DetectingObjectOutsideOfScreen

//the object of this methode is to create 2 rectangles, from our two objects and see they intersect or not
protected bool IsObjectHidden(FrameworkElement child, FrameworkElement scrollViewer, int Offset)
{
    //Getting the information related to the scrollViewer
    GeneralTransform childTransform = child.TransformToVisual(scrollViewer);
    //creating out first rectangle using the object that i wish to ttrack
    Rect childRectangle = childTransform.TransformBounds(new Rect(new Point(0, 0), child.RenderSize));
    //creating out second rectangle  using the scrollViewer
    Rect ownerRectangle = new Rect(new Point(0, 0), scrollViewer.RenderSize);
    //Testing
    bool isInterset = IntersectsWith(childRectangle, ownerRectangle, Offset);
    return !isInterset;
}
 

//the object of this methode is to create 2 rectangles, from our two objects and see they intersect or not
public static bool IntersectsWith(Rect rect, Rect other, int offset)
{
    // Test for separating axis on the two rectangles
    if (other.Bottom < rect.Top || other.Right < rect.Left
    || other.Top > rect.Bottom || other.Left > (rect.Right - offset))
    {
        return false;
    }
    return true;
}