##// END OF EJS Templates
Multiple improvements to tab completion....
Multiple improvements to tab completion. I refactored the API quite a bit, to retain readline compatibility but make it more independent of readline. There's still more to do in cleaning up our init_readline() method, but now the completer objects have separate rlcomplete() and complete() methods. The former uses the quirky readline API with a state flag, while the latter is stateless, takes only text information, and is more suitable for GUIs and other frontends to call programatically. Made other minor fixes to ensure the test suite passes in full. While all this code is a bit messy, we're getting in the direction of the APIs we need in the long run.

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frontend_widget.py
384 lines | 14.4 KiB | text/x-python | PythonLexer
# Standard library imports
import signal
import sys
# System library imports
from pygments.lexers import PythonLexer
from PyQt4 import QtCore, QtGui
import zmq
# Local imports
from IPython.core.inputsplitter import InputSplitter
from IPython.frontend.qt.base_frontend_mixin import BaseFrontendMixin
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 PygmentsHighlighter that can be turned on and off and that 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, qstring):
""" Highlight a block of text. Reimplemented to highlight selectively.
"""
if not self.highlighting_on:
return
# The input to this function is 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
# Don't highlight the part of the string that contains the prompt.
if string.startswith(prompt):
self._current_offset = len(prompt)
qstring.remove(0, len(prompt))
else:
self._current_offset = 0
PygmentsHighlighter.highlightBlock(self, qstring)
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
PygmentsHighlighter.setFormat(self, start, count, format)
class FrontendWidget(HistoryConsoleWidget, BaseFrontendMixin):
""" A Qt frontend for a generic Python kernel.
"""
# Emitted when an 'execute_reply' has been received from the kernel and
# processed by the FrontendWidget.
executed = QtCore.pyqtSignal(object)
# Protected class attributes.
_highlighter_class = FrontendHighlighter
_input_splitter_class = InputSplitter
#---------------------------------------------------------------------------
# 'object' interface
#---------------------------------------------------------------------------
def __init__(self, *args, **kw):
super(FrontendWidget, self).__init__(*args, **kw)
# FrontendWidget protected variables.
self._call_tip_widget = CallTipWidget(self._control)
self._completion_lexer = CompletionLexer(PythonLexer())
self._hidden = False
self._highlighter = self._highlighter_class(self)
self._input_splitter = self._input_splitter_class(input_mode='replace')
self._kernel_manager = None
# Configure the ConsoleWidget.
self.tab_width = 4
self._set_continuation_prompt('... ')
# Connect signal handlers.
document = self._control.document()
document.contentsChange.connect(self._document_contents_change)
#---------------------------------------------------------------------------
# '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.expandtabs(4))
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 _execute_interrupt(self):
""" Attempts to stop execution. Returns whether this method has an
implementation.
"""
self._interrupt_kernel()
return True
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.
"""
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.
"""
self._keep_cursor_in_buffer()
cursor = self._get_cursor()
return not self._complete()
#---------------------------------------------------------------------------
# 'ConsoleWidget' protected interface
#---------------------------------------------------------------------------
def _show_continuation_prompt(self):
""" Reimplemented for auto-indentation.
"""
super(FrontendWidget, self)._show_continuation_prompt()
spaces = self._input_splitter.indent_spaces
self._append_plain_text('\t' * (spaces / self.tab_width))
self._append_plain_text(' ' * (spaces % self.tab_width))
#---------------------------------------------------------------------------
# 'BaseFrontendMixin' abstract interface
#---------------------------------------------------------------------------
def _handle_complete_reply(self, rep):
""" Handle replies for tab completion.
"""
cursor = self._get_cursor()
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_execute_reply(self, msg):
""" Handles replies for code execution.
"""
if 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()
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.rep_channel.input(line)
self._readline(msg['content']['prompt'], callback=callback)
def _handle_object_info_reply(self, rep):
""" Handle replies for call tips.
"""
cursor = self._get_cursor()
if rep['parent_header']['msg_id'] == self._call_tip_id and \
cursor.position() == self._call_tip_pos:
doc = rep['content']['docstring']
if doc:
self._call_tip_widget.show_docstring(doc)
def _handle_pyout(self, msg):
""" Handle display hook output.
"""
if not self._hidden and self._is_from_this_session(msg):
self._append_plain_text(msg['content']['data'] + '\n')
def _handle_stream(self, msg):
""" Handle stdout, stderr, and stdin.
"""
if not self._hidden and self._is_from_this_session(msg):
self._append_plain_text(msg['content']['data'])
self._control.moveCursor(QtGui.QTextCursor.End)
def _started_channels(self):
""" Called when the KernelManager channels have started listening or
when the frontend is assigned an already listening KernelManager.
"""
self._reset()
self._append_plain_text(self._get_banner())
self._show_interpreter_prompt()
def _stopped_channels(self):
""" Called when the KernelManager channels have stopped listening or
when a listening KernelManager is removed from the frontend.
"""
# FIXME: Print a message here?
pass
#---------------------------------------------------------------------------
# '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)
#---------------------------------------------------------------------------
# '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._get_cursor()
cursor.movePosition(QtGui.QTextCursor.Left)
document = self._control.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._call_tip_id = self.kernel_manager.xreq_channel.object_info(name)
self._call_tip_pos = self._get_cursor().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)
# FIXME - Evan: we need the position of the cursor in the current input
# buffer. I tried this line below but the numbers I get are bogus. -
# Not sure what to do. fperez.
cursor_pos = self._get_cursor().position()
self._complete_id = self.kernel_manager.xreq_channel.complete(
text, self._get_input_buffer_cursor_line(), cursor_pos,
self.input_buffer)
self._complete_pos = self._get_cursor().position()
return True
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 at the current cursor location.
"""
if cursor is None:
cursor = self._get_cursor()
cursor.movePosition(QtGui.QTextCursor.StartOfBlock,
QtGui.QTextCursor.KeepAnchor)
text = str(cursor.selection().toPlainText())
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._append_plain_text('Kernel process is either remote or '
'unspecified. Cannot interrupt.\n')
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']
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 = 'Received unknown payload of type %s\n'
self._append_plain_text(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()