How to zoom into a specific point in an image?

[UbiMiles]

I'm using a wheelEvent and a paintEvent to implement zooming functionality into an image , I use a custom class derived from QLabel and paint to it in my paintEvent
my question is how can I zoom into a specific point instead of (0,0) changing x,y for the drawImage function shifts my whole image out of the component
here is my code for refrence

void zoompan::paintEvent ( QPaintEvent * event )
{
    QPainter p(this);
     p.scale(scale,scale);
    //paint here
     p.drawImage(0,0,img);
}

void zoompan::wheelEvent ( QWheelEvent * event )
{
    scale+=event->angleDelta().y()/240.0;
    origin=event->position();
    if(scale<1)
    {
        scale=1;
        origin=QPointF(0,0);
    }
    update();
}

[SGaist]

Hi,

Do you mean grab the mouse pointer position to start the zoom ?

[UbiMiles]

@SGaist
how to zoom at the mouse position rather, grabbing it from the wheel event is where I got , now I am stuck trying to zoom into that point..

[SGaist]

I just realised something, you would likely simplify your life using the Graphics View framework.

You have an example here.

[UbiMiles]

@SGaist
a QLabel would be way more efficient I believe given that I keep updating the images
creating a pixmap item for each image would be a bit of an overhead I would imagine

[SGaist]

You can replace the content of the time with QGraphicsPixmapItem::setPixmap.

[UbiMiles]

@SGaist
I see , thanks !