Make subviews touchable even if it is outside its superview bounds.

UIView+TouchableViews.swift

    // Make subviews touchable even if it is outside its superview bounds.
    
    // ** Add more views here **
    lazy var touchableViews: [UIView] = {
        return [self.voteUpButton, self.voteDownButton, self.authorDetailButton]
    }()
    
    // Boilerplate
    override func hitTest(point: CGPoint, withEvent event: UIEvent?) -> UIView? {
        for view in touchableViews {
            if let v = view.hitTest(view.convertPoint(point, fromView: self), withEvent: event) {
                return v
            }
        }
        return super.hitTest(point, withEvent: event)
    }
    
    // Boilerplate
    override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
        if super.pointInside(point, withEvent: event) {
            return true
        }
        for view in touchableViews {
            return !view.hidden && view.pointInside(view.convertPoint(point, fromView: self), withEvent: event)
        }
        return false
    }