QMainWindow (top level window) is not animating with QPropertyAnimation

[shanmugaraja]

In my app, I have created the main window by deriving QMainWindowand that window will be displayed after some time later with animation. I am trying to implement the opacity animation for that window using QPropertyAnimation and ```
QGraphicsOpacityEffect

mainwindow.hpp

class MainWindow : public QMainWindow
{
QBasicTimer *display_timer;
void show_overlay_with_delay(void);

};

mainwindow.cpp

MainWindow::MainWindow(QWidget *parent)
: ui(new Ui::MainWindow)
{
setWindowOpacity(0.0);

display_timer = new QBasicTimer();
display_timer->start(5000, this);

}

void MainWindow::timerEvent(QTimerEvent *event)
{
if (this->display_timer->timerId() == event->timerId()) {
this->show_overlay();
}
}

void MainWindow::show_overlay(void)
{
    QGraphicsOpacityEffect *eff = new QGraphicsOpacityEffect(this);
    this->setGraphicsEffect(eff);
    QPropertyAnimation *animation = new QPropertyAnimation(eff,"opacity");
    animation->setDuration(5000);
    animation->setStartValue(0);
    animation->setEndValue(1);
    animation->setEasingCurve(QEasingCurve::InBack);
    animation->start(QPropertyAnimation::DeleteWhenStopped);
}

But the window is not animating and also not displayed. I tried it by changing the attributes as opacity and also windowOpacity attributes. But now luck.

I am trying this Mac platform. But it should be working in Windows platform as per the answer on [Qt Topic.](https://forum.qt.io/topic/60977/animate-window-top-level-widget-opacity/2)

Is there any other way, Can we animate the window (top-level) with opacity animation?

[mrjj]

Hi
QEasingCurve::InBack seems not to work (didnt look into why)
and im not sure QGraphicsOpacityEffect can work on a top level widget aka
a window.
Same code applied to a widget in a form works.

Also does
setWindowOpacity(xxx); work on macOS. ?
that is other kind of transparency than QGraphicsOpacityEffect provides.
(impl. details may vary pr platform.)

Please note "windowOpacity" versus"opacity" for 2 codes.