Drag from outside the JT3DScrollView frame

[andrewzboard]

The first thing I wanted to do with this View was drag on one of the images that was outside the View's frame. (The JT3DScrollView has clipsToBounds set to false, so the previous and next — and maybe others — show outside the View proper.)

The way to do this is to embed the JT3DScrollView in another view. Make the enclosing view a custom subclass of UIView and add this and only this method:

 override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
    if self.point(inside: point, with: nil) {
        return subviews.first
    } else {
        return super.hitTest(point, with: event)
    }
}

Now drags in the enclosing view will be passed to the enclosed JT3DScrollView. Have fun! And thanks JT for such a clean implementation.