Holding Alt key and scolling with the scrollwheel only scrolls one way

[johnratius]

I don't know why, but whenever I hold down alt and scroll, I get 0 returned. No other key does this.

This is code from my custom GraphicsView class:

void View::wheelEvent(QWheelEvent * event)
{
if (keyAltDown)
	{
		std::cout << "Alt Scroll Amount: " << event->angleDelta().y() << "\n";
		if (event->angleDelta().y() > 0)
			verticalScrollBar()->setValue(verticalScrollBar()->value() + 150 * zoomDelta);
		else
			verticalScrollBar()->setValue(verticalScrollBar()->value() - 150 * zoomDelta);
	}
	else if (keyCtrlDown)
	{
		std::cout << "Ctrl Scroll Amount: " << event->angleDelta().y() << "\n";
		if (event->angleDelta().y() > 0)
			horizontalScrollBar()->setValue(horizontalScrollBar()->value() + 150 * zoomDelta);
		else
			horizontalScrollBar()->setValue(horizontalScrollBar()->value() - 150 * zoomDelta);
	}
}

As you can see, I am printing the y() value to the console. Nothing changes except the key I hold down. When I hold Ctrl (Windows), I either get 120, or -120. When holding Alt, it's 0 both ways. Why is this happening?

BTW, I am already overriding the wheelEvent function. Doesn't work when I add override or not.

[SGaist]

Hi,

What kind of values are you expecting ?

And is it alt or alt gr ?

[johnratius]

@SGaist I should have clarified, that I am expecting to get 120 or -120. That's what I usually get when scrolling works successfully. I am unsure of what Alt gr is. I am just holding the left Alt key on my keyboard and this happens.

[SGaist]

Alt usually serves to activate the menu accelerators. So there might be something with that.

Alt Gr is usually the one at the right.