Can a UIView subclass create other custom view instances? - ios

Question

I have a UIView subclass called LifeCounter, of which I want to create one for each player. I was able to add two views to Main.storyboard, set their class to LifeCounter through the Attributes panel and create multiple instances that way, connect to the view controller, change properties, etc.
What I was thinking about now was creating a larger view, GameHeader, that will hold the LifeCounters and some other supplementary information such as time, game reset button, etc. GameHeader is a UIView subclass, but I can't get it to draw my LifeCounter views in the simulator and I have no idea why.
GameHeader is currently a view dragged into the storyboard, and given it's class with the Attributes panel.
GameHeader.swift
import UIKit
class GameHeader: UIView {
// MARK: Properties
// The Frame
let topFrame = CGRect(x: 0, y: 0, width: 320, height: 200)
// MARK: Initlization
required init() {
super.init(frame: topFrame)
// Adds the player one counter
let playerOneCounter = LifeCounter()
addSubview(playerOneCounter)
}
required init(coder aDecoder: NSCoder) {
// Calls the super class (UIView) initializer
super.init(coder: aDecoder)
}
}
LifeCounter.swift
import UIKit
class LifeCounter: UIView {
// MARK: Propterties
// Starting life total
var lifeTotal = 20 {
didSet {
// Updates the layout whenever the lifeTotal is updated
setNeedsLayout()
}
}
// Creates the UI Labels
// All created views need a defined frame for where they sit
// Is this neccesary outside of the init? Is there a better way?
var counter = UILabel(frame: CGRect(x: 0, y: 20, width: 100, height: 90))
var playerName = UILabel(frame: CGRect(x: 0, y: 0, width: 100, height: 40))
var winner = ""
// MARK: Initlization
// First init. LifeCounter takes a frame parameter, the adds the labels etc.
init() {
super.init(frame: CGRect(x: 0, y: 0, width: 200, height: 100))
self.addLifeCounter()
}
required init(coder aDecoder: NSCoder) {
// Calls the super class (UIView) initializer
super.init(coder: aDecoder)
}
func addLifeCounter() {
print("addLifeCounter is running")
// Styles life counter label
counter.textColor = UIColor.blackColor()
counter.textAlignment = .Center
counter.font = UIFont.boldSystemFontOfSize(72)
counter.text = String(lifeTotal)
// Styles playerName label
playerName.text = "Player Name"
playerName.textAlignment = .Center
// Button
let minusButton = UIButton(frame: CGRect(x: 5, y: 110, width: 40, height: 40))
let plusButton = UIButton(frame: CGRect(x: 55, y: 110, width: 40, height: 40))
minusButton.backgroundColor = UIColor.redColor()
plusButton.backgroundColor = UIColor.blueColor()
// Button action
minusButton.addTarget(self, action: "minusLife:", forControlEvents: .TouchDown)
plusButton.addTarget(self, action: "plusLife:", forControlEvents: .TouchDown)
addSubview(playerName)
addSubview(counter)
addSubview(minusButton)
addSubview(plusButton)
}
// MARK: Button actions
func minusLife(minusButton: UIButton) {
lifeTotal -= 1
counter.text = String(lifeTotal)
}
func plusLife(plusButton: UIButton) {
lifeTotal += 1
counter.text = String(lifeTotal)
}
}

Answer 1

init(coder:) is the initializer that is called when a view is created from a storyboard or nib. If you move the code that creates and adds LifeCounter instances there, it should work.
A good strategy to make it more reusable is to create a setup method that is called from both initializers so that it will run whether it comes from a storyboard/nib or it is instantiated programmatically.
class GameHeader: UIView {
let topFrame = CGRect(x: 0, y: 0, width: 320, height: 200)
required init() {
super.init(frame: topFrame)
self.setupSubviews()
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.setupSubviews()
}
func setupSubviews() {
let playerOneCounter = LifeCounter()
addSubview(playerOneCounter)
}
}

Answer 2

I discovered the error was in putting the LifeController drawing code inside the init(frame:) block instead of with the Coder block. When a view is added through Interface Builder, it uses init(coder:) instead of init(frame:)