Scrolling on Mouse Wheel

[penny]

I have an application, where i've enabled zooming on Ctrl+Mousewheel, using the following code
void GraphWidget::wheelEvent(QWheelEvent *event)

{
	if (event->modifiers().testFlag(Qt::ControlModifier)) 
	{
		scaleView(pow((double)2, -event->delta() / 240.0));
	}
}

{
	if (event->modifiers().testFlag(Qt::ControlModifier)) 
	{
		scaleView(pow((double)2, -event->delta() / 240.0));
	}
}

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However, i also want the scrollbars to respond to wheelevents when mouse wheel is moved without Ctrl being pressed. How do i do that ?

[JohannesMunk]

You want the default implementation to work? Then you need to call the inherited wheelEvent, when you don't handle the event yourself.

HIH

Joh

[penny]

Thanks for the reply.
How do i call the default wheelevent? Isn't it called automatically when i move the mouse wheel?

[JohannesMunk]

You need to call the base class implementation. Otherwise you are overriding its functionality. Your GraphWidget inherits from QGraphicsView?

Then it would look like this:

void GraphWidget::wheelEvent(QWheelEvent *event)
{
    if (event->modifiers().testFlag(Qt::ControlModifier)) 
    {
        scaleView(pow((double)2, -event->delta() / 240.0));
    } else {
        QGraphicsView::wheelEvent(event);
    }
}

void GraphWidget::wheelEvent(QWheelEvent *event)
{
    if (event->modifiers().testFlag(Qt::ControlModifier)) 
    {
        scaleView(pow((double)2, -event->delta() / 240.0));
    } else {
        QGraphicsView::wheelEvent(event);
    }
}

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HIH

Johannes

[penny]

Thank you so much!! It works properly now..