Progress on raw_input.

IPython/frontend/qt/console/console_widget.py

@@ -1,823 +1,846 b''
 # Standard library imports
 import re
 import sys
 
 # System library imports
 from PyQt4 import QtCore, QtGui
 
 # Local imports
 from completion_widget import CompletionWidget
 
 
 class AnsiCodeProcessor(object):
     """ Translates ANSI escape codes into readable attributes.
     """
 
     def __init__(self):
         self.ansi_colors = ( # Normal, Bright/Light
                              ('#000000', '#7f7f7f'), # 0: black
                              ('#cd0000', '#ff0000'), # 1: red
                              ('#00cd00', '#00ff00'), # 2: green
                              ('#cdcd00', '#ffff00'), # 3: yellow
                              ('#0000ee', '#0000ff'), # 4: blue
                              ('#cd00cd', '#ff00ff'), # 5: magenta
                              ('#00cdcd', '#00ffff'), # 6: cyan
                              ('#e5e5e5', '#ffffff')) # 7: white
         self.reset()
         
     def set_code(self, code):
         """ Set attributes based on code.
         """
         if code == 0:
             self.reset()
         elif code == 1:
             self.intensity = 1
             self.bold = True
         elif code == 3:
             self.italic = True
         elif code == 4:
             self.underline = True
         elif code == 22:
             self.intensity = 0
             self.bold = False
         elif code == 23:
             self.italic = False
         elif code == 24:
             self.underline = False
         elif code >= 30 and code <= 37:
             self.foreground_color = code - 30
         elif code == 39:
             self.foreground_color = None
         elif code >= 40 and code <= 47:
             self.background_color = code - 40
         elif code == 49:
             self.background_color = None
         
     def reset(self):
         """ Reset attributs to their default values.
         """
         self.intensity = 0
         self.italic = False
         self.bold = False
         self.underline = False
         self.foreground_color = None
         self.background_color = None
 
 
 class QtAnsiCodeProcessor(AnsiCodeProcessor):
     """ Translates ANSI escape codes into QTextCharFormats.
     """
     
     def get_format(self):
         """ Returns a QTextCharFormat that encodes the current style attributes.
         """
         format = QtGui.QTextCharFormat()
 
         # Set foreground color
         if self.foreground_color is not None:
             color = self.ansi_colors[self.foreground_color][self.intensity]
             format.setForeground(QtGui.QColor(color))
 
         # Set background color
         if self.background_color is not None:
             color = self.ansi_colors[self.background_color][self.intensity]
             format.setBackground(QtGui.QColor(color))
 
         # Set font weight/style options
         if self.bold:
             format.setFontWeight(QtGui.QFont.Bold)
         else:
             format.setFontWeight(QtGui.QFont.Normal)
         format.setFontItalic(self.italic)
         format.setFontUnderline(self.underline)
 
         return format
 
 
 class ConsoleWidget(QtGui.QPlainTextEdit):
     """ Base class for console-type widgets. This class is mainly concerned with
         dealing with the prompt, keeping the cursor inside the editing line, and
         handling ANSI escape sequences.
     """
 
     # Whether to process ANSI escape codes.
     ansi_codes = True
 
     # The maximum number of lines of text before truncation.
     buffer_size = 500
 
     # Whether to use a CompletionWidget or plain text output for tab completion.
     gui_completion = True
 
     # Whether to override ShortcutEvents for the keybindings defined by this
     # widget (Ctrl+n, Ctrl+a, etc). Enable this if you want this widget to take
     # priority (when it has focus) over, e.g., window-level menu shortcuts.
     override_shortcuts = False
 
     # Protected class variables.
     _ansi_pattern = re.compile('\x01?\x1b\[(.*?)m\x02?')
     _ctrl_down_remap = { QtCore.Qt.Key_B : QtCore.Qt.Key_Left,
                          QtCore.Qt.Key_F : QtCore.Qt.Key_Right,
                          QtCore.Qt.Key_A : QtCore.Qt.Key_Home,
                          QtCore.Qt.Key_E : QtCore.Qt.Key_End,
                          QtCore.Qt.Key_P : QtCore.Qt.Key_Up,
                          QtCore.Qt.Key_N : QtCore.Qt.Key_Down,
                          QtCore.Qt.Key_D : QtCore.Qt.Key_Delete, }
     _shortcuts = set(_ctrl_down_remap.keys() +
                      [ QtCore.Qt.Key_C, QtCore.Qt.Key_V ])
 
     #---------------------------------------------------------------------------
     # 'QObject' interface
     #---------------------------------------------------------------------------
 
     def __init__(self, parent=None):
         QtGui.QPlainTextEdit.__init__(self, parent)
 
         # Initialize protected variables.
         self._ansi_processor = QtAnsiCodeProcessor()
         self._completion_widget = CompletionWidget(self)
         self._continuation_prompt = '> '
         self._executing = False
         self._prompt = ''
         self._prompt_pos = 0
         self._reading = False
 
         # Set a monospaced font.
         self.reset_font()
 
         # Define a custom context menu.
         self._context_menu = QtGui.QMenu(self)
 
         copy_action = QtGui.QAction('Copy', self)
         copy_action.triggered.connect(self.copy)
         self.copyAvailable.connect(copy_action.setEnabled)
         self._context_menu.addAction(copy_action)
 
         self._paste_action = QtGui.QAction('Paste', self)
         self._paste_action.triggered.connect(self.paste)
         self._context_menu.addAction(self._paste_action)
         self._context_menu.addSeparator()
 
         select_all_action = QtGui.QAction('Select All', self)
         select_all_action.triggered.connect(self.selectAll)
         self._context_menu.addAction(select_all_action)
 
     def event(self, event):
         """ Reimplemented to override shortcuts, if necessary.
         """
         # On Mac OS, it is always unnecessary to override shortcuts, hence the
         # check below. Users should just use the Control key instead of the
         # Command key.
         if self.override_shortcuts and \
                 sys.platform != 'darwin' and \
                 event.type() == QtCore.QEvent.ShortcutOverride and \
                 self._control_down(event.modifiers()) and \
                 event.key() in self._shortcuts:
             event.accept()
             return True
         else:
             return QtGui.QPlainTextEdit.event(self, event)
 
     #---------------------------------------------------------------------------
     # 'QWidget' interface
     #---------------------------------------------------------------------------
 
     def contextMenuEvent(self, event):
         """ Reimplemented to create a menu without destructive actions like
             'Cut' and 'Delete'.
         """
         clipboard_empty = QtGui.QApplication.clipboard().text().isEmpty()
         self._paste_action.setEnabled(not clipboard_empty)
         
         self._context_menu.exec_(event.globalPos())
 
     def keyPressEvent(self, event):
         """ Reimplemented to create a console-like interface.
         """
         intercepted = False
         cursor = self.textCursor()
         position = cursor.position()
         key = event.key()
         ctrl_down = self._control_down(event.modifiers())
         alt_down = event.modifiers() & QtCore.Qt.AltModifier
         shift_down = event.modifiers() & QtCore.Qt.ShiftModifier
 
         # Even though we have reimplemented 'paste', the C++ level slot is still
         # called by Qt. So we intercept the key press here.
         if event.matches(QtGui.QKeySequence.Paste):
             self.paste()
             intercepted = True
 
         elif ctrl_down:
             if key in self._ctrl_down_remap:
                 ctrl_down = False
                 key = self._ctrl_down_remap[key]
                 event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress, key, 
                                         QtCore.Qt.NoModifier)
 
             elif key == QtCore.Qt.Key_K:
                 if self._in_buffer(position):
                     cursor.movePosition(QtGui.QTextCursor.EndOfLine,
                                         QtGui.QTextCursor.KeepAnchor)
                     cursor.removeSelectedText()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_X:
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Y:
                 self.paste()
                 intercepted = True
 
         elif alt_down:
             if key == QtCore.Qt.Key_B:
                 self.setTextCursor(self._get_word_start_cursor(position))
                 intercepted = True
                 
             elif key == QtCore.Qt.Key_F:
                 self.setTextCursor(self._get_word_end_cursor(position))
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Backspace:
                 cursor = self._get_word_start_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 cursor.removeSelectedText()
                 intercepted = True
 
             elif key == QtCore.Qt.Key_D:
                 cursor = self._get_word_end_cursor(position)
                 cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
                 cursor.removeSelectedText()
                 intercepted = True
 
         if self._completion_widget.isVisible():
             self._completion_widget.keyPressEvent(event)
             intercepted = event.isAccepted()
         
         else:
             if key in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
+                intercepted = True
                 if self._reading:
+                    intercepted = False
                     self._reading = False
                 elif not self._executing:
                     self.execute(interactive=True)
-                intercepted = True
 
             elif key == QtCore.Qt.Key_Up:
                 if self._reading or not self._up_pressed():
                     intercepted = True
                 else:
                     prompt_line = self._get_prompt_cursor().blockNumber()
                     intercepted = cursor.blockNumber() <= prompt_line
 
             elif key == QtCore.Qt.Key_Down:
                 if self._reading or not self._down_pressed():
                     intercepted = True
                 else:
                     end_line = self._get_end_cursor().blockNumber()
                     intercepted = cursor.blockNumber() == end_line
 
             elif key == QtCore.Qt.Key_Tab:
                 if self._reading:
                     intercepted = False
                 else:
                     intercepted = not self._tab_pressed()
 
             elif key == QtCore.Qt.Key_Left:
                 intercepted = not self._in_buffer(position - 1)
 
             elif key == QtCore.Qt.Key_Home:
                 cursor.movePosition(QtGui.QTextCursor.StartOfLine)
                 start_pos = cursor.position()
                 start_line = cursor.blockNumber()
                 if start_line == self._get_prompt_cursor().blockNumber():
                     start_pos += len(self._prompt)
                 else:
                     start_pos += len(self._continuation_prompt)
                 if shift_down and self._in_buffer(position):
                     self._set_selection(position, start_pos)
                 else:
                     self._set_position(start_pos)
                 intercepted = True
 
             elif key == QtCore.Qt.Key_Backspace and not alt_down:
 
                 # Line deletion (remove continuation prompt)
                 len_prompt = len(self._continuation_prompt)
                 if cursor.columnNumber() == len_prompt and \
                         position != self._prompt_pos:
                     cursor.setPosition(position - len_prompt, 
                                        QtGui.QTextCursor.KeepAnchor)
                     cursor.removeSelectedText()
 
                 # 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:
                 anchor = cursor.anchor()
                 intercepted = not self._in_buffer(min(anchor, position))
 
         # Don't move cursor if control is down to allow copy-paste using
         # the keyboard in any part of the buffer.
         if not ctrl_down:
             self._keep_cursor_in_buffer()
 
         if not intercepted:
             QtGui.QPlainTextEdit.keyPressEvent(self, event)
 
     #--------------------------------------------------------------------------
     # 'QPlainTextEdit' interface
     #--------------------------------------------------------------------------
 
     def appendPlainText(self, text):
         """ Reimplemented to not append text as a new paragraph, which doesn't
             make sense for a console widget. Also, if enabled, handle ANSI
             codes.
         """
         cursor = self.textCursor()
         cursor.movePosition(QtGui.QTextCursor.End)
 
         if self.ansi_codes:
             format = QtGui.QTextCharFormat()
             previous_end = 0
             for match in self._ansi_pattern.finditer(text):
                 cursor.insertText(text[previous_end:match.start()], format)
                 previous_end = match.end()
                 for code in match.group(1).split(';'):
                     self._ansi_processor.set_code(int(code))
                 format = self._ansi_processor.get_format()
             cursor.insertText(text[previous_end:], format)
         else:
             cursor.insertText(text)
 
     def clear(self, keep_input=False):
         """ Reimplemented to write a new prompt. If 'keep_input' is set,
             restores the old input buffer when the new prompt is written.
         """
         super(ConsoleWidget, self).clear()
 
         if keep_input:
             input_buffer = self.input_buffer
         self._show_prompt()
         if keep_input:
             self.input_buffer = input_buffer
 
     def paste(self):
         """ Reimplemented to ensure that text is pasted in the editing region.
         """
         self._keep_cursor_in_buffer()
         QtGui.QPlainTextEdit.paste(self)
 
     def print_(self, printer):
         """ Reimplemented to work around a bug in PyQt: the C++ level 'print_'
             slot has the wrong signature.
         """
         QtGui.QPlainTextEdit.print_(self, printer)
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     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 not possible to prompt for more input.
 
         Returns:
         --------
         A boolean indicating whether the source was executed.
         """
         if not hidden:
             if source is not None:
                 self.input_buffer = source
 
             self.appendPlainText('\n')
             self._executing_input_buffer = self.input_buffer
             self._executing = True
             self._prompt_finished()
 
         real_source = self.input_buffer if source is None else source
         complete = self._is_complete(real_source, interactive)
         if complete:
             if not hidden:
                 # The maximum block count is only in effect during execution.
                 # This ensures that _prompt_pos does not become invalid due to
                 # text truncation.
                 self.setMaximumBlockCount(self.buffer_size)
             self._execute(real_source, hidden)
         elif hidden:
             raise RuntimeError('Incomplete noninteractive input: "%s"' % source)
         else:
             self._show_continuation_prompt()
 
         return complete
 
     def _get_input_buffer(self):
         """ The text that the user has entered entered at the current prompt.
         """
         # If we're executing, the input buffer may not even exist anymore due to
         # the limit imposed by 'buffer_size'. Therefore, we store it.
         if self._executing:
             return self._executing_input_buffer
 
         cursor = self._get_end_cursor()
         cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
 
         # Use QTextDocumentFragment intermediate object because it strips
         # out the Unicode line break characters that Qt insists on inserting.
         input_buffer = str(cursor.selection().toPlainText())
 
         # Strip out continuation prompts.
         return input_buffer.replace('\n' + self._continuation_prompt, '\n')
 
     def _set_input_buffer(self, string):
         """ Replaces the text in the input buffer with 'string'.
         """
         # Add continuation prompts where necessary.
         lines = string.splitlines()
         for i in xrange(1, len(lines)):
             lines[i] = self._continuation_prompt + lines[i]
         string = '\n'.join(lines)
 
         # Replace buffer with new text.
         cursor = self._get_end_cursor()
         cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
         cursor.insertText(string)
         self.moveCursor(QtGui.QTextCursor.End)
 
     input_buffer = property(_get_input_buffer, _set_input_buffer)
 
     def _get_input_buffer_cursor_line(self):
         """ The text in the line of the input buffer in which the user's cursor
             rests. Returns a string if there is such a line; otherwise, None.
         """
         if self._executing:
             return None
         cursor = self.textCursor()
         if cursor.position() >= self._prompt_pos:
             text = str(cursor.block().text())
             if cursor.blockNumber() == self._get_prompt_cursor().blockNumber():
                 return text[len(self._prompt):]
             else:
                 return text[len(self._continuation_prompt):]
         else:
             return None
 
     input_buffer_cursor_line = property(_get_input_buffer_cursor_line)
 
     def _get_font(self):
         """ The base font being used by the ConsoleWidget.
         """
         return self.document().defaultFont()
 
     def _set_font(self, font):
         """ Sets the base font for the ConsoleWidget to the specified QFont.
         """
         self._completion_widget.setFont(font)
         self.document().setDefaultFont(font)
 
     font = property(_get_font, _set_font)
 
     def reset_font(self):
         """ Sets the font to the default fixed-width font for this platform.
         """
         if sys.platform == 'win32':
             name = 'Courier'
         elif sys.platform == 'darwin':
             name = 'Monaco'
         else:
             name = 'Monospace'
         font = QtGui.QFont(name, QtGui.qApp.font().pointSize())
         font.setStyleHint(QtGui.QFont.TypeWriter)
         self._set_font(font)
         
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' abstract interface
     #---------------------------------------------------------------------------
 
     def _is_complete(self, source, interactive):
         """ Returns whether 'source' can be executed. When triggered by an
             Enter/Return key press, 'interactive' is True; otherwise, it is
             False.
         """
         raise NotImplementedError
 
     def _execute(self, source, hidden):
         """ Execute 'source'. If 'hidden', do not show any output.
         """
         raise NotImplementedError
 
     def _prompt_started_hook(self):
         """ Called immediately after a new prompt is displayed.
         """
         pass
 
     def _prompt_finished_hook(self):
         """ Called immediately after a prompt is finished, i.e. when some input
             will be processed and a new prompt displayed.
         """
         pass
 
     def _up_pressed(self):
         """ Called when the up key is pressed. Returns whether to continue
             processing the event.
         """
         return True
 
     def _down_pressed(self):
         """ Called when the down key is pressed. Returns whether to continue
             processing the event.
         """
         return True
 
     def _tab_pressed(self):
         """ Called when the tab key is pressed. Returns whether to continue
             processing the event.
         """
         return False
 
     #--------------------------------------------------------------------------
     # 'ConsoleWidget' protected interface
     #--------------------------------------------------------------------------
 
     def _control_down(self, modifiers):
         """ Given a KeyboardModifiers flags object, return whether the Control
             key is down (on Mac OS, treat the Command key as a synonym for
             Control).
         """
         down = bool(modifiers & QtCore.Qt.ControlModifier)
 
         # Note: on Mac OS, ControlModifier corresponds to the Command key while
         # MetaModifier corresponds to the Control key.
         if sys.platform == 'darwin':
             down = down ^ bool(modifiers & QtCore.Qt.MetaModifier)
             
         return down
     
     def _complete_with_items(self, cursor, items):
         """ Performs completion with 'items' at the specified cursor location.
         """
         if len(items) == 1:
             cursor.setPosition(self.textCursor().position(), 
                                QtGui.QTextCursor.KeepAnchor)
             cursor.insertText(items[0])
         elif len(items) > 1:
             if self.gui_completion:
                 self._completion_widget.show_items(cursor, items) 
             else:
                 text = '\n'.join(items) + '\n'
                 self._write_text_keeping_prompt(text)
                 
     def _get_end_cursor(self):
         """ Convenience method that returns a cursor for the last character.
         """
         cursor = self.textCursor()
         cursor.movePosition(QtGui.QTextCursor.End)
         return cursor
 
     def _get_prompt_cursor(self):
         """ Convenience method that returns a cursor for the prompt position.
         """
         cursor = self.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.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.document()
         position -= 1
         while self._in_buffer(position) and \
                 not document.characterAt(position).isLetterOrNumber():
             position -= 1
         while self._in_buffer(position) and \
                 document.characterAt(position).isLetterOrNumber():
             position -= 1
         cursor = self.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.document()
         end = self._get_end_cursor().position()
         while position < end and \
                 not document.characterAt(position).isLetterOrNumber():
             position += 1
         while position < end and \
                 document.characterAt(position).isLetterOrNumber():
             position += 1
         cursor = self.textCursor()
         cursor.setPosition(position)
         return cursor
 
     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.setMaximumBlockCount(0)
         self.setUndoRedoEnabled(True)
 
         self.setReadOnly(False)
         self.moveCursor(QtGui.QTextCursor.End)
         self.centerCursor()
 
         self._executing = False
         self._prompt_started_hook()
 
     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.setUndoRedoEnabled(False)
         self.setReadOnly(True)
         self._prompt_finished_hook()
 
+    def _readline(self, prompt=''):
+        """ Read and return one line of input from the user. The trailing 
+            newline is stripped.
+        """
+        if not self.isVisible():
+            raise RuntimeError('Cannot read a line if widget is not visible!')
+
+        self._reading = True
+        self._show_prompt(prompt)
+        while self._reading:
+            QtCore.QCoreApplication.processEvents()
+        return self.input_buffer.rstrip('\n\r')
+
     def _set_position(self, position):
         """ Convenience method to set the position of the cursor.
         """
         cursor = self.textCursor()
         cursor.setPosition(position)
         self.setTextCursor(cursor)
 
     def _set_selection(self, start, end):
         """ Convenience method to set the current selected text.
         """
         self.setTextCursor(self._get_selection_cursor(start, end))
 
     def _show_prompt(self, prompt=None):
         """ Writes a new prompt at the end of the buffer. If 'prompt' is not
-            specified, uses the previous prompt.
+            specified, the previous prompt is used.
         """
+        # Use QTextDocumentFragment intermediate object because it strips
+        # out the Unicode line break characters that Qt insists on inserting.
+        cursor = self._get_end_cursor()
+        cursor.movePosition(QtGui.QTextCursor.Left, 
+                            QtGui.QTextCursor.KeepAnchor)
+        if str(cursor.selection().toPlainText()) not in '\r\n':
+            self.appendPlainText('\n')
+
         if prompt is not None:
             self._prompt = prompt
-        self.appendPlainText('\n' + self._prompt)
+        self.appendPlainText(self._prompt)
+
         self._prompt_pos = self._get_end_cursor().position()
         self._prompt_started()
 
     def _show_continuation_prompt(self):
         """ Writes a new continuation prompt at the end of the buffer.
         """
         self.appendPlainText(self._continuation_prompt)
         self._prompt_started()
 
     def _write_text_keeping_prompt(self, text):
         """ Writes 'text' after the current prompt, then restores the old prompt
             with its old input buffer.
         """
         input_buffer = self.input_buffer
         self.appendPlainText('\n')
         self._prompt_finished()
 
         self.appendPlainText(text)
         self._show_prompt()
         self.input_buffer = input_buffer
 
     def _in_buffer(self, position):
         """ Returns whether the given position is inside the editing region.
         """
         return position >= self._prompt_pos
 
     def _keep_cursor_in_buffer(self):
         """ Ensures that the cursor is inside the editing region. Returns
             whether the cursor was moved.
         """
         cursor = self.textCursor()
         if cursor.position() < self._prompt_pos:
             cursor.movePosition(QtGui.QTextCursor.End)
             self.setTextCursor(cursor)
             return True
         else:
             return False
 
 
 class HistoryConsoleWidget(ConsoleWidget):
     """ A ConsoleWidget that keeps a history of the commands that have been
         executed.
     """
     
     #---------------------------------------------------------------------------
     # 'QObject' interface
     #---------------------------------------------------------------------------
 
     def __init__(self, parent=None):
         super(HistoryConsoleWidget, self).__init__(parent)
 
         self._history = []
         self._history_index = 0
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     def execute(self, source=None, hidden=False, interactive=False):
         """ Reimplemented to the store history.
         """
         if not hidden:
             history = self.input_buffer if source is None else source
 
         executed = super(HistoryConsoleWidget, self).execute(
             source, hidden, interactive)
 
         if executed and not hidden:
             self._history.append(history.rstrip())
             self._history_index = len(self._history)
 
         return executed
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' abstract interface
     #---------------------------------------------------------------------------
 
     def _up_pressed(self):
         """ Called when the up key is pressed. Returns whether to continue
             processing the event.
         """
         prompt_cursor = self._get_prompt_cursor()
         if self.textCursor().blockNumber() == prompt_cursor.blockNumber():
             self.history_previous()
 
             # Go to the first line of prompt for seemless history scrolling.
             cursor = self._get_prompt_cursor()
             cursor.movePosition(QtGui.QTextCursor.EndOfLine)
             self.setTextCursor(cursor)
 
             return False
         return True
 
     def _down_pressed(self):
         """ Called when the down key is pressed. Returns whether to continue
             processing the event.
         """
         end_cursor = self._get_end_cursor()
         if self.textCursor().blockNumber() == end_cursor.blockNumber():
             self.history_next()
             return False
         return True
 
     #---------------------------------------------------------------------------
     # 'HistoryConsoleWidget' interface
     #---------------------------------------------------------------------------
 
     def history_previous(self):
         """ If possible, set the input buffer to the previous item in the
             history.
         """
         if self._history_index > 0:
             self._history_index -= 1
             self.input_buffer = self._history[self._history_index]
 
     def history_next(self):
         """ Set the input buffer to the next item in the history, or a blank
             line if there is no subsequent item.
         """
         if self._history_index < len(self._history):
             self._history_index += 1
             if self._history_index < len(self._history):
                 self.input_buffer = self._history[self._history_index]
             else:
                 self.input_buffer = ''

IPython/frontend/qt/console/frontend_widget.py

@@ -1,330 +1,349 b''
 # Standard library imports
 import signal
 
 # System library imports
 from pygments.lexers import PythonLexer
 from PyQt4 import QtCore, QtGui
 import zmq
 
 # Local imports
 from IPython.core.inputsplitter import InputSplitter
 from call_tip_widget import CallTipWidget
 from completion_lexer import CompletionLexer
 from console_widget import HistoryConsoleWidget
 from pygments_highlighter import PygmentsHighlighter
 
 
 class FrontendHighlighter(PygmentsHighlighter):
     """ A Python PygmentsHighlighter that can be turned on and off and which 
         knows about continuation prompts.
     """
 
     def __init__(self, frontend):
         PygmentsHighlighter.__init__(self, frontend.document(), PythonLexer())
         self._current_offset = 0
         self._frontend = frontend
         self.highlighting_on = False
 
     def highlightBlock(self, qstring):
         """ Highlight a block of text. Reimplemented to highlight selectively.
         """
         if self.highlighting_on:
             for prompt in (self._frontend._continuation_prompt,
                            self._frontend._prompt):                           
                 if qstring.startsWith(prompt):
                     qstring.remove(0, len(prompt))
                     self._current_offset = len(prompt)
                     break
             PygmentsHighlighter.highlightBlock(self, qstring)
 
     def setFormat(self, start, count, format):
         """ Reimplemented to avoid highlighting continuation prompts.
         """
         start += self._current_offset
         PygmentsHighlighter.setFormat(self, start, count, format)
 
 
 class FrontendWidget(HistoryConsoleWidget):
     """ A Qt frontend for a generic Python kernel.
     """
 
     # Emitted when an 'execute_reply' is received from the kernel.
     executed = QtCore.pyqtSignal(object)
 
     #---------------------------------------------------------------------------
     # 'QObject' interface
     #---------------------------------------------------------------------------
     
     def __init__(self, parent=None):
         super(FrontendWidget, self).__init__(parent)
 
         # ConsoleWidget protected variables.
         self._continuation_prompt = '... '
-        self._prompt = '>>> '
 
         # FrontendWidget protected variables.
         self._call_tip_widget = CallTipWidget(self)
         self._completion_lexer = CompletionLexer(PythonLexer())
         self._hidden = True
         self._highlighter = FrontendHighlighter(self)
         self._input_splitter = InputSplitter(input_mode='replace')
         self._kernel_manager = None
 
         self.document().contentsChange.connect(self._document_contents_change)
 
     #---------------------------------------------------------------------------
     # 'QWidget' interface
     #---------------------------------------------------------------------------
 
     def focusOutEvent(self, event):
         """ Reimplemented to hide calltips.
         """
         self._call_tip_widget.hide()
         super(FrontendWidget, self).focusOutEvent(event)
 
     def keyPressEvent(self, event):
         """ Reimplemented to allow calltips to process events and to send
             signals to the kernel.
         """
         if self._executing and event.key() == QtCore.Qt.Key_C and \
                 self._control_down(event.modifiers()):
             self._interrupt_kernel()
         else:
             if self._call_tip_widget.isVisible():
                 self._call_tip_widget.keyPressEvent(event)
             super(FrontendWidget, self).keyPressEvent(event)
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' abstract interface
     #---------------------------------------------------------------------------
 
     def _is_complete(self, source, interactive):
         """ Returns whether 'source' can be completely processed and a new
             prompt created. When triggered by an Enter/Return key press,
             'interactive' is True; otherwise, it is False.
         """
         complete = self._input_splitter.push(source)
         if interactive:
             complete = not self._input_splitter.push_accepts_more()
         return complete
 
     def _execute(self, source, hidden):
         """ Execute 'source'. If 'hidden', do not show any output.
         """
         self.kernel_manager.xreq_channel.execute(source)
         self._hidden = hidden
         
     def _prompt_started_hook(self):
         """ Called immediately after a new prompt is displayed.
         """
         self._highlighter.highlighting_on = True
 
         # Auto-indent if this is a continuation prompt.
         if self._get_prompt_cursor().blockNumber() != \
                 self._get_end_cursor().blockNumber():
             self.appendPlainText(' ' * self._input_splitter.indent_spaces)
 
     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.
         """
         self._highlighter.highlighting_on = False
 
     def _tab_pressed(self):
         """ Called when the tab key is pressed. Returns whether to continue
             processing the event.
         """
         self._keep_cursor_in_buffer()
         cursor = self.textCursor()
         if not self._complete():
             cursor.insertText('    ')
         return False
 
     #---------------------------------------------------------------------------
+    # 'ConsoleWidget' protected interface
+    #---------------------------------------------------------------------------
+
+    def _show_prompt(self, prompt=None):
+        """ Reimplemented to set a default prompt.
+        """
+        if prompt is None:
+            prompt = '>>> '
+        super(FrontendWidget, self)._show_prompt(prompt)
+
+    #---------------------------------------------------------------------------
     # 'FrontendWidget' interface
     #---------------------------------------------------------------------------
 
     def execute_file(self, path, hidden=False):
         """ Attempts to execute file with 'path'. If 'hidden', no output is
             shown.
         """
         self.execute('execfile("%s")' % path, hidden=hidden)
 
     def _get_kernel_manager(self):
         """ Returns the current kernel manager.
         """
         return self._kernel_manager
 
     def _set_kernel_manager(self, kernel_manager):
         """ Disconnect from the current kernel manager (if any) and set a new
             kernel manager.
         """
         # Disconnect the old kernel manager, if necessary.
         if self._kernel_manager is not None:
             self._kernel_manager.started_channels.disconnect(
                 self._started_channels)
             self._kernel_manager.stopped_channels.disconnect(
                 self._stopped_channels)
 
             # Disconnect the old kernel manager's channels.
             sub = self._kernel_manager.sub_channel
             xreq = self._kernel_manager.xreq_channel
             sub.message_received.disconnect(self._handle_sub)
             xreq.execute_reply.disconnect(self._handle_execute_reply)
             xreq.complete_reply.disconnect(self._handle_complete_reply)
             xreq.object_info_reply.disconnect(self._handle_object_info_reply)
 
             # Handle the case where the old kernel manager is still listening.
             if self._kernel_manager.channels_running:
                 self._stopped_channels()
 
         # Set the new kernel manager.
         self._kernel_manager = kernel_manager
         if kernel_manager is None:
             return
 
         # Connect the new kernel manager.
         kernel_manager.started_channels.connect(self._started_channels)
         kernel_manager.stopped_channels.connect(self._stopped_channels)
 
         # Connect the new kernel manager's channels.
         sub = kernel_manager.sub_channel
         xreq = kernel_manager.xreq_channel
         sub.message_received.connect(self._handle_sub)
         xreq.execute_reply.connect(self._handle_execute_reply)
         xreq.complete_reply.connect(self._handle_complete_reply)
         xreq.object_info_reply.connect(self._handle_object_info_reply)
         
         # Handle the case where the kernel manager started channels before
         # we connected.
         if kernel_manager.channels_running:
             self._started_channels()
 
     kernel_manager = property(_get_kernel_manager, _set_kernel_manager)
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _call_tip(self):
         """ Shows a call tip, if appropriate, at the current cursor location.
         """
         # Decide if it makes sense to show a call tip
         cursor = self.textCursor()
         cursor.movePosition(QtGui.QTextCursor.Left)
         document = self.document()
         if document.characterAt(cursor.position()).toAscii() != '(':
             return False
         context = self._get_context(cursor)
         if not context:
             return False
 
         # Send the metadata request to the kernel
         name = '.'.join(context)
         self._calltip_id = self.kernel_manager.xreq_channel.object_info(name)
         self._calltip_pos = self.textCursor().position()
         return True
 
     def _complete(self):
         """ Performs completion at the current cursor location.
         """
         # Decide if it makes sense to do completion
         context = self._get_context()
         if not context:
             return False
 
         # Send the completion request to the kernel
         text = '.'.join(context)
         self._complete_id = self.kernel_manager.xreq_channel.complete(
             text, self.input_buffer_cursor_line, self.input_buffer)
         self._complete_pos = self.textCursor().position()
         return True
 
     def _get_context(self, cursor=None):
         """ Gets the context at the current cursor location.
         """
         if cursor is None:
             cursor = self.textCursor()
         cursor.movePosition(QtGui.QTextCursor.StartOfLine, 
                             QtGui.QTextCursor.KeepAnchor)
         text = unicode(cursor.selectedText())
         return self._completion_lexer.get_context(text)
 
     def _interrupt_kernel(self):
         """ Attempts to the interrupt the kernel.
         """
         if self.kernel_manager.has_kernel:
             self.kernel_manager.signal_kernel(signal.SIGINT)
         else:
             self.appendPlainText('Kernel process is either remote or '
                                  'unspecified. Cannot interrupt.\n')
 
     #------ Signal handlers ----------------------------------------------------
 
+    def _started_channels(self):
+        """ Called when the kernel manager has started listening.
+        """
+        self.clear()
+
+    def _stopped_channels(self):
+        """ Called when the kernel manager has stopped listening.
+        """
+        pass
+
     def _document_contents_change(self, position, removed, added):
         """ Called whenever the document's content changes. Display a calltip
             if appropriate.
         """
         # Calculate where the cursor should be *after* the change:
         position += added
 
         document = self.document()
         if position == self.textCursor().position():
             self._call_tip()
 
+    def _handle_req(self):
+        print self._readline()
+
     def _handle_sub(self, omsg):
         if self._hidden:
             return
         handler = getattr(self, '_handle_%s' % omsg['msg_type'], None)
         if handler is not None:
             handler(omsg)
 
     def _handle_pyout(self, omsg):
         session = omsg['parent_header']['session']
         if session == self.kernel_manager.session.session:
             self.appendPlainText(omsg['content']['data'] + '\n')
 
     def _handle_stream(self, omsg):
         self.appendPlainText(omsg['content']['data'])
         self.moveCursor(QtGui.QTextCursor.End)
         
     def _handle_execute_reply(self, rep):
         if self._hidden:
             return
 
         # Make sure that all output from the SUB channel has been processed
         # before writing a new prompt.
         self.kernel_manager.sub_channel.flush()
 
         content = rep['content']
         status = content['status']
         if status == 'error':
             self.appendPlainText(content['traceback'][-1])
         elif status == 'aborted':
             text = "ERROR: ABORTED\n"
             self.appendPlainText(text)
         self._hidden = True
         self._show_prompt()
         self.executed.emit(rep)
 
     def _handle_complete_reply(self, rep):
         cursor = self.textCursor()
         if rep['parent_header']['msg_id'] == self._complete_id and \
                 cursor.position() == self._complete_pos:
             text = '.'.join(self._get_context())
             cursor.movePosition(QtGui.QTextCursor.Left, n=len(text))
             self._complete_with_items(cursor, rep['content']['matches'])
 
     def _handle_object_info_reply(self, rep):
         cursor = self.textCursor()
         if rep['parent_header']['msg_id'] == self._calltip_id and \
                 cursor.position() == self._calltip_pos:
             doc = rep['content']['docstring']
             if doc:
                 self._call_tip_widget.show_docstring(doc)
 
-    def _started_channels(self):
-        self.clear()
 
-    def _stopped_channels(self):
-        pass

IPython/zmq/kernel.py

@@ -1,410 +1,451 b''
 #!/usr/bin/env python
 """A simple interactive kernel that talks to a frontend over 0MQ.
 
 Things to do:
 
 * Finish implementing `raw_input`.
 * Implement `set_parent` logic. Right before doing exec, the Kernel should
   call set_parent on all the PUB objects with the message about to be executed.
 * Implement random port and security key logic.
 * Implement control messages.
 * Implement event loop and poll version.
 """
 
 # Standard library imports.
 import __builtin__
 import os
 import sys
 import time
 import traceback
 from code import CommandCompiler
 
 # System library imports.
 import zmq
 
 # Local imports.
 from IPython.external.argparse import ArgumentParser
 from session import Session, Message, extract_header
 from completer import KernelCompleter
 
 
+class InStream(object):
+    """ A file like object that reads from a 0MQ XREQ socket."""
+
+    def __init__(self, session, socket):
+        self.session = session
+        self.socket = socket
+
+    def close(self):
+        self.socket = None
+
+    def flush(self):
+        if self.socket is None:
+            raise ValueError(u'I/O operation on closed file')
+        
+    def isatty(self):
+        return False
+
+    def next(self):
+        raise IOError('Seek not supported.')
+
+    def read(self, size=-1):
+        raise NotImplementedError
+
+    def readline(self, size=-1):
+        if self.socket is None:
+            raise ValueError(u'I/O operation on closed file')
+        else:
+            content = { u'size' : unicode(size) }
+            msg = self.session.msg(u'readline', content=content) 
+            return self._request(msg)
+
+    def readlines(self, size=-1):
+        raise NotImplementedError
+
+    def seek(self, offset, whence=None):
+        raise IOError('Seek not supported.')
+
+    def write(self, string):
+        raise IOError('Write not supported on a read only stream.')
+
+    def writelines(self, sequence):
+        raise IOError('Write not supported on a read only stream.')
+    
+    def _request(self, msg):
+        self.socket.send_json(msg)
+        while True:
+            try:
+                reply = self.socket.recv_json(zmq.NOBLOCK)
+            except zmq.ZMQError, e:
+                if e.errno == zmq.EAGAIN:
+                    pass
+                else:
+                    raise
+            else:
+                break
+        return reply[u'content'][u'data']
+
+
 class OutStream(object):
     """A file like object that publishes the stream to a 0MQ PUB socket."""
 
     def __init__(self, session, pub_socket, name, max_buffer=200):
         self.session = session
         self.pub_socket = pub_socket
         self.name = name
         self._buffer = []
         self._buffer_len = 0
         self.max_buffer = max_buffer
         self.parent_header = {}
 
     def set_parent(self, parent):
         self.parent_header = extract_header(parent)
 
     def close(self):
         self.pub_socket = None
 
     def flush(self):
         if self.pub_socket is None:
             raise ValueError(u'I/O operation on closed file')
         else:
             if self._buffer:
                 data = ''.join(self._buffer)
                 content = {u'name':self.name, u'data':data}
                 msg = self.session.msg(u'stream', content=content,
                                        parent=self.parent_header)
                 print>>sys.__stdout__, Message(msg)
                 self.pub_socket.send_json(msg)
                 self._buffer_len = 0
                 self._buffer = []
 
-    def isattr(self):
+    def isatty(self):
         return False
 
     def next(self):
         raise IOError('Read not supported on a write only stream.')
 
     def read(self, size=None):
         raise IOError('Read not supported on a write only stream.')
 
     readline=read
 
     def write(self, s):
         if self.pub_socket is None:
             raise ValueError('I/O operation on closed file')
         else:
             self._buffer.append(s)
             self._buffer_len += len(s)
             self._maybe_send()
 
     def _maybe_send(self):
         if '\n' in self._buffer[-1]:
             self.flush()
         if self._buffer_len > self.max_buffer:
             self.flush()
 
     def writelines(self, sequence):
         if self.pub_socket is None:
             raise ValueError('I/O operation on closed file')
         else:
             for s in sequence:
                 self.write(s)
 
 
 class DisplayHook(object):
 
     def __init__(self, session, pub_socket):
         self.session = session
         self.pub_socket = pub_socket
         self.parent_header = {}
 
     def __call__(self, obj):
         if obj is None:
             return
 
         __builtin__._ = obj
         msg = self.session.msg(u'pyout', {u'data':repr(obj)},
                                parent=self.parent_header)
         self.pub_socket.send_json(msg)
 
     def set_parent(self, parent):
         self.parent_header = extract_header(parent)
 
 
-class RawInput(object):
-
-    def __init__(self, session, socket):
-        self.session = session
-        self.socket = socket
-
-    def __call__(self, prompt=None):
-        msg = self.session.msg(u'raw_input')
-        self.socket.send_json(msg)
-        while True:
-            try:
-                reply = self.socket.recv_json(zmq.NOBLOCK)
-            except zmq.ZMQError, e:
-                if e.errno == zmq.EAGAIN:
-                    pass
-                else:
-                    raise
-            else:
-                break
-        return reply[u'content'][u'data']
-
-
 class Kernel(object):
 
     def __init__(self, session, reply_socket, pub_socket):
         self.session = session
         self.reply_socket = reply_socket
         self.pub_socket = pub_socket
         self.user_ns = {}
         self.history = []
         self.compiler = CommandCompiler()
         self.completer = KernelCompleter(self.user_ns)
         self.poll_ppid = False
         
         # Build dict of handlers for message types
         msg_types = [ 'execute_request', 'complete_request', 
                       'object_info_request' ]
         self.handlers = {}
         for msg_type in msg_types:
             self.handlers[msg_type] = getattr(self, msg_type)
 
     def abort_queue(self):
         while True:
             try:
                 ident = self.reply_socket.recv(zmq.NOBLOCK)
             except zmq.ZMQError, e:
                 if e.errno == zmq.EAGAIN:
                     break
             else:
                 assert self.reply_socket.rcvmore(), "Unexpected missing message part."
                 msg = self.reply_socket.recv_json()
             print>>sys.__stdout__, "Aborting:"
             print>>sys.__stdout__, Message(msg)
             msg_type = msg['msg_type']
             reply_type = msg_type.split('_')[0] + '_reply'
             reply_msg = self.session.msg(reply_type, {'status' : 'aborted'}, msg)
             print>>sys.__stdout__, Message(reply_msg)
             self.reply_socket.send(ident,zmq.SNDMORE)
             self.reply_socket.send_json(reply_msg)
             # We need to wait a bit for requests to come in. This can probably
             # be set shorter for true asynchronous clients.
             time.sleep(0.1)
 
     def execute_request(self, ident, parent):
         try:
             code = parent[u'content'][u'code']
         except:
             print>>sys.__stderr__, "Got bad msg: "
             print>>sys.__stderr__, Message(parent)
             return
         pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent)
         self.pub_socket.send_json(pyin_msg)
         try:
             comp_code = self.compiler(code, '<zmq-kernel>')
             sys.displayhook.set_parent(parent)
             exec comp_code in self.user_ns, self.user_ns
         except:
             result = u'error'
             etype, evalue, tb = sys.exc_info()
             tb = traceback.format_exception(etype, evalue, tb)
             exc_content = {
                 u'status' : u'error',
                 u'traceback' : tb,
                 u'etype' : unicode(etype),
                 u'evalue' : unicode(evalue)
             }
             exc_msg = self.session.msg(u'pyerr', exc_content, parent)
             self.pub_socket.send_json(exc_msg)
             reply_content = exc_content
         else:
             reply_content = {'status' : 'ok'}
         reply_msg = self.session.msg(u'execute_reply', reply_content, parent)
         print>>sys.__stdout__, Message(reply_msg)
         self.reply_socket.send(ident, zmq.SNDMORE)
         self.reply_socket.send_json(reply_msg)
         if reply_msg['content']['status'] == u'error':
             self.abort_queue()
 
     def complete_request(self, ident, parent):
         matches = {'matches' : self.complete(parent),
                    'status' : 'ok'}
         completion_msg = self.session.send(self.reply_socket, 'complete_reply',
                                            matches, parent, ident)
         print >> sys.__stdout__, completion_msg
 
     def complete(self, msg):
         return self.completer.complete(msg.content.line, msg.content.text)
 
     def object_info_request(self, ident, parent):
         context = parent['content']['oname'].split('.')
         object_info = self.object_info(context)
         msg = self.session.send(self.reply_socket, 'object_info_reply',
                                 object_info, parent, ident)
         print >> sys.__stdout__, msg
 
     def object_info(self, context):
         symbol, leftover = self.symbol_from_context(context)
         if symbol is not None and not leftover:
             doc = getattr(symbol, '__doc__', '')
         else:
             doc = ''
         object_info = dict(docstring = doc)
         return object_info
 
     def symbol_from_context(self, context):
         if not context:
             return None, context
 
         base_symbol_string = context[0]
         symbol = self.user_ns.get(base_symbol_string, None)
         if symbol is None:
             symbol = __builtin__.__dict__.get(base_symbol_string, None)
         if symbol is None:
             return None, context
 
         context = context[1:]
         for i, name in enumerate(context):
             new_symbol = getattr(symbol, name, None)
             if new_symbol is None:
                 return symbol, context[i:]
             else:
                 symbol = new_symbol
 
         return symbol, []
 
     def start(self):
         while True:
             if self.poll_ppid and os.getppid() == 1:
                 print>>sys.__stderr__, "KILLED KERNEL. No parent process."
                 os._exit(1)
 
             ident = self.reply_socket.recv()
             assert self.reply_socket.rcvmore(), "Unexpected missing message part."
             msg = self.reply_socket.recv_json()
             omsg = Message(msg)
             print>>sys.__stdout__
             print>>sys.__stdout__, omsg
             handler = self.handlers.get(omsg.msg_type, None)
             if handler is None:
                 print >> sys.__stderr__, "UNKNOWN MESSAGE TYPE:", omsg
             else:
                 handler(ident, omsg)
 
 
 def bind_port(socket, ip, port):
     """ Binds the specified ZMQ socket. If the port is less than zero, a random
     port is chosen. Returns the port that was bound.
     """
     connection = 'tcp://%s' % ip
     if port <= 0:
         port = socket.bind_to_random_port(connection)
     else:
         connection += ':%i' % port
         socket.bind(connection)
     return port
 
 def main():
     """ Main entry point for launching a kernel.
     """
     # Parse command line arguments.
     parser = ArgumentParser()
     parser.add_argument('--ip', type=str, default='127.0.0.1',
                         help='set the kernel\'s IP address [default: local]')
     parser.add_argument('--xrep', type=int, metavar='PORT', default=0,
                         help='set the XREP channel port [default: random]')
     parser.add_argument('--pub', type=int, metavar='PORT', default=0,
                         help='set the PUB channel port [default: random]')
     parser.add_argument('--req', type=int, metavar='PORT', default=0,
                         help='set the REQ channel port [default: random]')
     parser.add_argument('--require-parent', action='store_true', 
                         help='ensure that this process dies with its parent')
     namespace = parser.parse_args()
 
     # Create a context, a session, and the kernel sockets.
     print >>sys.__stdout__, "Starting the kernel..."
     context = zmq.Context()
     session = Session(username=u'kernel')
 
     reply_socket = context.socket(zmq.XREP)
     xrep_port = bind_port(reply_socket, namespace.ip, namespace.xrep)
     print >>sys.__stdout__, "XREP Channel on port", xrep_port
 
     pub_socket = context.socket(zmq.PUB)
     pub_port = bind_port(pub_socket, namespace.ip, namespace.pub)
     print >>sys.__stdout__, "PUB Channel on port", pub_port
 
+    req_socket = context.socket(zmq.XREQ)
+    req_port = bind_port(req_socket, namespace.ip, namespace.req)
+    print >>sys.__stdout__, "REQ Channel on port", req_port
+
     # Redirect input streams and set a display hook.
+    sys.stdin = InStream(session, req_socket)
     sys.stdout = OutStream(session, pub_socket, u'stdout')
     sys.stderr = OutStream(session, pub_socket, u'stderr')
     sys.displayhook = DisplayHook(session, pub_socket)
 
     # Create the kernel.
     kernel = Kernel(session, reply_socket, pub_socket)
 
     # Configure this kernel/process to die on parent termination, if necessary.
     if namespace.require_parent:
         if sys.platform == 'linux2':
             import ctypes, ctypes.util, signal
             PR_SET_PDEATHSIG = 1
             libc = ctypes.CDLL(ctypes.util.find_library('c'))
             libc.prctl(PR_SET_PDEATHSIG, signal.SIGKILL)
 
         elif sys.platform != 'win32':
             kernel.poll_ppid = True
 
     # Start the kernel mainloop.
     kernel.start()
 
 
 def launch_kernel(xrep_port=0, pub_port=0, req_port=0, independent=False):
     """ Launches a localhost kernel, binding to the specified ports.
 
     Parameters
     ----------
     xrep_port : int, optional
         The port to use for XREP channel.
 
     pub_port : int, optional
         The port to use for the SUB channel.
 
     req_port : int, optional
         The port to use for the REQ (raw input) channel.
 
     independent : bool, optional (default False) 
         If set, the kernel process is guaranteed to survive if this process
         dies. If not set, an effort is made to ensure that the kernel is killed
         when this process dies. Note that in this case it is still good practice
         to attempt to kill kernels manually before exiting.
 
     Returns
     -------
     A tuple of form:
         (kernel_process, xrep_port, pub_port, req_port)
     where kernel_process is a Popen object and the ports are integers.
     """
     import socket
     from subprocess import Popen
 
     # Find open ports as necessary.
     ports = []
     ports_needed = int(xrep_port <= 0) + int(pub_port <= 0) + int(req_port <= 0)
     for i in xrange(ports_needed):
         sock = socket.socket()
         sock.bind(('', 0))
         ports.append(sock)
     for i, sock in enumerate(ports):
         port = sock.getsockname()[1]
         sock.close()
         ports[i] = port
     if xrep_port <= 0:
         xrep_port = ports.pop(0)
     if pub_port <= 0:
         pub_port = ports.pop(0)
     if req_port <= 0:
         req_port = ports.pop(0)
         
     # Spawn a kernel.
     command = 'from IPython.zmq.kernel import main; main()'
     arguments = [ sys.executable, '-c', command, '--xrep', str(xrep_port), 
                   '--pub', str(pub_port), '--req', str(req_port) ]
 
     if independent:
         if sys.platform == 'win32':
             proc = Popen(['start', '/b'] + arguments, shell=True)
         else:
             proc = Popen(arguments, preexec_fn=lambda: os.setsid())
 
     else:
         proc = Popen(arguments + ['--require-parent'])
 
     return proc, xrep_port, pub_port, req_port
     
 
 if __name__ == '__main__':
     main()

IPython/zmq/kernelmanager.py

@@ -1,535 +1,534 b''
 """Classes to manage the interaction with a running kernel.
 
 Todo
 ====
 
 * Create logger to handle debugging and console messages.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2010  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports.
 from Queue import Queue, Empty
 from subprocess import Popen
 from threading import Thread
 import time
 
 # System library imports.
 import zmq
 from zmq import POLLIN, POLLOUT, POLLERR
 from zmq.eventloop import ioloop
 
 # Local imports.
 from IPython.utils.traitlets import HasTraits, Any, Instance, Type
 from kernel import launch_kernel
 from session import Session
 
 #-----------------------------------------------------------------------------
 # Constants and exceptions
 #-----------------------------------------------------------------------------
 
 LOCALHOST = '127.0.0.1'
 
 class InvalidPortNumber(Exception):
     pass
 
 #-----------------------------------------------------------------------------
 # ZMQ Socket Channel classes
 #-----------------------------------------------------------------------------
 
 class ZmqSocketChannel(Thread):
     """The base class for the channels that use ZMQ sockets.
     """
     context = None
     session = None
     socket = None
     ioloop = None
     iostate = None
     _address = None
 
     def __init__(self, context, session, address):
         """Create a channel
 
         Parameters
         ----------
         context : zmq.Context
             The ZMQ context to use.
         session : session.Session
             The session to use.
         address : tuple
             Standard (ip, port) tuple that the kernel is listening on.
         """
         super(ZmqSocketChannel, self).__init__()
         self.daemon = True
 
         self.context = context
         self.session = session
         if address[1] == 0:
             message = 'The port number for a channel cannot be 0.'
             raise InvalidPortNumber(message)
         self._address = address
 
     def stop(self):
         """Stop the channel's activity.
 
         This calls :method:`Thread.join` and returns when the thread
         terminates. :class:`RuntimeError` will be raised if 
         :method:`self.start` is called again.
         """
         self.join()
 
     @property
     def address(self):
         """Get the channel's address as an (ip, port) tuple.
         
         By the default, the address is (localhost, 0), where 0 means a random
         port.
         """
         return self._address
 
     def add_io_state(self, state):
         """Add IO state to the eventloop.
 
         Parameters
         ----------
         state : zmq.POLLIN|zmq.POLLOUT|zmq.POLLERR
             The IO state flag to set.
 
         This is thread safe as it uses the thread safe IOLoop.add_callback.
         """
         def add_io_state_callback():
             if not self.iostate & state:
                 self.iostate = self.iostate | state
                 self.ioloop.update_handler(self.socket, self.iostate)
         self.ioloop.add_callback(add_io_state_callback)
 
     def drop_io_state(self, state):
         """Drop IO state from the eventloop.
 
         Parameters
         ----------
         state : zmq.POLLIN|zmq.POLLOUT|zmq.POLLERR
             The IO state flag to set.
 
         This is thread safe as it uses the thread safe IOLoop.add_callback.
         """
         def drop_io_state_callback():
             if self.iostate & state:
                 self.iostate = self.iostate & (~state)
                 self.ioloop.update_handler(self.socket, self.iostate)
         self.ioloop.add_callback(drop_io_state_callback)
 
 
 class XReqSocketChannel(ZmqSocketChannel):
     """The XREQ channel for issues request/replies to the kernel.
     """
 
     command_queue = None
 
     def __init__(self, context, session, address):
         self.command_queue = Queue()
         super(XReqSocketChannel, self).__init__(context, session, address)
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.socket = self.context.socket(zmq.XREQ)
         self.socket.setsockopt(zmq.IDENTITY, self.session.session)
         self.socket.connect('tcp://%s:%i' % self.address)
         self.ioloop = ioloop.IOLoop()
         self.iostate = POLLERR|POLLIN
         self.ioloop.add_handler(self.socket, self._handle_events, 
                                 self.iostate)
         self.ioloop.start()
 
     def stop(self):
         self.ioloop.stop()
         super(XReqSocketChannel, self).stop()
 
     def call_handlers(self, msg):
         """This method is called in the ioloop thread when a message arrives.
 
         Subclasses should override this method to handle incoming messages.
         It is important to remember that this method is called in the thread
         so that some logic must be done to ensure that the application leve
         handlers are called in the application thread.
         """
         raise NotImplementedError('call_handlers must be defined in a subclass.')
 
     def execute(self, code):
         """Execute code in the kernel.
 
         Parameters
         ----------
         code : str
             A string of Python code.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         # Create class for content/msg creation. Related to, but possibly
         # not in Session.
         content = dict(code=code)
         msg = self.session.msg('execute_request', content)
         self._queue_request(msg)
         return msg['header']['msg_id']
 
     def complete(self, text, line, block=None):
         """Tab complete text, line, block in the kernel's namespace.
 
         Parameters
         ----------
         text : str
             The text to complete.
         line : str
             The full line of text that is the surrounding context for the 
             text to complete.
         block : str
             The full block of code in which the completion is being requested.
 
         Returns
         -------
         The msg_id of the message sent.
 
         """
         content = dict(text=text, line=line)
         msg = self.session.msg('complete_request', content)
         self._queue_request(msg)
         return msg['header']['msg_id']
 
     def object_info(self, oname):
         """Get metadata information about an object.
 
         Parameters
         ----------
         oname : str
             A string specifying the object name.
         
         Returns
         -------
         The msg_id of the message sent.
         """
-        print oname
         content = dict(oname=oname)
         msg = self.session.msg('object_info_request', content)
         self._queue_request(msg)
         return msg['header']['msg_id']
 
     def _handle_events(self, socket, events):
         if events & POLLERR:
             self._handle_err()
         if events & POLLOUT:
             self._handle_send()
         if events & POLLIN:
             self._handle_recv()
 
     def _handle_recv(self):
         msg = self.socket.recv_json()
         self.call_handlers(msg)
 
     def _handle_send(self):
         try:
             msg = self.command_queue.get(False)
         except Empty:
             pass
         else:
             self.socket.send_json(msg)
         if self.command_queue.empty():
             self.drop_io_state(POLLOUT)
 
     def _handle_err(self):
         # We don't want to let this go silently, so eventually we should log.
         raise zmq.ZMQError()
 
     def _queue_request(self, msg):
         self.command_queue.put(msg)
         self.add_io_state(POLLOUT)
 
 
 class SubSocketChannel(ZmqSocketChannel):
     """The SUB channel which listens for messages that the kernel publishes.
     """
 
     def __init__(self, context, session, address):
         super(SubSocketChannel, self).__init__(context, session, address)
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.socket = self.context.socket(zmq.SUB)
         self.socket.setsockopt(zmq.SUBSCRIBE,'')
         self.socket.setsockopt(zmq.IDENTITY, self.session.session)
         self.socket.connect('tcp://%s:%i' % self.address)
         self.ioloop = ioloop.IOLoop()
         self.iostate = POLLIN|POLLERR
         self.ioloop.add_handler(self.socket, self._handle_events, 
                                 self.iostate)
         self.ioloop.start()
 
     def stop(self):
         self.ioloop.stop()
         super(SubSocketChannel, self).stop()
 
     def call_handlers(self, msg):
         """This method is called in the ioloop thread when a message arrives.
 
         Subclasses should override this method to handle incoming messages.
         It is important to remember that this method is called in the thread
         so that some logic must be done to ensure that the application leve
         handlers are called in the application thread.
         """
         raise NotImplementedError('call_handlers must be defined in a subclass.')
 
     def flush(self, timeout=1.0):
         """Immediately processes all pending messages on the SUB channel.
 
         This method is thread safe.
 
         Parameters
         ----------
         timeout : float, optional
             The maximum amount of time to spend flushing, in seconds. The
             default is one second.
         """
         # We do the IOLoop callback process twice to ensure that the IOLoop
         # gets to perform at least one full poll.
         stop_time = time.time() + timeout
         for i in xrange(2):
             self._flushed = False
             self.ioloop.add_callback(self._flush)
             while not self._flushed and time.time() < stop_time:
                 time.sleep(0.01)
 
     def _handle_events(self, socket, events):
         # Turn on and off POLLOUT depending on if we have made a request
         if events & POLLERR:
             self._handle_err()
         if events & POLLIN:
             self._handle_recv()
 
     def _handle_err(self):
         # We don't want to let this go silently, so eventually we should log.
         raise zmq.ZMQError()
 
     def _handle_recv(self):
         # Get all of the messages we can
         while True:
             try:
                 msg = self.socket.recv_json(zmq.NOBLOCK)
             except zmq.ZMQError:
                 # Check the errno?
                 # Will this tigger POLLERR?
                 break
             else:
                 self.call_handlers(msg)
 
     def _flush(self):
         """Callback for :method:`self.flush`."""
         self._flushed = True
 
 
 class RepSocketChannel(ZmqSocketChannel):
     """A reply channel to handle raw_input requests that the kernel makes."""
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.ioloop = ioloop.IOLoop()
         self.ioloop.start()
 
     def stop(self):
         self.ioloop.stop()
         super(RepSocketChannel, self).stop()
 
     def on_raw_input(self):
         pass
 
 
 #-----------------------------------------------------------------------------
 # Main kernel manager class
 #-----------------------------------------------------------------------------
 
 
 class KernelManager(HasTraits):
     """ Manages a kernel for a frontend.
 
     The SUB channel is for the frontend to receive messages published by the
     kernel.
         
     The REQ channel is for the frontend to make requests of the kernel.
     
     The REP channel is for the kernel to request stdin (raw_input) from the
     frontend.
     """
     # The PyZMQ Context to use for communication with the kernel.
     context = Instance(zmq.Context)
 
     # The Session to use for communication with the kernel.
     session = Instance(Session)
 
     # The classes to use for the various channels.
     xreq_channel_class = Type(XReqSocketChannel)
     sub_channel_class = Type(SubSocketChannel)
     rep_channel_class = Type(RepSocketChannel)
     
     # Protected traits.
     _kernel = Instance(Popen)
     _xreq_address = Any
     _sub_address = Any
     _rep_address = Any
     _xreq_channel = Any
     _sub_channel = Any
     _rep_channel = Any
 
     def __init__(self, xreq_address=None, sub_address=None, rep_address=None,
                  context=None, session=None):
         self._xreq_address = (LOCALHOST, 0) if xreq_address is None else xreq_address
         self._sub_address = (LOCALHOST, 0) if sub_address is None else sub_address
         self._rep_address = (LOCALHOST, 0) if rep_address is None else rep_address
         self.context = zmq.Context() if context is None else context
         self.session = Session() if session is None else session
 
     #--------------------------------------------------------------------------
     # Channel management methods:
     #--------------------------------------------------------------------------
 
     def start_channels(self):
         """Starts the channels for this kernel.
 
         This will create the channels if they do not exist and then start
         them. If port numbers of 0 are being used (random ports) then you
         must first call :method:`start_kernel`. If the channels have been
         stopped and you call this, :class:`RuntimeError` will be raised.
         """
         self.xreq_channel.start()
         self.sub_channel.start()
         self.rep_channel.start()
 
     def stop_channels(self):
         """Stops the channels for this kernel.
 
         This stops the channels by joining their threads. If the channels
         were not started, :class:`RuntimeError` will be raised.
         """
         self.xreq_channel.stop()
         self.sub_channel.stop()
         self.rep_channel.stop()
 
     @property
     def channels_running(self):
         """Are all of the channels created and running?"""
         return self.xreq_channel.is_alive() \
             and self.sub_channel.is_alive() \
             and self.rep_channel.is_alive()
 
     #--------------------------------------------------------------------------
     # Kernel process management methods:
     #--------------------------------------------------------------------------
 
     def start_kernel(self):
         """Starts a kernel process and configures the manager to use it.
 
         If random ports (port=0) are being used, this method must be called
         before the channels are created.
         """
         xreq, sub, rep = self.xreq_address, self.sub_address, self.rep_address
         if xreq[0] != LOCALHOST or sub[0] != LOCALHOST or rep[0] != LOCALHOST:
             raise RuntimeError("Can only launch a kernel on localhost."
                                "Make sure that the '*_address' attributes are "
                                "configured properly.")
 
         kernel, xrep, pub, req = launch_kernel(
             xrep_port=xreq[1], pub_port=sub[1], req_port=rep[1])
         self._kernel = kernel
         self._xreq_address = (LOCALHOST, xrep)
         self._sub_address = (LOCALHOST, pub)
         self._rep_address = (LOCALHOST, req)
 
     @property
     def has_kernel(self):
         """Returns whether a kernel process has been specified for the kernel
         manager.
 
         A kernel process can be set via 'start_kernel' or 'set_kernel'.
         """
         return self._kernel is not None
 
     def kill_kernel(self):
         """ Kill the running kernel. """
         if self._kernel is not None:
             self._kernel.kill()
             self._kernel = None
         else:
             raise RuntimeError("Cannot kill kernel. No kernel is running!")
 
     def signal_kernel(self, signum):
         """ Sends a signal to the kernel. """
         if self._kernel is not None:
             self._kernel.send_signal(signum)
         else:
             raise RuntimeError("Cannot signal kernel. No kernel is running!")
 
     @property
     def is_alive(self):
         """Is the kernel process still running?"""
         if self._kernel is not None:
             if self._kernel.poll() is None:
                 return True
             else:
                 return False
         else:
             # We didn't start the kernel with this KernelManager so we don't
             # know if it is running. We should use a heartbeat for this case.
             return True
 
     #--------------------------------------------------------------------------
     # Channels used for communication with the kernel:
     #--------------------------------------------------------------------------
 
     @property
     def xreq_channel(self):
         """Get the REQ socket channel object to make requests of the kernel."""
         if self._xreq_channel is None:
             self._xreq_channel = self.xreq_channel_class(self.context, 
                                                          self.session,
                                                          self.xreq_address)
         return self._xreq_channel
 
     @property
     def sub_channel(self):
         """Get the SUB socket channel object."""
         if self._sub_channel is None:
             self._sub_channel = self.sub_channel_class(self.context,
                                                        self.session,
                                                        self.sub_address)
         return self._sub_channel
 
     @property
     def rep_channel(self):
         """Get the REP socket channel object to handle stdin (raw_input)."""
         if self._rep_channel is None:
             self._rep_channel = self.rep_channel_class(self.context, 
                                                        self.session,
                                                        self.rep_address)
         return self._rep_channel
 
     @property
     def xreq_address(self):
         return self._xreq_address
 
     @property
     def sub_address(self):
         return self._sub_address
 
     @property
     def rep_address(self):
         return self._rep_address