Alternative to Inheritance from multiple classes swift - ios

Question

I have a class that manages positioning of UIKit elements using 'frame':
class EasyPos: UIView {
var screenWidth = UIScreen.main.bounds.width
var screenHeight = UIScreen.main.bounds.height
var x: CGFloat = 0 { didSet { self.updateFrame() } }
var y: CGFloat = 0 { didSet { self.updateFrame() } }
var width: CGFloat = 0 { didSet { self.updateFrame() } }
var height: CGFloat = 0 { didSet { self.updateFrame() } }
func updateFrame() {
frame = CGRect(x: x, y: y, width: width, height: height)
if x < 0 {
frame = CGRect(x: screenWidth - abs(x) - width, y: frame.minY, width: frame.width, height: frame.height)
}
if y < 0 {
frame = CGRect(x: frame.minX, y: screenHeight - abs(y) - height, width: frame.width, height: frame.height)
}
}
required init(x: CGFloat = 0, y: CGFloat = 0, width: CGFloat = 40, height: CGFloat = 40) {
self.x = x
self.y = y
self.width = width
self.height = height
super.init(frame: .zero)
updateFrame()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Now I want to add one class that inherits from UIbutton and one that inherits from a UILabel. And they should both be able to use the methods from the EasyPos class. How do I do this? (I tried inheritance from two classes, didn't work)
I know it has something to do with protocols. But I couldn't get this to work either.
Thanks for you help ;)

Answer 1

One way you could do this is to write a protocol extension. Because you have properties you'll need to implement a component but it shouldn't be too difficult -
struct FrameComponent {
var x: CGFloat = 0
var y: CGFloat = 0
var width: CGFloat = 0
var height: CGFloat = 0
}
protocol EasyPos {
var fc: FrameComponent { get, set }
func updateFrame()
}
extension EasyPos where Self: UIView {
func updateFrame() {
frame = CGRect(x: fc.x, y: fc.y, width: fc.width, height: fc.height)
if fc.x < 0 {
frame = CGRect(x: screenWidth - abs(fc.x) - fc.width, y: frame.minY, width:
frame.width, height: frame.height)
}
if fc.y < 0 {
frame = CGRect(x: frame.minX, y: screenHeight - abs(fc.y) - fc.height, width:
frame.width, height: frame.height)
}
}
}
Something you should remember is extensions can't add property observers, so you will need to call updateFrame() manually.