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""" A FrontendWidget that emulates the interface of the console IPython and
supports the additional functionality provided by the IPython kernel.
# Imports
# Standard library imports
from collections import namedtuple
import os.path
import re
from subprocess import Popen
import sys
import time
from textwrap import dedent
# System library imports
from IPython.external.qt import QtCore, QtGui
# Local imports
from IPython.core.inputsplitter import IPythonInputSplitter
from IPython.core.inputtransformer import ipy_prompt
from IPython.utils.traitlets import Bool, Unicode
from frontend_widget import FrontendWidget
import styles
# Constants
# Default strings to build and display input and output prompts (and separators
# in between)
default_in_prompt = 'In [<span class="in-prompt-number">%i</span>]: '
default_out_prompt = 'Out[<span class="out-prompt-number">%i</span>]: '
default_input_sep = '\n'
default_output_sep = ''
default_output_sep2 = ''
# Base path for most payload sources.
zmq_shell_source = 'IPython.kernel.zmq.zmqshell.ZMQInteractiveShell'
if sys.platform.startswith('win'):
default_editor = 'notepad'
default_editor = ''
# IPythonWidget class
class IPythonWidget(FrontendWidget):
""" A FrontendWidget for an IPython kernel.
# If set, the 'custom_edit_requested(str, int)' signal will be emitted when
# an editor is needed for a file. This overrides 'editor' and 'editor_line'
# settings.
custom_edit = Bool(False)
custom_edit_requested = QtCore.Signal(object, object)
editor = Unicode(default_editor, config=True,
A command for invoking a system text editor. If the string contains a
{filename} format specifier, it will be used. Otherwise, the filename
will be appended to the end the command.
editor_line = Unicode(config=True,
The editor command to use when a specific line number is requested. The
string should contain two format specifiers: {line} and {filename}. If
this parameter is not specified, the line number option to the %edit
magic will be ignored.
style_sheet = Unicode(config=True,
A CSS stylesheet. The stylesheet can contain classes for:
1. Qt: QPlainTextEdit, QFrame, QWidget, etc
2. Pygments: .c, .k, .o, etc. (see PygmentsHighlighter)
3. IPython: .error, .in-prompt, .out-prompt, etc
syntax_style = Unicode(config=True,
If not empty, use this Pygments style for syntax highlighting.
Otherwise, the style sheet is queried for Pygments style
# Prompts.
in_prompt = Unicode(default_in_prompt, config=True)
out_prompt = Unicode(default_out_prompt, config=True)
input_sep = Unicode(default_input_sep, config=True)
output_sep = Unicode(default_output_sep, config=True)
output_sep2 = Unicode(default_output_sep2, config=True)
# FrontendWidget protected class variables.
_input_splitter_class = IPythonInputSplitter
_prompt_transformer = IPythonInputSplitter(physical_line_transforms=[ipy_prompt()],
# IPythonWidget protected class variables.
_PromptBlock = namedtuple('_PromptBlock', ['block', 'length', 'number'])
_payload_source_edit = zmq_shell_source + '.edit_magic'
_payload_source_exit = zmq_shell_source + '.ask_exit'
_payload_source_next_input = zmq_shell_source + '.set_next_input'
_payload_source_page = ''
_retrying_history_request = False
# 'object' interface
def __init__(self, *args, **kw):
super(IPythonWidget, self).__init__(*args, **kw)
# IPythonWidget protected variables.
self._payload_handlers = {
self._payload_source_edit : self._handle_payload_edit,
self._payload_source_exit : self._handle_payload_exit,
self._payload_source_page : self._handle_payload_page,
self._payload_source_next_input : self._handle_payload_next_input }
self._previous_prompt_obj = None
self._keep_kernel_on_exit = None
# Initialize widget styling.
if self.style_sheet:
# 'BaseFrontendMixin' abstract interface
def _handle_complete_reply(self, rep):
""" Reimplemented to support IPython's improved completion machinery.
self.log.debug("complete: %s", rep.get('content', ''))
cursor = self._get_cursor()
info = self._request_info.get('complete')
if info and == rep['parent_header']['msg_id'] and \
info.pos == cursor.position():
matches = rep['content']['matches']
text = rep['content']['matched_text']
offset = len(text)
# Clean up matches with period and path separators if the matched
# text has not been transformed. This is done by truncating all
# but the last component and then suitably decreasing the offset
# between the current cursor position and the start of completion.
if len(matches) > 1 and matches[0][:offset] == text:
parts = re.split(r'[./\\]', text)
sep_count = len(parts) - 1
if sep_count:
chop_length = sum(map(len, parts[:sep_count])) + sep_count
matches = [ match[chop_length:] for match in matches ]
offset -= chop_length
# Move the cursor to the start of the match and complete.
cursor.movePosition(QtGui.QTextCursor.Left, n=offset)
self._complete_with_items(cursor, matches)
def _handle_execute_reply(self, msg):
""" Reimplemented to support prompt requests.
msg_id = msg['parent_header'].get('msg_id')
info = self._request_info['execute'].get(msg_id)
if info and info.kind == 'prompt':
number = msg['content']['execution_count'] + 1
super(IPythonWidget, self)._handle_execute_reply(msg)
def _handle_history_reply(self, msg):
""" Implemented to handle history tail replies, which are only supported
by the IPython kernel.
content = msg['content']
if 'history' not in content:
self.log.error("History request failed: %r"%content)
if content.get('status', '') == 'aborted' and \
not self._retrying_history_request:
# a *different* action caused this request to be aborted, so
# we should try again.
self.log.error("Retrying aborted history request")
# prevent multiple retries of aborted requests:
self._retrying_history_request = True
# wait out the kernel's queue flush, which is currently timed at 0.1s
self._retrying_history_request = False
# reset retry flag
self._retrying_history_request = False
history_items = content['history']
self.log.debug("Received history reply with %i entries", len(history_items))
items = []
last_cell = u""
for _, _, cell in history_items:
cell = cell.rstrip()
if cell != last_cell:
last_cell = cell
def _handle_pyout(self, msg):
""" Reimplemented for IPython-style "display hook".
self.log.debug("pyout: %s", msg.get('content', ''))
if not self._hidden and self._is_from_this_session(msg):
content = msg['content']
prompt_number = content.get('execution_count', 0)
data = content['data']
if 'text/html' in data:
self._append_plain_text(self.output_sep, True)
self._append_html(self._make_out_prompt(prompt_number), True)
html = data['text/html']
self._append_plain_text('\n', True)
self._append_html(html + self.output_sep2, True)
elif 'text/plain' in data:
self._append_plain_text(self.output_sep, True)
self._append_html(self._make_out_prompt(prompt_number), True)
text = data['text/plain']
# If the repr is multiline, make sure we start on a new line,
# so that its lines are aligned.
if "\n" in text and not self.output_sep.endswith("\n"):
self._append_plain_text('\n', True)
self._append_plain_text(text + self.output_sep2, True)
def _handle_display_data(self, msg):
""" The base handler for the ``display_data`` message.
self.log.debug("display: %s", msg.get('content', ''))
# For now, we don't display data from other frontends, but we
# eventually will as this allows all frontends to monitor the display
# data. But we need to figure out how to handle this in the GUI.
if not self._hidden and self._is_from_this_session(msg):
source = msg['content']['source']
data = msg['content']['data']
metadata = msg['content']['metadata']
# In the regular IPythonWidget, we simply print the plain text
# representation.
if 'text/html' in data:
html = data['text/html']
self._append_html(html, True)
elif 'text/plain' in data:
text = data['text/plain']
self._append_plain_text(text, True)
# This newline seems to be needed for text and html output.
self._append_plain_text(u'\n', True)
def _started_channels(self):
"""Reimplemented to make a history request and load %guiref."""
super(IPythonWidget, self)._started_channels()
def _started_kernel(self):
"""Load %guiref when the kernel starts (if channels are also started).
Principally triggered by kernel restart.
if self.kernel_manager.shell_channel is not None:
def _load_guiref_magic(self):
"""Load %guiref magic."""
" _usage",
" from IPython.core import usage as _usage",
" get_ipython().register_magic_function(_usage.page_guiref, 'line', 'guiref')",
" del _usage",
]), silent=True)
# 'ConsoleWidget' public interface
# 'FrontendWidget' public interface
def execute_file(self, path, hidden=False):
""" Reimplemented to use the 'run' magic.
# Use forward slashes on Windows to avoid escaping each separator.
if sys.platform == 'win32':
path = os.path.normpath(path).replace('\\', '/')
# Perhaps we should not be using %run directly, but while we
# are, it is necessary to quote or escape filenames containing spaces
# or quotes.
# In earlier code here, to minimize escaping, we sometimes quoted the
# filename with single quotes. But to do this, this code must be
# platform-aware, because run uses shlex rather than python string
# parsing, so that:
# * In Win: single quotes can be used in the filename without quoting,
# and we cannot use single quotes to quote the filename.
# * In *nix: we can escape double quotes in a double quoted filename,
# but can't escape single quotes in a single quoted filename.
# So to keep this code non-platform-specific and simple, we now only
# use double quotes to quote filenames, and escape when needed:
if ' ' in path or "'" in path or '"' in path:
path = '"%s"' % path.replace('"', '\\"')
self.execute('%%run %s' % path, hidden=hidden)
# 'FrontendWidget' protected interface
def _complete(self):
""" Reimplemented to support IPython's improved completion machinery.
# We let the kernel split the input line, so we *always* send an empty
# text field. Readline-based frontends do get a real text field which
# they can use.
text = ''
# Send the completion request to the kernel
msg_id = self.kernel_manager.shell_channel.complete(
text, # text
self._get_input_buffer_cursor_line(), # line
self._get_input_buffer_cursor_column(), # cursor_pos
self.input_buffer) # block
pos = self._get_cursor().position()
info = self._CompletionRequest(msg_id, pos)
self._request_info['complete'] = info
def _process_execute_error(self, msg):
""" Reimplemented for IPython-style traceback formatting.
content = msg['content']
traceback = '\n'.join(content['traceback']) + '\n'
if False:
# FIXME: For now, tracebacks come as plain text, so we can't use
# the html renderer yet. Once we refactor ultratb to produce
# properly styled tracebacks, this branch should be the default
traceback = traceback.replace(' ', '&nbsp;')
traceback = traceback.replace('\n', '<br/>')
ename = content['ename']
ename_styled = '<span class="error">%s</span>' % ename
traceback = traceback.replace(ename, ename_styled)
# This is the fallback for now, using plain text with ansi escapes
def _process_execute_payload(self, item):
""" Reimplemented to dispatch payloads to handler methods.
handler = self._payload_handlers.get(item['source'])
if handler is None:
# We have no handler for this type of payload, simply ignore it
return False
return True
def _show_interpreter_prompt(self, number=None):
""" Reimplemented for IPython-style prompts.
# If a number was not specified, make a prompt number request.
if number is None:
msg_id = self.kernel_manager.shell_channel.execute('', silent=True)
info = self._ExecutionRequest(msg_id, 'prompt')
self._request_info['execute'][msg_id] = info
# Show a new prompt and save information about it so that it can be
# updated later if the prompt number turns out to be wrong.
self._prompt_sep = self.input_sep
self._show_prompt(self._make_in_prompt(number), html=True)
block = self._control.document().lastBlock()
length = len(self._prompt)
self._previous_prompt_obj = self._PromptBlock(block, length, number)
# Update continuation prompt to reflect (possibly) new prompt length.
self._make_continuation_prompt(self._prompt), html=True)
def _show_interpreter_prompt_for_reply(self, msg):
""" Reimplemented for IPython-style prompts.
# Update the old prompt number if necessary.
content = msg['content']
# abort replies do not have any keys:
if content['status'] == 'aborted':
if self._previous_prompt_obj:
previous_prompt_number = self._previous_prompt_obj.number
previous_prompt_number = 0
previous_prompt_number = content['execution_count']
if self._previous_prompt_obj and \
self._previous_prompt_obj.number != previous_prompt_number:
block = self._previous_prompt_obj.block
# Make sure the prompt block has not been erased.
if block.isValid() and block.text():
# Remove the old prompt and insert a new prompt.
cursor = QtGui.QTextCursor(block)
prompt = self._make_in_prompt(previous_prompt_number)
self._prompt = self._insert_html_fetching_plain_text(
cursor, prompt)
# When the HTML is inserted, Qt blows away the syntax
# highlighting for the line, so we need to rehighlight it.
self._previous_prompt_obj = None
# Show a new prompt with the kernel's estimated prompt number.
self._show_interpreter_prompt(previous_prompt_number + 1)
# 'IPythonWidget' interface
def set_default_style(self, colors='lightbg'):
""" Sets the widget style to the class defaults.
colors : str, optional (default lightbg)
Whether to use the default IPython light background or dark
background or B&W style.
colors = colors.lower()
if colors=='lightbg':
self.style_sheet = styles.default_light_style_sheet
self.syntax_style = styles.default_light_syntax_style
elif colors=='linux':
self.style_sheet = styles.default_dark_style_sheet
self.syntax_style = styles.default_dark_syntax_style
elif colors=='nocolor':
self.style_sheet = styles.default_bw_style_sheet
self.syntax_style = styles.default_bw_syntax_style
raise KeyError("No such color scheme: %s"%colors)
# 'IPythonWidget' protected interface
def _edit(self, filename, line=None):
""" Opens a Python script for editing.
filename : str
A path to a local system file.
line : int, optional
A line of interest in the file.
if self.custom_edit:
self.custom_edit_requested.emit(filename, line)
elif not self.editor:
self._append_plain_text('No default editor available.\n'
'Specify a GUI text editor in the `IPythonWidget.editor` '
'configurable to enable the %edit magic')
filename = '"%s"' % filename
if line and self.editor_line:
command = self.editor_line.format(filename=filename,
command = self.editor.format()
except KeyError:
command = self.editor.format(filename=filename)
command += ' ' + filename
except KeyError:
self._append_plain_text('Invalid editor command.\n')
Popen(command, shell=True)
except OSError:
msg = 'Opening editor with command "%s" failed.\n'
self._append_plain_text(msg % command)
def _make_in_prompt(self, number):
""" Given a prompt number, returns an HTML In prompt.
body = self.in_prompt % number
except TypeError:
# allow in_prompt to leave out number, e.g. '>>> '
body = self.in_prompt
return '<span class="in-prompt">%s</span>' % body
def _make_continuation_prompt(self, prompt):
""" Given a plain text version of an In prompt, returns an HTML
continuation prompt.
end_chars = '...: '
space_count = len(prompt.lstrip('\n')) - len(end_chars)
body = '&nbsp;' * space_count + end_chars
return '<span class="in-prompt">%s</span>' % body
def _make_out_prompt(self, number):
""" Given a prompt number, returns an HTML Out prompt.
body = self.out_prompt % number
return '<span class="out-prompt">%s</span>' % body
#------ Payload handlers --------------------------------------------------
# Payload handlers with a generic interface: each takes the opaque payload
# dict, unpacks it and calls the underlying functions with the necessary
# arguments.
def _handle_payload_edit(self, item):
self._edit(item['filename'], item['line_number'])
def _handle_payload_exit(self, item):
self._keep_kernel_on_exit = item['keepkernel']
def _handle_payload_next_input(self, item):
self.input_buffer = dedent(item['text'].rstrip())
def _handle_payload_page(self, item):
# Since the plain text widget supports only a very small subset of HTML
# and we have no control over the HTML source, we only page HTML
# payloads in the rich text widget.
if item['html'] and self.kind == 'rich':
self._page(item['html'], html=True)
self._page(item['text'], html=False)
#------ Trait change handlers --------------------------------------------
def _style_sheet_changed(self):
""" Set the style sheets of the underlying widgets.
if self._control is not None:
bg_color = self._control.palette().window().color()
if self._page_control is not None:
def _syntax_style_changed(self):
""" Set the style for the syntax highlighter.
if self._highlighter is None:
# ignore premature calls
if self.syntax_style:
#------ Trait default initializers -----------------------------------------
def _banner_default(self):
from IPython.core.usage import default_gui_banner
return default_gui_banner
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