Validate entered path

def validate(self, qstr, editing=True):
        """Validate entered path"""
        if self.selected_text == qstr and qstr != '':
            self.valid.emit(True, True)
            return

        valid = self.is_valid(qstr)
        if editing:
            if valid:
                self.valid.emit(True, False)
            else:
                self.valid.emit(False, False)