def onShortcutUnindentWithBackspace(self):
        """Backspace pressed, unindent
        """
        assert self._qpart.textBeforeCursor().endswith(self.text())

        charsToRemove = len(self._qpart.textBeforeCursor()) % len(self.text())
        if charsToRemove == 0:
            charsToRemove = len(self.text())

        cursor = self._qpart.textCursor()
        cursor.setPosition(cursor.position() - charsToRemove, QTextCursor.KeepAnchor)
        cursor.removeSelectedText()
def getT(self):
        x = self.p2.x - self.p1.x
        y = self.p2.y - self.p1.y
        if (math.fabs(x) < math.pow(10,-100)):
            if(y < 0.0):
                return (-math.pi/2)
            else:
                return (math.pi/2)
        else:
            return math.atan2(y, x)