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, Unicode 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. """ # The text to show when the kernel is (re)started. banner = Unicode() # 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() # Whether to automatically show calltips on open-parentheses. enable_calltips = Bool(True, config=True, help="Whether to draw information calltips on open-parentheses.") # 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(object) # 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 request_interrupt_kernel(self): if self._executing: self.interrupt_kernel() def request_restart_kernel(self): message = 'Are you sure you want to restart the kernel?' self.restart_kernel(message, now=False) 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.request_interrupt_kernel() return True elif key == QtCore.Qt.Key_Period: self.request_restart_kernel() 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. """ self.log.debug("complete: %s", rep.get('content', '')) 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. """ self.log.debug("execute: %s", msg.get('content', '')) info = self._request_info.get('execute') # unset reading flag, because if execute finished, raw_input can't # still be pending. self._reading = False 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 == 'aborted': self._process_execute_abort(msg) self._show_interpreter_prompt_for_reply(msg) self.executed.emit(msg) else: super(FrontendWidget, self)._handle_execute_reply(msg) def _handle_input_request(self, msg): """ Handle requests for raw_input. """ self.log.debug("input: %s", msg.get('content', '')) 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) if self._reading: self.log.debug("Got second input request, assuming first was interrupted.") self._reading = False 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. """ self.log.debug("kernel died: %s", since_last_heartbeat) 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. """ self.log.debug("oinfo: %s", rep.get('content', '')) 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. """ self.log.debug("pyout: %s", msg.get('content', '')) 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. """ self.log.debug("stream: %s", msg.get('content', '')) 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. """ self.log.debug("shutdown: %s", msg.get('content', '')) if not self._hidden and not self._is_from_this_session(msg): if self._local_kernel: if not msg['content']['restart']: self.exit_requested.emit(self) 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: self.exit_requested.emit(self) 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. Also unsets _reading flag, to avoid runtime errors if raw_input is called again. """ if self.custom_interrupt: self._reading = False self.custom_interrupt_requested.emit() elif self.kernel_manager.has_kernel: self._reading = False 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.banner) # update output marker for stdout/stderr, so that startup # messages appear after banner: self._append_before_prompt_pos = self._get_cursor().position() 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_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(self) 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() #------ Trait default initializers ----------------------------------------- def _banner_default(self): """ Returns the standard Python banner. """ banner = 'Python %s on %s\nType "help", "copyright", "credits" or ' \ '"license" for more information.' return banner % (sys.version, sys.platform)