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