didBeginContact not working in Swift 2 + SpriteKit - swift

Question

I'm working on a game, and I'm using spritekit and Swift.
This is my code:
import SpriteKit
struct collision {
static let arrow:UInt32 = 0x1 << 1
static let runner:UInt32 = 0x1 << 2
static let target:UInt32 = 0x1 << 3
static let targetCenter:UInt32 = 0x1 << 4
}
class GameScene: SKScene, SKPhysicsContactDelegate {
var person = SKSpriteNode()
var box = SKSpriteNode()
var screenSize:CGSize!
var gameScreenSize:CGSize!
var gameStarted:Bool = false
var moveAndRemove = SKAction()
var boxVelocity:NSTimeInterval = 5.5
override func didMoveToView(view: SKView) {
self.physicsWorld.gravity = CGVectorMake(0, -1.0)
self.physicsWorld.contactDelegate = self
screenSize = self.frame.size
gameScreenSize = view.frame.size
createPerson()
}
func createPerson() -> Void {
person.texture = SKTexture(imageNamed:"person")
person.setScale(1.0)
person.size = CGSize(width: 80, height: 80)
person.position = CGPoint(x: screenSize.width / 2, y: 150)
person.physicsBody = SKPhysicsBody(rectangleOfSize: person.size)
person.physicsBody?.affectedByGravity = false
person.physicsBody?.dynamic = false
self.addChild(person)
}
func createTarget() -> Void {
box = SKSpriteNode()
box.size = CGSize(width: 70, height: 100)
box.setScale(1.0)
box.position = CGPoint(x: (screenSize.width / 3) * 2, y: screenSize.height + box.size.height)
box.texture = SKTexture(imageNamed: "box")
box.physicsBody? = SKPhysicsBody(rectangleOfSize: box.size)
box.physicsBody?.categoryBitMask = collision.target
box.physicsBody?.collisionBitMask = collision.arrow
box.physicsBody?.contactTestBitMask = collision.targetCenter
box.physicsBody?.affectedByGravity = false
box.physicsBody?.dynamic = true
box.physicsBody?.usesPreciseCollisionDetection = true
self.addChild(box)
let distance = CGFloat(self.frame.height - box.frame.height)
let moveTargets = SKAction.moveToY(-distance, duration: boxVelocity)
let removeTargets = SKAction.removeFromParent()
moveAndRemove = SKAction.sequence([moveTargets,removeTargets])
box.runAction(moveAndRemove)
}
func createBall() ->Void {
let ball = SKSpriteNode()
ball.size = CGSize(width: 20, height: 22)
ball.zPosition = 5
let moveToXY = CGPoint(x: self.size.width, y: self.size.height)
ball.texture = SKTexture(imageNamed: "ball")
ball.position = CGPointMake(person.position.x + ball.size.width, person.position.y + ball.size.height)
ball.physicsBody? = SKPhysicsBody(rectangleOfSize: ball.size)
ball.physicsBody?.categoryBitMask = collision.arrow
ball.physicsBody?.collisionBitMask = collision.target
ball.physicsBody?.affectedByGravity = false
ball.physicsBody?.dynamic = true
ball.physicsBody?.usesPreciseCollisionDetection = true
let action = SKAction.moveTo(moveToXY, duration: 1.5)
let delay = SKAction.waitForDuration(1.5)
ball.runAction(SKAction.sequence([action,delay]))
self.addChild(ball)
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
if gameStarted == false {
gameStarted = true
let spawn = SKAction.runBlock { () in
self.createTarget()
}
let delay = SKAction.waitForDuration(1.5)
let spawnDelay = SKAction.sequence([spawn, delay])
let spanDelayForever = SKAction.repeatActionForever(spawnDelay)
self.runAction(spanDelayForever)
} else {
createBall()
boxVelocity -= 0.1
}
}
func didBeginContact(contact: SKPhysicsContact) {
print("Detect")
}
func didEndContact(contact: SKPhysicsContact) {
print("end detect")
}
override func update(currentTime: CFTimeInterval) {
}
}
But when I run the game, the collision between objects does not. I'm trying to solve a while, but found nothing. Can someone help me?
Project files.

Answer 1

Try with these to modifications:
box.physicsBody = SKPhysicsBody(rectangleOfSize: box.size)
box.physicsBody?.categoryBitMask = collision.target
box.physicsBody?.collisionBitMask = collision.arrow
box.physicsBody?.contactTestBitMask = collision.targetCenter
and
ball.physicsBody = SKPhysicsBody(rectangleOfSize: ball.size)
ball.physicsBody?.categoryBitMask = collision.arrow
ball.physicsBody?.collisionBitMask = collision.target
ball.physicsBody?.contactTestBitMask = collision.target
Note the absence of "?" while you init the physicsBody and the new contactTestBitMask