How to integrate UIDevice rotation and creating a new UIBezierPath after rotation?
My challenge here is to successfully integrate UIDevice rotation and creating a new UIBezierPath every time the UIDevice is rotated.
(Please accept my apologies for this Post’s length .. but I can’t seem to avoid it)
As a preamble, I have bounced back and forth between
NotificationCenter.default.addObserver(self,
selector: #selector(rotated),
name: UIDevice.orientationDidChangeNotification,
object: nil)
called within my viewDidLoad() together with
@objc func rotated() {
}
and
override func viewWillLayoutSubviews() {
// please see code below
}
My success was much better when I implemented viewWillLayoutSubviews(), versus rotated() .. so let me provide detailed code just for viewWillLayoutSubviews().
I have concluded that every time I rotate the UIDevice, a new UIBezierPath needs to be generated because positions and sizes of my various SKSprieNodes change.
I am definitely not saying that I have to create a new UIBezierPath with every rotation .. just saying I think I have to.
Start of Code
// declared at the top of my `GameViewController`:
var myTrain: SKSpriteNode!
var savedTrainPosition: CGPoint?
var trackOffset = 60.0
var trackRect: CGRect!
var trainPath: UIBezierPath!
My UIBezierPath creation and SKAction.follow code is as follows:
// called with my setTrackPaths() – see way below
func createTrainPath() {
// savedTrainPosition initially set within setTrackPaths()
// and later reset when stopping + resuming moving myTrain
// via stopFollowTrainPath()
trackRect = CGRect(x: savedTrainPosition!.x,
y: savedTrainPosition!.y,
width: tracksWidth,
height: tracksHeight)
trainPath = UIBezierPath(ovalIn: trackRect)
trainPath = trainPath.reversing() // makes myTrain move CW
} // createTrainPath
func startFollowTrainPath() {
let theSpeed = Double(5*thisSpeed)
var trainAction = SKAction.follow(
trainPath.cgPath,
asOffset: false,
orientToPath: true,
speed: theSpeed)
trainAction = SKAction.repeatForever(trainAction)
createPivotNodeFor(myTrain)
myTrain.run(trainAction, withKey: runTrainKey)
} // startFollowTrainPath
func stopFollowTrainPath() {
guard myTrain == nil else {
myTrain.removeAction(forKey: runTrainKey)
savedTrainPosition = myTrain.position
return
}
} // stopFollowTrainPath
Here is the detailed viewWillLayoutSubviews I promised earlier:
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
if (thisSceneName == "GameScene") {
// code to pause moving game pieces
setGamePieceParms() // for GamePieces, e.g., trainWidth
setTrackPaths() // for trainPath
reSizeAndPositionNodes()
// code to resume moving game pieces
} // if (thisSceneName == "GameScene")
} // viewWillLayoutSubviews
func setGamePieceParms() {
if (thisSceneName == "GameScene") {
roomScale = 1.0
let roomRect = UIScreen.main.bounds
roomWidth = roomRect.width
roomHeight = roomRect.height
roomPosX = 0.0
roomPosY = 0.0
tracksScale = 1.0
tracksWidth = roomWidth - 4*trackOffset // inset from screen edge
#if os(iOS)
if UIDevice.current.orientation.isLandscape {
tracksHeight = 0.30*roomHeight
}
else {
tracksHeight = 0.38*roomHeight
}
#endif
// center horizontally
tracksPosX = roomPosX
// flush with bottom of UIScreen
let temp = roomPosY - roomHeight/2
tracksPosY = temp + trackOffset + tracksHeight/2
trainScale = 2.8
trainWidth = 96.0*trainScale // original size = 96 x 110
trainHeight = 110.0*trainScale
trainPosX = roomPosX
#if os(iOS)
if UIDevice.current.orientation.isLandscape {
trainPosY = temp + trackOffset + tracksHeight + 0.30*trainHeight
}
else {
trainPosY = temp + trackOffset + tracksHeight + 0.20*trainHeight
}
#endif
} // setGamePieceParms
// a work in progress
func setTrackPaths() {
if (thisSceneName == "GameScene") {
if (savedTrainPosition == nil) {
savedTrainPosition = CGPoint(x: tracksPosX - tracksWidth/2, y: tracksPosY)
}
else {
savedTrainPosition = CGPoint(x: tracksPosX - tracksWidth/2, y: tracksPosY)
}
createTrainPath()
} // if (thisSceneName == "GameScene")
} // setTrackPaths
func reSizeAndPositionNodes() {
myTracks.size = CGSize(width: tracksWidth, height: tracksHeight)
myTracks.position = CGPoint(x: tracksPosX, y: tracksPosY)
// more Nodes here ..
}
End of Code
My theory says when I call setTrackPaths() with every UIDevice rotation, createTrainPath() is called.
Nothing happens of significance visually as far as the UIBezierPath is concerned .. until I call startFollowTrainPath().
Bottom Line
It is then that I see for sure that a new UIBezierPath has not been created as it should have been when I called createTrainPath() when I rotated the UIDevice.
The new UIBezierPath is not new, but the old one.
If you’ve made it this far through my long code, the question is what do I need to do to make a new UIBezierPath that fits the resized and repositioned SKSpriteNode?
