def autoIndentBlock(self, block, char = '\n'):
        """Indent block after Enter pressed or trigger character typed
        """
        cursor = QTextCursor(block)
        currentText = block.text()
        spaceAtStartLen = len(currentText) - len(currentText.lstrip())
        currentIndent = currentText[:spaceAtStartLen]
        indent = self._smartIndenter.computeIndent(block, char)
        if indent is not None and indent != currentIndent:
            self._qpart.replaceText(block.position(), spaceAtStartLen, indent)
def getAp2(self):
        ret =math.acos(((self.getLenp1() * self.getLenp1() + self.getLenp3() * self.getLenp3()) - self.getLenp2() * self.getLenp2()) / (2* self.getLenp1() * self.getLenp3()))
        return ret