new completer for qtconsole.

add a completer to the qtconsole that is navigable by arraow keys and
tab. One need to call it twice to get it on focus and be able to select
completion with Return. looks like zsh completer, not the gui drop down
list of --gui-completer.

This also try to split the completion logic from console_widget, and try
to keep the old completer qui around. The plain completer that never
takes focus back, and the QlistWidget completer.

to switch between the 3, the --gui-completion flag as been changed to
take an argument (plain, droplist, ncurses).

IPython/frontend/qt/console/completion_html.py

@@ -0,0 +1,226 b''
+# System library imports
+from IPython.external.qt import QtCore, QtGui
+import IPython.utils.html_utils as html_utils
+
+
+class CompletionHtml(QtGui.QWidget):
+    """ A widget for tab completion,  navigable by arrow keys """
+
+    #--------------------------------------------------------------------------
+    # 'QObject' interface
+    #--------------------------------------------------------------------------
+
+    _items = ()
+    _index = (0, 0)
+    _consecutive_tab = 0
+    _size = (1, 1)
+    _old_cursor = None
+    _start_position = 0
+
+    def __init__(self, console_widget):
+        """ Create a completion widget that is attached to the specified Qt
+            text edit widget.
+        """
+        assert isinstance(console_widget._control, (QtGui.QTextEdit, QtGui.QPlainTextEdit))
+        super(CompletionHtml, self).__init__()
+
+        self._text_edit = console_widget._control
+        self._console_widget = console_widget
+        self._text_edit.installEventFilter(self)
+
+        # Ensure that the text edit keeps focus when widget is displayed.
+        self.setFocusProxy(self._text_edit)
+
+
+    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 = event.key()
+                if self._consecutive_tab == 0 and key in (QtCore.Qt.Key_Tab,):
+                    return False
+                elif self._consecutive_tab == 1 and key in (QtCore.Qt.Key_Tab,):
+                    # ok , called twice, we grab focus, and show the cursor
+                    self._consecutive_tab = self._consecutive_tab+1
+                    self._update_list()
+                    return True
+                elif self._consecutive_tab == 2:
+                    if key in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
+                        self._complete_current()
+                        return True
+                    if key in (QtCore.Qt.Key_Tab,):
+                        self.select_right()
+                        self._update_list()
+                        return True
+                    elif key in ( QtCore.Qt.Key_Down,):
+                        self.select_down()
+                        self._update_list()
+                        return True
+                    elif key in (QtCore.Qt.Key_Right,):
+                        self.select_right()
+                        self._update_list()
+                        return True
+                    elif key in ( QtCore.Qt.Key_Up,):
+                        self.select_up()
+                        self._update_list()
+                        return True
+                    elif key in ( QtCore.Qt.Key_Left,):
+                        self.select_left()
+                        self._update_list()
+                        return True
+                    else :
+                        self._cancel_completion()
+                else:
+                    self._cancel_completion()
+
+            elif etype == QtCore.QEvent.FocusOut:
+                self._cancel_completion()
+
+        return super(CompletionHtml, self).eventFilter(obj, event)
+
+    #--------------------------------------------------------------------------
+    # 'CompletionHtml' interface
+    #--------------------------------------------------------------------------
+    def _cancel_completion(self):
+        """Cancel the completion, reseting internal variable, clearing buffer """
+        self._consecutive_tab = 0
+        self._console_widget._clear_temporary_buffer()
+        self._index = (0, 0)
+
+    #
+    #  ...  2 4 4 4 4 4 4 4 4 4 4  4  4
+    #   2   2 4 4 4 4 4 4 4 4 4 4  4  4
+    #
+    #2  2   x x x x x x x x x x x  5  5
+    #6  6   x x x x x x x x x x x  5  5
+    #6  6   x x x x x x x x x x ?  5  5
+    #6  6   x x x x x x x x x x ?  1  1
+    #
+    #3  3   3 3 3 3 3 3 3 3 3 3 1  1  1 ...
+    #3  3   3 3 3 3 3 3 3 3 3 3 1  1  1 ...
+    def _select_index(self, row, col):
+        """Change the selection index, and make sure it stays in the right range
+
+        A little more complicated than just dooing modulo the number of row columns
+        to be sure to cycle through all element.
+
+        horizontaly, the element are maped like this :
+        to r <-- a b c d e f --> to g
+        to f <-- g h i j k l --> to m
+        to l <-- m n o p q r --> to a
+
+        and vertically
+        a d g j m p
+        b e h k n q
+        c f i l o r
+        """
+
+        nr, nc = self._size
+        nr = nr-1
+        nc = nc-1
+
+        # case 1
+        if (row > nr and col >= nc) or (row >= nr and col > nc):
+            self._select_index(0, 0)
+        # case 2
+        elif (row <= 0 and col < 0) or  (row < 0 and col <= 0):
+            self._select_index(nr, nc)
+        # case 3
+        elif row > nr :
+            self._select_index(0, col+1)
+        # case 4
+        elif row < 0 :
+            self._select_index(nr, col-1)
+        # case 5
+        elif col > nc :
+            self._select_index(row+1, 0)
+        # case 6
+        elif col < 0 :
+            self._select_index(row-1, nc)
+        elif 0 <= row and row <= nr and 0 <= col and col <= nc :
+            self._index = (row, col)
+        else :
+            raise NotImplementedError("you'r trying to go where no completion\
+                           have gone before : %d:%d (%d:%d)"%(row, col, nr, nc) )
+
+
+
+    def select_up(self):
+        """move cursor up"""
+        r, c = self._index
+        self._select_index(r-1, c)
+
+    def select_down(self):
+        """move cursor down"""
+        r, c = self._index
+        self._select_index(r+1, c)
+
+    def select_left(self):
+        """move cursor left"""
+        r, c = self._index
+        self._select_index(r, c-1)
+
+    def select_right(self):
+        """move cursor right"""
+        r, c = self._index
+        self._select_index(r, c+1)
+
+    def show_items(self, cursor, items):
+        """ Shows the completion widget with 'items' at the position specified
+            by 'cursor'.
+        """
+        if not items :
+            return
+        self._start_position = cursor.position()
+        self._consecutive_tab = 1
+        ci = html_utils.columnize_info(items, empty=' ')
+        self._items = ci['item_matrix']
+        self._size = (ci['rows_number'], ci['columns_number'])
+        self._old_cursor = cursor
+        self._index = (0, 0)
+        self._update_list(hilight=False)
+
+
+    def _update_list(self, hilight=True):
+        """ update the list of completion and hilight the currently selected completion """
+        if len(self._items) > 100:
+            items = self._items[:100]
+        else :
+            items = self._items
+        items_m = items
+
+        self._console_widget._clear_temporary_buffer()
+        if(hilight):
+            strng = html_utils.html_tableify(items_m, select=self._index)
+        else:
+            strng = html_utils.html_tableify(items_m, select=None)
+        self._console_widget._fill_temporary_buffer(self._old_cursor, strng, html=True)
+
+    #--------------------------------------------------------------------------
+    # Protected interface
+    #--------------------------------------------------------------------------
+
+    def _complete_current(self):
+        """ Perform the completion with the currently selected item.
+        """
+        i = self._index
+        item = self._items[i[0]][i[1]]
+        item = item.strip()
+        if item :
+            self._current_text_cursor().insertText(item)
+        self._cancel_completion()
+
+    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
+
+

IPython/frontend/qt/console/completion_plain.py

@@ -0,0 +1,73 b''
+# System library imports
+from IPython.external.qt import QtCore, QtGui
+import IPython.utils.html_utils as html_utils
+
+
+class CompletionPlain(QtGui.QWidget):
+    """ A widget for tab completion,  navigable by arrow keys """
+
+    #--------------------------------------------------------------------------
+    # 'QObject' interface
+    #--------------------------------------------------------------------------
+
+    _items = ()
+    _index = (0, 0)
+    _old_cursor = None
+
+    def __init__(self, console_widget):
+        """ Create a completion widget that is attached to the specified Qt
+            text edit widget.
+        """
+        assert isinstance(console_widget._control, (QtGui.QTextEdit, QtGui.QPlainTextEdit))
+        super(CompletionPlain, self).__init__()
+
+        self._text_edit = console_widget._control
+        self._console_widget = console_widget
+
+        self._text_edit.installEventFilter(self)
+
+    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:
+                self._cancel_completion()
+
+        return super(CompletionPlain, self).eventFilter(obj, event)
+
+    #--------------------------------------------------------------------------
+    # 'CompletionPlain' interface
+    #--------------------------------------------------------------------------
+    def _cancel_completion(self):
+        """Cancel the completion, reseting internal variable, clearing buffer """
+        self._console_widget._clear_temporary_buffer()
+        self._index = (0, 0)
+
+
+    def show_items(self, cursor, items):
+        """ Shows the completion widget with 'items' at the position specified
+            by 'cursor'.
+        """
+        if not items :
+            return
+
+        ci = html_utils.columnize_info(items, empty=' ')
+        self._items = ci['item_matrix']
+        self._old_cursor = cursor
+        self._update_list()
+
+
+    def _update_list(self):
+        """ update the list of completion and hilight the currently selected completion """
+        if len(self._items) > 100:
+            items = self._items[:100]
+        else :
+            items = self._items
+        items_m = items
+
+        self._console_widget._clear_temporary_buffer()
+        strng = html_utils.html_tableify(items_m, select=None)
+        self._console_widget._fill_temporary_buffer(self._old_cursor, strng, html=True)

IPython/utils/html_utils.py

@@ -0,0 +1,124 b''
+"""some html utilis"""
+from IPython.core.display import HTML
+
+
+def columnize_info(items, separator_width=1, displaywidth=80, empty=None):
+    """ Get info on a list of string to display it as a multicolumns list
+
+    returns :
+    ---------
+
+    a dict containing several parameters:
+
+    'item_matrix'  : list of list with the innermost list representing a row
+    'columns_number': number of columns
+    'rows_number'   : number of rown
+    'columns_width' : a list indicating the maximum length of the element in each columns
+
+    Parameters :
+    ------------
+    separator_width : when trying to ajust the number of column, consider a separator size of this much caracters
+    displaywidth    : try to fit the columns in this width
+    empty           : if the number of items is different from nrows * ncols, fill with empty
+
+    """
+    # Note: this code is adapted from columnize 0.3.2.
+    # See http://code.google.com/p/pycolumnize/
+
+    # Some degenerate cases.
+    size = len(items)
+    if size == 0:
+        return {'item_matrix' :[[empty]],
+                'columns_number':1,
+                'rows_number':1,
+                'columns_width':[0]}
+    elif size == 1:
+        return {'item_matrix' :[[items[0]]],
+                'columns_number':1,
+                'rows_number':1,
+                'columns_width':[len(items[0])]}
+
+    # Special case: if any item is longer than the maximum width, there's no
+    # point in triggering the logic below...
+    item_len = map(len, items) # save these, we can reuse them below
+    #longest = max(item_len)
+    #if longest >= displaywidth:
+    #    return (items, [longest])
+
+    # Try every row count from 1 upwards
+    array_index = lambda nrows, row, col: nrows*col + row
+    nrows = 1
+    for nrows in range(1, size):
+        ncols = (size + nrows - 1) // nrows
+        colwidths = []
+        totwidth = -separator_width
+        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
+                len_x = item_len[i]
+                colwidth = max(colwidth, len_x)
+            colwidths.append(colwidth)
+            totwidth += colwidth + separator_width
+            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.
+    reorderd_items = []
+    for row in range(nrows):
+        texts = []
+        for col in range(ncols):
+            i = row + nrows*col
+            if i >= size:
+                texts.append(empty)
+            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])
+        reorderd_items.append(texts)
+
+    return {'item_matrix' :reorderd_items,
+            'columns_number':ncols,
+            'rows_number':nrows,
+            'columns_width':colwidths}
+
+
+def column_table(items, select=None) :
+    """ return a html table of the item with a select class on one"""
+    items_m = columnize_info(items)['item_matrix']
+    return HTML(html_tableify(items_m, select=select))
+
+def html_tableify(item_matrix, select=None) :
+    """ returnr a string for an html table"""
+    if not item_matrix :
+        return ''
+    html_cols = []
+    tds = lambda text : u'<td>'+text+u'</td>'
+    trs = lambda text : u'<tr>'+text+u'</tr>'
+    tds_items = [map(tds, row) for row in item_matrix ]
+    if select :
+        row, col = select
+        try :
+            tds_items[row][col] = u'<td class="inverted">'\
+                    +item_matrix[row][col]\
+                    +u'</td>'
+        except IndexError :
+            pass
+    #select the right item
+    html_cols = map(trs, (u''.join(row) for row in tds_items))
+    html = (u'<table class="completion">'+(u''.join(html_cols))+u'</table>')
+    css = u"""
+    <style>
+    table.completion tr td
+    { padding-right : 4px; }
+    </style>
+    """
+    return css+html

IPython/frontend/qt/console/completion_widget.py

@@ -1,134 +1,135 b''
 # System library imports
 from IPython.external.qt import QtCore, QtGui
 
 
 class CompletionWidget(QtGui.QListWidget):
     """ A widget for GUI tab completion.
     """
 
     #--------------------------------------------------------------------------
     # 'QObject' interface
     #--------------------------------------------------------------------------
 
-    def __init__(self, text_edit):
+    def __init__(self, console_widget):
         """ Create a completion widget that is attached to the specified Qt
             text edit widget.
         """
+        text_edit = console_widget._text_edit
         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)
         height = self.sizeHint().height()
         screen_rect = QtGui.QApplication.desktop().availableGeometry(self)
         if screen_rect.size().height() - point.y() - height < 0:
             point = text_edit.mapToGlobal(text_edit.cursorRect().topRight())
             point.setY(point.y() - 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

@@ -1,1878 +1,1880 b''
 """ An abstract base class for console-type widgets.
 """
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports
-import os
 from os.path import commonprefix
 import re
 import sys
 from textwrap import dedent
 from unicodedata import category
 
 # System library imports
 from IPython.external.qt import QtCore, QtGui
 
 # Local imports
 from IPython.config.configurable import LoggingConfigurable
 from IPython.frontend.qt.rich_text import HtmlExporter
 from IPython.frontend.qt.util import MetaQObjectHasTraits, get_font
 from IPython.utils.text import columnize
 from IPython.utils.traitlets import Bool, Enum, Integer, Unicode
 from ansi_code_processor import QtAnsiCodeProcessor
 from completion_widget import CompletionWidget
+from completion_html import CompletionHtml
+from completion_plain import CompletionPlain
 from kill_ring import QtKillRing
 
 #-----------------------------------------------------------------------------
 # Functions
 #-----------------------------------------------------------------------------
 
 def is_letter_or_number(char):
     """ Returns whether the specified unicode character is a letter or a number.
     """
     cat = category(char)
     return cat.startswith('L') or cat.startswith('N')
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class ConsoleWidget(LoggingConfigurable, QtGui.QWidget):
     """ An abstract base class for console-type widgets. This class has
         functionality for:
 
             * Maintaining a prompt and editing region
             * Providing the traditional Unix-style console keyboard shortcuts
             * Performing tab completion
             * Paging text
             * Handling ANSI escape codes
 
         ConsoleWidget also provides a number of utility methods that will be
         convenient to implementors of a console-style widget.
     """
     __metaclass__ = MetaQObjectHasTraits
 
     #------ Configuration ------------------------------------------------------
 
     ansi_codes = Bool(True, config=True,
         help="Whether to process ANSI escape codes."
     )
     buffer_size = Integer(500, config=True,
         help="""
         The maximum number of lines of text before truncation. Specifying a
         non-positive number disables text truncation (not recommended).
         """
     )
-    gui_completion = Bool(False, config=True,
-        help="""
-        Use a list widget instead of plain text output for tab completion.
-        """
+    gui_completion = Enum(['plain', 'droplist', 'ncurses'], config=True,
+                    default_value = 'ncurses',
+                    help="""
+                    The type of completer to use. Valid values are:
+
+                    'plain'   : Show the availlable completion as a text list
+                                Below the editting area.
+                    'droplist': Show the completion in a drop down list navigable
+                                by the arrow keys, and from which you can select
+                                completion by pressing Return.
+                    'ncurses' : Show the completion as a text list which is navigable by
+                                `tab` and arrow keys.
+                    """
     )
     # NOTE: this value can only be specified during initialization.
     kind = Enum(['plain', 'rich'], default_value='plain', config=True,
         help="""
         The type of underlying text widget to use. Valid values are 'plain',
         which specifies a QPlainTextEdit, and 'rich', which specifies a
         QTextEdit.
         """
     )
     # NOTE: this value can only be specified during initialization.
     paging = Enum(['inside', 'hsplit', 'vsplit', 'custom', 'none'],
                   default_value='inside', config=True,
         help="""
         The type of paging to use. Valid values are:
 
             'inside' : The widget pages like a traditional terminal.
             'hsplit' : When paging is requested, the widget is split
                        horizontally. The top pane contains the console, and the
                        bottom pane contains the paged text.
             '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.
         """)
 
     font_family = Unicode(config=True,
         help="""The font family to use for the console.
         On OSX this defaults to Monaco, on Windows the default is
         Consolas with fallback of Courier, and on other platforms
         the default is Monospace.
         """)
     def _font_family_default(self):
         if sys.platform == 'win32':
             # Consolas ships with Vista/Win7, fallback to Courier if needed
             return 'Consolas'
         elif sys.platform == 'darwin':
             # OSX always has Monaco, no need for a fallback
             return 'Monaco'
         else:
             # Monospace should always exist, no need for a fallback
             return 'Monospace'
 
     font_size = Integer(config=True,
         help="""The font size. If unconfigured, Qt will be entrusted
         with the size of the font.
         """)
 
     # Whether to override ShortcutEvents for the keybindings defined by this
     # widget (Ctrl+n, Ctrl+a, etc). Enable this if you want this widget to take
     # priority (when it has focus) over, e.g., window-level menu shortcuts.
     override_shortcuts = Bool(False)
 
     #------ Signals ------------------------------------------------------------
 
     # Signals that indicate ConsoleWidget state.
     copy_available = QtCore.Signal(bool)
     redo_available = QtCore.Signal(bool)
     undo_available = QtCore.Signal(bool)
 
     # Signal emitted when paging is needed and the paging style has been
     # specified as 'custom'.
     custom_page_requested = QtCore.Signal(object)
 
     # Signal emitted when the font is changed.
     font_changed = QtCore.Signal(QtGui.QFont)
 
     #------ Protected class variables ------------------------------------------
-    
+
     # control handles
     _control = None
     _page_control = None
     _splitter = None
-    
+
     # When the control key is down, these keys are mapped.
     _ctrl_down_remap = { QtCore.Qt.Key_B : QtCore.Qt.Key_Left,
                          QtCore.Qt.Key_F : QtCore.Qt.Key_Right,
                          QtCore.Qt.Key_A : QtCore.Qt.Key_Home,
                          QtCore.Qt.Key_P : QtCore.Qt.Key_Up,
                          QtCore.Qt.Key_N : QtCore.Qt.Key_Down,
                          QtCore.Qt.Key_H : QtCore.Qt.Key_Backspace, }
     if not sys.platform == 'darwin':
         # On OS X, Ctrl-E already does the right thing, whereas End moves the
         # cursor to the bottom of the buffer.
         _ctrl_down_remap[QtCore.Qt.Key_E] = QtCore.Qt.Key_End
 
     # The shortcuts defined by this widget. We need to keep track of these to
     # support 'override_shortcuts' above.
     _shortcuts = set(_ctrl_down_remap.keys() +
                      [ QtCore.Qt.Key_C, QtCore.Qt.Key_G, QtCore.Qt.Key_O,
                        QtCore.Qt.Key_V ])
 
+    _is_completing = False
+
     #---------------------------------------------------------------------------
     # '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)
         LoggingConfigurable.__init__(self, **kw)
 
         # While scrolling the pager on Mac OS X, it tears badly.  The
         # NativeGesture is platform and perhaps build-specific hence
         # we take adequate precautions here.
         self._pager_scroll_events = [QtCore.QEvent.Wheel]
         if hasattr(QtCore.QEvent, 'NativeGesture'):
             self._pager_scroll_events.append(QtCore.QEvent.NativeGesture)
 
         # Create the layout and underlying text widget.
         layout = QtGui.QStackedLayout(self)
         layout.setContentsMargins(0, 0, 0, 0)
         self._control = self._create_control()
         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._append_before_prompt_pos = 0
         self._ansi_processor = QtAnsiCodeProcessor()
-        self._completion_widget = CompletionWidget(self._control)
+        if self.gui_completion == 'ncurses':
+            self._completion_widget = CompletionHtml(self)
+        elif self.gui_completion == 'droplist':
+            self._completion_widget = CompletionWidget(self)
+        elif self.gui_completion == 'plain':
+            self._completion_widget = CompletionPlain(self)
+
         self._continuation_prompt = '> '
         self._continuation_prompt_html = None
         self._executing = False
         self._filter_drag = False
         self._filter_resize = False
         self._html_exporter = HtmlExporter(self._control)
         self._input_buffer_executing = ''
         self._input_buffer_pending = ''
         self._kill_ring = QtKillRing(self._control)
         self._prompt = ''
         self._prompt_html = None
         self._prompt_pos = 0
         self._prompt_sep = ''
         self._reading = False
         self._reading_callback = None
         self._tab_width = 8
-        self._text_completing_pos = 0
 
         # Set a monospaced font.
         self.reset_font()
 
         # Configure actions.
         action = QtGui.QAction('Print', None)
         action.setEnabled(True)
         printkey = QtGui.QKeySequence(QtGui.QKeySequence.Print)
         if printkey.matches("Ctrl+P") and sys.platform != 'darwin':
             # Only override the default if there is a collision.
             # Qt ctrl = cmd on OSX, so the match gets a false positive on OSX.
             printkey = "Ctrl+Shift+P"
         action.setShortcut(printkey)
         action.setShortcutContext(QtCore.Qt.WidgetWithChildrenShortcut)
         action.triggered.connect(self.print_)
         self.addAction(action)
         self.print_action = action
 
         action = QtGui.QAction('Save as HTML/XML', None)
         action.setShortcut(QtGui.QKeySequence.Save)
         action.setShortcutContext(QtCore.Qt.WidgetWithChildrenShortcut)
         action.triggered.connect(self.export_html)
         self.addAction(action)
         self.export_action = action
 
         action = QtGui.QAction('Select All', None)
         action.setEnabled(True)
         selectall = QtGui.QKeySequence(QtGui.QKeySequence.SelectAll)
         if selectall.matches("Ctrl+A") and sys.platform != 'darwin':
             # Only override the default if there is a collision.
             # Qt ctrl = cmd on OSX, so the match gets a false positive on OSX.
             selectall = "Ctrl+Shift+A"
         action.setShortcut(selectall)
         action.setShortcutContext(QtCore.Qt.WidgetWithChildrenShortcut)
         action.triggered.connect(self.select_all)
         self.addAction(action)
         self.select_all_action = action
 
         self.increase_font_size = QtGui.QAction("Bigger Font",
                 self,
                 shortcut=QtGui.QKeySequence.ZoomIn,
                 shortcutContext=QtCore.Qt.WidgetWithChildrenShortcut,
                 statusTip="Increase the font size by one point",
                 triggered=self._increase_font_size)
         self.addAction(self.increase_font_size)
 
         self.decrease_font_size = QtGui.QAction("Smaller Font",
                 self,
                 shortcut=QtGui.QKeySequence.ZoomOut,
                 shortcutContext=QtCore.Qt.WidgetWithChildrenShortcut,
                 statusTip="Decrease the font size by one point",
                 triggered=self._decrease_font_size)
         self.addAction(self.decrease_font_size)
 
         self.reset_font_size = QtGui.QAction("Normal Font",
                 self,
                 shortcut="Ctrl+0",
                 shortcutContext=QtCore.Qt.WidgetWithChildrenShortcut,
                 statusTip="Restore the Normal font size",
                 triggered=self.reset_font)
         self.addAction(self.reset_font_size)
 
 
 
     def eventFilter(self, obj, event):
         """ Reimplemented to ensure a console-like behavior in the underlying
             text widgets.
         """
         etype = event.type()
         if etype == QtCore.QEvent.KeyPress:
 
             # Re-map keys for all filtered widgets.
             key = event.key()
             if self._control_key_down(event.modifiers()) and \
                     key in self._ctrl_down_remap:
                 new_event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress,
                                             self._ctrl_down_remap[key],
                                             QtCore.Qt.NoModifier)
                 QtGui.qApp.sendEvent(obj, new_event)
                 return True
 
             elif obj == self._control:
                 return self._event_filter_console_keypress(event)
 
             elif obj == self._page_control:
                 return self._event_filter_page_keypress(event)
 
         # Make middle-click paste safe.
         elif etype == QtCore.QEvent.MouseButtonRelease and \
                 event.button() == QtCore.Qt.MidButton and \
                 obj == self._control.viewport():
             cursor = self._control.cursorForPosition(event.pos())
             self._control.setTextCursor(cursor)
             self.paste(QtGui.QClipboard.Selection)
             return True
 
         # Manually adjust the scrollbars *after* a resize event is dispatched.
         elif etype == QtCore.QEvent.Resize and not self._filter_resize:
             self._filter_resize = True
             QtGui.qApp.sendEvent(obj, event)
             self._adjust_scrollbars()
             self._filter_resize = False
             return True
 
         # Override shortcuts for all filtered widgets.
         elif etype == QtCore.QEvent.ShortcutOverride and \
                 self.override_shortcuts and \
                 self._control_key_down(event.modifiers()) and \
                 event.key() in self._shortcuts:
             event.accept()
 
         # Ensure that drags are safe. The problem is that the drag starting
         # logic, which determines whether the drag is a Copy or Move, is locked
         # down in QTextControl. If the widget is editable, which it must be if
         # we're not executing, the drag will be a Move. The following hack
         # prevents QTextControl from deleting the text by clearing the selection
         # when a drag leave event originating from this widget is dispatched.
         # The fact that we have to clear the user's selection is unfortunate,
         # but the alternative--trying to prevent Qt from using its hardwired
         # drag logic and writing our own--is worse.
         elif etype == QtCore.QEvent.DragEnter and \
                 obj == self._control.viewport() and \
                 event.source() == self._control.viewport():
             self._filter_drag = True
         elif etype == QtCore.QEvent.DragLeave and \
                 obj == self._control.viewport() and \
                 self._filter_drag:
             cursor = self._control.textCursor()
             cursor.clearSelection()
             self._control.setTextCursor(cursor)
             self._filter_drag = False
 
         # Ensure that drops are safe.
         elif etype == QtCore.QEvent.Drop and obj == self._control.viewport():
             cursor = self._control.cursorForPosition(event.pos())
             if self._in_buffer(cursor.position()):
                 text = event.mimeData().text()
                 self._insert_plain_text_into_buffer(cursor, text)
 
             # Qt is expecting to get something here--drag and drop occurs in its
             # own event loop. Send a DragLeave event to end it.
             QtGui.qApp.sendEvent(obj, QtGui.QDragLeaveEvent())
             return True
 
         # Handle scrolling of the vsplit pager. This hack attempts to solve
         # problems with tearing of the help text inside the pager window.  This
         # happens only on Mac OS X with both PySide and PyQt. This fix isn't
         # perfect but makes the pager more usable.
         elif etype in self._pager_scroll_events and \
                 obj == self._page_control:
             self._page_control.repaint()
             return True
         return super(ConsoleWidget, self).eventFilter(obj, event)
 
     #---------------------------------------------------------------------------
     # 'QWidget' interface
     #---------------------------------------------------------------------------
 
     def sizeHint(self):
         """ Reimplemented to suggest a size that is 80 characters wide and
             25 lines high.
         """
         font_metrics = QtGui.QFontMetrics(self.font)
         margin = (self._control.frameWidth() +
                   self._control.document().documentMargin()) * 2
         style = self.style()
         splitwidth = style.pixelMetric(QtGui.QStyle.PM_SplitterWidth)
 
         # Note 1: Despite my best efforts to take the various margins into
         # account, the width is still coming out a bit too small, so we include
         # a fudge factor of one character here.
         # Note 2: QFontMetrics.maxWidth is not used here or anywhere else due
         # to a Qt bug on certain Mac OS systems where it returns 0.
         width = font_metrics.width(' ') * 81 + margin
         width += style.pixelMetric(QtGui.QStyle.PM_ScrollBarExtent)
         if self.paging == 'hsplit':
             width = width * 2 + splitwidth
 
         height = font_metrics.height() * 25 + margin
         if self.paging == 'vsplit':
             height = height * 2 + splitwidth
 
         return QtCore.QSize(width, height)
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     def can_copy(self):
         """ Returns whether text can be copied to the clipboard.
         """
         return self._control.textCursor().hasSelection()
 
     def can_cut(self):
         """ Returns whether text can be cut to the clipboard.
         """
         cursor = self._control.textCursor()
         return (cursor.hasSelection() and
                 self._in_buffer(cursor.anchor()) and
                 self._in_buffer(cursor.position()))
 
     def can_paste(self):
         """ Returns whether text can be pasted from the clipboard.
         """
         if self._control.textInteractionFlags() & QtCore.Qt.TextEditable:
             return bool(QtGui.QApplication.clipboard().text())
         return False
 
     def clear(self, keep_input=True):
         """ Clear the console.
 
         Parameters:
         -----------
         keep_input : bool, optional (default True)
             If set, restores the old input buffer if a new prompt is written.
         """
         if self._executing:
             self._control.clear()
         else:
             if keep_input:
                 input_buffer = self.input_buffer
             self._control.clear()
             self._show_prompt()
             if keep_input:
                 self.input_buffer = input_buffer
 
     def copy(self):
         """ Copy the currently selected text to the clipboard.
         """
         self.layout().currentWidget().copy()
 
     def cut(self):
         """ Copy the currently selected text to the clipboard and delete it
             if it's inside the input buffer.
         """
         self.copy()
         if self.can_cut():
             self._control.textCursor().removeSelectedText()
 
     def execute(self, source=None, hidden=False, interactive=False):
         """ Executes source or the input buffer, possibly prompting for more
         input.
 
         Parameters:
         -----------
         source : str, optional
 
             The source to execute. If not specified, the input buffer will be
             used. If specified and 'hidden' is False, the input buffer will be
             replaced with the source before execution.
 
         hidden : bool, optional (default False)
 
             If set, no output will be shown and the prompt will not be modified.
             In other words, it will be completely invisible to the user that
             an execution has occurred.
 
         interactive : bool, optional (default False)
 
             Whether the console is to treat the source as having been manually
             entered by the user. The effect of this parameter depends on the
             subclass implementation.
 
         Raises:
         -------
         RuntimeError
             If incomplete input is given and 'hidden' is True. In this case,
             it is not possible to prompt for more input.
 
         Returns:
         --------
         A boolean indicating whether the source was executed.
         """
         # WARNING: The order in which things happen here is very particular, in
         # large part because our syntax highlighting is fragile. If you change
         # something, test carefully!
 
         # Decide what to execute.
         if source is None:
             source = self.input_buffer
             if not hidden:
                 # A newline is appended later, but it should be considered part
                 # of the input buffer.
                 source += '\n'
         elif not hidden:
             self.input_buffer = source
 
         # Execute the source or show a continuation prompt if it is incomplete.
         complete = self._is_complete(source, interactive)
         if hidden:
             if complete:
                 self._execute(source, hidden)
             else:
                 error = 'Incomplete noninteractive input: "%s"'
                 raise RuntimeError(error % source)
         else:
             if complete:
                 self._append_plain_text('\n')
                 self._input_buffer_executing = self.input_buffer
                 self._executing = True
                 self._prompt_finished()
 
                 # The maximum block count is only in effect during execution.
                 # This ensures that _prompt_pos does not become invalid due to
                 # text truncation.
                 self._control.document().setMaximumBlockCount(self.buffer_size)
 
                 # Setting a positive maximum block count will automatically
                 # disable the undo/redo history, but just to be safe:
                 self._control.setUndoRedoEnabled(False)
 
                 # Perform actual execution.
                 self._execute(source, hidden)
 
             else:
                 # Do this inside an edit block so continuation prompts are
                 # removed seamlessly via undo/redo.
                 cursor = self._get_end_cursor()
                 cursor.beginEditBlock()
                 cursor.insertText('\n')
                 self._insert_continuation_prompt(cursor)
                 cursor.endEditBlock()
 
                 # Do not do this inside the edit block. It works as expected
                 # when using a QPlainTextEdit control, but does not have an
                 # effect when using a QTextEdit. I believe this is a Qt bug.
                 self._control.moveCursor(QtGui.QTextCursor.End)
 
         return complete
 
     def export_html(self):
         """ Shows a dialog to export HTML/XML in various formats.
         """
         self._html_exporter.export()
 
     def _get_input_buffer(self, force=False):
         """ The text that the user has entered entered at the current prompt.
 
         If the console is currently executing, the text that is executing will
         always be returned.
         """
         # If we're executing, the input buffer may not even exist anymore due to
         # the limit imposed by 'buffer_size'. Therefore, we store it.
         if self._executing and not force:
             return self._input_buffer_executing
 
         cursor = self._get_end_cursor()
         cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
         input_buffer = cursor.selection().toPlainText()
 
         # Strip out continuation prompts.
         return input_buffer.replace('\n' + self._continuation_prompt, '\n')
 
     def _set_input_buffer(self, string):
         """ Sets the text in the input buffer.
 
         If the console is currently executing, this call has no *immediate*
         effect. When the execution is finished, the input buffer will be updated
         appropriately.
         """
         # If we're executing, store the text for later.
         if self._executing:
             self._input_buffer_pending = string
             return
 
         # Remove old text.
         cursor = self._get_end_cursor()
         cursor.beginEditBlock()
         cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
         cursor.removeSelectedText()
 
         # Insert new text with continuation prompts.
         self._insert_plain_text_into_buffer(self._get_prompt_cursor(), string)
         cursor.endEditBlock()
         self._control.moveCursor(QtGui.QTextCursor.End)
 
     input_buffer = property(_get_input_buffer, _set_input_buffer)
 
     def _get_font(self):
         """ The base font being used by the ConsoleWidget.
         """
         return self._control.document().defaultFont()
 
     def _set_font(self, font):
         """ Sets the base font for the ConsoleWidget to the specified QFont.
         """
         font_metrics = QtGui.QFontMetrics(font)
         self._control.setTabStopWidth(self.tab_width * font_metrics.width(' '))
 
         self._completion_widget.setFont(font)
         self._control.document().setDefaultFont(font)
         if self._page_control:
             self._page_control.document().setDefaultFont(font)
 
         self.font_changed.emit(font)
 
     font = property(_get_font, _set_font)
 
     def paste(self, mode=QtGui.QClipboard.Clipboard):
         """ Paste the contents of the clipboard into the input region.
 
         Parameters:
         -----------
         mode : QClipboard::Mode, optional [default QClipboard::Clipboard]
 
             Controls which part of the system clipboard is used. This can be
             used to access the selection clipboard in X11 and the Find buffer
             in Mac OS. By default, the regular clipboard is used.
         """
         if self._control.textInteractionFlags() & QtCore.Qt.TextEditable:
             # Make sure the paste is safe.
             self._keep_cursor_in_buffer()
             cursor = self._control.textCursor()
 
             # Remove any trailing newline, which confuses the GUI and forces the
             # user to backspace.
             text = QtGui.QApplication.clipboard().text(mode).rstrip()
             self._insert_plain_text_into_buffer(cursor, dedent(text))
 
     def print_(self, printer = None):
         """ Print the contents of the ConsoleWidget to the specified QPrinter.
         """
         if (not printer):
             printer = QtGui.QPrinter()
             if(QtGui.QPrintDialog(printer).exec_() != QtGui.QDialog.Accepted):
                 return
         self._control.print_(printer)
 
     def prompt_to_top(self):
         """ Moves the prompt to the top of the viewport.
         """
         if not self._executing:
             prompt_cursor = self._get_prompt_cursor()
             if self._get_cursor().blockNumber() < prompt_cursor.blockNumber():
                 self._set_cursor(prompt_cursor)
             self._set_top_cursor(prompt_cursor)
 
     def redo(self):
         """ Redo the last operation. If there is no operation to redo, nothing
             happens.
         """
         self._control.redo()
 
     def reset_font(self):
         """ Sets the font to the default fixed-width font for this platform.
         """
         if sys.platform == 'win32':
             # Consolas ships with Vista/Win7, fallback to Courier if needed
             fallback = 'Courier'
         elif sys.platform == 'darwin':
             # OSX always has Monaco
             fallback = 'Monaco'
         else:
             # Monospace should always exist
             fallback = 'Monospace'
         font = get_font(self.font_family, fallback)
         if self.font_size:
             font.setPointSize(self.font_size)
         else:
             font.setPointSize(QtGui.qApp.font().pointSize())
         font.setStyleHint(QtGui.QFont.TypeWriter)
         self._set_font(font)
 
     def change_font_size(self, delta):
         """Change the font size by the specified amount (in points).
         """
         font = self.font
         size = max(font.pointSize() + delta, 1) # minimum 1 point
         font.setPointSize(size)
         self._set_font(font)
 
     def _increase_font_size(self):
         self.change_font_size(1)
 
     def _decrease_font_size(self):
         self.change_font_size(-1)
 
     def select_all(self):
         """ Selects all the text in the buffer.
         """
         self._control.selectAll()
 
     def _get_tab_width(self):
         """ The width (in terms of space characters) for tab characters.
         """
         return self._tab_width
 
     def _set_tab_width(self, tab_width):
         """ Sets the width (in terms of space characters) for tab characters.
         """
         font_metrics = QtGui.QFontMetrics(self.font)
         self._control.setTabStopWidth(tab_width * font_metrics.width(' '))
 
         self._tab_width = tab_width
 
     tab_width = property(_get_tab_width, _set_tab_width)
 
     def undo(self):
         """ Undo the last operation. If there is no operation to undo, nothing
             happens.
         """
         self._control.undo()
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' abstract interface
     #---------------------------------------------------------------------------
 
     def _is_complete(self, source, interactive):
         """ Returns whether 'source' can be executed. When triggered by an
             Enter/Return key press, 'interactive' is True; otherwise, it is
             False.
         """
         raise NotImplementedError
 
     def _execute(self, source, hidden):
         """ Execute 'source'. If 'hidden', do not show any output.
         """
         raise NotImplementedError
 
     def _prompt_started_hook(self):
         """ Called immediately after a new prompt is displayed.
         """
         pass
 
     def _prompt_finished_hook(self):
         """ Called immediately after a prompt is finished, i.e. when some input
             will be processed and a new prompt displayed.
         """
         pass
 
     def _up_pressed(self, shift_modifier):
         """ Called when the up key is pressed. Returns whether to continue
             processing the event.
         """
         return True
 
     def _down_pressed(self, shift_modifier):
         """ Called when the down key is pressed. Returns whether to continue
             processing the event.
         """
         return True
 
     def _tab_pressed(self):
         """ Called when the tab key is pressed. Returns whether to continue
             processing the event.
         """
         return False
 
     #--------------------------------------------------------------------------
     # 'ConsoleWidget' protected interface
     #--------------------------------------------------------------------------
 
     def _append_custom(self, insert, input, before_prompt=False):
         """ A low-level method for appending content to the end of the buffer.
 
         If 'before_prompt' is enabled, the content will be inserted before the
         current prompt, if there is one.
         """
         # Determine where to insert the content.
         cursor = self._control.textCursor()
         if before_prompt and (self._reading or not self._executing):
             cursor.setPosition(self._append_before_prompt_pos)
         else:
             cursor.movePosition(QtGui.QTextCursor.End)
         start_pos = cursor.position()
 
         # Perform the insertion.
         result = insert(cursor, input)
 
         # Adjust the prompt position if we have inserted before it. This is safe
         # because buffer truncation is disabled when not executing.
         if before_prompt and not self._executing:
             diff = cursor.position() - start_pos
             self._append_before_prompt_pos += diff
             self._prompt_pos += diff
 
         return result
 
     def _append_html(self, html, before_prompt=False):
         """ Appends HTML at the end of the console buffer.
         """
         self._append_custom(self._insert_html, html, before_prompt)
 
     def _append_html_fetching_plain_text(self, html, before_prompt=False):
         """ Appends HTML, then returns the plain text version of it.
         """
         return self._append_custom(self._insert_html_fetching_plain_text,
                                    html, before_prompt)
 
     def _append_plain_text(self, text, before_prompt=False):
         """ Appends plain text, processing ANSI codes if enabled.
         """
         self._append_custom(self._insert_plain_text, text, before_prompt)
 
-    def _cancel_text_completion(self):
+    def _cancel_completion(self):
         """ If text completion is progress, cancel it.
         """
-        if self._text_completing_pos:
-            self._clear_temporary_buffer()
-            self._text_completing_pos = 0
+        self._completion_widget._cancel_completion()
 
     def _clear_temporary_buffer(self):
         """ Clears the "temporary text" buffer, i.e. all the text following
             the prompt region.
         """
         # Select and remove all text below the input buffer.
         cursor = self._get_prompt_cursor()
         prompt = self._continuation_prompt.lstrip()
         while cursor.movePosition(QtGui.QTextCursor.NextBlock):
             temp_cursor = QtGui.QTextCursor(cursor)
             temp_cursor.select(QtGui.QTextCursor.BlockUnderCursor)
             text = temp_cursor.selection().toPlainText().lstrip()
             if not text.startswith(prompt):
                 break
         else:
             # We've reached the end of the input buffer and no text follows.
             return
         cursor.movePosition(QtGui.QTextCursor.Left) # Grab the newline.
         cursor.movePosition(QtGui.QTextCursor.End,
                             QtGui.QTextCursor.KeepAnchor)
         cursor.removeSelectedText()
 
         # After doing this, we have no choice but to clear the undo/redo
         # history. Otherwise, the text is not "temporary" at all, because it
         # can be recalled with undo/redo. Unfortunately, Qt does not expose
         # fine-grained control to the undo/redo system.
         if self._control.isUndoRedoEnabled():
             self._control.setUndoRedoEnabled(False)
             self._control.setUndoRedoEnabled(True)
 
     def _complete_with_items(self, cursor, items):
         """ Performs completion with 'items' at the specified cursor location.
         """
-        self._cancel_text_completion()
+        self._cancel_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.movePosition(QtGui.QTextCursor.Left, n=len(prefix))
+            self._completion_widget.show_items(cursor, items)
+            self._is_completing = True
+
+
+    def _fill_temporary_buffer(self, cursor, text, html=False):
+        """fill the area below the active editting zone with text"""
+
+        current_pos = self._control.textCursor().position()
+
+        cursor.beginEditBlock()
+        self._append_plain_text('\n')
+        self._page(text, html=html)
+        cursor.endEditBlock()
+
+        cursor.setPosition(current_pos)
+        self._control.moveCursor(QtGui.QTextCursor.End)
+        self._control.setTextCursor(cursor)
 
-                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)
 
         self.cut_action = menu.addAction('Cut', self.cut)
         self.cut_action.setEnabled(self.can_cut())
         self.cut_action.setShortcut(QtGui.QKeySequence.Cut)
 
         self.copy_action = menu.addAction('Copy', self.copy)
         self.copy_action.setEnabled(self.can_copy())
         self.copy_action.setShortcut(QtGui.QKeySequence.Copy)
 
         self.paste_action = menu.addAction('Paste', self.paste)
         self.paste_action.setEnabled(self.can_paste())
         self.paste_action.setShortcut(QtGui.QKeySequence.Paste)
 
         menu.addSeparator()
         menu.addAction(self.select_all_action)
 
         menu.addSeparator()
         menu.addAction(self.export_action)
         menu.addAction(self.print_action)
 
         return menu
 
     def _control_key_down(self, modifiers, include_command=False):
         """ Given a KeyboardModifiers flags object, return whether the Control
         key is down.
 
         Parameters:
         -----------
         include_command : bool, optional (default True)
             Whether to treat the Command key as a (mutually exclusive) synonym
             for Control when in Mac OS.
         """
         # Note that on Mac OS, ControlModifier corresponds to the Command key
         # while MetaModifier corresponds to the Control key.
         if sys.platform == 'darwin':
             down = include_command and (modifiers & QtCore.Qt.ControlModifier)
             return bool(down) ^ bool(modifiers & QtCore.Qt.MetaModifier)
         else:
             return bool(modifiers & QtCore.Qt.ControlModifier)
 
     def _create_control(self):
         """ Creates and connects the underlying text widget.
         """
         # Create the underlying control.
         if self.kind == 'plain':
             control = QtGui.QPlainTextEdit()
         elif self.kind == 'rich':
             control = QtGui.QTextEdit()
             control.setAcceptRichText(False)
 
         # Install event filters. The filter on the viewport is needed for
         # mouse events and drag events.
         control.installEventFilter(self)
         control.viewport().installEventFilter(self)
 
         # Connect signals.
-        control.cursorPositionChanged.connect(self._cursor_position_changed)
         control.customContextMenuRequested.connect(
             self._custom_context_menu_requested)
         control.copyAvailable.connect(self.copy_available)
         control.redoAvailable.connect(self.redo_available)
         control.undoAvailable.connect(self.undo_available)
 
         # Hijack the document size change signal to prevent Qt from adjusting
         # the viewport's scrollbar. We are relying on an implementation detail
         # of Q(Plain)TextEdit here, which is potentially dangerous, but without
         # this functionality we cannot create a nice terminal interface.
         layout = control.document().documentLayout()
         layout.documentSizeChanged.disconnect()
         layout.documentSizeChanged.connect(self._adjust_scrollbars)
 
         # Configure the control.
         control.setAttribute(QtCore.Qt.WA_InputMethodEnabled, True)
         control.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
         control.setReadOnly(True)
         control.setUndoRedoEnabled(False)
         control.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOn)
         return control
 
     def _create_page_control(self):
         """ Creates and connects the underlying paging widget.
         """
         if self.kind == 'plain':
             control = QtGui.QPlainTextEdit()
         elif self.kind == 'rich':
             control = QtGui.QTextEdit()
         control.installEventFilter(self)
         viewport = control.viewport()
         viewport.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()
+            self._cancel_completion()
 
             if self._in_buffer(position):
                 # Special handling when a reading a line of raw input.
                 if self._reading:
                     self._append_plain_text('\n')
                     self._reading = False
                     if self._reading_callback:
                         self._reading_callback()
 
                 # If the input buffer is a single line or there is only
                 # whitespace after the cursor, execute. Otherwise, split the
                 # line with a continuation prompt.
                 elif not self._executing:
                     cursor.movePosition(QtGui.QTextCursor.End,
                                         QtGui.QTextCursor.KeepAnchor)
                     at_end = len(cursor.selectedText().strip()) == 0
                     single_line = (self._get_end_cursor().blockNumber() ==
                                    self._get_prompt_cursor().blockNumber())
                     if (at_end or shift_down or single_line) and not ctrl_down:
                         self.execute(interactive = not shift_down)
                     else:
                         # Do this inside an edit block for clean undo/redo.
                         cursor.beginEditBlock()
                         cursor.setPosition(position)
                         cursor.insertText('\n')
                         self._insert_continuation_prompt(cursor)
                         cursor.endEditBlock()
 
                         # Ensure that the whole input buffer is visible.
                         # FIXME: This will not be usable if the input buffer is
                         # taller than the console widget.
                         self._control.moveCursor(QtGui.QTextCursor.End)
                         self._control.setTextCursor(cursor)
 
         #------ Control/Cmd modifier -------------------------------------------
 
         elif ctrl_down:
             if key == QtCore.Qt.Key_G:
                 self._keyboard_quit()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_K:
                 if self._in_buffer(position):
                     cursor.clearSelection()
                     cursor.movePosition(QtGui.QTextCursor.EndOfLine,
                                         QtGui.QTextCursor.KeepAnchor)
                     if not cursor.hasSelection():
                         # Line deletion (remove continuation prompt)
                         cursor.movePosition(QtGui.QTextCursor.NextBlock,
                                             QtGui.QTextCursor.KeepAnchor)
                         cursor.movePosition(QtGui.QTextCursor.Right,
                                             QtGui.QTextCursor.KeepAnchor,
                                             len(self._continuation_prompt))
                     self._kill_ring.kill_cursor(cursor)
                     self._set_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_L:
                 self.prompt_to_top()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_O:
                 if self._page_control and self._page_control.isVisible():
                     self._page_control.setFocus()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_U:
                 if self._in_buffer(position):
                     cursor.clearSelection()
                     start_line = cursor.blockNumber()
                     if start_line == self._get_prompt_cursor().blockNumber():
                         offset = len(self._prompt)
                     else:
                         offset = len(self._continuation_prompt)
                     cursor.movePosition(QtGui.QTextCursor.StartOfBlock,
                                         QtGui.QTextCursor.KeepAnchor)
                     cursor.movePosition(QtGui.QTextCursor.Right,
                                         QtGui.QTextCursor.KeepAnchor, offset)
                     self._kill_ring.kill_cursor(cursor)
                     self._set_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Y:
                 self._keep_cursor_in_buffer()
                 self._kill_ring.yank()
                 intercepted = True
 
             elif key in (QtCore.Qt.Key_Backspace, QtCore.Qt.Key_Delete):
                 if key == QtCore.Qt.Key_Backspace:
                     cursor = self._get_word_start_cursor(position)
                 else: # key == QtCore.Qt.Key_Delete
                     cursor = self._get_word_end_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 self._kill_ring.kill_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_D:
                 if len(self.input_buffer) == 0:
                     self.exit_requested.emit(self)
                 else:
                     new_event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress,
                                                 QtCore.Qt.Key_Delete,
                                                 QtCore.Qt.NoModifier)
                     QtGui.qApp.sendEvent(self._control, new_event)
                     intercepted = True
 
         #------ Alt modifier ---------------------------------------------------
 
         elif alt_down:
             if key == QtCore.Qt.Key_B:
                 self._set_cursor(self._get_word_start_cursor(position))
                 intercepted = True
 
             elif key == QtCore.Qt.Key_F:
                 self._set_cursor(self._get_word_end_cursor(position))
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Y:
                 self._kill_ring.rotate()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Backspace:
                 cursor = self._get_word_start_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 self._kill_ring.kill_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_D:
                 cursor = self._get_word_end_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 self._kill_ring.kill_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Delete:
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Greater:
                 self._control.moveCursor(QtGui.QTextCursor.End)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Less:
                 self._control.setTextCursor(self._get_prompt_cursor())
                 intercepted = True
 
         #------ No modifiers ---------------------------------------------------
 
         else:
             if shift_down:
                 anchormode = QtGui.QTextCursor.KeepAnchor
             else:
                 anchormode = QtGui.QTextCursor.MoveAnchor
 
             if key == QtCore.Qt.Key_Escape:
                 self._keyboard_quit()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Up:
                 if self._reading or not self._up_pressed(shift_down):
                     intercepted = True
                 else:
                     prompt_line = self._get_prompt_cursor().blockNumber()
                     intercepted = cursor.blockNumber() <= prompt_line
 
             elif key == QtCore.Qt.Key_Down:
                 if self._reading or not self._down_pressed(shift_down):
                     intercepted = True
                 else:
                     end_line = self._get_end_cursor().blockNumber()
                     intercepted = cursor.blockNumber() == end_line
 
             elif key == QtCore.Qt.Key_Tab:
                 if not self._reading:
                     if self._tab_pressed():
                         # real tab-key, insert four spaces
                         cursor.insertText(' '*4)
                     intercepted = True
 
             elif key == QtCore.Qt.Key_Left:
 
                 # Move to the previous line
                 line, col = cursor.blockNumber(), cursor.columnNumber()
                 if line > self._get_prompt_cursor().blockNumber() and \
                         col == len(self._continuation_prompt):
                     self._control.moveCursor(QtGui.QTextCursor.PreviousBlock,
                                              mode=anchormode)
                     self._control.moveCursor(QtGui.QTextCursor.EndOfBlock,
                                              mode=anchormode)
                     intercepted = True
 
                 # Regular left movement
                 else:
                     intercepted = not self._in_buffer(position - 1)
 
             elif key == QtCore.Qt.Key_Right:
                 original_block_number = cursor.blockNumber()
                 cursor.movePosition(QtGui.QTextCursor.Right,
                                 mode=anchormode)
                 if cursor.blockNumber() != original_block_number:
                     cursor.movePosition(QtGui.QTextCursor.Right,
                                         n=len(self._continuation_prompt),
                                         mode=anchormode)
                 self._set_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Home:
                 start_line = cursor.blockNumber()
                 if start_line == self._get_prompt_cursor().blockNumber():
                     start_pos = self._prompt_pos
                 else:
                     cursor.movePosition(QtGui.QTextCursor.StartOfBlock,
                                         QtGui.QTextCursor.KeepAnchor)
                     start_pos = cursor.position()
                     start_pos += len(self._continuation_prompt)
                     cursor.setPosition(position)
                 if shift_down and self._in_buffer(position):
                     cursor.setPosition(start_pos, QtGui.QTextCursor.KeepAnchor)
                 else:
                     cursor.setPosition(start_pos)
                 self._set_cursor(cursor)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Backspace:
 
                 # Line deletion (remove continuation prompt)
                 line, col = cursor.blockNumber(), cursor.columnNumber()
                 if not self._reading and \
                         col == len(self._continuation_prompt) and \
                         line > self._get_prompt_cursor().blockNumber():
                     cursor.beginEditBlock()
                     cursor.movePosition(QtGui.QTextCursor.StartOfBlock,
                                         QtGui.QTextCursor.KeepAnchor)
                     cursor.removeSelectedText()
                     cursor.deletePreviousChar()
                     cursor.endEditBlock()
                     intercepted = True
 
                 # Regular backwards deletion
                 else:
                     anchor = cursor.anchor()
                     if anchor == position:
                         intercepted = not self._in_buffer(position - 1)
                     else:
                         intercepted = not self._in_buffer(min(anchor, position))
 
             elif key == QtCore.Qt.Key_Delete:
 
                 # Line deletion (remove continuation prompt)
                 if not self._reading and self._in_buffer(position) and \
                         cursor.atBlockEnd() and not cursor.hasSelection():
                     cursor.movePosition(QtGui.QTextCursor.NextBlock,
                                         QtGui.QTextCursor.KeepAnchor)
                     cursor.movePosition(QtGui.QTextCursor.Right,
                                         QtGui.QTextCursor.KeepAnchor,
                                         len(self._continuation_prompt))
                     cursor.removeSelectedText()
                     intercepted = True
 
                 # Regular forwards deletion:
                 else:
                     anchor = cursor.anchor()
                     intercepted = (not self._in_buffer(anchor) or
                                    not self._in_buffer(position))
 
         # Don't move the cursor if Control/Cmd is pressed to allow copy-paste
         # using the keyboard in any part of the buffer. Also, permit scrolling
         # with Page Up/Down keys. Finally, if we're executing, don't move the
         # cursor (if even this made sense, we can't guarantee that the prompt
         # position is still valid due to text truncation).
         if not (self._control_key_down(event.modifiers(), include_command=True)
                 or key in (QtCore.Qt.Key_PageUp, QtCore.Qt.Key_PageDown)
                 or (self._executing and not self._reading)):
             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()
                 self._control.setFocus()
             else:
                 self.layout().setCurrentWidget(self._control)
             return True
 
         elif key in (QtCore.Qt.Key_Enter, QtCore.Qt.Key_Return,
                      QtCore.Qt.Key_Tab):
             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.
         """
         # 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)
 
         return columnize(items, separator, displaywidth)
 
     def _get_block_plain_text(self, block):
         """ Given a QTextBlock, return its unformatted text.
         """
         cursor = QtGui.QTextCursor(block)
         cursor.movePosition(QtGui.QTextCursor.StartOfBlock)
         cursor.movePosition(QtGui.QTextCursor.EndOfBlock,
                             QtGui.QTextCursor.KeepAnchor)
         return cursor.selection().toPlainText()
 
     def _get_cursor(self):
         """ Convenience method that returns a cursor for the current position.
         """
         return self._control.textCursor()
 
     def _get_end_cursor(self):
         """ Convenience method that returns a cursor for the last character.
         """
         cursor = self._control.textCursor()
         cursor.movePosition(QtGui.QTextCursor.End)
         return cursor
 
     def _get_input_buffer_cursor_column(self):
         """ Returns the column of the cursor in the input buffer, excluding the
             contribution by the prompt, or -1 if there is no such column.
         """
         prompt = self._get_input_buffer_cursor_prompt()
         if prompt is None:
             return -1
         else:
             cursor = self._control.textCursor()
             return cursor.columnNumber() - len(prompt)
 
     def _get_input_buffer_cursor_line(self):
         """ Returns the text of the line of the input buffer that contains the
             cursor, or None if there is no such line.
         """
         prompt = self._get_input_buffer_cursor_prompt()
         if prompt is None:
             return None
         else:
             cursor = self._control.textCursor()
             text = self._get_block_plain_text(cursor.block())
             return text[len(prompt):]
 
     def _get_input_buffer_cursor_prompt(self):
         """ Returns the (plain text) prompt for line of the input buffer that
             contains the cursor, or None if there is no such line.
         """
         if self._executing:
             return None
         cursor = self._control.textCursor()
         if cursor.position() >= self._prompt_pos:
             if cursor.blockNumber() == self._get_prompt_cursor().blockNumber():
                 return self._prompt
             else:
                 return self._continuation_prompt
         else:
             return None
 
     def _get_prompt_cursor(self):
         """ Convenience method that returns a cursor for the prompt position.
         """
         cursor = self._control.textCursor()
         cursor.setPosition(self._prompt_pos)
         return cursor
 
     def _get_selection_cursor(self, start, end):
         """ Convenience method that returns a cursor with text selected between
             the positions 'start' and 'end'.
         """
         cursor = self._control.textCursor()
         cursor.setPosition(start)
         cursor.setPosition(end, QtGui.QTextCursor.KeepAnchor)
         return cursor
 
     def _get_word_start_cursor(self, position):
         """ Find the start of the word to the left the given position. If a
             sequence of non-word characters precedes the first word, skip over
             them. (This emulates the behavior of bash, emacs, etc.)
         """
         document = self._control.document()
         position -= 1
         while position >= self._prompt_pos and \
                   not is_letter_or_number(document.characterAt(position)):
             position -= 1
         while position >= self._prompt_pos and \
                   is_letter_or_number(document.characterAt(position)):
             position -= 1
         cursor = self._control.textCursor()
         cursor.setPosition(position + 1)
         return cursor
 
     def _get_word_end_cursor(self, position):
         """ Find the end of the word to the right the given position. If a
             sequence of non-word characters precedes the first word, skip over
             them. (This emulates the behavior of bash, emacs, etc.)
         """
         document = self._control.document()
         end = self._get_end_cursor().position()
         while position < end and \
                   not is_letter_or_number(document.characterAt(position)):
             position += 1
         while position < end and \
                   is_letter_or_number(document.characterAt(position)):
             position += 1
         cursor = self._control.textCursor()
         cursor.setPosition(position)
         return cursor
 
     def _insert_continuation_prompt(self, cursor):
         """ Inserts new continuation prompt using the specified cursor.
         """
         if self._continuation_prompt_html is None:
             self._insert_plain_text(cursor, self._continuation_prompt)
         else:
             self._continuation_prompt = self._insert_html_fetching_plain_text(
                 cursor, self._continuation_prompt_html)
 
     def _insert_html(self, cursor, html):
         """ Inserts HTML using the specified cursor in such a way that future
             formatting is unaffected.
         """
         cursor.beginEditBlock()
         cursor.insertHtml(html)
 
         # After inserting HTML, the text document "remembers" it's in "html
         # mode", which means that subsequent calls adding plain text will result
         # in unwanted formatting, lost tab characters, etc. The following code
         # hacks around this behavior, which I consider to be a bug in Qt, by
         # (crudely) resetting the document's style state.
         cursor.movePosition(QtGui.QTextCursor.Left,
                             QtGui.QTextCursor.KeepAnchor)
         if cursor.selection().toPlainText() == ' ':
             cursor.removeSelectedText()
         else:
             cursor.movePosition(QtGui.QTextCursor.Right)
         cursor.insertText(' ', QtGui.QTextCharFormat())
         cursor.endEditBlock()
 
     def _insert_html_fetching_plain_text(self, cursor, html):
         """ Inserts HTML using the specified cursor, then returns its plain text
             version.
         """
         cursor.beginEditBlock()
         cursor.removeSelectedText()
 
         start = cursor.position()
         self._insert_html(cursor, html)
         end = cursor.position()
         cursor.setPosition(start, QtGui.QTextCursor.KeepAnchor)
         text = cursor.selection().toPlainText()
 
         cursor.setPosition(end)
         cursor.endEditBlock()
         return text
 
     def _insert_plain_text(self, cursor, text):
         """ Inserts plain text using the specified cursor, processing ANSI codes
             if enabled.
         """
         cursor.beginEditBlock()
         if self.ansi_codes:
             for substring in self._ansi_processor.split_string(text):
                 for act in self._ansi_processor.actions:
 
                     # Unlike real terminal emulators, we don't distinguish
                     # between the screen and the scrollback buffer. A screen
                     # erase request clears everything.
                     if act.action == 'erase' and act.area == 'screen':
                         cursor.select(QtGui.QTextCursor.Document)
                         cursor.removeSelectedText()
 
                     # Simulate a form feed by scrolling just past the last line.
                     elif act.action == 'scroll' and act.unit == 'page':
                         cursor.insertText('\n')
                         cursor.endEditBlock()
                         self._set_top_cursor(cursor)
                         cursor.joinPreviousEditBlock()
                         cursor.deletePreviousChar()
 
                     elif act.action == 'carriage-return':
                         cursor.movePosition(
                             cursor.StartOfLine, cursor.KeepAnchor)
 
                     elif act.action == 'beep':
                         QtGui.qApp.beep()
 
                     elif act.action == 'backspace':
                         if not cursor.atBlockStart():
                             cursor.movePosition(
                                 cursor.PreviousCharacter, cursor.KeepAnchor)
 
                     elif act.action == 'newline':
                         cursor.movePosition(cursor.EndOfLine)
 
                 format = self._ansi_processor.get_format()
 
                 selection = cursor.selectedText()
                 if len(selection) == 0:
                     cursor.insertText(substring, format)
                 elif substring is not None:
                     # BS and CR are treated as a change in print
                     # position, rather than a backwards character
                     # deletion for output equivalence with (I)Python
                     # terminal.
                     if len(substring) >= len(selection):
                         cursor.insertText(substring, format)
                     else:
                         old_text = selection[len(substring):]
                         cursor.insertText(substring + old_text, format)
                         cursor.movePosition(cursor.PreviousCharacter,
                                cursor.KeepAnchor, len(old_text))
         else:
             cursor.insertText(text)
         cursor.endEditBlock()
 
     def _insert_plain_text_into_buffer(self, cursor, text):
         """ Inserts text into the input buffer using the specified cursor (which
             must be in the input buffer), ensuring that continuation prompts are
             inserted as necessary.
         """
         lines = text.splitlines(True)
         if lines:
             cursor.beginEditBlock()
             cursor.insertText(lines[0])
             for line in lines[1:]:
                 if self._continuation_prompt_html is None:
                     cursor.insertText(self._continuation_prompt)
                 else:
                     self._continuation_prompt = \
                         self._insert_html_fetching_plain_text(
                             cursor, self._continuation_prompt_html)
                 cursor.insertText(line)
             cursor.endEditBlock()
 
     def _in_buffer(self, position=None):
         """ Returns whether the current cursor (or, if specified, a position) is
             inside the editing region.
         """
         cursor = self._control.textCursor()
         if position is None:
             position = cursor.position()
         else:
             cursor.setPosition(position)
         line = cursor.blockNumber()
         prompt_line = self._get_prompt_cursor().blockNumber()
         if line == prompt_line:
             return position >= self._prompt_pos
         elif line > prompt_line:
             cursor.movePosition(QtGui.QTextCursor.StartOfBlock)
             prompt_pos = cursor.position() + len(self._continuation_prompt)
             return position >= prompt_pos
         return False
 
     def _keep_cursor_in_buffer(self):
         """ Ensures that the cursor is inside the editing region. Returns
             whether the cursor was moved.
         """
         moved = not self._in_buffer()
         if moved:
             cursor = self._control.textCursor()
             cursor.movePosition(QtGui.QTextCursor.End)
             self._control.setTextCursor(cursor)
         return moved
 
     def _keyboard_quit(self):
         """ Cancels the current editing task ala Ctrl-G in Emacs.
         """
-        if self._text_completing_pos:
-            self._cancel_text_completion()
+        if self._is_completing:
+            self._cancel_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_html(text)
         else:
             self._append_plain_text(text)
 
     def _prompt_finished(self):
         """ Called immediately after a prompt is finished, i.e. when some input
             will be processed and a new prompt displayed.
         """
         self._control.setReadOnly(True)
         self._prompt_finished_hook()
 
     def _prompt_started(self):
         """ Called immediately after a new prompt is displayed.
         """
         # Temporarily disable the maximum block count to permit undo/redo and
         # to ensure that the prompt position does not change due to truncation.
         self._control.document().setMaximumBlockCount(0)
         self._control.setUndoRedoEnabled(True)
 
         # Work around bug in QPlainTextEdit: input method is not re-enabled
         # when read-only is disabled.
         self._control.setReadOnly(False)
         self._control.setAttribute(QtCore.Qt.WA_InputMethodEnabled, True)
 
         if not self._reading:
             self._executing = False
         self._prompt_started_hook()
 
         # If the input buffer has changed while executing, load it.
         if self._input_buffer_pending:
             self.input_buffer = self._input_buffer_pending
             self._input_buffer_pending = ''
 
         self._control.moveCursor(QtGui.QTextCursor.End)
 
     def _readline(self, prompt='', callback=None):
         """ Reads one line of input from the user.
 
         Parameters
         ----------
         prompt : str, optional
             The prompt to print before reading the line.
 
         callback : callable, optional
             A callback to execute with the read line. If not specified, input is
             read *synchronously* and this method does not return until it has
             been read.
 
         Returns
         -------
         If a callback is specified, returns nothing. Otherwise, returns the
         input string with the trailing newline stripped.
         """
         if self._reading:
             raise RuntimeError('Cannot read a line. Widget is already reading.')
 
         if not callback and not self.isVisible():
             # If the user cannot see the widget, this function cannot return.
             raise RuntimeError('Cannot synchronously read a line if the widget '
                                'is not visible!')
 
         self._reading = True
         self._show_prompt(prompt, newline=False)
 
         if callback is None:
             self._reading_callback = None
             while self._reading:
                 QtCore.QCoreApplication.processEvents()
             return self._get_input_buffer(force=True).rstrip('\n')
 
         else:
             self._reading_callback = lambda: \
                 callback(self._get_input_buffer(force=True).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.
         """
         # Save the current end position to support _append*(before_prompt=True).
         cursor = self._get_end_cursor()
         self._append_before_prompt_pos = cursor.position()
 
         # Insert a preliminary newline, if necessary.
         if newline and cursor.position() > 0:
             cursor.movePosition(QtGui.QTextCursor.Left,
                                 QtGui.QTextCursor.KeepAnchor)
             if cursor.selection().toPlainText() != '\n':
                 self._append_plain_text('\n')
 
         # Write the prompt.
         self._append_plain_text(self._prompt_sep)
         if prompt is None:
             if self._prompt_html is None:
                 self._append_plain_text(self._prompt)
             else:
                 self._append_html(self._prompt_html)
         else:
             if html:
                 self._prompt = self._append_html_fetching_plain_text(prompt)
                 self._prompt_html = prompt
             else:
                 self._append_plain_text(prompt)
                 self._prompt = prompt
                 self._prompt_html = None
 
         self._prompt_pos = self._get_end_cursor().position()
         self._prompt_started()
 
     #------ Signal handlers ----------------------------------------------------
 
     def _adjust_scrollbars(self):
         """ Expands the vertical scrollbar beyond the range set by Qt.
         """
         # This code is adapted from _q_adjustScrollbars in qplaintextedit.cpp
         # and qtextedit.cpp.
         document = self._control.document()
         scrollbar = self._control.verticalScrollBar()
         viewport_height = self._control.viewport().height()
         if isinstance(self._control, QtGui.QPlainTextEdit):
             maximum = max(0, document.lineCount() - 1)
             step = viewport_height / self._control.fontMetrics().lineSpacing()
         else:
             # QTextEdit does not do line-based layout and blocks will not in
             # general have the same height. Therefore it does not make sense to
             # attempt to scroll in line height increments.
             maximum = document.size().height()
             step = viewport_height
         diff = maximum - scrollbar.maximum()
         scrollbar.setRange(0, maximum)
         scrollbar.setPageStep(step)
 
         # Compensate for undesirable scrolling that occurs automatically due to
         # maximumBlockCount() text truncation.
         if diff < 0 and document.blockCount() == document.maximumBlockCount():
             scrollbar.setValue(scrollbar.value() + diff)
 
-    def _cursor_position_changed(self):
-        """ Clears the temporary buffer based on the cursor position.
-        """
-        if self._text_completing_pos:
-            document = self._control.document()
-            if self._text_completing_pos < document.characterCount():
-                cursor = self._control.textCursor()
-                pos = cursor.position()
-                text_cursor = self._control.textCursor()
-                text_cursor.setPosition(self._text_completing_pos)
-                if pos < self._text_completing_pos or \
-                        cursor.blockNumber() > text_cursor.blockNumber():
-                    self._clear_temporary_buffer()
-                    self._text_completing_pos = 0
-            else:
-                self._clear_temporary_buffer()
-                self._text_completing_pos = 0
-
     def _custom_context_menu_requested(self, pos):
         """ Shows a context menu at the given QPoint (in widget coordinates).
         """
         menu = self._context_menu_make(pos)
         menu.exec_(self._control.mapToGlobal(pos))

IPython/frontend/qt/console/qtconsoleapp.py

@@ -1,372 +1,375 b''
 """ A minimal application using the Qt console-style IPython frontend.
 
 This is not a complete console app, as subprocess will not be able to receive
 input, there is no real readline support, among other limitations.
 
 Authors:
 
 * Evan Patterson
 * Min RK
 * Erik Tollerud
 * Fernando Perez
 * Bussonnier Matthias
 * Thomas Kluyver
 * Paul Ivanov
 
 """
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # stdlib imports
 import json
 import os
 import signal
 import sys
 import uuid
 
 # If run on Windows, install an exception hook which pops up a
 # message box. Pythonw.exe hides the console, so without this
 # the application silently fails to load.
 #
 # We always install this handler, because the expectation is for
 # qtconsole to bring up a GUI even if called from the console.
 # The old handler is called, so the exception is printed as well.
 # If desired, check for pythonw with an additional condition
 # (sys.executable.lower().find('pythonw.exe') >= 0).
 if os.name == 'nt':
     old_excepthook = sys.excepthook
 
     def gui_excepthook(exctype, value, tb):
         try:
             import ctypes, traceback
             MB_ICONERROR = 0x00000010L
             title = u'Error starting IPython QtConsole'
             msg = u''.join(traceback.format_exception(exctype, value, tb))
             ctypes.windll.user32.MessageBoxW(0, msg, title, MB_ICONERROR)
         finally:
             # Also call the old exception hook to let it do
             # its thing too.
             old_excepthook(exctype, value, tb)
 
     sys.excepthook = gui_excepthook
 
 # System library imports
 from IPython.external.qt import QtCore, QtGui
 
 # Local imports
 from IPython.config.application import boolean_flag, catch_config_error
 from IPython.core.application import BaseIPythonApplication
 from IPython.core.profiledir import ProfileDir
 from IPython.lib.kernel import tunnel_to_kernel, find_connection_file
 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.console.mainwindow import MainWindow
 from IPython.frontend.qt.kernelmanager import QtKernelManager
 from IPython.utils.path import filefind
 from IPython.utils.py3compat import str_to_bytes
 from IPython.utils.traitlets import (
     Dict, List, Unicode, Integer, CaselessStrEnum, CBool, Any
 )
 from IPython.zmq.ipkernel import IPKernelApp
 from IPython.zmq.session import Session, default_secure
 from IPython.zmq.zmqshell import ZMQInteractiveShell
 
 from IPython.frontend.consoleapp import (
         IPythonConsoleApp, app_aliases, app_flags, flags, aliases
     )
 
 #-----------------------------------------------------------------------------
 # Network Constants
 #-----------------------------------------------------------------------------
 
 from IPython.utils.localinterfaces import LOCALHOST, LOCAL_IPS
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 
 _examples = """
 ipython qtconsole                 # start the qtconsole
 ipython qtconsole --pylab=inline  # start with pylab in inline plotting mode
 """
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 
 # start with copy of flags
 flags = dict(flags)
 qt_flags = {
     'plain' : ({'IPythonQtConsoleApp' : {'plain' : True}},
             "Disable rich text support."),
 }
-qt_flags.update(boolean_flag(
-    'gui-completion', 'ConsoleWidget.gui_completion',
-    "use a GUI widget for tab completion",
-    "use plaintext output for completion"
-))
+
+# not quite sure on how this works
+#qt_flags.update(boolean_flag(
+#    'gui-completion', 'ConsoleWidget.gui_completion',
+#    "use a GUI widget for tab completion",
+#    "use plaintext output for completion"
+#))
+
 # and app_flags from the Console Mixin
 qt_flags.update(app_flags)
 # add frontend flags to the full set
 flags.update(qt_flags)
 
 # start with copy of front&backend aliases list
 aliases = dict(aliases)
 qt_aliases = dict(
-
     style = 'IPythonWidget.syntax_style',
     stylesheet = 'IPythonQtConsoleApp.stylesheet',
     colors = 'ZMQInteractiveShell.colors',
 
     editor = 'IPythonWidget.editor',
     paging = 'ConsoleWidget.paging',
 )
 # and app_aliases from the Console Mixin
 qt_aliases.update(app_aliases)
+qt_aliases.update({'gui-completion':'ConsoleWidget.gui_completion'})
 # add frontend aliases to the full set
 aliases.update(qt_aliases)
 
 # get flags&aliases into sets, and remove a couple that
 # shouldn't be scrubbed from backend flags:
 qt_aliases = set(qt_aliases.keys())
 qt_aliases.remove('colors')
 qt_flags = set(qt_flags.keys())
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # IPythonQtConsole
 #-----------------------------------------------------------------------------
 
 
 class IPythonQtConsoleApp(BaseIPythonApplication, IPythonConsoleApp):
     name = 'ipython-qtconsole'
 
     description = """
         The IPython QtConsole.
         
         This launches a Console-style application using Qt.  It is not a full
         console, in that launched terminal subprocesses will not be able to accept
         input.
         
         The QtConsole supports various extra features beyond the Terminal IPython
         shell, such as inline plotting with matplotlib, via:
         
             ipython qtconsole --pylab=inline
         
         as well as saving your session as HTML, and printing the output.
         
     """
     examples = _examples
 
     classes = [IPythonWidget] + IPythonConsoleApp.classes
     flags = Dict(flags)
     aliases = Dict(aliases)
     frontend_flags = Any(qt_flags)
     frontend_aliases = Any(qt_aliases)
     kernel_manager_class = QtKernelManager
 
     stylesheet = Unicode('', config=True,
         help="path to a custom CSS stylesheet")
 
     plain = CBool(False, config=True,
         help="Use a plaintext widget instead of rich text (plain can't print/save).")
 
     def _plain_changed(self, name, old, new):
         kind = 'plain' if new else 'rich'
         self.config.ConsoleWidget.kind = kind
         if new:
             self.widget_factory = IPythonWidget
         else:
             self.widget_factory = RichIPythonWidget
 
     # the factory for creating a widget
     widget_factory = Any(RichIPythonWidget)
 
     def parse_command_line(self, argv=None):
         super(IPythonQtConsoleApp, self).parse_command_line(argv)
         self.build_kernel_argv(argv)
 
 
     def new_frontend_master(self):
         """ Create and return new frontend attached to new kernel, launched on localhost.
         """
         ip = self.ip if self.ip in LOCAL_IPS else LOCALHOST
         kernel_manager = self.kernel_manager_class(
                                 ip=ip,
                                 connection_file=self._new_connection_file(),
                                 config=self.config,
         )
         # start the kernel
         kwargs = dict()
         kwargs['extra_arguments'] = self.kernel_argv
         kernel_manager.start_kernel(**kwargs)
         kernel_manager.start_channels()
         widget = self.widget_factory(config=self.config,
                                    local_kernel=True)
         self.init_colors(widget)
         widget.kernel_manager = kernel_manager
         widget._existing = False
         widget._may_close = True
         widget._confirm_exit = self.confirm_exit
         return widget
 
     def new_frontend_slave(self, current_widget):
         """Create and return a new frontend attached to an existing kernel.
         
         Parameters
         ----------
         current_widget : IPythonWidget
             The IPythonWidget whose kernel this frontend is to share
         """
         kernel_manager = self.kernel_manager_class(
                                 connection_file=current_widget.kernel_manager.connection_file,
                                 config = self.config,
         )
         kernel_manager.load_connection_file()
         kernel_manager.start_channels()
         widget = self.widget_factory(config=self.config,
                                 local_kernel=False)
         self.init_colors(widget)
         widget._existing = True
         widget._may_close = False
         widget._confirm_exit = False
         widget.kernel_manager = kernel_manager
         return widget
 
     def init_qt_elements(self):
         # Create the widget.
         self.app = QtGui.QApplication([])
 
         base_path = os.path.abspath(os.path.dirname(__file__))
         icon_path = os.path.join(base_path, 'resources', 'icon', 'IPythonConsole.svg')
         self.app.icon = QtGui.QIcon(icon_path)
         QtGui.QApplication.setWindowIcon(self.app.icon)
 
         local_kernel = (not self.existing) or self.ip in LOCAL_IPS
         self.widget = self.widget_factory(config=self.config,
                                         local_kernel=local_kernel)
         self.init_colors(self.widget)
         self.widget._existing = self.existing
         self.widget._may_close = not self.existing
         self.widget._confirm_exit = self.confirm_exit
 
         self.widget.kernel_manager = self.kernel_manager
         self.window = MainWindow(self.app,
                                 confirm_exit=self.confirm_exit,
                                 new_frontend_factory=self.new_frontend_master,
                                 slave_frontend_factory=self.new_frontend_slave,
                                 )
         self.window.log = self.log
         self.window.add_tab_with_frontend(self.widget)
         self.window.init_menu_bar()
 
         self.window.setWindowTitle('IPython')
 
     def init_colors(self, widget):
         """Configure the coloring of the widget"""
         # Note: This will be dramatically simplified when colors
         # are removed from the backend.
 
         # parse the colors arg down to current known labels
         try:
             colors = self.config.ZMQInteractiveShell.colors
         except AttributeError:
             colors = None
         try:
             style = self.config.IPythonWidget.syntax_style
         except AttributeError:
             style = None
         try:
             sheet = self.config.IPythonWidget.style_sheet
         except AttributeError:
             sheet = None
 
         # find the value for colors:
         if colors:
             colors=colors.lower()
             if colors in ('lightbg', 'light'):
                 colors='lightbg'
             elif colors in ('dark', 'linux'):
                 colors='linux'
             else:
                 colors='nocolor'
         elif style:
             if style=='bw':
                 colors='nocolor'
             elif styles.dark_style(style):
                 colors='linux'
             else:
                 colors='lightbg'
         else:
             colors=None
 
         # Configure the style
         if style:
             widget.style_sheet = styles.sheet_from_template(style, colors)
             widget.syntax_style = style
             widget._syntax_style_changed()
             widget._style_sheet_changed()
         elif colors:
             # use a default dark/light/bw style
             widget.set_default_style(colors=colors)
 
         if self.stylesheet:
             # we got an explicit stylesheet
             if os.path.isfile(self.stylesheet):
                 with open(self.stylesheet) as f:
                     sheet = f.read()
             else:
                 raise IOError("Stylesheet %r not found." % self.stylesheet)
         if sheet:
             widget.style_sheet = sheet
             widget._style_sheet_changed()
             
 
     def init_signal(self):
         """allow clean shutdown on sigint"""
         signal.signal(signal.SIGINT, lambda sig, frame: self.exit(-2))
         # need a timer, so that QApplication doesn't block until a real
         # Qt event fires (can require mouse movement)
         # timer trick from http://stackoverflow.com/q/4938723/938949
         timer = QtCore.QTimer()
          # Let the interpreter run each 200 ms:
         timer.timeout.connect(lambda: None)
         timer.start(200)
         # hold onto ref, so the timer doesn't get cleaned up
         self._sigint_timer = timer
 
     @catch_config_error
     def initialize(self, argv=None):
         super(IPythonQtConsoleApp, self).initialize(argv)
         IPythonConsoleApp.initialize(self,argv)
         self.init_qt_elements()
         self.init_signal()
 
     def start(self):
 
         # draw the window
         self.window.show()
         self.window.raise_()
 
         # Start the application main loop.
         self.app.exec_()
 
 #-----------------------------------------------------------------------------
 # Main entry point
 #-----------------------------------------------------------------------------
 
 def main():
     app = IPythonQtConsoleApp()
     app.initialize()
     app.start()
 
 
 if __name__ == '__main__':
     main()

IPython/frontend/qt/console/styles.py

@@ -1,119 +1,122 b''
 """ Style utilities, templates, and defaults for syntax highlighting widgets.
 """
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from colorsys import rgb_to_hls
 from pygments.styles import get_style_by_name
 from pygments.token import Token
 
 #-----------------------------------------------------------------------------
 # Constants
 #-----------------------------------------------------------------------------
 
 # The default light style sheet: black text on a white background.
 default_light_style_template = '''
     QPlainTextEdit, QTextEdit { background-color: %(bgcolor)s;
             color: %(fgcolor)s ;
             selection-background-color: %(select)s}
     .error { color: red; }
     .in-prompt { color: navy; }
     .in-prompt-number { font-weight: bold; }
     .out-prompt { color: darkred; }
     .out-prompt-number { font-weight: bold; }
+    .inverted { background-color: %(fgcolor)s ; color:%(bgcolor)s;}
 '''
 default_light_style_sheet = default_light_style_template%dict(
                 bgcolor='white', fgcolor='black', select="#ccc")
 default_light_syntax_style = 'default'
 
 # The default dark style sheet: white text on a black background.
 default_dark_style_template = '''
     QPlainTextEdit, QTextEdit { background-color: %(bgcolor)s;
             color: %(fgcolor)s ;
             selection-background-color: %(select)s}
     QFrame { border: 1px solid grey; }
     .error { color: red; }
     .in-prompt { color: lime; }
     .in-prompt-number { color: lime; font-weight: bold; }
     .out-prompt { color: red; }
     .out-prompt-number { color: red; font-weight: bold; }
+    .inverted { background-color: %(fgcolor)s ; color:%(bgcolor)s;}
 '''
 default_dark_style_sheet = default_dark_style_template%dict(
                 bgcolor='black', fgcolor='white', select="#555")
 default_dark_syntax_style = 'monokai'
 
 # The default monochrome
 default_bw_style_sheet = '''
     QPlainTextEdit, QTextEdit { background-color: white;
             color: black ;
             selection-background-color: #cccccc}
     .in-prompt-number { font-weight: bold; }
     .out-prompt-number { font-weight: bold; }
+    .inverted { background-color: black ; color: white;}
 '''
 default_bw_syntax_style = 'bw'
 
 
 def hex_to_rgb(color):
     """Convert a hex color to rgb integer tuple."""
     if color.startswith('#'):
         color = color[1:]
     if len(color) == 3:
         color = ''.join([c*2 for c in color])
     if len(color) != 6:
         return False
     try:
         r = int(color[:2],16)
         g = int(color[2:4],16)
         b = int(color[4:],16)
     except ValueError:
         return False
     else:
         return r,g,b
 
 def dark_color(color):
     """Check whether a color is 'dark'.
 
     Currently, this is simply whether the luminance is <50%"""
     rgb = hex_to_rgb(color)
     if rgb:
         return rgb_to_hls(*rgb)[1] < 128
     else: # default to False
         return False
 
 def dark_style(stylename):
     """Guess whether the background of the style with name 'stylename'
     counts as 'dark'."""
     return dark_color(get_style_by_name(stylename).background_color)
 
 def get_colors(stylename):
     """Construct the keys to be used building the base stylesheet
     from a templatee."""
     style = get_style_by_name(stylename)
     fgcolor = style.style_for_token(Token.Text)['color'] or ''
     if len(fgcolor) in (3,6):
         # could be 'abcdef' or 'ace' hex, which needs '#' prefix
         try:
             int(fgcolor, 16)
         except TypeError:
             pass
         else:
             fgcolor = "#"+fgcolor
 
     return dict(
         bgcolor = style.background_color,
         select = style.highlight_color,
         fgcolor = fgcolor
     )
 
 def sheet_from_template(name, colors='lightbg'):
     """Use one of the base templates, and set bg/fg/select colors."""
     colors = colors.lower()
     if colors=='lightbg':
         return default_light_style_template%get_colors(name)
     elif colors=='linux':
         return default_dark_style_template%get_colors(name)
     elif colors=='nocolor':
         return default_bw_style_sheet
     else:
         raise KeyError("No such color scheme: %s"%colors)