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c++qtqmenuqaction

How to set focus after execution QAction

Main widget steals focus after execution QAction. I need the focus to be set to popup widget.

QAction *action = new QAction(tr("show popup"), this);
connect(action, &QAction::triggered, this, &MyWidget::showPopup);
addAction(action);

void MyWidget::showPopup()
{
  QMessageBox* popup = new QMessageBox(this);
  popup->setModal(true);
  popup->show();
  popup->setFocus();
}

MyWidget inherits from QWidget.

Solution

  • Because you just created popup, it's not 'there' yet in the GUI. Even the show() doesn't instantly show it. After you leave the scope of MyWidget::showPopup(), the GUI event loop will continue looping and be able to process your new popup. Thus the setFocus() call comes too early.

    But there is help underway:

    QWidget::setFocus() is a slot, so you can invoke it.

    If you use a timer (QTimer::singleShot(0, popup, SLOT(setFocus()));), it should work.
    Maybe you'll need to use 10ms instead of 0ms.