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

Good day, In Spritekit my code fails because I am obliged by GKComponent to implement:
a. a "required init" I do not need.
b. At run time it calls this instead of my normal init() and fails.
c. super.init(coder: aDecoder) does not solve my problem of calling it
Question: A Solution to call my init instead of this forced required init
In other answers suggest a solution to use super.init(coder: aDecoder) but it has not solved my problem of not calling it.
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
//This code is supposed to add a simple eplipse under the sprite to make //a shadow effect by making it a GKComponent and add it to a GKEntity.
import Foundation
import GameplayKit
import SpriteKit
//GKEntity to add GKComponents
class Entity: GKEntity{
//A variable that is a GKComponent defined as ShadowComponent: GKComponent
var shadow: ShadowComponent
//My init
override init() {
shadow = ShadowComponent(size: CGSize(width: 50, height: 50), offset: CGPoint(x: 0, y: -20))
super.init()
addComponent(shadow)
}
//Forced by compiler to have it
**required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}**
}

The required init is required by the system; it will be called when the system autoload your component. With the interface builder for example. You can take a look at this answer for more informations. Is your entity added in the Scene editor?
So you need to focus on the way your Entity is created. If you want to call your custom init, you need to init it programmatically.
I can suggest to make the required init work, if you want to keep using your Entity in your Scene editor:
required init?(coder aDecoder: NSCoder) {
shadow = ShadowComponent(size: CGSize(width: 50, height: 50), offset: CGPoint(x: 0, y: -20))
super.init(coder: aDecoder)
addComponent(shadow)
}

All variables need to have a value assigned to it before init. Because your shadow does not have a value, the compiler is forcing you to override required init so that you can give shadow a value.
To fix this, just make shadow lazy:
lazy var shadow =
{
[unowned self] in
let shadow = ShadowComponent(size: CGSize(width: 50, height: 50), offset: CGPoint(x: 0, y: -20))
addComponent(shadow)
return shadow
}()
Then, the first time shadow is used, it will create and add the component for you.
The only reason we need to made it lazy is because of the addComponent aspect of it. Your code could be written like this to avoid having to use a lazy, but you would need to call a function to add your component.
let shadow = ShadowComponent(size: CGSize(width: 50, height: 50), offset: CGPoint(x: 0, y: -20))
func addComponents(){
addComponent(shadow)
}

Related

Why am I unable to subclass the SKSpriteNode

Forgive me, I might have asked this before, but it hit me in a different manner, and am still learning Swift
In my main scene I can easily initialize a node and then manipulate it as I like:
let myGSlot = SKSpriteNode(color : .green, size: CGSize(width: 100.0, height: 100.0))
However when I try to subclass it:
class GuessSlot : SKSpriteNode{
init(color: SKColor, size: CGSize) {
super.init()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
No matter what I do, the editor gives me many errors. The main one being:
Must call a designated initializer of the superclass 'SKSpriteNode'
Whether I put it in init() or super.init()
I know I'm new to Swift, but this is killing me!
********* latest update and the only way I can get it to compiles but still crashes with the error:
Thread 1: EXC_BAD_ACCESS (code=2, address=0x7ffeec64aff0)
In the debugger I can see that zero values are coming in for the parameters
convenience init(color: SKColor, size: CGSize) {
self.init(color: color, size: size)
}
I do feel less stupid when I see all the threads out there with confusion over this info
In Swift, you need to call an initializer that is implemented directly from your super class, in this case, SKSpriteNode. super.init() is implemented by another class that is in SKSpriteNode's inheritance tree, like SKNode or NSObject. You can always check the documentation for which constructors can you call for each class. It's very important to pay understand that you need to call designated initializers in your subclass
For example, you can do
class GuessSlot : SKSpriteNode{
init(color: SKColor, size: CGSize) {
super.init(texture: nil, color: color, size: size)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
}
I am not sure where the disconnect is, but as mentioned in the comments, you just needed to override the proper designated init texture, color,size.
class TestSpriteNode : SKSpriteNode{
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override init(texture: SKTexture?, color: UIColor, size: CGSize) {
super.init(texture: texture,color:color,size:size)
}
}
This will get you access to all of the inits of your parent class.
You will now be able to do var s = TestSpriteNode(color:.red,size:CGSize(width:1,height:1))
If you need to override this convenience init, you need to refer to one of the designated inits you overrode, not the convenience init.
class TestSpriteNode : SKSpriteNode{
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override init(texture: SKTexture?, color: UIColor, size: CGSize) {
super.init(texture: texture,color:color,size:size)
}
convenience init(color: UIColor, size: CGSize) {
self.init(texture: nil,color:color,size:size)
}
}

Initialize a Custom SKSpriteNode with its properties from the editor

I made my own simple custom class called SKGlowNode as a subclass of SKSpriteNode. I originally wanted to be able to create a custom class and input all the init parameters in the editor like you can with a SKSpriteNode. However, I found out that this is not possible yet and I had to try to do it with user data. I set up my node in the editor like this:
And simply did the custom class like this:
Here is my class for SKGlowNode
import Foundation
import SpriteKit
class SKGlowNode: SKSpriteNode{
let colors = [UIColor.blue,UIColor.green,UIColor.red,UIColor.orange,UIColor.purple,UIColor.yellow,UIColor.white,UIColor.magenta]
required init?(coder aDecoder: NSCoder) {
super.init(texture: texture, color: .black, size: size)//error here
let glowIndex = self.userData?.value(forKey: "glowColorIndex") as? Int ?? 0
let glowTexture = self.userData?.value(forKey: "glowTexture") as? String ?? "squareBg"
addGlow(radius: 75, texture: SKTexture(imageNamed: glowTexture), color: colors[glowIndex])
//This glow function works and is an extension from a SKSpriteNode where it creates a glow from a texture with certain color
}
}
Obviously I get an error on the line specified because I cant initialize the superclass using those variables, but I have no idea what to put in order to get it to initialize with the values already defined in the editor as it would work if there was no custom class. Thanks
You need to have the appropriate Super.init for your class init.
If you are instantiating the subclassed SKSpriteNode in an init() whether it be the default or a custom init with custom parameters you use
super.init(texture: SKTexture, color: SKColor, size: CGSize)
if you are instantiating it from an sks scene file then required init?(coder aDecoder: NSCoder) gets called and you need to have
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}

Editing properties of an SKSpriteNode custom class?

In my custom SKSpriteNode class, I want to be able to change properties such as anchorPoint, posistion, etc. within the custom class so I don't need to elsewhere.
import Foundation
import SpriteKit
open class Crank:SKSpriteNode {
init() {
super.init(texture: SKTexture(imageNamed: "crank"), color:
NSColor.white, size: CGSize(width: 155.0, height: 188.0))
}
required public init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
How would I edit other properties?
import Foundation
import SpriteKit
class Crank: SKSpriteNode {
init(imageNamed image: String, position at: CGPoint, withAnchor anchor: CGPoint) {
super.init(imageNamed: image)
self.position = position
self.anchorPoint = anchor
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
(Written from memory, so may contain small errors, but is broadly correct).
and then in your main code:
let myCrank = Crank(imageNamed: "Crank.png", at: CGPoint(300, 500), withAnchor: CGpointZero)
My answer notwithstanding, Alessandro has a point. I think that it's better to set 'standard' properties in the normal place.
If you are going to set any of the standard SKSpriteNode properties inside the actual class, then I think specifying them in an initialiser is good practice as it makes the m more visible,. Debugging a program where you don't appears to set a node's position, or texture etc. would be problematic.
Another way to do it would be to create a protocol and apply it to the standard SpriteKit classes that you are subclassing (or their ancestor).
For example:
protocol CustomSKNode
{
var position:CGFloat { get set }
var zRotation:CGFloat { get set }
// ...
}
extension SKNode: CustomSKNode {}
Once you've done this somewhere in your project, you'll be able to access these properties of on any of your custom SKNode or SKSpriteNode without having to import SpriteKit.

Using a class (or instance) property inside of another classes initilizer in swift

I'm relatively new to Swift, and I wanted to know if there was a way to reference a class's property inside of a separate class initializer? For example: if I have a class Person with the property position, is there a way to initialize a Pants class such that its position is the same as Person's? Here's my code:
class Pants:SKSpriteNode{
init(){
let pants = SKTexture(imageNamed: "Sprites/pants.jpg")
pants.setScale(0.5)
super.init(texture: pants, color: UIColor.clearColor(), size: pants.size())
//self.position.x = aPerson.position.x + (aPerson.size.width / 2)
//self.position.y = aPerson.position.y - (aPerson.size.height * 0.04)
self.position = Person.getPos()//CGPoint(x: 200,y: 200)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
}
At first I tried referencing aPerson which is an instance of Person but I received the error: Instance member aPerson cannot be used on type GameScene. I think understand why it doesn't make much sense to reference an instance in this case- as the instance may not exist by the time of reference? But I don't really know what this error message means- any clarification would be great. I then thought to use a static getter method within the Person class that just returned it's position property. This also doesn't seem to work. Any suggestions would be awesome!
One solution is to add a parameter to your initializer (as suggested by Paul Griffiths in a comment above):
class Pants: SKSpriteNode {
init(aPerson: Person) {
let pants = SKTexture(imageNamed: "Sprites/pants.jpg")
pants.setScale(0.5)
super.init(texture: pants, color: UIColor.clearColor(), size: pants.size())
self.position.x = aPerson.position.x + (aPerson.size.width / 2)
self.position.y = aPerson.position.y - (aPerson.size.height * 0.04)
self.position = aPerson.getPos()//CGPoint(x: 200,y: 200)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Then wherever you want to create a Pants instance, you must pass a person:
let somePerson = Person()
let pants = Pants(aPerson: somePerson)
I assume Pants are worn by Person? so instead, work relative, not absolute.
Make Pants a child node of person, then all you need to worry about is the distance from the center of Person, to the Pant line. If this will always be a constant number (Like 10 pixels below center) then hard code it. If the Pant line changes, then pass in the pant line like #Santa Claus suggests
====Assume some code here please======
person.pantline = -10;
person.addChild(Pants(pantline:person.pantline))
=====================================
class Pants: SKSpriteNode {
convenience init(pantline: Int) {
self.init(imageNamed: "Sprites/pants.jpg")
self.setScale(0.5) //Why?
self.anchorPoint = CGPointMake(0.5,1)
self.position.y = pantline
}
required init?(coder aDecoder: NSCoder) {
super.init(coder:aDecoder)
}
override init (texture: SKTexture, color: UIColor, size: CGSize)
{
super.init(texture: texture, color: color, size: size)
}
}

sknode can't see added children

Here i created a menu class which contains a few items. I want to display these sprites in the main class. I experimented with this by creating an object associating with the sknode class in the touches began method, but when i added the menu object in the main class using the addChild thing, nothing showed up.
class menu:SKNode {
let background = SKSpriteNode(imageNamed:"background")
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override init(){
super.init()
var fixedSize = self.frame.width/11
background.size = CGSizeMake(self.frame.width-fixedSize, self.frame.size.height-fixedSize)
background.position = CGPointMake(self.frame.size.width/2, self.frame.size.height/2)
self.addChild(background)
}
}
//In the main method i said let settings = menu() self.addChild(settings) nothing shows up
The frame property of an SKNode is equal to CGRectZero, so when you try to set the size of your background node it will also end up as CGRectZero.
An easy fix to your problem would be to add custom initializer and call that with the size of the scene.
class menu:SKNode {
let background = SKSpriteNode(imageNamed:"background")
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
init(size: CGSize) {
super.init()
var fixedSize = size.width/11
background.size = CGSizeMake(size.width-fixedSize, size.height-fixedSize)
background.position = CGPointMake(size.width/2, size.height/2)
self.addChild(background)
}
}