ExpandedHitButton.swift

/// Expands the touch target of the button to be at least as large as the minimum iOS guidelines.
class ExpandedHitButton: UIButton {
    let minimumHitSize: CGSize

    /// Creates an instance of `ExpandedHitButton`.
    ///
    /// - Parameters:
    ///   - minimumHitSize: Size of the minimum hit rectangle, centered at the bounds midpoint. Default is 44x44
    ///                     points (iOS Guidelines).
    init(minimumHitSize: CGSize = CGSize(width: 44, height: 44)) {
        self.minimumHitSize = minimumHitSize
        super.init(frame: .zero)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
        let halfWidth = minimumHitSize.width / 2
        let halfHeight = minimumHitSize.height / 2
        let hitTestEdgeInsets = UIEdgeInsets(top: -halfHeight, left: -halfWidth, bottom: -halfHeight, right: -halfWidth)

        let center = CGPoint(x: bounds.midX, y: bounds.midY)
        let centerRectZero = CGRect(origin: center, size: .zero)
        let minimumHitRect = UIEdgeInsetsInsetRect(centerRectZero, hitTestEdgeInsets)

        let hitRect = bounds.union(minimumHitRect)

        return hitRect.contains(point)
    }
}