Reimplement QTextDocument's find method

        Add support for *multiline* regular expressions

def find_multiline_pattern(self, regexp, cursor, findflag):
        """Reimplement QTextDocument's find method

        Add support for *multiline* regular expressions"""
        pattern = to_text_string(regexp.pattern())
        text = to_text_string(self.toPlainText())
        try:
            regobj = re.compile(pattern)
        except sre_constants.error:
            return
        if findflag & QTextDocument.FindBackward:
            # Find backward
            offset = min([cursor.selectionEnd(), cursor.selectionStart()])
            text = text[:offset]
            matches = [_m for _m in regobj.finditer(text, 0, offset)]
            if matches:
                match = matches[-1]
            else:
                return
        else:
            # Find forward
            offset = max([cursor.selectionEnd(), cursor.selectionStart()])
            match = regobj.search(text, offset)
        if match:
            pos1, pos2 = match.span()
            fcursor = self.textCursor()
            fcursor.setPosition(pos1)
            fcursor.setPosition(pos2, QTextCursor.KeepAnchor)
            return fcursor