environment/lib/python2.7/site-packages/IPython/frontend/qt/console/history_console_widget.py
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
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
Called when the down key is pressed. Returns whether to continue
            processing the event.