QLabel underline for accelerator doesn't update when Alt is pressed

thinkinmachine

Starting from Windows 10, the underline for accelerator (set by ampersand) is visible after Alt is pressed with default settings. I tested this with QMenu and it worked well. However for QLabel, the underline didn't show, even after I changed system settings. But it's visible after recreating the widget object. Then I realized that probably that's because there's no update slot to update QLabel when accelerator is activated. Is there anyway to fix this bug? Thanks.

Christian Ehrlicher

Please provide a minimal, compileable example of the problem. Also the exact Qt version and style you are using.

thinkinmachine

Environment

Qt: v6.8.1 (mingw_64)
Windows 11

Minimal Example

Problem

When the program is running, toggle "Underline keyboard short cuts and keys" in "Control Panel\Ease of Access\Ease of Access Center\Make the keyboard easier to use". The label doesn't update the underline, until the program is exited and restarted. QMenu can update this without restarting the program. Probably QLabel doesn't have a slot to update display when this system setting changes.

Code

My code is recognized as spam and prohibited from posting here. I'll attach download link.
https://drive.google.com/file/d/18V_E4UvpG2e9h9MDhHR_YLOanw9t_leJ/view?usp=sharing
The key part is

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
{
    lineEdit1 = new QLineEdit;
    lineEdit2 = new QLineEdit;

    // bug: QLabel underline for accelerator doesn't update when Alt is pressed in Windows
    label1 = new QLabel(tr("Field &A:"));
    label1->setBuddy(lineEdit1);

    label2 = new QLabel(tr("Field &B:"));
    label2->setBuddy(lineEdit2);

    QWidget *centralWidget = new QWidget;
    setCentralWidget(centralWidget);

    QGridLayout *mainLayout = new QGridLayout(centralWidget);
    mainLayout->addWidget(label1, 0, 0);
    mainLayout->addWidget(lineEdit1, 0, 1);
    mainLayout->addWidget(label2, 1, 0);
    mainLayout->addWidget(lineEdit2, 1, 1);

    menuBar()->addMenu(tr("&Menu"));
}