Custom transition in Swift 3 does not translate correctly - swift

I've implemented a Navigation controller to incorporate an rotating-disc type of layout (imagine each VC laid out in a circle, that rotates as a whole, into view sequentially. The navigation controller is configured to use a custom transition class, as below :-
import UIKit
class RotaryTransition: NSObject, UIViewControllerAnimatedTransitioning {
let isPresenting :Bool
let duration :TimeInterval = 0.5
let animationDuration: TimeInterval = 0.7
let delay: TimeInterval = 0
let damping: CGFloat = 1.4
let spring: CGFloat = 6.0
init(isPresenting: Bool) {
self.isPresenting = isPresenting
super.init()
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
//Get references to the view hierarchy
let fromViewController: UIViewController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)!
let toViewController: UIViewController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)!
let sourceRect: CGRect = transitionContext.initialFrame(for: fromViewController)
let containerView: UIView = transitionContext.containerView
if self.isPresenting { // Push
//1. Settings for the fromVC ............................
// fromViewController.view.frame = sourceRect
fromViewController.view.layer.anchorPoint = CGPoint(x: 0.5, y: 3);
fromViewController.view.layer.position = CGPoint(x: fromViewController.view.frame.size.width/2, y: fromViewController.view.frame.size.height * 3);
//2. Setup toVC view...........................
containerView.insertSubview(toViewController.view, belowSubview:fromViewController.view)
toViewController.view.layer.anchorPoint = CGPoint(x: 0.5, y: 3);
toViewController.view.layer.position = CGPoint(x: toViewController.view.frame.size.width/2, y: toViewController.view.frame.size.height * 3);
toViewController.view.transform = CGAffineTransform(rotationAngle: 15 * CGFloat(M_PI / 180));
//3. Perform the animation...............................
UIView.animate(withDuration: animationDuration, delay:delay, usingSpringWithDamping: damping, initialSpringVelocity: spring, options: [], animations: {
fromViewController.view.transform = CGAffineTransform(rotationAngle: -15 * CGFloat(M_PI / 180));
toViewController.view.transform = CGAffineTransform(rotationAngle: 0);
}, completion: {
(animated: Bool) -> () in transitionContext.completeTransition(true)
})
} else { // Pop
//1. Settings for the fromVC ............................
fromViewController.view.frame = sourceRect
fromViewController.view.layer.anchorPoint = CGPoint(x: 0.5, y: 3);
fromViewController.view.layer.position = CGPoint(x: fromViewController.view.frame.size.width/2, y: fromViewController.view.frame.size.height * 3);
//2. Setup toVC view...........................
// toViewController.view.frame = transitionContext.finalFrame(for: toViewController)
toViewController.view.layer.anchorPoint = CGPoint(x: 0.5, y: 3);
toViewController.view.layer.position = CGPoint(x: toViewController.view.frame.size.width/2, y: toViewController.view.frame.size.height * 3);
toViewController.view.transform = CGAffineTransform(rotationAngle: -15 * CGFloat(M_PI / 180));
containerView.insertSubview(toViewController.view, belowSubview:fromViewController.view)
//3. Perform the animation...............................
UIView.animate(withDuration: animationDuration, delay:delay, usingSpringWithDamping: damping, initialSpringVelocity: spring, options: [], animations: {
fromViewController.view.transform = CGAffineTransform(rotationAngle: 15 * CGFloat(M_PI / 180));
toViewController.view.transform = CGAffineTransform(rotationAngle: 0);
}, completion: {
//When the animation is completed call completeTransition
(animated: Bool) -> () in transitionContext.completeTransition(true)
})
}
}
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return duration;
}
}
A representation of how the views move is show in the illustration below... The two red areas are the problems, as explained later.
The presenting (push) translation works fine - 2 moves to 1 and 3 moves to 2. However, the dismissing (pop) translation does not, whereby the dismissing VC moves out of view seemingly correctly (2 moving to 3), but the presenting (previous) VC arrives either in the wrong place, or with an incorrectly sized frame...
With the class as-is, the translation results in 2 moving to 3 (correctly) but 1 then moves to 4, the view is correctly sized, yet seems offset, by a seemingly arbitrary distance, from the intended location. I have since tried a variety of different solutions.
In the pop section I tried adding the following line (commented in the code) :-
toViewController.view.frame = transitionContext.finalFrame(for: toViewController)
...but the VC now ends up being shrunk (1 moves to 5). I hope someone can see the likely stupid error I'm making. I tried simply duplicating the push section to the pop section (and reversing everything), but it just doesn't work!
FYI... Those needing to know how to hookup the transition to a UINavigationController - Add the UINavigationControllerDelegate to your nav controller, along with the following function...
func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
let transition: SwingTransition = SwingTransition.init(isPresenting: ( operation == .push ? true : false ))
return transition;
}
The diagram below shows how all views would share the same originating point (for the translation). The objective is to give the illusion of a revolver barrel moving each VC into view. The top centre view represents the viewing window, showing the third view in the stack. Apologies for the poor visuals...

The problem is that one of the properties in the restored view controller's view isn't getting reset properly. I'd suggest resetting it when the animation is done (you probably don't want to keep the non-standard transform and anchorPoint in case you do other animations later that presume the view is not transformed). So, in the completion block of the animation, reset the position, anchorPoint and transform of the views.
class RotaryTransition: NSObject, UIViewControllerAnimatedTransitioning {
let isPresenting: Bool
let duration: TimeInterval = 0.5
let delay: TimeInterval = 0
let damping: CGFloat = 1.4
let spring: CGFloat = 6
init(isPresenting: Bool) {
self.isPresenting = isPresenting
super.init()
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let from = transitionContext.viewController(forKey: .from)!
let to = transitionContext.viewController(forKey: .to)!
let frame = transitionContext.initialFrame(for: from)
let height = frame.size.height
let width = frame.size.width
let angle: CGFloat = 15.0 * .pi / 180.0
let rotationCenterOffset: CGFloat = width / 2 / tan(angle / 2) / height + 1 // use fixed value, e.g. 3, if you want, or use this to ensure that the corners of the two views just touch, but don't overlap
let rightTransform = CATransform3DMakeRotation(angle, 0, 0, 1)
let leftTransform = CATransform3DMakeRotation(-angle, 0, 0, 1)
transitionContext.containerView.insertSubview(to.view, aboveSubview: from.view)
// save the anchor and position
let anchorPoint = from.view.layer.anchorPoint
let position = from.view.layer.position
// prepare `to` layer for rotation
to.view.layer.anchorPoint = CGPoint(x: 0.5, y: rotationCenterOffset)
to.view.layer.position = CGPoint(x: width / 2, y: height * rotationCenterOffset)
to.view.layer.transform = self.isPresenting ? rightTransform : leftTransform
//to.view.layer.opacity = 0
// prepare `from` layer for rotation
from.view.layer.anchorPoint = CGPoint(x: 0.5, y: rotationCenterOffset)
from.view.layer.position = CGPoint(x: width / 2, y: height * rotationCenterOffset)
// rotate
UIView.animate(withDuration: duration, delay: delay, usingSpringWithDamping: damping, initialSpringVelocity: spring, animations: {
from.view.layer.transform = self.isPresenting ? leftTransform : rightTransform
to.view.layer.transform = CATransform3DIdentity
//to.view.layer.opacity = 1
//from.view.layer.opacity = 0
}, completion: { finished in
// restore the layers to their default configuration
for view in [to.view, from.view] {
view?.layer.transform = CATransform3DIdentity
view?.layer.anchorPoint = anchorPoint
view?.layer.position = position
//view?.layer.opacity = 1
}
transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
})
}
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return duration
}
}
I did a few other sundry changes, while I was here:
eliminated the semicolons;
eliminated one of the duration properties;
fixed the name of the parameter of the completion closure of animate method to finished rather than animated to more accurately reflect what it's real purpose is ... you could use _, too;
set the completeTransition based upon whether the animation was canceled or not (because if you ever make this interactive/cancelable, you don't want to always use true);
use .pi rather than M_PI;
I commented out my adjustments of opacity, but I generally do that to give the effect a touch more polish and to ensure that if you tweak angles so the views overlap, you don't get any weird artifacts of the other view just as the animation starts or just as its finishing; I've actually calculated the parameters so there's no overlapping, regardless of screen dimensions, so that wasn't necessary and I commented out the opacity lines, but you might consider using them, depending upon the desired effect.
Previously I showed how to simplify the process a bit, but the resulting effect wasn't exactly what you were looking for, but see the previous rendition of this answer if you're interested.

Your problem is a common one that happens when you do custom view controller transitions. I know this because I've done it a lot :)
You're looking for a problem in the pop transition, but the actual problem is in the push. If you inspect the view of the first controller in the stack after the transition, you'll see that it has an unusual frame, because you've messed about with its transform and anchor point and layer position and so forth. Really, you need to clean all that up before you end the transition, otherwise it bites you later on, as you're seeing in the pop.
A much simpler and safer way to do your custom transitions is to add a "canvas" view, then to that canvas add snapshots of your outgoing and incoming views instead and manipulate those. This means you have no cleanup at the end of the transition - just remove the canvas view. I've written about this technique here. For your case, I added the following convenience method:
extension UIView {
func snapshot(view: UIView, afterUpdates: Bool) -> UIView? {
guard let snapshot = view.snapshotView(afterScreenUpdates: afterUpdates) else { return nil }
self.addSubview(snapshot)
snapshot.frame = convert(view.bounds, from: view)
return snapshot
}
}
Then updated your transition code to move the snapshots around on a canvas view instead:
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
//Get references to the view hierarchy
let fromViewController: UIViewController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)!
let toViewController: UIViewController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)!
let sourceRect: CGRect = transitionContext.initialFrame(for: fromViewController)
let containerView: UIView = transitionContext.containerView
// The canvas is used for all animation and discarded at the end
let canvas = UIView(frame: containerView.bounds)
containerView.addSubview(canvas)
let fromView = transitionContext.view(forKey: .from)!
let toView = transitionContext.view(forKey: .to)!
toView.frame = transitionContext.finalFrame(for: toViewController)
toView.layoutIfNeeded()
let toSnap = canvas.snapshot(view: toView, afterUpdates: true)!
if self.isPresenting { // Push
//1. Settings for the fromVC ............................
// fromViewController.view.frame = sourceRect
let fromSnap = canvas.snapshot(view: fromView, afterUpdates: false)!
fromView.removeFromSuperview()
fromSnap.layer.anchorPoint = CGPoint(x: 0.5, y: 3);
fromSnap.layer.position = CGPoint(x: fromViewController.view.frame.size.width/2, y: fromViewController.view.frame.size.height * 3);
//2. Setup toVC view...........................
toSnap.layer.anchorPoint = CGPoint(x: 0.5, y: 3);
toSnap.layer.position = CGPoint(x: toViewController.view.frame.size.width/2, y: toViewController.view.frame.size.height * 3);
toSnap.transform = CGAffineTransform(rotationAngle: 15 * CGFloat(M_PI / 180));
//3. Perform the animation...............................
UIView.animate(withDuration: animationDuration, delay:delay, usingSpringWithDamping: damping, initialSpringVelocity: spring, options: [], animations: {
fromSnap.transform = CGAffineTransform(rotationAngle: -15 * CGFloat(M_PI / 180));
toSnap.transform = CGAffineTransform(rotationAngle: 0);
}, completion: {
(animated: Bool) -> () in
containerView.insertSubview(toViewController.view, belowSubview:canvas)
canvas.removeFromSuperview()
transitionContext.completeTransition(true)
})
} else { // Pop
//1. Settings for the fromVC ............................
fromViewController.view.frame = sourceRect
fromViewController.view.layer.anchorPoint = CGPoint(x: 0.5, y: 3);
fromViewController.view.layer.position = CGPoint(x: fromViewController.view.frame.size.width/2, y: fromViewController.view.frame.size.height * 3);
//2. Setup toVC view...........................
let toSnap = canvas.snapshot(view: toView, afterUpdates: true)!
toSnap.layer.anchorPoint = CGPoint(x: 0.5, y: 3);
toSnap.layer.position = CGPoint(x: toViewController.view.frame.size.width/2, y: toViewController.view.frame.size.height * 3);
toSnap.transform = CGAffineTransform(rotationAngle: -15 * CGFloat(M_PI / 180));
//3. Perform the animation...............................
UIView.animate(withDuration: animationDuration, delay:delay, usingSpringWithDamping: damping, initialSpringVelocity: spring, options: [], animations: {
fromViewController.view.transform = CGAffineTransform(rotationAngle: 15 * CGFloat(M_PI / 180));
toSnap.transform = CGAffineTransform(rotationAngle: 0);
}, completion: {
//When the animation is completed call completeTransition
(animated: Bool) -> () in
containerView.insertSubview(toViewController.view, belowSubview: canvas)
canvas.removeFromSuperview()
transitionContext.completeTransition(true)
})
}
}
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return duration;
}
}
This particular transition is pretty simple so it's not too difficult to reset the properties of the view frames, but if you do anything more complex then the canvas and snapshot approach works really well, so I tend to just use it everywhere.

Related

Identical SKActions performs slower than the other

I have a scene that acts as a menu page for a game and use a UI Button to activate an skaction that moves the camera on the scene and change the menu buttons using a UIView Container.
The code simply moves the camera from the far left to the far right. At the exact same speed. And yet for some reason, the movement to the right is slower than the left?
func MoveCameraToRight () {
let CameraWidth = StartingWidth * SceneCamera.xScale
let MoveRight = SKAction.move(to: CGPoint(x: (scene?.frame.maxX)!-(CameraWidth/2), y: (camera?.position.y)!), duration: 1)
camera?.run(MoveRight)
}
func MoveCameraToLeft () {
let CameraWidth = StartingWidth * SceneCamera.xScale
let MoveLeft = SKAction.move(to: CGPoint(x: (scene?.frame.minX)!-(CameraWidth/2), y: (camera?.position.y)!), duration: 1)
camera?.run(MoveLeft)
}
As you can see, the durations are exactly the same. Yet for some reason on an iPhone XS Max it appears to be significantly slower than the move left action?
Here's the code that makes those actions run:
#IBAction func Openlevels () {
let Game = (self.view as! SKView).scene as! MainMenuScene
Game.MoveCameraToRight()
LevelsContainer.isHidden = false
}
func HideLevels () {
let Game = (self.view as! SKView).scene as! MainMenuScene
Game.MoveCameraToLeft()
UIView.animate(withDuration: 0.25, animations: {
self.LevelsContainer.alpha = 0
}) { (complete: Bool) in
self.LevelsContainer.isHidden = true
}
}
And then on the container view to dismiss (and move camera back to the left):
#IBAction func Home () {
let Parent = self.parent as! MainMenu
Parent.HideLevels()
Parent.ShowMenu()
}
Both SKActions for the camera's position are set to 1, so why would one be slower than the other?
The solution was actually very simple:
let MoveLeft = SKAction.move(to: CGPoint(x: (scene?.frame.minX)!-(CameraWidth/2), y: (camera?.position.y)!), duration: 1)
Move left should be min + camWidth/2 not minus. The problem was it was telling the camera to go further than the distance of moving to the right.
let MoveRight = SKAction.move(to: CGPoint(x: (scene?.frame.maxX)!-(CameraWidth/2), y: (camera?.position.y)!), duration: 1)

How to properly transform UIView's scale on UIScrollView movement

To have a similar effect to Snapchat's HUD movement, I have created a movement of the HUD elements based on UIScollView's contentOffset. Edit: Link to the Github project.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
self.view.layoutIfNeeded()
let factor = scrollView.contentOffset.y / self.view.frame.height
self.transformElements(self.playButton,
0.45 + 0.55 * factor, // 0.45 = desired scale + 0.55 = 1.0 == original scale
Roots.screenSize.height - 280, // 280 == original Y
Roots.screenSize.height - 84, // 84 == minimum desired Y
factor)
}
func transformElements(_ element: UIView?,
_ scale: CGFloat,
_ originY: CGFloat,
_ desiredY: CGFloat,
_ factor: CGFloat) {
if let e = element {
e.transform = CGAffineTransform(scaleX: scale, y: scale) // this line lagging
let resultY = desiredY + (originY - desiredY) * factor
var frame = e.frame
frame.origin.y = resultY
e.frame = frame
}
}
With this code implemented the scroll as well as the transition appeared to be "laggy"/not smooth. (Physical iPhone 6S+ and 7+).
Deleting the following line: e.transform = CGAffineTransform(scaleX: scale, y: scale) erased the issue. The scroll as well as the Y-movement of the UIView object is smooth again.
What's the best approach to transform the scale of an object?
There are no Layout Constraints.
func setupPlayButton() {
let rect = CGRect(x: Roots.screenSize.width / 2 - 60,
y: Roots.screenSize.height - 280,
width: 120,
height: 120)
self.playButton = UIButton(frame: rect)
self.playButton.setImage(UIImage(named: "playBtn")?.withRenderingMode(.alwaysTemplate), for: .normal)
self.playButton.tintColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
self.view.addSubview(playButton)
}
This is happening because you are applying both: transform and frame. It will be smoother, if you apply only transform. Update your transformElements function as below:
func transformElements(_ element: UIView?,
_ scale: CGFloat,
_ originY: CGFloat,
_ desiredY: CGFloat,
_ factor: CGFloat) {
if let e = element {
e.transform = CGAffineTransform(scaleX: scale, y: scale).translatedBy(x: 0, y: desiredY * (1 - factor))
}
}
You can make these kinds of animation smoother by creating an animation then setting the speed of the layer to 0 and then changing the timeOffset of the layer.
first add the animation in the setupPlayButton method
let animation = CABasicAnimation.init(keyPath: "transform.scale")
animation.fromValue = 1.0
animation.toValue = 0.45
animation.duration = 1.0
//Set the speed of the layer to 0 so it doesn't animate until we tell it to
self.playButton.layer.speed = 0.0;
self.playButton.layer.add(animation, forKey: "transform");
next in the scrollViewDidScroll change the timeOffset of the layer and move the center of the button.
if let btn = self.playButton{
var factor:CGFloat = 1.0
if isVertically {
factor = scrollView.contentOffset.y / self.view.frame.height
} else {
factor = scrollView.contentOffset.x / Roots.screenSize.width
var transformedFractionalPage: CGFloat = 0
if factor > 1 {
transformedFractionalPage = 2 - factor
} else {
transformedFractionalPage = factor
}
factor = transformedFractionalPage;
}
//This will change the size
let timeOffset = CFTimeInterval(1-factor)
btn.layer.timeOffset = timeOffset
//now change the positions. only use center - not frame - so you don't mess up the animation. These numbers aren't right I don't know why
let desiredY = Roots.screenSize.height - (280-60);
let originY = Roots.screenSize.height - (84-60);
let resultY = desiredY + (originY - desiredY) * (1-factor)
btn.center = CGPoint.init(x: btn.center.x, y: resultY);
}
I couldn't quite get the position of the button correct - so something is wrong with my math there, but I trust you can fix it.
If you want more info about this technique see here: http://ronnqvi.st/controlling-animation-timing/

Continuous Rotation of NSImageView (so it appears to be animated)

SWIFT - OSX
I have a bunch of imageViews set in my Main.storyboard. I am trying to make them spin when the app starts and i would like them to indefinitely. I came across the roateByAngle(angle: CGFloat), but this doesn't animate it, instead it just jumps to the new angle.
I would like to make two functions, spinClockwise() and spinAntiClockwise() so I can just call them in the viewDidLoad and they will just keep turning.
Ive been playing with CATransform3DMakeRotation but cannot seem to get my desired results
let width = myImg.frame.width / 2
let height = myImg.frame.height / 2
myImg.layer?.transform = CATransform3DMakeRotation(180, width, height, 1)
Let me know if i can be more specific.
Thanks
You could add an extension of UIView or UIImageView like this:
extension UIView {
///The less is the timeToRotate, the more fast the animation is !
func spinClockwise(timeToRotate: Double) {
startRotate(CGFloat(M_PI_2), timeToRotate: timeToRotate)
}
///The less is the timeToRotate, the more fast the animation is !
func spinAntiClockwise(timeToRotate: Double) {
startRotate(CGFloat(-M_PI_2), timeToRotate: timeToRotate)
}
func startRotate(angle: CGFloat, timeToRotate: Double) {
UIView.animateWithDuration(timeToRotate, delay: 0.0, options:[UIViewAnimationOptions.CurveLinear, UIViewAnimationOptions.Repeat], animations: {
self.transform = CGAffineTransformMakeRotation(angle)
}, completion: nil)
print("Start rotating")
}
func stopAnimations() {
self.layer.removeAllAnimations()
print("Stop rotating")
}
}
So when you want to rotate your myImg, you just have to call:
myImg.spinClockwise(3)
And when you want to stop it:
myImg.stopAnimations()
NOTE:
I added a playground just so you can test it out ;)
Cheers!
EDIT:
My bad, Here is the example for NSView:
extension NSView {
///The less is the timeToRotate, the more fast the animation is !
func spinClockwise(timeToRotate: Double) {
startRotate(CGFloat(-1 * M_PI * 2.0), timeToRotate: timeToRotate)
}
///The less is the timeToRotate, the more fast the animation is !
func spinAntiClockwise(timeToRotate: Double) {
startRotate(CGFloat(M_PI * 2.0), timeToRotate: timeToRotate)
}
func startRotate(angle: CGFloat, timeToRotate: Double) {
let rotateAnimation = CABasicAnimation(keyPath: "transform.rotation")
rotateAnimation.fromValue = 0.0
rotateAnimation.toValue = angle
rotateAnimation.duration = timeToRotate
rotateAnimation.repeatCount = .infinity
self.layer?.addAnimation(rotateAnimation, forKey: nil)
Swift.print("Start rotating")
}
func stopAnimations() {
self.layer?.removeAllAnimations()
Swift.print("Stop rotating")
}
}
Important note: Now, after my tests, I noticed that you must set the anchor point of your NSView in the middle so that it can rotate around its center:
view.layer?.anchorPoint = CGPointMake(0.5, 0.5)
I added a new playground with the OSX example
For me, I could not change the anchor point. It was spinning around (0,0) which is bottom left. I moved the anchor point to (0.5, 0.5), but still no luck. Then I came accross with this answer. I modified my code like below, and it begins to rotate around itself. I observed a drawback though, the place of the view somehow shifted, but it can be fixed by trial and error, trying to get it to the right place.
extension NSView {
func startRotating(duration: Double = 1) {
let kAnimationKey = "rotation"
//self.wantsLayer = true
if layer?.animation(forKey: kAnimationKey) == nil {
var oldFrame = self.frame
self.layer?.anchorPoint = CGPoint(x: 1, y: 1)
self.frame = oldFrame
let animate = CABasicAnimation(keyPath: "transform.rotation")
animate.duration = duration
animate.repeatCount = Float.infinity
animate.fromValue = 0.0
animate.toValue = Double.pi * 2.0
self.layer?.add(animate, forKey: kAnimationKey)
oldFrame = self.frame
self.layer?.anchorPoint = CGPoint(x: 0.5, y: 0.5)
self.frame = oldFrame
}
}
}

how to replace panGestureDidMove with fixed start to end position

I have been using UIPanGestureRecognizer to recognise touches but I want to replace it with a fixed start to end position for my animation. Please see the code below:
panGestureDidMove:
func panGestureDidMove(gesture: UIPanGestureRecognizer) {
if gesture.state == .Ended || gesture.state == .Failed || gesture.state == .Cancelled {
} else {
let additionalHeight = max(gesture.translationInView(view).y, 0)
let waveHeight = min(additionalHeight * 0.6, maxWaveHeight)
let baseHeight = minimalHeight + additionalHeight - waveHeight
let locationX = gesture.locationInView(gesture.view).x
layoutControlPoints(baseHeight: baseHeight, waveHeight: waveHeight, locationX: locationX)
updateShapeLayer()
}
}
layoutControlPoints:
private func layoutControlPoints(baseHeight baseHeight: CGFloat, waveHeight: CGFloat, locationX: CGFloat) {
let width = view.bounds.width
let minLeftX = min((locationX - width / 2.0) * 0.28, 0.0)
let maxRightX = max(width + (locationX - width / 2.0) * 0.28, width)
let leftPartWidth = locationX - minLeftX
let rightPartWidth = maxRightX - locationX
l3ControlPointView.center = CGPoint(x: minLeftX, y: baseHeight)
l2ControlPointView.center = CGPoint(x: minLeftX + leftPartWidth * 0.44, y: baseHeight)
l1ControlPointView.center = CGPoint(x: minLeftX + leftPartWidth * 0.71, y: baseHeight + waveHeight * 0.64)
cControlPointView.center = CGPoint(x: locationX , y: baseHeight + waveHeight * 1.36)
r1ControlPointView.center = CGPoint(x: maxRightX - rightPartWidth * 0.71, y: baseHeight + waveHeight * 0.64)
r2ControlPointView.center = CGPoint(x: maxRightX - (rightPartWidth * 0.44), y: baseHeight)
r3ControlPointView.center = CGPoint(x: maxRightX, y: baseHeight)
}
I am trying to replace the panGestureDidMove with CABasicAnimation to animate the start to end position, something like the code below:
let startValue = CGPointMake(70.0, 50.0)
let endValue = CGPointMake(90.0, 150.0)
CATransaction.setDisableActions(true) //Not necessary
view.layer.bounds.size.height = endValue
let positionAnimation = CABasicAnimation(keyPath:"bounds.size.height")
positionAnimation.fromValue = startValue
positionAnimation.toValue = endValue
positionAnimation.duration = 2.0
view.layer.addAnimation(positionAnimation, forKey: "bounds")
A lot of things are affected as the position changes, how can I achieve this?
If you want fine control of animation, you can use CADisplayLink to do any custom layout or drawing prior to the screens pixel refresh. The run loop attempts to draw 60 frames per second, so with that in mind you can modify your code to simulate touch events.
You'll need to add some properties:
var displayLink:CADisplayLink? // let's us tap into the drawing run loop
var startTime:NSDate? // while let us keep track of how long we've been animating
var deltaX:CGFloat = 0.0 // how much we should update in the x direction between frames
var deltaY:CGFloat = 0.0 // same but in the y direction
var startValue = CGPointMake(70.0, 50.0) // where we want our touch simulation to start
var currentPoint = CGPoint(x:0.0, y:0.0)
let endValue = CGPointMake(90.0, 150.0) // where we want our touch simulation to end
Then whenever we want the animation to run we can call:
func animate()
{
let duration:CGFloat = 2.0
self.currentPoint = self.startValue
self.deltaX = (endValue.x - startValue.x) / (duration * 60.0) // 60 frames per second so getting the difference then dividing by the duration in seconds times 60
self.deltaY = (endValue.y - startValue.y) / (duration * 60.0)
self.startTime = NSDate()
self.displayLink = CADisplayLink(target: self, selector: #selector(self.performAnimation))
self.displayLink?.addToRunLoop(NSRunLoop.mainRunLoop(), forMode: NSDefaultRunLoopMode)
}
This will set up the display link and determine my how much our touch simulation should move between frames and begin calling the function that will be called prior to every drawing of the screen performAnimation:
func performAnimation(){
if self.startTime?.timeIntervalSinceNow > -2 {
self.updateViewsFor(self.currentPoint, translation: CGPoint(x:self.currentPoint.x - self.startValue.x, y: self.currentPoint.y - self.startValue.y))
self.currentPoint.x += self.deltaX
self.currentPoint.y += self.deltaY
}
else
{
self.displayLink?.removeFromRunLoop(NSRunLoop.mainRunLoop(), forMode: NSDefaultRunLoopMode)
self.currentPoint = self.startValue
}
}
Here we check if we are within the duration of the animation. Then call updateViewsFor(point:CGPoint,translation:CGPoint) which is what you had in your gesture target and then update our touch simulation if we're within it, else we just reset our properties.
Finally,
func updateViewsFor(point:CGPoint,translation:CGPoint)
{
let additionalHeight = max(translation.y, 0)
let waveHeight = min(additionalHeight * 0.6, maxWaveHeight)
let baseHeight = minimalHeight + additionalHeight - waveHeight
let locationX = point.x
layoutControlPoints(baseHeight: baseHeight, waveHeight: waveHeight, locationX: locationX)
updateShapeLayer()
}
You could also change your panGestureDidMove to:
#objc func panGestureDidMove(gesture: UIPanGestureRecognizer) {
if gesture.state == .Ended || gesture.state == .Failed || gesture.state == .Cancelled {
} else {
self.updateViewsFor(gesture.locationInView(gesture.view), translation: gesture.translationInView(view))
}
}
Edit
There is an easier way of doing this using keyframe animation. But I'm not sure it will animate your updateShapeLayer(). But for animating views we can write a function like:
func animate(fromPoint:CGPoint, toPoint:CGPoint, duration:NSTimeInterval)
{
// Essentually simulates the beginning of a touch event at our start point and the touch hasn't moved so tranlation is zero
self.updateViewsFor(fromPoint, translation: CGPointZero)
// Create our keyframe animation using UIView animation blocks
UIView.animateKeyframesWithDuration(duration, delay: 0.0, options: .CalculationModeLinear, animations: {
// We really only have one keyframe which is the end. We want everything in between animated.
// So start time zero and relativeDuration 1.0 because we want it to be 100% of the animation
UIView.addKeyframeWithRelativeStartTime(0.0, relativeDuration: 1.0, animations: {
// we want our "touch" to move to the endValue and the translation will just be the difference between end point and start point in the x and y direction.
self.updateViewsFor(toPoint, translation: CGPoint(x: toPoint.x - fromPoint.x, y: toPoint.y - fromPoint.y))
})
}, completion: { _ in
// do anything you need done after the animation
})
}
This will move the views into place then create a keyframe for where the views end up and animate everything in between. We could call it like:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
self.animate(CGPointMake(70.0, 50.0), toPoint: CGPointMake(90.0, 150.0), duration: 2.0)
}

Custom Flip Segue in Swift

Here's my Code for my Custom Segue
class FlipFromRightSegue: UIStoryboardSegue {
override func perform() {
let source:UIViewController = self.sourceViewController as UIViewController
let destination:UIViewController = self.destinationViewController as UIViewController
UIView.transitionWithView(source.view, duration: 1.0, options: .CurveEaseInOut | .TransitionFlipFromRight, animations: { () -> Void in
source.view.addSubview(destination.view)
}) { (finished) -> Void in
destination.view.removeFromSuperview()
source.presentViewController(destination, animated: false, completion: nil)
}
}
}
I thought this works but actually the view changes only when the segue is already performed. What should I do so that the view changes when the "Flip" is in the middle?
Thanks in advance.
As of iOS 7, we generally don't animate transitions using a custom segue. We'd either use a standard modal presentation, specifying a modalTransitionStyle (i.e. a fixed list of a few animations we can pick for our modal transitions), or you'd implement custom animation transitions. Both of those are described below:
If you are simply presenting another view controller's view, the simple solution for changing the animation to a flip is by setting the modalTransitionStyle in the destination view controller. You can do this entirely in Interface Builder under the segue's properties.
If you want to do it programmatically, in the destination controller you could do the following in Swift 3:
override func viewDidLoad() {
super.viewDidLoad()
modalTransitionStyle = .flipHorizontal // use `.FlipHorizontal` in Swift 2
}
Then, when you call show/showViewController or present/presentViewController, and your presentation will be performed with horizontal flip. And, when you dismiss the view controller, the animation is reversed automatically for you.
If you need more control, in iOS 7 and later, you would use custom animation transitions, in which you'd specify a modalPresentationStyle of .custom. For example, in Swift 3:
class SecondViewController: UIViewController {
let customTransitionDelegate = TransitioningDelegate()
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
modalPresentationStyle = .custom // use `.Custom` in Swift 2
transitioningDelegate = customTransitionDelegate
}
...
}
That specifies the UIViewControllerTransitioningDelegate that would instantiate the animation controller. For example, in Swift 3:
class TransitioningDelegate: NSObject, UIViewControllerTransitioningDelegate {
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
return AnimationController(transitionType: .presenting)
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
return AnimationController(transitionType: .dismissing)
}
}
And the animation controller would simply do .transitionFlipFromRight is a presentation, or .transitionFlipFromLeft if dismissing in Swift 3:
class AnimationController: NSObject, UIViewControllerAnimatedTransitioning {
enum TransitionType {
case presenting
case dismissing
}
var animationTransitionOptions: UIViewAnimationOptions
init(transitionType: TransitionType) {
switch transitionType {
case .presenting:
animationTransitionOptions = .transitionFlipFromRight
case .dismissing:
animationTransitionOptions = .transitionFlipFromLeft
}
super.init()
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
//let inView = transitionContext.containerView
let toView = transitionContext.viewController(forKey: .to)?.view
let fromView = transitionContext.viewController(forKey: .from)?.view
UIView.transition(from: fromView!, to: toView!, duration: transitionDuration(using: transitionContext), options: animationTransitionOptions.union(.curveEaseInOut)) { finished in
transitionContext.completeTransition(true)
}
}
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 1.0
}
}
For more information on the custom transitions introduced in iOS 7, see WWDC 2013 video Custom Transitions Using View Controllers.
If should be acknowledged that the above AnimationController is actually a over-simplification, because we're using transform(from:to:...). That results in an animation that isn't cancelable (in case you're using interactive transition). It's also removing the "from" view itself, and as of iOS 8, that's now really the job of the presentation controller.
So, you really want to do the flip animation using UIView.animate API. I apologize because the following involves using some unintuitive CATransform3D in key frame animations, but it results in a flip animation that can then be subjected to cancelable interactive transitions.
So, in Swift 3:
class AnimationController: NSObject, UIViewControllerAnimatedTransitioning {
enum TransitionType {
case presenting
case dismissing
}
let transitionType: TransitionType
init(transitionType: TransitionType) {
self.transitionType = transitionType
super.init()
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let inView = transitionContext.containerView
let toView = transitionContext.view(forKey: .to)!
let fromView = transitionContext.view(forKey: .from)!
var frame = inView.bounds
func flipTransform(angle: CGFloat, offset: CGFloat = 0) -> CATransform3D {
var transform = CATransform3DMakeTranslation(offset, 0, 0)
transform.m34 = -1.0 / 1600
transform = CATransform3DRotate(transform, angle, 0, 1, 0)
return transform
}
toView.frame = inView.bounds
toView.alpha = 0
let transformFromStart: CATransform3D
let transformFromEnd: CATransform3D
let transformFromMiddle: CATransform3D
let transformToStart: CATransform3D
let transformToMiddle: CATransform3D
let transformToEnd: CATransform3D
switch transitionType {
case .presenting:
transformFromStart = flipTransform(angle: 0, offset: inView.bounds.size.width / 2)
transformFromEnd = flipTransform(angle: -.pi, offset: inView.bounds.size.width / 2)
transformFromMiddle = flipTransform(angle: -.pi / 2)
transformToStart = flipTransform(angle: .pi, offset: -inView.bounds.size.width / 2)
transformToMiddle = flipTransform(angle: .pi / 2)
transformToEnd = flipTransform(angle: 0, offset: -inView.bounds.size.width / 2)
toView.layer.anchorPoint = CGPoint(x: 0, y: 0.5)
fromView.layer.anchorPoint = CGPoint(x: 1, y: 0.5)
case .dismissing:
transformFromStart = flipTransform(angle: 0, offset: -inView.bounds.size.width / 2)
transformFromEnd = flipTransform(angle: .pi, offset: -inView.bounds.size.width / 2)
transformFromMiddle = flipTransform(angle: .pi / 2)
transformToStart = flipTransform(angle: -.pi, offset: inView.bounds.size.width / 2)
transformToMiddle = flipTransform(angle: -.pi / 2)
transformToEnd = flipTransform(angle: 0, offset: inView.bounds.size.width / 2)
toView.layer.anchorPoint = CGPoint(x: 1, y: 0.5)
fromView.layer.anchorPoint = CGPoint(x: 0, y: 0.5)
}
toView.layer.transform = transformToStart
fromView.layer.transform = transformFromStart
inView.addSubview(toView)
UIView.animateKeyframes(withDuration: self.transitionDuration(using: transitionContext), delay: 0, options: [], animations: {
UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 0.0) {
toView.alpha = 0
fromView.alpha = 1
}
UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 0.5) {
toView.layer.transform = transformToMiddle
fromView.layer.transform = transformFromMiddle
}
UIView.addKeyframe(withRelativeStartTime: 0.5, relativeDuration: 0.0) {
toView.alpha = 1
fromView.alpha = 0
}
UIView.addKeyframe(withRelativeStartTime: 0.5, relativeDuration: 0.5) {
toView.layer.transform = transformToEnd
fromView.layer.transform = transformFromEnd
}
}, completion: { finished in
toView.layer.transform = CATransform3DIdentity
fromView.layer.transform = CATransform3DIdentity
toView.layer.anchorPoint = CGPoint(x: 0.5, y: 0.5)
fromView.layer.anchorPoint = CGPoint(x: 0.5, y: 0.5)
transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
})
}
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 1.0
}
}
FYI, iOS 8 extends the custom transition model with presentation controllers. For more information, see WWDC 2014 video A Look Inside Presentation Controllers.
Anyway, if, at the end of the transition, the "from" view is no longer visible, you'd instruct your presentation controller to remove it from the view hierarchy, e.g.:
class PresentationController: UIPresentationController {
override var shouldRemovePresentersView: Bool { return true }
}
And, obviously, you have to inform your TransitioningDelegate of this presentation controller:
class TransitioningDelegate: NSObject, UIViewControllerTransitioningDelegate {
...
func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
return PresentationController(presentedViewController: presented, presenting: presenting)
}
}
This answer has been updated for Swift 3. Please refer to the previous revision of this answer if you want to see the Swift 2 implementation.