Selectable Color Button

ColorButton.swift

import UIKit

/// The Selectable Color Button
class ColorButton: UIButton {

    /// Highlighted Background Color
    @IBInspectable var highlightedColor: UIColor?

    /// Selected Background Color
    @IBInspectable var selectedColor: UIColor?

    /// Disabled Background Color
    @IBInspectable var disabledColor: UIColor?

    /// Original Background Color
    private var originalColor: UIColor?

    /// Whether changing color by user or not.
    private var isChanging = true

    override var backgroundColor: UIColor? {
        didSet {
            guard isChanging else { return }
            originalColor = backgroundColor
        }
    }

    override var isHighlighted: Bool {
        didSet { changeColor(highlightedColor, changing: isHighlighted) }
    }

    override var isSelected: Bool {
        didSet { changeColor(selectedColor, changing: isSelected) }
    }

    override var isEnabled: Bool {
        didSet { changeColor(disabledColor, changing: !isEnabled) }
    }

    /// Changing Background Color
    ///
    /// - Parameters:
    ///   - color: Color
    ///   - changing: Whether changing or not.
    private func changeColor(_ color: UIColor?, changing: Bool) {
        guard let color = color else { return }
        isChanging = false
        UIView.animate(withDuration: 0.25, animations: { [weak self] in
            self?.backgroundColor = changing ? color : self?.originalColor
        })
        isChanging = true
    }
}