QLineedit disabling/re-enabling.

Question

I have an equation with four variables, only 3 need to be defined for the program to run. When 3 of the parameters have been defined (via lineedits in my GUI) I'd like the fourth to be greyed out. I only know how to link two parameters at the moment by disabling one lineedit when another is edited. e.g.

void WaveformGen::on_samples_textEdited(const QString &arg1)
{
    ui->cycles->setDisabled(true);
}

So when samples is edited I disable another lineedit called cycles

svlasov · Accepted Answer · 2015-03-24T14:22:50.013

1

Using one single slot:

class WaveformGen {
private:
    QList<QLineEdit *> m_lineEdits;
private slots:
    void lineEditTextEdited(const QString &text);
    ...
};

WaveformGen::WaveformGen()
{
    ...
    // create an ordered list of line edits:
    m_lineEdits << ui->lineEdit1 << ui->lineEdit2 << ui->lineEdit3 << ui->lineEdit4;
    // connect all to same slot:
    foreach(QLineEdit *lineEdit, m_lineEdits) {
        connect(lineEdit, SIGNAL(textEdited(const QString &)), this, SLOT(lineEditTextEdited(const QString &)));
    }
}

void WaveformGen::lineEditTextEdited(const QString &str)
{
    // iterate over all lineEdits:
    for (int i = 0; i < m_lineEdits.count() - 1; ++i) {
        // enable the next lineEdit if the previous one has some text and not disabled
        m_lineEdits.at(i+1)->setEnabled(!m_lineEdits.at(i)->text().isEmpty() && m_lineEdits.at(i)->isEnabled());
    }
}

edited Mar 24 '15 at 14:22

answered Mar 24 '15 at 13:57

svlasov

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That's the better way to do it @SageDO – Thomas Ayoub Mar 24 '15 at 14:09
Could I get a little more explanation on what's going on in the code please? I don't fully follow. – SageDO Mar 24 '15 at 14:16
@SageDO I added some comments. – svlasov Mar 24 '15 at 14:23
@svlasov thanks, I was stuck trying to understand what conditions enabled the lineedits. – SageDO Mar 24 '15 at 14:26

score 0 · Answer 2 · answered Mar 24 '15 at 13:46

0

Make one slot, connect as many textEdited(const QString &arg1) from diffrent lineEdits as you need to, and then in the slot's body retrieve signal sender using the QObject::sender() method

answered Mar 24 '15 at 13:46

murison

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How do you suggest using `sender()` to find the line edut which was not edited? – hyde Mar 24 '15 at 13:50

QLineedit disabling/re-enabling.

2 Answers2