# System library imports from IPython.external.qt import QtGui # Local imports from IPython.utils.traitlets import Bool from console_widget import ConsoleWidget class HistoryConsoleWidget(ConsoleWidget): """ A ConsoleWidget that keeps a history of the commands that have been executed and provides a readline-esque interface to this history. """ #------ Configuration ------------------------------------------------------ # If enabled, the input buffer will become "locked" to history movement when # an edit is made to a multi-line input buffer. To override the lock, use # Shift in conjunction with the standard history cycling keys. history_lock = Bool(False, config=True) #--------------------------------------------------------------------------- # 'object' interface #--------------------------------------------------------------------------- def __init__(self, *args, **kw): super(HistoryConsoleWidget, self).__init__(*args, **kw) # HistoryConsoleWidget protected variables. self._history = [] self._history_edits = {} self._history_index = 0 self._history_prefix = '' #--------------------------------------------------------------------------- # 'ConsoleWidget' public interface #--------------------------------------------------------------------------- def execute(self, source=None, hidden=False, interactive=False): """ Reimplemented to the store history. """ if not hidden: history = self.input_buffer if source is None else source executed = super(HistoryConsoleWidget, self).execute( source, hidden, interactive) if executed and not hidden: # Save the command unless it was an empty string or was identical # to the previous command. history = history.rstrip() if history and (not self._history or self._history[-1] != history): self._history.append(history) # Emulate readline: reset all history edits. self._history_edits = {} # Move the history index to the most recent item. self._history_index = len(self._history) return executed #--------------------------------------------------------------------------- # 'ConsoleWidget' abstract interface #--------------------------------------------------------------------------- def _up_pressed(self, shift_modifier): """ Called when the up key is pressed. Returns whether to continue processing the event. """ prompt_cursor = self._get_prompt_cursor() if self._get_cursor().blockNumber() == prompt_cursor.blockNumber(): # Bail out if we're locked. if self._history_locked() and not shift_modifier: return False # Set a search prefix based on the cursor position. col = self._get_input_buffer_cursor_column() input_buffer = self.input_buffer if self._history_index == len(self._history) or \ (self._history_prefix and col != len(self._history_prefix)): self._history_index = len(self._history) self._history_prefix = input_buffer[:col] # Perform the search. self.history_previous(self._history_prefix, as_prefix=not shift_modifier) # Go to the first line of the prompt for seemless history scrolling. # Emulate readline: keep the cursor position fixed for a prefix # search. cursor = self._get_prompt_cursor() if self._history_prefix: cursor.movePosition(QtGui.QTextCursor.Right, n=len(self._history_prefix)) else: cursor.movePosition(QtGui.QTextCursor.EndOfLine) self._set_cursor(cursor) return False return True def _down_pressed(self, shift_modifier): """ Called when the down key is pressed. Returns whether to continue processing the event. """ end_cursor = self._get_end_cursor() if self._get_cursor().blockNumber() == end_cursor.blockNumber(): # Bail out if we're locked. if self._history_locked() and not shift_modifier: return False # Perform the search. replaced = self.history_next(self._history_prefix, as_prefix=not shift_modifier) # Emulate readline: keep the cursor position fixed for a prefix # search. (We don't need to move the cursor to the end of the buffer # in the other case because this happens automatically when the # input buffer is set.) if self._history_prefix and replaced: cursor = self._get_prompt_cursor() cursor.movePosition(QtGui.QTextCursor.Right, n=len(self._history_prefix)) self._set_cursor(cursor) return False return True #--------------------------------------------------------------------------- # 'HistoryConsoleWidget' public interface #--------------------------------------------------------------------------- def history_previous(self, substring='', as_prefix=True): """ If possible, set the input buffer to a previous history item. Parameters: ----------- substring : str, optional If specified, search for an item with this substring. as_prefix : bool, optional If True, the substring must match at the beginning (default). Returns: -------- Whether the input buffer was changed. """ index = self._history_index replace = False while index > 0: index -= 1 history = self._get_edited_history(index) if (as_prefix and history.startswith(substring)) \ or (not as_prefix and substring in history): replace = True break if replace: self._store_edits() self._history_index = index self.input_buffer = history return replace def history_next(self, substring='', as_prefix=True): """ If possible, set the input buffer to a subsequent history item. Parameters: ----------- substring : str, optional If specified, search for an item with this substring. as_prefix : bool, optional If True, the substring must match at the beginning (default). Returns: -------- Whether the input buffer was changed. """ index = self._history_index replace = False while self._history_index < len(self._history): index += 1 history = self._get_edited_history(index) if (as_prefix and history.startswith(substring)) \ or (not as_prefix and substring in history): replace = True break if replace: self._store_edits() self._history_index = index self.input_buffer = history return replace def history_tail(self, n=10): """ Get the local history list. Parameters: ----------- n : int The (maximum) number of history items to get. """ return self._history[-n:] #--------------------------------------------------------------------------- # 'HistoryConsoleWidget' protected interface #--------------------------------------------------------------------------- def _history_locked(self): """ Returns whether history movement is locked. """ return (self.history_lock and (self._get_edited_history(self._history_index) != self.input_buffer) and (self._get_prompt_cursor().blockNumber() != self._get_end_cursor().blockNumber())) def _get_edited_history(self, index): """ Retrieves a history item, possibly with temporary edits. """ if index in self._history_edits: return self._history_edits[index] elif index == len(self._history): return unicode() return self._history[index] def _set_history(self, history): """ Replace the current history with a sequence of history items. """ self._history = list(history) self._history_edits = {} self._history_index = len(self._history) def _store_edits(self): """ If there are edits to the current input buffer, store them. """ current = self.input_buffer if self._history_index == len(self._history) or \ self._history[self._history_index] != current: self._history_edits[self._history_index] = current