Enabling buttons when lineEdit has text

[wagmare]

if (lineEdit_name->text() != " ") {
emit allfieldsfull();
}

also dont use like this condition ..

use
QString text = lineEdit_name->text();
if (!text.isEmpty())
emit allfieldsfull();

[Lykurg]

QString text = lineEdit_name->text();
if (!text.isEmpty())
emit allfieldsfull();

if (!lineEdit_name->text().isEmpty())
        emit allfieldsfull();

if (!lineEdit_name->text().isEmpty())
        emit allfieldsfull();

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Is even more better because of avoiding a temporary variable. But nonetheless in that case a signal is not necessary, because you can simply call your member function.

[wagmare]

if (!lineEdit_name->text().isEmpty())

yes i know this is more simpler ... but for newbie i explained clearly that we check in QString function ..

and see i use "also" .. to tell him in future u use conditions like this in different application ..
here using textChanged() signal is the better one ... i agree ...