After calling setFocus, can I restore focus to its previous holder without explicitly knowing which widget it was?

Violet Giraffe

clearFocus on the widget that was activated by setFocus just removes focus altogether. How can I transfer focus back to the widget that had it last?

andreyc

You can call "QWidget * QApplication::focusWidget() [static]":http://qt-project.org/doc/qt-5/qapplication.html#focusWidget before calling setFocus to get the widget with the focus (or 0 if none has it)
Or you can connect to "void QApplication::focusChanged(QWidget * old, QWidget * now) [signal]":http://qt-project.org/doc/qt-5/qapplication.html#focusChanged to get the widget that had focus before.

mbnoimi

You can use focusNextPrevChild()

Below a snippet may help you:
[code]MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QList<QWidget *> lines = ui->centralWidget->findChildren<QWidget *>();
foreach (QWidget *widget, lines) {
widget->installEventFilter(this);
}
}

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
if(event->type() == QEvent::KeyPress) {
QKeyEvent *key = static_cast<QKeyEvent *>(event);

    if((key->key() == Qt::Key_Enter) || (key->key() == Qt::Key_Return)) {
        this->focusNextPrevChild(false);
    } else {
        return QObject::eventFilter(obj, event);
    }
    return true;
} else {
    return QObject::eventFilter(obj, event);
}
return false;

}[/code]