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?
-
—
JohnLove
-
—
JohnLove
Add a CommentElsewhere, someone properly suggested to change
viewWillLayoutSubviewstoviewDidLayoutSubviews.This makes total sense because I wish to generate a new
UIBezierPathafter rotation when all theSKSpriteNodeshave been resized and repositioned. Regrettably this did not work. So, I'm still on the prowl for the correct solution.I have even tried to delete the current
UIBezierPathby callingtrainPath.cgPath.getPoints().removeAlland then re-create it when theUIDeviceis rotated. Once again, visually it shows that theSKSpriteNodefollows the oldUIBezierPath