SpriteKit: add UIGestureRecognizer and detect which node was swiped - ios

Question

In which method do I add a UIGestureRecognizer to my SKScene. And how do I detect which node was swiped? This doesn't seem to work:
-(id)initWithSize:(CGSize)size {
if (self = [super initWithSize:size]) {
...
UISwipeGestureRecognizer *recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleSwipe:)];
recognizer.direction = UISwipeGestureRecognizerDirectionUp;
[[self view] addGestureRecognizer:recognizer];
}
return self;
}

Answer 1

You add the UISwipeGestureRecognizer in this method:
- (void)didMoveToView:(SKView *)view
{
UISwipeGestureRecognizer *recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleSwipe:)];
recognizer.direction = UISwipeGestureRecognizerDirectionUp;
[[self view] addGestureRecognizer:recognizer];
}
And that's how you detect which SKNode was swiped:
- (void)handleSwipe:(UISwipeGestureRecognizer *)sender
{
if (sender.state == UIGestureRecognizerStateEnded)
{
CGPoint touchLocation = [sender locationInView:sender.view];
touchLocation = [self convertPointFromView:touchLocation];
SKSpriteNode *touchedNode = (SKSpriteNode *)[self nodeAtPoint:touchLocation];
NSLog(#"%#", touchedNode);
}
}

Answer 2

Swift 3 version inspired by S.E.'s answer:
func didSceneViewPan(_ sender: UIPanGestureRecognizer) {
if sender.state == .began {
let touchPoint = sender.location(in: sender.view)
let touchLocation = convertPoint(fromView: touchPoint)
if isPointInNode(point: touchLocation, node: testNode) {
print("yes, node touched!")
} else {
print("no bueno :(")
}
}
}
fileprivate func isPointInNode(point: CGPoint, node: SKNode) -> Bool {
// Get all nodes intersecting <point>
let nodes = self.nodes(at: point)
// Return true on first one that matches <node>
for n in nodes {
if n == node {
return true
}
}
// If here, <point> not inside <node> so return false
return false
}

Answer 3

For 2017...
Say you have a scene with various sprites.
Tap on one of them. You need to know which one was tapped ...
class YourScene: SKScene {
override func didMove(to view: SKView) {
super.didMove(to: view)
// your setup for the scene - example, add objects etc
setupTapDetection()
}
func setupTapDetection() {
let t = UITapGestureRecognizer(target: self, action: #selector(tapped(_:)))
view?.addGestureRecognizer(t)
}
#objc func tapped(_ tap: UITapGestureRecognizer) {
// critical...
if tap.state != .ended { return }
// Note: you actually do NOT "invert the Y axis",
// these two calls in fact take care of that properly.
let viewPoint = tap.location(in: tap.view)
let scenePoint = convertPoint(fromView: viewPoint)
// technically there could be more than one node...
let nn = nodes(at: scenePoint)
if nn.count == 0 {
print("you very like tapped 'nowhere'")
return
}
if nn.count != 1 {
// in almost all games or physics scenes,
// it is not possible this would happen
print("something odd happened - overlapping nodes?")
return
}
// you must have a custom class for your sprites
// Say it is class YourSprites: SKSpriteNode
if let dotSpriteTapped = nn.first! as? YourSprites {
// we are done. dotSpriteTapped is the YourSprite,
// which was tapped. now do whatever you want.
let nm = String(describing: dotSpriteTapped.name)
print(" \(nm)")
// you can now access your own properties:
let whichTank = dotSpriteTapped.someID
print(" \(whichTank)")
let tankPower = dotSpriteTapped.sheildStrength
print(" \(tankPower)")
}
}
Enjoy

Answer 4

You can check of the nodes at a location include a node you're looking for using this:
nodes(at: touchLocation).contains(nodeYouAreLookingFor)