Detecting when a user taps a SKSpriteNode - ios

Question

I'm new to swift programming and I decided I would make a simple game to start with SpriteKit. I have a SpriteNode that is supposed to pick 1 of 6 locations and move there when it is tapped, however from the methods I've seen I can't figure out how to implement it (again I'm new at this) Here is my code from the GameScene.swift file:
import SpriteKit
class GameScene: SKScene {
override func didMoveToView(view: SKView) {
let screenSize: CGRect = UIScreen.mainScreen().bounds
let greenTileWidth = screenSize.width * 0.5
let greenTileHeight = screenSize.height * 0.33
let greenTilePositionY = [greenTileHeight / 2, greenTileHeight / 2 + greenTileHeight, greenTileHeight / 2 + greenTileHeight * 2 ]
let greenTilePositionX = [greenTileWidth / 2, greenTileWidth / 2 + greenTileWidth]
let backgroundTile = SKSpriteNode(imageNamed: "whiteTile")
backgroundTile.size.width = screenSize.width * 100
backgroundTile.size.height = screenSize.height * 100
addChild(backgroundTile)
let greenTile = SKSpriteNode(imageNamed: "greenTile")
greenTile.size.width = greenTileWidth
greenTile.size.height = greenTileHeight
greenTile.position.y = greenTilePositionY[0]
greenTile.position.x = greenTilePositionX[0]
greenTile.userInteractionEnabled = true
addChild(greenTile)
var randomX:Int = 0
var randomY:Int = 0
func getRandomY() -> Int{
randomY = Int(arc4random_uniform(26))%3
return randomY
}
func getRandomX() -> Int{
randomX = Int(arc4random_uniform(26))%2
return randomX
}
func moveGreenTile(){
greenTile.position.x = greenTilePositionX[randomX]
greenTile.position.y = greenTilePositionY[randomY]
}
getRandomX()
getRandomY()
moveGreenTile()
}
when the SpriteNode greenTile is tapped, getRandomY() getRandomX() and moveGreenTile() should be called.

Answer 1

First you have to set the name attribute of your SKSpriteNodes:
greenTile.name = "greenTile"
First I see some errors in your code. The return values of getRandomX and getRandomY never get really used. Because you set the randomX and randomY variables without actually calling getRandom. So you should update it to:
func moveGreenTile(){
greenTile.position.x = greenTilePositionX[getRandomX()]
greenTile.position.y = greenTilePositionY[getRandomY()]
}
That way you only have to call moveGreenTile and it will call the getRandom methods by itself.
Then you have to use the touchesBegan method to check if the user touches the screen. So with the name you can check if the user touched the greenTile by checking the name you've set earlier:
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
for touch in touches{
let location = touch.locationInNode(self)
let node:SKNode = self.nodeAtPoint(location)
if(node.name == "greenTile"){
moveGreenTile()
}
}
}

Answer 2

This code detects tap events, not only touches, on a SKSpriteNode.
You can change how sensitive the tap gesture is by modifying TapMaxDelta.
class TapNode : SKSpriteNode {
// Tap Vars
var firstPoint : CGPoint?
var TapMaxDelta = CGFloat(10)
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
init() {
let texture = SKTexture(imageNamed: "Test.png")
super.init(texture: texture, color: UIColor.clear, size: texture.size())
isUserInteractionEnabled = true
}
// ================================================================================================
// Touch Functions
// ================================================================================================
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let firstTouch = touches.first {
firstPoint = firstTouch.location(in: self)
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
if let firstTouch = touches.first, let firstPoint = firstPoint {
let curPoint = firstTouch.location(in: self)
if abs(curPoint.x - firstPoint.x) <= TapMaxDelta && abs(curPoint.y - firstPoint.y) <= TapMaxDelta {
print("tap yo")
}
}
}
}