Interactive application icon

[Mizmas]

[JonB]

@Mizmas At a guess, depends on your platform/window manager?

[Mizmas]

@JonB It's actually really simple, the application's icon is just an image, so you just need an image representation of a widget, and when that widget changes, you can just update the application's icon like this:

pixmap = self.slider_frame.grab()
self.setWindowIcon(QIcon(pixmap))

grab() returns a pixmap, update the pixmap each time the slider moves, set the pixmap as the new icon.
You can also do the same thing for the tray icon.
You can also use a QMovie animation, for example

pixmap = self.animation.currentPixmap()

So if you combine everything, you can have an event driven interactive application icon / system tray icon

[JonB]

@Mizmas And that would work in, say, GNOME? I thought that just uses a static file for its icon?

[Mizmas]

@JonB I don't use Linux so IDK

[JonB]

@Mizmas
...which is why I said it would probably depend on your platform/window manager which you didn't say...

[TBH I had not noticed initially that this was Showcase, I thought you were asking if you could do this from Qt.] Your showcase is fine, just you might like to mention this if it's e.g. Windows-only as Qt is cross-platform.

[GrecKo]

@JonB using QWindow::setIcon this also works on Gnome/X11.

rough PoC:

    QTimer timer;
    int i = 0;
    int iconSize = 32;
    int rectSize = 5;
    QPixmap pixmap(QSize{iconSize, iconSize});

    timer.start(20);
    timer.callOnTimeout([&] {
        pixmap.fill(Qt::transparent);
        {
            QPainter painter(&pixmap);
            painter.drawRect(i, i , rectSize, rectSize);
        }
        i = (i + 1) % (iconSize - rectSize + 1);
        QIcon icon(pixmap);
        QGuiApplication::setWindowIcon(icon);
        QGuiApplication::allWindows().first()->setIcon(icon);
    });

[Dawinch]

@Mizmas haha, looks funny :)