from configHandler import idleConf class History:     def __init__(self, text, output_sep = "\n"):        self.text = text        self.history = []        self.history_prefix = None        self.history_pointer = None        self.output_sep = output_sep        self.cyclic = idleConf.GetOption("main", "History", "cyclic", 1, "bool")        text.bind("<<history-previous>>", self.history_prev)        text.bind("<<history-next>>", self.history_next)     def history_next(self, event):        self.history_do(0)        return "break"     def history_prev(self, event):        self.history_do(1)        return "break"     def _get_source(self, start, end):        # Get source code from start index to end index.  Lines in the        # text control may be separated by sys.ps2 .        lines = self.text.get(start, end).split(self.output_sep)        return "\n".join(lines)     def _put_source(self, where, source):        output = self.output_sep.join(source.split("\n"))        self.text.insert(where, output)     def history_do(self, reverse):        nhist = len(self.history)        pointer = self.history_pointer        prefix = self.history_prefix        if pointer is not None and prefix is not None:            if self.text.compare("insert", "!=", "end-1c") or \               self._get_source("iomark", "end-1c") != self.history[pointer]:                pointer = prefix = None        if pointer is None or prefix is None:            prefix = self._get_source("iomark", "end-1c")            if reverse:                pointer = nhist            else:                if self.cyclic:                    pointer = -1                else:                    self.text.bell()                    return        nprefix = len(prefix)        while 1:            if reverse:                pointer = pointer - 1            else:                pointer = pointer + 1            if pointer < 0 or pointer >= nhist:                self.text.bell()                if not self.cyclic and pointer < 0:                    return                else:                    if self._get_source("iomark", "end-1c") != prefix:                        self.text.delete("iomark", "end-1c")                        self._put_source("iomark", prefix)                    pointer = prefix = None                break            item = self.history[pointer]            if item[:nprefix] == prefix and len(item) > nprefix:                self.text.delete("iomark", "end-1c")                self._put_source("iomark", item)                break        self.text.mark_set("insert", "end-1c")        self.text.see("insert")        self.text.tag_remove("sel", "1.0", "end")        self.history_pointer = pointer        self.history_prefix = prefix     def history_store(self, source):        source = source.strip()        if len(source) > 2:            # avoid duplicates            try:                self.history.remove(source)            except ValueError:                pass            self.history.append(source)        self.history_pointer = None        self.history_prefix = None