Draggable Button View - Inspired by the scroll button on the Reddit iOS app
Long press to allow dragging, which is indicated by the button scaling up.
Single tap to call the delegate method.
let size = 50.0
let x = 100.0
let y = 100.0
let buttonFrame = CGRect(x: x, y: y, width: size, height: size)
let dragView = DraggableButtonView(frame: buttonFrame)
dragView.delegate = self // Where self implements DraggableButtonViewDelegate
dragView.dataSource = self // Where self implements DraggableButtonViewDataSource
view.addSubview(dragView)
TODO: Implement IBDesignable