Make a guess:

                // If the focused widget doesn't have the mouse,
                // send the mouse input to the focused widget.
                if (!focused) {
                    KInputTest::mouseButtonPressed(button, pressed);
                }
            }
        }

        // Update mouse button state.
        const bool mousebuttonup = button.button() == Qt::LeftButton;

        const int num =  KInputTest::mouseButtonsToPress(button);

        // If mouse button is down, send mouse input to the user (shift + mouse).
        // If not, send mouse input to the focused widget (not visible).
        if (num != -1) {
            if (pressed && !mousebuttonup) {
                KInputTest::mouseButtonReleased(button, pressed);
            }

            if (!pressed && mousebuttonup) {
                KInputTest::mouseButtonPressed(button, pressed);
            }
        }

        // If mouse button is not up (which is the default), stop polling.
        // The alternative to polling in the context of using an app
        // that has a button to poll, is to use polling events (like
        // mouse button pressed above, but without a window manager)
        // as a workaround to make sure that a KInputTest::mouseButtonPressed
        // gets emitted with 'false' for a button press regardless of the
        // button pressed.
        if (num == -1) {
            KInputTest::mouseButtonReleased(button, false);
            return;
        }

        // Update mouse event.
        Q_EMIT mouseButtonPressed(button, pressed);
    }

    // Update the state of the window manager and the desktop.
    KWindowSystem::setState(winId(), KWindowSystem::WindowState(windowType));

    const bool toplayer = KWindowSystem::isPlatformX11() || KWindowSystem::isPlatformWayland();

    // Update the active desktop.
    if (toplayer) {
        KWindowSystem::setCurrentDesktop(KWindowSystem::desktop() + 1);
    } else {
        KWindowSystem::setCurrentDesktop(winId());
    }

    // Update the active window title.
    if (toplayer) {
        QString title = QString::number(KWindowSystem::activeWindow() + 1);
        KWindowSystem::setUserTitle(winId(), title);
    } else {
        KWindowSystem::setUserTitle(winId(), title);
    }
}