the kernel split the input line, so we *always* send an empty
         # text field. Readline-based frontends do get a real text field which
         # they can use.
         text = ''
         
         # Send the completion request to the kernel
         msg_id = self.kernel_manager.xreq_channel.complete(
             text,                                    # text
             self._get_input_buffer_cursor_line(),    # line
             self._get_input_buffer_cursor_column(),  # cursor_pos
             self.input_buffer)                       # block 
         pos = self._get_cursor().position()
         info = self._CompletionRequest(msg_id, pos)
         self._request_info['complete'] = info
 
     def _get_banner(self):
         """ Reimplemented to return IPython's default banner.
         """
         return default_gui_banner
 
     def _process_execute_error(self, msg):
         """ Reimplemented for IPython-style traceback formatting.
         """
         content = msg['content']
         traceback = '\n'.join(content['traceback']) + '\n'
         if False:
             # FIXME: For now, tracebacks come as plain text, so we can't use
             # the html renderer yet.  Once we refactor ultratb to produce
             # properly styled tracebacks, this branch should be the default
             traceback = traceback.replace(' ', '&nbsp;')
             traceback = traceback.replace('\n', '<br/>')
 
             ename = content['ename']
             ename_styled = '<span class="error">%s</span>' % ename
             traceback = traceback.replace(ename, ename_styled)
 
             self._append_html(traceback)
         else:
             # This is the fallback for now, using plain text with ansi escapes
             self._append_plain_text(traceback)    
 
     def _process_execute_payload(self, item):
         """ Reimplemented to dispatch payloads to handler methods.
         """
         handler = self._payload_handlers.get(item['source'])
         if handler is None:
             # We have no handler for this type of payload, simply ignore it
             return False
         else:
             handler(item)
             return True
         
     def _show_interpreter_prompt(self, number=None):
         """ Reimplemented for IPython-style prompts.
         """
         # If a number was not specified, make a prompt number request.
         if number is None:
             msg_id = self.kernel_manager.xreq_channel.execute('', silent=True)
             info = self._ExecutionRequest(msg_id, 'prompt')
             self._request_info['execute'] = info
             return
 
         # Show a new prompt and save information about it so that it can be
         # updated later if the prompt number turns out to be wrong.
         self._prompt_sep = self.input_sep
         self._show_prompt(self._make_in_prompt(number), html=True)
         block = self._control.document().lastBlock()
         length = len(self._prompt)
         self._previous_prompt_obj = self._PromptBlock(block, length, number)
 
         # Update continuation prompt to reflect (possibly) new prompt length.
         self._set_continuation_prompt(
             self._make_continuation_prompt(self._prompt), html=True)
 
         # Load code from the %loadpy magic, if necessary.
         if self._code_to_load is not None:
-            self.input_buffer = dedent(unicode(self._code_to_load).rstrip())
+            self.input_buffer = dedent(self._code_to_load.rstrip())
             self._code_to_load = None
 
     def _show_interpreter_prompt_for_reply(self, msg):
         """ Reimplemented for IPython-style prompts.
         """
         # Update the old prompt number if necessary.
         content = msg['content']
         previous_prompt_number = content['execution_count']
         if self._previous_prompt_obj and \
                 self._previous_prompt_obj.number != previous_prompt_number:
             block = self._previous_prompt_obj.block
 
             # Make sure the prompt block has not been erased.
             if block.isValid() and not block.text().isEmpty():
 
                 # Remove the old prompt and insert a new prompt.
                 cursor = QtGui.QTextCursor(block)
                 cursor.movePosition(QtGui.QTextCursor.Right,
                                     QtGui.QTextCursor.KeepAnchor, 
                                     self._previous_prompt_obj.length)
                 prompt = self._make_in_prompt(previous_prompt_number)
                 self._prompt = self._insert_html_fetching_plain_text(
                     cursor, prompt)
 
                 # When the HTML is inserted, Qt blows away the syntax
                 # highlighting for the line, so we need to rehighlight it.
                 self._highlighter.rehighlightBlock(cursor.block())
 
             self._previous_prompt_obj = None
 
         # Show a new prompt with the kernel's estimated prompt number.
         self._show_interpreter_prompt(previous_prompt_number + 1)
 
     #---------------------------------------------------------------------------
     # 'IPythonWidget' interface
     #---------------------------------------------------------------------------
 
     def set_default_style(self, colors='lightbg'):
         """ Sets the widget style to the class defaults.
 
         Parameters:
         -----------
         colors : str, optional (default lightbg)
             Whether to use the default IPython light background or dark
             background or B&W style.
         """
         colors = colors.lower()
         if colors=='lightbg':
             self.style_sheet = default_light_style_sheet
             self.syntax_style = default_light_syntax_style
         elif colors=='linux':
             self.style_sheet = default_dark_style_sheet
             self.syntax_style = default_dark_syntax_style
         elif colors=='nocolor':
             self.style_sheet = default_bw_style_sheet
             self.syntax_style = default_bw_syntax_style
         else:
             raise KeyError("No such color scheme: %s"%colors)
 
     #---------------------------------------------------------------------------
     # 'IPythonWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _edit(self, filename, line=None):
         """ Opens a Python script for editing.
 
         Parameters:
         -----------
         filename : str
             A path to a local system file.
 
         line : int, optional
             A line of interest in the file.
         """
         if self.custom_edit:
             self.custom_edit_requested.emit(filename, line)
         elif self.editor == 'default':
             self._append_plain_text('No default editor available.\n')
         else:
             try:
                 filename = '"%s"' % filename
                 if line and self.editor_line:
                     command = self.editor_line.format(filename=filename,
                                                       line=line)
                 else:
                     try:
                         command = self.editor.format()
                     except KeyError:
                         command = self.editor.format(filename=filename)
                     else:
                         command += ' ' + filename
             except KeyError:
                 self._append_plain_text('Invalid editor command.\n')
             else:
                 try:
                     Popen(command, shell=True)
                 except OSError:
                     msg = 'Opening editor with command "%s" failed.\n'
                     self._append_plain_text(msg % command)
 
     def _make_in_prompt(self, number):
         """ Given a prompt number, returns an HTML In prompt.
         """
         body = self.in_prompt % number
         return '<span class="in-prompt">%s</span>' % body
 
     def _make_continuation_prompt(self, prompt):
         """ Given a plain text version of an In prompt, returns an HTML
             continuation prompt.
         """
         end_chars = '...: '
         space_count = len(prompt.lstrip('\n')) - len(end_chars)
         body = '&nbsp;' * space_count + end_chars
         return '<span class="in-prompt">%s</span>' % body
         
     def _make_out_prompt(self, number):
         """ Given a prompt number, returns an HTML Out prompt.
         """
         body = self.out_prompt % number
         return '<span class="out-prompt">%s</span>' % body
 
     #------ Payload handlers --------------------------------------------------
 
     # Payload handlers with a generic interface: each takes the opaque payload
     # dict, unpacks it and calls the underlying functions with the necessary
     # arguments.
 
     def _handle_payload_edit(self, item):
         self._edit(item['filename'], item['line_number'])
 
     def _handle_payload_exit(self, item):
         self._keep_kernel_on_exit = item['keepkernel']
         self.exit_requested.emit()
 
     def _handle_payload_loadpy(self, item):
         # Simple save the text of the .py file for later. The text is written
         # to the buffer when _prompt_started_hook is called.
         self._code_to_load = item['text']
 
     def _handle_payload_page(self, item):
         # Since the plain text widget supports only a very small subset of HTML
         # and we have no control over the HTML source, we only page HTML
         # payloads in the rich text widget.
         if item['html'] and self.kind == 'rich':
             self._page(item['html'], html=True)
         else:
             self._page(item['text'], html=False)
 
     #------ Trait change handlers --------------------------------------------
 
     def _style_sheet_changed(self):
         """ Set the style sheets of the underlying widgets.
         """
         self.setStyleSheet(self.style_sheet)
         self._control.document().setDefaultStyleSheet(self.style_sheet)
         if self._page_control:
             self._page_control.document().setDefaultStyleSheet(self.style_sheet)
 
         bg_color = self._control.palette().background().color()
         self._ansi_processor.set_background_color(bg_color)
 
     def _syntax_style_changed(self):
         """ Set the style for the syntax highlighter.
         """
         if self.syntax_style:
             self._highlighter.set_style(self.syntax_style)
         else:
             self._highlighter.set_style_sheet(self.style_sheet)
 

IPython/frontend/qt/console/ipythonqt.py

@@ -1,273 +1,275 b''
 """ A minimal application using the Qt console-style IPython frontend.
 """
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Systemm library imports
-from PyQt4 import QtGui
+from IPython.external.qt import QtGui
 from pygments.styles import get_all_styles
+
 # Local imports
 from IPython.external.argparse import ArgumentParser
 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
 
 #-----------------------------------------------------------------------------
 # 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):
         """ 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.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: #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 = 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()
 
 #-----------------------------------------------------------------------------
 # Main entry point
 #-----------------------------------------------------------------------------
 
 def main():
     """ Entry point for application.
     """
     # Parse command line arguments.
     parser = ArgumentParser()
     kgroup = parser.add_argument_group('kernel options')
     kgroup.add_argument('-e', '--existing', action='store_true',
                         help='connect to an existing kernel')
     kgroup.add_argument('--ip', type=str, default=LOCALHOST,
                         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!")
     kgroup.add_argument('--xreq', type=int, metavar='PORT', default=0,
                         help='set the XREQ channel port [default random]')
     kgroup.add_argument('--sub', type=int, metavar='PORT', default=0,
                         help='set the SUB channel port [default random]')
     kgroup.add_argument('--rep', type=int, metavar='PORT', default=0,
                         help='set the REP channel port [default random]')
     kgroup.add_argument('--hb', type=int, metavar='PORT', default=0,
                         help='set the heartbeat port [default random]')
 
     egroup = kgroup.add_mutually_exclusive_group()
     egroup.add_argument('--pure', action='store_true', help = \
                         'use a pure Python kernel instead of an IPython kernel')
     egroup.add_argument('--pylab', type=str, metavar='GUI', nargs='?', 
                        const='auto', help = \
         "Pre-load matplotlib and numpy for interactive use. If GUI is not \
          given, the GUI backend is matplotlib's, otherwise use one of: \
          ['tk', 'gtk', 'qt', 'wx', 'inline'].")
 
     wgroup = parser.add_argument_group('widget options')
     wgroup.add_argument('--paging', type=str, default='inside',
                         choices = ['inside', 'hsplit', 'vsplit', 'none'],
                         help='set the paging style [default inside]')
     wgroup.add_argument('--rich', action='store_true',
                         help='enable rich text support')
     wgroup.add_argument('--gui-completion', action='store_true',
                         help='use a GUI widget for tab completion')
     wgroup.add_argument('--style', type=str,
                         choices = list(get_all_styles()),
                         help='specify a pygments style for by name.')
     wgroup.add_argument('--stylesheet', type=str,
                         help="path to a custom CSS stylesheet.")
     wgroup.add_argument('--colors', type=str,
                         help="Set the color scheme (LightBG,Linux,NoColor). This is guessed\
                         based on the pygments style if not set.")
 
     args = parser.parse_args()
 
     # parse the colors arg down to current known labels
     if args.colors:
         colors=args.colors.lower()
         if colors in ('lightbg', 'light'):
             colors='lightbg'
         elif colors in ('dark', 'linux'):
             colors='linux'
         else:
             colors='nocolor'
     elif args.style:
         if args.style=='bw':
             colors='nocolor'
         elif styles.dark_style(args.style):
             colors='linux'
         else:
             colors='lightbg'
     else:
         colors=None
 
     # Don't let Qt or ZMQ swallow KeyboardInterupts.
     import signal
     signal.signal(signal.SIGINT, signal.SIG_DFL)
 
     # Create a KernelManager and start a kernel.
     kernel_manager = QtKernelManager(xreq_address=(args.ip, args.xreq),
                                      sub_address=(args.ip, args.sub),
                                      rep_address=(args.ip, args.rep),
                                      hb_address=(args.ip, args.hb))
     if not args.existing:
         # if not args.ip in LOCAL_IPS+ALL_ALIAS:
         #     raise ValueError("Must bind a local ip, such as: %s"%LOCAL_IPS)
 
         kwargs = dict(ip=args.ip)
         if args.pure:
             kwargs['ipython']=False
         else:
             kwargs['colors']=colors
             if args.pylab:
                 kwargs['pylab']=args.pylab
 
         kernel_manager.start_kernel(**kwargs)
     kernel_manager.start_channels()
 
     local_kernel = (not args.existing) or args.ip in LOCAL_IPS
     # Create the widget.
     app = QtGui.QApplication([])
     if args.pure:
         kind = 'rich' if args.rich else 'plain'
         widget = FrontendWidget(kind=kind, paging=args.paging, local_kernel=local_kernel)
     elif args.rich or args.pylab:
         widget = RichIPythonWidget(paging=args.paging, local_kernel=local_kernel)
     else:
         widget = IPythonWidget(paging=args.paging, local_kernel=local_kernel)
     widget.gui_completion = args.gui_completion
     widget.kernel_manager = kernel_manager
 
     # configure the style:
     if not args.pure: # only IPythonWidget supports styles
         if args.style:
             widget.syntax_style = args.style
             widget.style_sheet = styles.sheet_from_template(args.style, colors)
             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 args.stylesheet:
             # we got an expicit stylesheet
             if os.path.isfile(args.stylesheet):
                 with open(args.stylesheet) as f:
                     sheet = f.read()
                 widget.style_sheet = sheet
                 widget._style_sheet_changed()
             else:
                 raise IOError("Stylesheet %r not found."%args.stylesheet)
 
     # Create the main window.
     window = MainWindow(app, widget, args.existing, may_close=local_kernel)
     window.setWindowTitle('Python' if args.pure else 'IPython')
     window.show()
 
     # Start the application main loop.
     app.exec_()
 
 
 if __name__ == '__main__':
     main()

IPython/frontend/qt/console/pygments_highlighter.py

@@ -1,226 +1,224 b''
 # System library imports.
-from PyQt4 import QtGui
+from IPython.external.qt import QtGui
 from pygments.formatters.html import HtmlFormatter
 from pygments.lexer import RegexLexer, _TokenType, Text, Error
 from pygments.lexers import PythonLexer
 from pygments.styles import get_style_by_name
 
 
 def get_tokens_unprocessed(self, text, stack=('root',)):
     """ Split ``text`` into (tokentype, text) pairs.
 
         Monkeypatched to store the final stack on the object itself.
     """
     pos = 0
     tokendefs = self._tokens
     if hasattr(self, '_saved_state_stack'):
         statestack = list(self._saved_state_stack)
     else:
         statestack = list(stack)
     statetokens = tokendefs[statestack[-1]]
     while 1:
         for rexmatch, action, new_state in statetokens:
             m = rexmatch(text, pos)
             if m:
                 if type(action) is _TokenType:
                     yield pos, action, m.group()
                 else:
                     for item in action(self, m):
                         yield item
                 pos = m.end()
                 if new_state is not None:
                     # state transition
                     if isinstance(new_state, tuple):
                         for state in new_state:
                             if state == '#pop':
                                 statestack.pop()
                             elif state == '#push':
                                 statestack.append(statestack[-1])
                             else:
                                 statestack.append(state)
                     elif isinstance(new_state, int):
                         # pop
                         del statestack[new_state:]
                     elif new_state == '#push':
                         statestack.append(statestack[-1])
                     else:
                         assert False, "wrong state def: %r" % new_state
                     statetokens = tokendefs[statestack[-1]]
                 break
         else:
             try:
                 if text[pos] == '\n':
                     # at EOL, reset state to "root"
                     pos += 1
                     statestack = ['root']
                     statetokens = tokendefs['root']
                     yield pos, Text, u'\n'
                     continue
                 yield pos, Error, text[pos]
                 pos += 1
             except IndexError:
                 break
     self._saved_state_stack = list(statestack)
 
 # Monkeypatch!
 RegexLexer.get_tokens_unprocessed = get_tokens_unprocessed
 
 
 class PygmentsBlockUserData(QtGui.QTextBlockUserData):
     """ Storage for the user data associated with each line.
     """
 
     syntax_stack = ('root',)
 
     def __init__(self, **kwds):
         for key, value in kwds.iteritems():
             setattr(self, key, value)
         QtGui.QTextBlockUserData.__init__(self)
 
     def __repr__(self):
         attrs = ['syntax_stack']
         kwds = ', '.join([ '%s=%r' % (attr, getattr(self, attr)) 
                            for attr in attrs ])
         return 'PygmentsBlockUserData(%s)' % kwds
 
 
 class PygmentsHighlighter(QtGui.QSyntaxHighlighter):
     """ Syntax highlighter that uses Pygments for parsing. """
 
     #---------------------------------------------------------------------------
     # 'QSyntaxHighlighter' interface
     #---------------------------------------------------------------------------
 
     def __init__(self, parent, lexer=None):
         super(PygmentsHighlighter, self).__init__(parent)
 
         self._document = QtGui.QTextDocument()
         self._formatter = HtmlFormatter(nowrap=True)
         self._lexer = lexer if lexer else PythonLexer()
         self.set_style('default')
 
-    def highlightBlock(self, qstring):
+    def highlightBlock(self, string):
         """ Highlight a block of text.
         """
-        qstring = unicode(qstring)
         prev_data = self.currentBlock().previous().userData()
-
         if prev_data is not None:
             self._lexer._saved_state_stack = prev_data.syntax_stack
         elif hasattr(self._lexer, '_saved_state_stack'):
             del self._lexer._saved_state_stack
 
         # Lex the text using Pygments
         index = 0
-        for token, text in self._lexer.get_tokens(qstring):
+        for token, text in self._lexer.get_tokens(string):
             length = len(text)
             self.setFormat(index, length, self._get_format(token))
             index += length
 
         if hasattr(self._lexer, '_saved_state_stack'):
             data = PygmentsBlockUserData(
                 syntax_stack=self._lexer._saved_state_stack)
             self.currentBlock().setUserData(data)
             # Clean up for the next go-round.
             del self._lexer._saved_state_stack
 
     #---------------------------------------------------------------------------
     # 'PygmentsHighlighter' interface
     #---------------------------------------------------------------------------
 
     def set_style(self, style):
         """ Sets the style to the specified Pygments style.
         """
         if isinstance(style, basestring):
             style = get_style_by_name(style)
         self._style = style
         self._clear_caches()
 
     def set_style_sheet(self, stylesheet):
         """ Sets a CSS stylesheet. The classes in the stylesheet should
         correspond to those generated by:
 
             pygmentize -S <style> -f html
 
         Note that 'set_style' and 'set_style_sheet' completely override each
         other, i.e. they cannot be used in conjunction.
         """
         self._document.setDefaultStyleSheet(stylesheet)
         self._style = None
         self._clear_caches()
 
     #---------------------------------------------------------------------------
     # Protected interface
     #---------------------------------------------------------------------------
 
     def _clear_caches(self):
         """ Clear caches for brushes and formats.
         """
         self._brushes = {}
         self._formats = {}
 
     def _get_format(self, token):
         """ Returns a QTextCharFormat for token or None.
         """
         if token in self._formats:
             return self._formats[token]
 
         if self._style is None:
             result = self._get_format_from_document(token, self._document)
         else:
             result = self._get_format_from_style(token, self._style)
 
         self._formats[token] = result
         return result
 
     def _get_format_from_document(self, token, document):
         """ Returns a QTextCharFormat for token by 
         """
         code, html = self._formatter._format_lines([(token, 'dummy')]).next()
         self._document.setHtml(html)
         return QtGui.QTextCursor(self._document).charFormat()
 
     def _get_format_from_style(self, token, style):
         """ Returns a QTextCharFormat for token by reading a Pygments style.
         """
         result = QtGui.QTextCharFormat()
         for key, value in style.style_for_token(token).items():
             if value:
                 if key == 'color':
                     result.setForeground(self._get_brush(value))
                 elif key == 'bgcolor':
                     result.setBackground(self._get_brush(value))
                 elif key == 'bold':
                     result.setFontWeight(QtGui.QFont.Bold)
                 elif key == 'italic':
                     result.setFontItalic(True)
                 elif key == 'underline':
                     result.setUnderlineStyle(
                         QtGui.QTextCharFormat.SingleUnderline)
                 elif key == 'sans':
                     result.setFontStyleHint(QtGui.QFont.SansSerif)
                 elif key == 'roman':
                     result.setFontStyleHint(QtGui.QFont.Times)
                 elif key == 'mono':
                     result.setFontStyleHint(QtGui.QFont.TypeWriter)
         return result
 
     def _get_brush(self, color):
         """ Returns a brush for the color.
         """
         result = self._brushes.get(color)
         if result is None:
             qcolor = self._get_color(color)
             result = QtGui.QBrush(qcolor)
             self._brushes[color] = result
         return result
 
     def _get_color(self, color):
         """ Returns a QColor built from a Pygments color string.
         """
         qcolor = QtGui.QColor()
         qcolor.setRgb(int(color[:2], base=16),
                       int(color[2:4], base=16),
                       int(color[4:6], base=16))
         return qcolor
 

IPython/frontend/qt/console/rich_ipython_widget.py

@@ -1,271 +1,273 b''
-# System library imports
+# Standard libary imports.
+from base64 import decodestring
 import os
 import re
-from base64 import decodestring
-from PyQt4 import QtCore, QtGui
+
+# System libary imports.
+from IPython.external.qt import QtCore, QtGui
 
 # Local imports
 from IPython.frontend.qt.svg import save_svg, svg_to_clipboard, svg_to_image
 from ipython_widget import IPythonWidget
 
 
 class RichIPythonWidget(IPythonWidget):
     """ An IPythonWidget that supports rich text, including lists, images, and
         tables. Note that raw performance will be reduced compared to the plain
         text version.
     """
 
     # RichIPythonWidget protected class variables.
     _payload_source_plot = 'IPython.zmq.pylab.backend_payload.add_plot_payload'
     _svg_text_format_property = 1
 
     #---------------------------------------------------------------------------
     # 'object' interface
     #---------------------------------------------------------------------------
 
     def __init__(self, *args, **kw):
         """ Create a RichIPythonWidget.
         """
         kw['kind'] = 'rich'
         super(RichIPythonWidget, self).__init__(*args, **kw)
         # Dictionary for resolving Qt names to images when
         # generating XHTML output
         self._name_to_svg = {}
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _context_menu_make(self, pos):
         """ Reimplemented to return a custom context menu for images.
         """
         format = self._control.cursorForPosition(pos).charFormat()
         name = format.stringProperty(QtGui.QTextFormat.ImageName)
         if name.isEmpty():
             menu = super(RichIPythonWidget, self)._context_menu_make(pos)
         else:
             menu = QtGui.QMenu()
 
             menu.addAction('Copy Image', lambda: self._copy_image(name))
             menu.addAction('Save Image As...', lambda: self._save_image(name))
             menu.addSeparator()
 
             svg = format.stringProperty(self._svg_text_format_property)
             if not svg.isEmpty():
                 menu.addSeparator()
                 menu.addAction('Copy SVG', lambda: svg_to_clipboard(svg))
                 menu.addAction('Save SVG As...', 
                                lambda: save_svg(svg, self._control))
         return menu
 
     #---------------------------------------------------------------------------
     # 'BaseFrontendMixin' abstract interface
     #---------------------------------------------------------------------------
 
     def _handle_pyout(self, msg):
         """ Overridden to handle rich data types, like SVG.
         """
         if not self._hidden and self._is_from_this_session(msg):
             content = msg['content']
             prompt_number = content['execution_count']
             data = content['data']
             if data.has_key('image/svg+xml'):
                 self._append_plain_text(self.output_sep)
                 self._append_html(self._make_out_prompt(prompt_number))
                 # TODO: try/except this call.
                 self._append_svg(data['image/svg+xml'])
                 self._append_html(self.output_sep2)
             elif data.has_key('image/png'):
                 self._append_plain_text(self.output_sep)
                 self._append_html(self._make_out_prompt(prompt_number))
                 # This helps the output to look nice.
                 self._append_plain_text('\n')
                 # TODO: try/except these calls
                 png = decodestring(data['image/png'])
                 self._append_png(png)
                 self._append_html(self.output_sep2)
             else:
                 # Default back to the plain text representation.
                 return super(RichIPythonWidget, self)._handle_pyout(msg)
 
     def _handle_display_data(self, msg):
         """ Overridden to handle rich data types, like SVG.
         """
         if not self._hidden and self._is_from_this_session(msg):
             source = msg['content']['source']
             data = msg['content']['data']
             metadata = msg['content']['metadata']
             # Try to use the svg or html representations.
             # FIXME: Is this the right ordering of things to try?
             if data.has_key('image/svg+xml'):
                 svg = data['image/svg+xml']
                 # TODO: try/except this call.
                 self._append_svg(svg)
             elif data.has_key('image/png'):
                 # TODO: try/except these calls
                 # PNG data is base64 encoded as it passes over the network
                 # in a JSON structure so we decode it.
                 png = decodestring(data['image/png'])
                 self._append_png(png)
             else:
                 # Default back to the plain text representation.
                 return super(RichIPythonWidget, self)._handle_display_data(msg)
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _process_execute_payload(self, item):
         """ Reimplemented to handle matplotlib plot payloads.
         """
         # TODO: remove this as all plot data is coming back through the
         # display_data message type.
         if item['source'] == self._payload_source_plot:
             if item['format'] == 'svg':
                 svg = item['data']
                 self._append_svg(svg)
                 return True
             else:
                 # Add other plot formats here!
                 return False
         else:
             return super(RichIPythonWidget, self)._process_execute_payload(item)
 
     #---------------------------------------------------------------------------
     # 'RichIPythonWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _append_svg(self, svg):
         """ Append raw svg data to the widget.
         """
         try:
             image = svg_to_image(svg)
         except ValueError:
             self._append_plain_text('Received invalid plot data.')
         else:
             format = self._add_image(image)
             self._name_to_svg[str(format.name())] = svg
             format.setProperty(self._svg_text_format_property, svg)
             cursor = self._get_end_cursor()
             cursor.insertBlock()
             cursor.insertImage(format)
             cursor.insertBlock()
 
     def _append_png(self, png):
         """ Append raw svg data to the widget.
         """
         try:
             image = QtGui.QImage()
             image.loadFromData(png, 'PNG')
         except ValueError:
             self._append_plain_text('Received invalid plot data.')
         else:
             format = self._add_image(image)
             cursor = self._get_end_cursor()
             cursor.insertBlock()
             cursor.insertImage(format)
             cursor.insertBlock()
 
     def _add_image(self, image):
         """ Adds the specified QImage to the document and returns a
             QTextImageFormat that references it.
         """
         document = self._control.document()
-        name = QtCore.QString.number(image.cacheKey())
+        name = str(image.cacheKey())
         document.addResource(QtGui.QTextDocument.ImageResource,
                              QtCore.QUrl(name), image)
         format = QtGui.QTextImageFormat()
         format.setName(name)
         return format
 
     def _copy_image(self, name):
         """ Copies the ImageResource with 'name' to the clipboard.
         """
         image = self._get_image(name)
         QtGui.QApplication.clipboard().setImage(image)
 
     def _get_image(self, name):
         """ Returns the QImage stored as the ImageResource with 'name'.
         """
         document = self._control.document()
         variant = document.resource(QtGui.QTextDocument.ImageResource,
                                     QtCore.QUrl(name))
         return variant.toPyObject()
 
     def _save_image(self, name, format='PNG'):
         """ Shows a save dialog for the ImageResource with 'name'.
         """
         dialog = QtGui.QFileDialog(self._control, 'Save Image')
         dialog.setAcceptMode(QtGui.QFileDialog.AcceptSave)
         dialog.setDefaultSuffix(format.lower())
         dialog.setNameFilter('%s file (*.%s)' % (format, format.lower()))
         if dialog.exec_():
             filename = dialog.selectedFiles()[0]
             image = self._get_image(name)
             image.save(filename, format)
 
     def image_tag(self, match, path = None, format = "png"):
         """ Return (X)HTML mark-up for the image-tag given by match.
 
         Parameters
         ----------
         match : re.SRE_Match 
             A match to an HTML image tag as exported by Qt, with
             match.group("Name") containing the matched image ID.
 
         path : string|None, optional [default None]
             If not None, specifies a path to which supporting files
             may be written (e.g., for linked images).
             If None, all images are to be included inline.
 
         format : "png"|"svg", optional [default "png"]
             Format for returned or referenced images.
 
         Subclasses supporting image display should override this
         method.
         """
 
         if(format == "png"):
             try:
                 image = self._get_image(match.group("name"))
             except KeyError:
                 return "<b>Couldn't find image %s</b>" % match.group("name")
 
             if(path is not None):
                 if not os.path.exists(path):
                     os.mkdir(path)
                 relpath = os.path.basename(path)
                 if(image.save("%s/qt_img%s.png" % (path,match.group("name")),
                               "PNG")):
                     return '<img src="%s/qt_img%s.png">' % (relpath,
                                                             match.group("name"))
                 else:
                     return "<b>Couldn't save image!</b>"
             else:
                 ba = QtCore.QByteArray()
                 buffer_ = QtCore.QBuffer(ba)
                 buffer_.open(QtCore.QIODevice.WriteOnly)
                 image.save(buffer_, "PNG")
                 buffer_.close()
                 return '<img src="data:image/png;base64,\n%s\n" />' % (
                     re.sub(r'(.{60})',r'\1\n',str(ba.toBase64())))
 
         elif(format == "svg"):
             try:
                 svg = str(self._name_to_svg[match.group("name")])
             except KeyError:
                 return "<b>Couldn't find image %s</b>" % match.group("name")
 
             # Not currently checking path, because it's tricky to find a
             # cross-browser way to embed external SVG images (e.g., via
             # object or embed tags).
 
             # Chop stand-alone header from matplotlib SVG
             offset = svg.find("<svg")
             assert(offset > -1)
             
             return svg[offset:]
 
         else:
             return '<b>Unrecognized image format</b>'
 

IPython/frontend/qt/kernelmanager.py

@@ -1,242 +1,242 b''
 """ Defines a KernelManager that provides signals and slots.
 """
 
 # System library imports.
-from PyQt4 import QtCore
+from IPython.external.qt import QtCore
 
 # IPython imports.
 from IPython.utils.traitlets import Type
 from IPython.zmq.kernelmanager import KernelManager, SubSocketChannel, \
     XReqSocketChannel, RepSocketChannel, HBSocketChannel
 from util import MetaQObjectHasTraits, SuperQObject
 
 
 class SocketChannelQObject(SuperQObject):
 
     # Emitted when the channel is started.
-    started = QtCore.pyqtSignal()
+    started = QtCore.Signal()
 
     # Emitted when the channel is stopped.
-    stopped = QtCore.pyqtSignal()
+    stopped = QtCore.Signal()
 
     #---------------------------------------------------------------------------
     # 'ZmqSocketChannel' interface
     #---------------------------------------------------------------------------
 
     def start(self):
         """ Reimplemented to emit signal.
         """
         super(SocketChannelQObject, self).start()
         self.started.emit()
 
     def stop(self):
         """ Reimplemented to emit signal.
         """
         super(SocketChannelQObject, self).stop()
         self.stopped.emit()
 
 
 class QtXReqSocketChannel(SocketChannelQObject, XReqSocketChannel):
 
     # Emitted when any message is received.
-    message_received = QtCore.pyqtSignal(object)
+    message_received = QtCore.Signal(object)
 
     # Emitted when a reply has been received for the corresponding request
     # type.
-    execute_reply = QtCore.pyqtSignal(object)
-    complete_reply = QtCore.pyqtSignal(object)
-    object_info_reply = QtCore.pyqtSignal(object)
+    execute_reply = QtCore.Signal(object)
+    complete_reply = QtCore.Signal(object)
+    object_info_reply = QtCore.Signal(object)
 
     # Emitted when the first reply comes back.
-    first_reply = QtCore.pyqtSignal()
+    first_reply = QtCore.Signal()
 
     # Used by the first_reply signal logic to determine if a reply is the 
     # first.
     _handlers_called = False
 
     #---------------------------------------------------------------------------
     # 'XReqSocketChannel' interface
     #---------------------------------------------------------------------------
     
     def call_handlers(self, msg):
         """ Reimplemented to emit signals instead of making callbacks.
         """
         # Emit the generic signal.
         self.message_received.emit(msg)
         
         # Emit signals for specialized message types.
         msg_type = msg['msg_type']
         signal = getattr(self, msg_type, None)
         if signal:
             signal.emit(msg)
 
         if not self._handlers_called:
             self.first_reply.emit()
             self._handlers_called = True
 
     #---------------------------------------------------------------------------
     # 'QtXReqSocketChannel' interface
     #---------------------------------------------------------------------------
 
     def reset_first_reply(self):
         """ Reset the first_reply signal to fire again on the next reply.
         """
         self._handlers_called = False
 
 
 class QtSubSocketChannel(SocketChannelQObject, SubSocketChannel):
 
     # Emitted when any message is received.
-    message_received = QtCore.pyqtSignal(object)
+    message_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'stream' is received.
-    stream_received = QtCore.pyqtSignal(object)
+    stream_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'pyin' is received.
-    pyin_received = QtCore.pyqtSignal(object)
+    pyin_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'pyout' is received.
-    pyout_received = QtCore.pyqtSignal(object)
+    pyout_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'pyerr' is received.
-    pyerr_received = QtCore.pyqtSignal(object)
+    pyerr_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'display_data' is received
     display_data_received = QtCore.pyqtSignal(object)
 
     # Emitted when a crash report message is received from the kernel's
     # last-resort sys.excepthook.
-    crash_received = QtCore.pyqtSignal(object)
+    crash_received = QtCore.Signal(object)
 
     # Emitted when a shutdown is noticed.
-    shutdown_reply_received = QtCore.pyqtSignal(object)
+    shutdown_reply_received = QtCore.Signal(object)
 
     #---------------------------------------------------------------------------
     # 'SubSocketChannel' interface
     #---------------------------------------------------------------------------
     
     def call_handlers(self, msg):
         """ Reimplemented to emit signals instead of making callbacks.
         """
         # Emit the generic signal.
         self.message_received.emit(msg)
         # Emit signals for specialized message types.
         msg_type = msg['msg_type']
         signal = getattr(self, msg_type + '_received', None)
         if signal:
             signal.emit(msg)
         elif msg_type in ('stdout', 'stderr'):
             self.stream_received.emit(msg)
 
     def flush(self):
         """ Reimplemented to ensure that signals are dispatched immediately.
         """
         super(QtSubSocketChannel, self).flush()
         QtCore.QCoreApplication.instance().processEvents()
 
 
 class QtRepSocketChannel(SocketChannelQObject, RepSocketChannel):
 
     # Emitted when any message is received.
-    message_received = QtCore.pyqtSignal(object)
+    message_received = QtCore.Signal(object)
 
     # Emitted when an input request is received.
-    input_requested = QtCore.pyqtSignal(object)
+    input_requested = QtCore.Signal(object)
 
     #---------------------------------------------------------------------------
     # 'RepSocketChannel' interface
     #---------------------------------------------------------------------------
 
     def call_handlers(self, msg):
         """ Reimplemented to emit signals instead of making callbacks.
         """
         # Emit the generic signal.
         self.message_received.emit(msg)
         
         # Emit signals for specialized message types.
         msg_type = msg['msg_type']
         if msg_type == 'input_request':
             self.input_requested.emit(msg)
 
 
 class QtHBSocketChannel(SocketChannelQObject, HBSocketChannel):
 
     # Emitted when the kernel has died.
-    kernel_died = QtCore.pyqtSignal(object)
+    kernel_died = QtCore.Signal(object)
 
     #---------------------------------------------------------------------------
     # 'HBSocketChannel' interface
     #---------------------------------------------------------------------------
 
     def call_handlers(self, since_last_heartbeat):
         """ Reimplemented to emit signals instead of making callbacks.
         """
         # Emit the generic signal.
         self.kernel_died.emit(since_last_heartbeat)
 
 
 class QtKernelManager(KernelManager, SuperQObject):
     """ A KernelManager that provides signals and slots.
     """
 
     __metaclass__ = MetaQObjectHasTraits
 
     # Emitted when the kernel manager has started listening.
-    started_channels = QtCore.pyqtSignal()
+    started_channels = QtCore.Signal()
 
     # Emitted when the kernel manager has stopped listening.
-    stopped_channels = QtCore.pyqtSignal()
+    stopped_channels = QtCore.Signal()
 
     # Use Qt-specific channel classes that emit signals.
     sub_channel_class = Type(QtSubSocketChannel)
     xreq_channel_class = Type(QtXReqSocketChannel)
     rep_channel_class = Type(QtRepSocketChannel)
     hb_channel_class = Type(QtHBSocketChannel)
 
     #---------------------------------------------------------------------------
     # 'KernelManager' interface
     #---------------------------------------------------------------------------
 
     #------ Kernel process management ------------------------------------------
 
     def start_kernel(self, *args, **kw):
         """ Reimplemented for proper heartbeat management.
         """
         if self._xreq_channel is not None:
             self._xreq_channel.reset_first_reply()
         super(QtKernelManager, self).start_kernel(*args, **kw)
 
     #------ Channel management -------------------------------------------------
     
     def start_channels(self, *args, **kw):
         """ Reimplemented to emit signal.
         """
         super(QtKernelManager, self).start_channels(*args, **kw)
         self.started_channels.emit()
 
     def stop_channels(self):
         """ Reimplemented to emit signal.
         """ 
         super(QtKernelManager, self).stop_channels()
         self.stopped_channels.emit()
 
     @property
     def xreq_channel(self):
         """ Reimplemented for proper heartbeat management.
         """
         if self._xreq_channel is None:
             self._xreq_channel = super(QtKernelManager, self).xreq_channel
             self._xreq_channel.first_reply.connect(self._first_reply)
         return self._xreq_channel
 
     #---------------------------------------------------------------------------
     # Protected interface
     #---------------------------------------------------------------------------
     
     def _first_reply(self):
         """ Unpauses the heartbeat channel when the first reply is received on
             the execute channel. Note that this will *not* start the heartbeat
             channel if it is not already running!
         """
         if self._hb_channel is not None:
             self._hb_channel.unpause()

IPython/frontend/qt/svg.py

@@ -1,89 +1,80 b''
 """ Defines utility functions for working with SVG documents in Qt.
 """
 
 # System library imports.
-from PyQt4 import QtCore, QtGui, QtSvg
+from IPython.external.qt import QtCore, QtGui, QtSvg
 
 
 def save_svg(string, parent=None):
     """ Prompts the user to save an SVG document to disk.
 
     Parameters:
     -----------
     string : str
-        A Python string or QString containing a SVG document.
+        A Python string containing a SVG document.
 
     parent : QWidget, optional
         The parent to use for the file dialog.
 
     Returns:
     --------
     The name of the file to which the document was saved, or None if the save
     was cancelled.
     """
     dialog = QtGui.QFileDialog(parent, 'Save SVG Document')
     dialog.setAcceptMode(QtGui.QFileDialog.AcceptSave)
     dialog.setDefaultSuffix('svg')
     dialog.setNameFilter('SVG document (*.svg)')
     if dialog.exec_():
         filename = dialog.selectedFiles()[0]
         f = open(filename, 'w')
         try:
             f.write(string)
         finally:
             f.close()
         return filename
     return None
 
 def svg_to_clipboard(string):
     """ Copy a SVG document to the clipboard.
 
     Parameters:
     -----------
     string : str
-        A Python string or QString containing a SVG document.
+        A Python string containing a SVG document.
     """
-    if isinstance(string, basestring):
-        bytes = QtCore.QByteArray(string)
-    else:
-        bytes = string.toAscii()
     mime_data = QtCore.QMimeData()
-    mime_data.setData('image/svg+xml', bytes)
+    mime_data.setData('image/svg+xml', string)
     QtGui.QApplication.clipboard().setMimeData(mime_data)
         
 def svg_to_image(string, size=None):
     """ Convert a SVG document to a QImage.
 
     Parameters:
     -----------
     string : str
-        A Python string or QString containing a SVG document.
+        A Python string containing a SVG document.
 
     size : QSize, optional
         The size of the image that is produced. If not specified, the SVG
         document's default size is used.
     
     Raises:
     -------
     ValueError
         If an invalid SVG string is provided.
 
     Returns:
     --------
     A QImage of format QImage.Format_ARGB32.
     """
-    if isinstance(string, basestring):
-        bytes = QtCore.QByteArray.fromRawData(string) # shallow copy
-    else:
-        bytes = string.toAscii()
-
-    renderer = QtSvg.QSvgRenderer(bytes)
+    renderer = QtSvg.QSvgRenderer(QtCore.QByteArray(string))
     if not renderer.isValid():
         raise ValueError('Invalid SVG data.')
 
     if size is None:
         size = renderer.defaultSize()
     image = QtGui.QImage(size, QtGui.QImage.Format_ARGB32)
     painter = QtGui.QPainter(image)
     renderer.render(painter)
     return image

IPython/frontend/qt/util.py

@@ -1,106 +1,106 b''
 """ Defines miscellaneous Qt-related helper classes and functions.
 """
 
 # Standard library imports.
 import inspect
 
 # System library imports.
-from PyQt4 import QtCore, QtGui
+from IPython.external.qt import QtCore, QtGui
 
 # IPython imports.
 from IPython.utils.traitlets import HasTraits, TraitType
 
 #-----------------------------------------------------------------------------
 # Metaclasses
 #-----------------------------------------------------------------------------
 
 MetaHasTraits = type(HasTraits)
 MetaQObject = type(QtCore.QObject)
 
 class MetaQObjectHasTraits(MetaQObject, MetaHasTraits):
     """ A metaclass that inherits from the metaclasses of HasTraits and QObject.
 
     Using this metaclass allows a class to inherit from both HasTraits and
     QObject. Using SuperQObject instead of QObject is highly recommended. See
     QtKernelManager for an example.
     """
     def __new__(mcls, name, bases, classdict):
         # FIXME: this duplicates the code from MetaHasTraits.
         # I don't think a super() call will help me here.
         for k,v in classdict.iteritems():
             if isinstance(v, TraitType):
                 v.name = k
             elif inspect.isclass(v):
                 if issubclass(v, TraitType):
                     vinst = v()
                     vinst.name = k
                     classdict[k] = vinst
         cls = MetaQObject.__new__(mcls, name, bases, classdict)
         return cls
 
     def __init__(mcls, name, bases, classdict):
         # Note: super() did not work, so we explicitly call these.
         MetaQObject.__init__(mcls, name, bases, classdict)
         MetaHasTraits.__init__(mcls, name, bases, classdict)
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class SuperQObject(QtCore.QObject):
     """ Permits the use of super() in class hierarchies that contain QObject.
 
     Unlike QObject, SuperQObject does not accept a QObject parent. If it did,
     super could not be emulated properly (all other classes in the heierarchy
     would have to accept the parent argument--they don't, of course, because
     they don't inherit QObject.)
 
     This class is primarily useful for attaching signals to existing non-Qt
     classes. See QtKernelManager for an example.
     """
 
     def __new__(cls, *args, **kw):
         # We initialize QObject as early as possible. Without this, Qt complains
         # if SuperQObject is not the first class in the super class list.
         inst = QtCore.QObject.__new__(cls)
         QtCore.QObject.__init__(inst)
         return inst
 
     def __init__(self, *args, **kw):
         # Emulate super by calling the next method in the MRO, if there is one.
         mro = self.__class__.mro()
         for qt_class in QtCore.QObject.mro():
             mro.remove(qt_class)
         next_index = mro.index(SuperQObject) + 1
         if next_index < len(mro):
             mro[next_index].__init__(self, *args, **kw)
 
 #-----------------------------------------------------------------------------
 # Functions
 #-----------------------------------------------------------------------------
 
 def get_font(family, fallback=None):
     """Return a font of the requested family, using fallback as alternative.
 
     If a fallback is provided, it is used in case the requested family isn't
     found.  If no fallback is given, no alternative is chosen and Qt's internal
     algorithms may automatically choose a fallback font.
 
     Parameters
     ----------
     family : str
       A font name.
     fallback : str
       A font name.
 
     Returns
     -------
     font : QFont object
     """
     font = QtGui.QFont(family)
     # Check whether we got what we wanted using QFontInfo, since exactMatch()
     # is overly strict and returns false in too many cases.
     font_info = QtGui.QFontInfo(font)
     if fallback is not None and font_info.family() != family:
         font = QtGui.QFont(fallback)
     return font