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* Implemented a proper main() function for kernel.py that reads command line input....
* Implemented a proper main() function for kernel.py that reads command line input. * Added options to launch_kernel() for specifying particular ports. * Wrote preliminary implementation for the KernelManager's start_kernel() and kill_kernel() methods * Updated IPythonWidget test script to reflect new functionality.

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console_widget.py
718 lines | 26.4 KiB | text/x-python | PythonLexer
# 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.
"""
# Regex to match ANSI escape sequences
_ansi_pattern = re.compile('\x01?\x1b\[(.*?)m\x02?')
# When ctrl is pressed, map certain keys to other keys (without the ctrl):
_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, }
#---------------------------------------------------------------------------
# 'QWidget' interface
#---------------------------------------------------------------------------
def __init__(self, parent=None):
QtGui.QPlainTextEdit.__init__(self, parent)
# Initialize public and protected variables.
self.ansi_codes = True
self.buffer_size = 500
self.gui_completion = True
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 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 = event.modifiers() & QtCore.Qt.ControlModifier
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_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):
if self._reading:
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, interactive=False):
""" Execute the text in the input buffer. Returns whether the input
buffer was completely processed and a new prompt created.
"""
self.appendPlainText('\n')
self._executing_input_buffer = self.input_buffer
self._executing = True
self._prompt_finished()
return self._execute(interactive=interactive)
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 _execute(self, interactive):
""" Called to execute the input buffer. When triggered by an the enter
key press, 'interactive' is True; otherwise, it is False. Returns
whether the input buffer was completely processed and a new prompt
created.
"""
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 _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.
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.
"""
# This has the (desired) side effect of disabling the undo/redo history.
self.setMaximumBlockCount(self.buffer_size)
self.setReadOnly(True)
self._prompt_finished_hook()
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.
"""
if prompt is not None:
self._prompt = prompt
self.appendPlainText('\n' + 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.
"""
#---------------------------------------------------------------------------
# 'QWidget' interface
#---------------------------------------------------------------------------
def __init__(self, parent=None):
super(HistoryConsoleWidget, self).__init__(parent)
self._history = []
self._history_index = 0
#---------------------------------------------------------------------------
# 'ConsoleWidget' public interface
#---------------------------------------------------------------------------
def execute(self, interactive=False):
""" Reimplemented to the store history.
"""
stripped = self.input_buffer.rstrip()
executed = super(HistoryConsoleWidget, self).execute(interactive)
if executed:
self._history.append(stripped)
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 = ''