# System library imports
from pygments.lexers import PythonLexer
from PyQt4 import QtCore, QtGui
import zmq
# Local imports
from IPython.core.blockbreaker import BlockBreaker
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)
#---------------------------------------------------------------------------
# 'QWidget' interface
#---------------------------------------------------------------------------
def __init__(self, parent=None):
super(FrontendWidget, self).__init__(parent)
# ConsoleWidget protected variables.
self._continuation_prompt = '... '
self._prompt = '>>> '
# FrontendWidget protected variables.
self._blockbreaker = BlockBreaker(input_mode='replace')
self._call_tip_widget = CallTipWidget(self)
self._completion_lexer = CompletionLexer(PythonLexer())
self._hidden = True
self._highlighter = FrontendHighlighter(self)
self._kernel_manager = None
self.document().contentsChange.connect(self._document_contents_change)
def focusOutEvent(self, event):
""" Reimplemented to hide calltips.
"""
self._call_tip_widget.hide()
return super(FrontendWidget, self).focusOutEvent(event)
def keyPressEvent(self, event):
""" Reimplemented to hide calltips.
"""
if event.key() == QtCore.Qt.Key_Escape:
self._call_tip_widget.hide()
return super(FrontendWidget, self).keyPressEvent(event)
#---------------------------------------------------------------------------
# '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.
"""
return self.execute_source(self.input_buffer, interactive=interactive)
def _prompt_started_hook(self):
""" Called immediately after a new prompt is displayed.
"""
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.
"""
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
#---------------------------------------------------------------------------
# 'FrontendWidget' interface
#---------------------------------------------------------------------------
def execute_source(self, source, hidden=False, interactive=False):
""" Execute a string containing Python code. If 'hidden', no output is
shown. Returns whether the source executed (i.e., returns True only
if no more input is necessary).
"""
self._blockbreaker.push(source)
executed = self._blockbreaker.interactive_block_ready()
if executed:
self.kernel_manager.xreq_channel.execute(source)
self._hidden = hidden
else:
self._show_continuation_prompt()
self.appendPlainText(' ' * self._blockbreaker.indent_spaces)
return executed
def execute_file(self, path, hidden=False):
""" Attempts to execute file with 'path'. If 'hidden', no output is
shown.
"""
self.execute_source('run %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_listening.disconnect(
self._started_listening)
self._kernel_manager.stopped_listening.disconnect(
self._stopped_listening)
# 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)
# Set the new kernel manager.
self._kernel_manager = kernel_manager
if kernel_manager is None:
return
# Connect the new kernel manager.
kernel_manager.started_listening.connect(self._started_listening)
kernel_manager.stopped_listening.connect(self._stopped_listening)
# 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 listening before
# we connected.
if kernel_manager.is_listening:
self._started_listening()
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)
#------ Signal handlers ----------------------------------------------------
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_sub(self, omsg):
if not self._hidden:
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'])
def _handle_execute_reply(self, rep):
# 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_listening(self):
self.clear()
def _stopped_listening(self):
pass