'Validate entered path'

def validate(self, qstr, editing=True):

    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)
