QLineEdit: how to put cursor at the end of typed text?

Question

There is a QLineEdit in which you need to enter a phone number. Gave him a mask

ui->lineEdit_4->setInputMask("+7\\(999\\)999\\-99\\-99;_");

Further, when saving the data, the entered string is checked by the validator:

QRegularExpression numberRegex ("^\\+\\d{1,1}\\(\\d{3,3}\\)\\d{3,3}\\-\\d{2,2}\\-\\d{2,2}$");
QRegularExpressionValidator *numberValidator = new QRegularExpressionValidator (numberRegex);
QString a = ui->lineEdit_4->text();
int b = ui->lineEdit_4->cursorPosition();
if(numberValidator->validate(a, b) == QValidator::Acceptable){
....
}

Above I described everything that is, and now the very essence of the problem. Typing is extremely inconvenient, since the cursor is not attached to anything. Wherever you click, the cursor will appear there. How to make the cursor appear where you need to type text? So far, in ideas there is only a check for the cursor position, and every time it changes, put it on the first "_" in the line. But something sounds crazy

Answer 1

Connect this signal: https://doc.qt.io/qt-5/qlineedit.html#cursorPositionChanged

In the target method, move cursor to the end of the field with this: https://doc.qt.io/qt-5/qlineedit.html#end

Something like this:

QObject::connect(
    ui->lineEdit_4,
    &QLineEdit::cursorPositionChanged,
    this,
    [this](){
        ui->lineEdit_4->end(false);
    });