No longer naive

dragging.swift

@objc func wasDragged(gesture: UIPanGestureRecognizer) {
    if gesture.state == .began || gesture.state == .changed {
        let translation = gesture.translation(in: superview!)
        guard let currentPosition = currentSnapPosition else { return }
        frame.origin = CGPoint(x: currentPosition.x + translation.x, y: currentPosition.y + translation.y)
    }
    
    if gesture.state == .ended {
        let velocity = gesture.velocity(in: superview!)
        let decelerationRate = UIScrollView().decelerationRate
        
        let projectedPosition = CGPoint(
            x: frame.origin.x + project(initialVelocity: velocity.x, decelerationRate: decelerationRate),
            y: frame.origin.y + project(initialVelocity: velocity.y, decelerationRate: decelerationRate)
        )

        let nearestCornerPosition = nearestCorner(to: projectedPosition)
        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 100, initialSpringVelocity: 30, options: [.curveEaseOut, .allowUserInteraction], animations: {
            self.frame.origin = nearestCornerPosition
        }, completion: nil)
    }
}