Custom ViewController Transition always starts from the center - ios

I'm trying to create a custom ViewController transition.
I'm basically trying to replicate Apple's animation when launching an app, the zoom in starts from the application's position.
I have a collection view, and when the user taps on a cell, I get the cell's point (which does work), and I'm trying to set the animation starting point to be that point.
And while I can see that I get the point the zoom in effect always starts from the center of the screen. This is what I have as the custom transition:
enum ZoomTransitionMode: Int {
case present, dismiss, pop
}
class ZoomTransition: NSObject{
var zoom = UIView()
var originFrame = CGRect.zero
var startingPoint: CGPoint!
var zoomColor = UIColor.appWhite
var animationDuration = 0.3
var transitionMode: ZoomTransitionMode = .present
}
extension ZoomTransition: UIViewControllerAnimatedTransitioning {
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return animationDuration
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let containerView = transitionContext.containerView
switch transitionMode {
case .present:
if let presentedView = transitionContext.view(forKey: UITransitionContextViewKey.to) {
print(startingPoint)
zoom = UIView()
zoom.frame = CGRect(origin: startingPoint, size: CGSize(width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height))
zoom.layer.cornerRadius = 20
zoom.backgroundColor = zoomColor
zoom.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
containerView.addSubview(zoom)
presentedView.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
presentedView.frame = UIScreen.main.bounds
presentedView.alpha = 0
presentedView.backgroundColor = .systemGreen
containerView.addSubview(presentedView)
containerView.bringSubviewToFront(presentedView)
UIView.animate(withDuration: 10, animations: {
self.zoom.transform = CGAffineTransform.identity
presentedView.transform = CGAffineTransform.identity
presentedView.alpha = 1
}) { (didSuccessed) in
transitionContext.completeTransition(didSuccessed)
}
}
default:
return
}
}
I also tried setting the zoom's and the presentedView center as the starting point, but still, the animation starts from the center of the screen instead of the starting point.

Related

How to combine translate and rotate transform animation in Swift(iOS)?

I created a small UIView object, First I use translate transform move UIView to new location, after animation stop, I want UIView rotate in new location, so the code is:
//circle2 is UIView
UIView.animate(withDuration: 1, delay:0,options:[.curveLinear],animations:{
self.circle2.transform=CGAffineTransform(translationX: 0, y: 35)
},completion: {(result) in
UIView.animate(withDuration: 1, delay:0,options:[.repeat],animations: {
self.circle2.transform=CGAffineTransform(rotationAngle: CGFloat.pi)
//self.circle2.transform=CGAffineTransform(rotationAngle: CGFloat.pi).translatedBy(x: 0, y: 35)
//self.circle2.transform=CGAffineTransform(translationX: 0, y: 35).rotated(by: CGFloat.pi)
//self.circle2.transform=CGAffineTransform(rotationAngle: CGFloat.pi).concatenating(CGAffineTransform(translationX: 0, y: 35))
})
})
But I found that when UIView is rotating, it also move upward to origin position.
I try three another combination method, none of then works....
Two of your examples do work but animation may be different than what you expected. You will need to do it manually. It is painful but please try and examine the following code:
private func startAnimation()
let startTime: Date = .init()
let translationDuration: TimeInterval = 1.0
var rotation: CGFloat = 0.0
let rotationDuration: TimeInterval = 1.0
var translation: CGPoint = .zero
func refreshView(_ controller: ViewController) {
controller.circle2.transform = CGAffineTransform(rotationAngle: rotation).concatenating(CGAffineTransform(translationX: translation.x, y: translation.y))
}
Timer.scheduledTimer(withTimeInterval: 1.0/60.0, repeats: true) { timer in
let now: Date = .init()
let scale: Double = (now.timeIntervalSince(startTime))/translationDuration
guard scale > 0.0 else { return } // Waiting part if delay is applied
if scale < 1.0 {
// Animate the view
translation = CGPoint(x: 0.0, y: 35.0*scale)
refreshView(self)
} else {
// Animation ended
timer.invalidate()
translation = CGPoint(x: 0.0, y: 35.0)
refreshView(self)
var rotationStartTime: Date = .init()
Timer.scheduledTimer(withTimeInterval: 1.0/60.0, repeats: true) { [weak self] timer in
guard let self = self else { timer.invalidate(); return }
let now: Date = .init()
let scale: Double = (now.timeIntervalSince(rotationStartTime))/rotationDuration
guard scale > 0.0 else { return } // Waiting part if delay is applied
if scale < 1.0 {
// Animate the view
rotation = .pi * CGFloat(scale)
refreshView(self)
} else {
// Animation ended
rotation = 0.0
rotationStartTime = .init()
refreshView(self)
}
}
}
}
}
If you have a need to stop the animation then you will need some references to timers.

How to make transition of a ViewController from Bottom to Top?

So here is a class for Slide in transition which adds a ViewController with animation from left to right and it works flawlessly I want a transition from bottom to top.
import UIKit
class SlideInTransition: NSObject, UIViewControllerAnimatedTransitioning {
var isPresenting = false
let dimmingView = UIView()
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 0.3
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
guard let toViewController = transitionContext.viewController(forKey: .to),
let fromViewController = transitionContext.viewController(forKey: .from) else { return }
let containerView = transitionContext.containerView
let finalWidth = toViewController.view.bounds.width * 0.8
let finalHeight = toViewController.view.bounds.height
if isPresenting {
// Add dimming view
dimmingView.backgroundColor = .black
dimmingView.alpha = 0.0
containerView.addSubview(dimmingView)
dimmingView.frame = containerView.bounds
// Add menu view controller to container
containerView.addSubview(toViewController.view)
// Init frame off the screen
toViewController.view.frame = CGRect(x: -finalWidth, y: 0, width: finalWidth, height: finalHeight)
}
// Move on screen
let transform = {
self.dimmingView.alpha = 0.5
toViewController.view.transform = CGAffineTransform(translationX: finalWidth, y: 0)
}
// Move back off screen
let identity = {
self.dimmingView.alpha = 0.0
fromViewController.view.transform = .identity
}
// Animation of the transition
let duration = transitionDuration(using: transitionContext)
let isCancelled = transitionContext.transitionWasCancelled
UIView.animate(withDuration: duration, animations: {
self.isPresenting ? transform() : identity()
}) { (_) in
transitionContext.completeTransition(!isCancelled)
}
}
}
To be honest I copied this code from somewhere a while ago and I don't have a source of it.
I'm fairly new to iOS so any help would be appreciated.
Try this,
class SlideInTransition: NSObject, UIViewControllerAnimatedTransitioning {
var isPresenting = false
let dimmingView = UIView()
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 0.3
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
guard let toViewController = transitionContext.viewController(forKey: .to),
let fromViewController = transitionContext.viewController(forKey: .from) else { return }
let containerView = transitionContext.containerView
let finalWidth = toViewController.view.bounds.width
let finalHeight = toViewController.view.bounds.height * 0.8
if isPresenting {
// Add dimming view
dimmingView.backgroundColor = .black
dimmingView.alpha = 0.0
containerView.addSubview(dimmingView)
dimmingView.frame = containerView.bounds
// Add menu view controller to container
containerView.addSubview(toViewController.view)
// Init frame off the screen
toViewController.view.frame = CGRect(x: 0, y: finalHeight, width: finalWidth, height: finalHeight)
}
// Move on screen
let transform = {
self.dimmingView.alpha = 0.5
toViewController.view.transform = CGAffineTransform(translationX: 0, y: -finalHeight)
}
// Move back off screen
let identity = {
self.dimmingView.alpha = 0.0
fromViewController.view.transform = .identity
}
// Animation of the transition
let duration = transitionDuration(using: transitionContext)
let isCancelled = transitionContext.transitionWasCancelled
UIView.animate(withDuration: duration, animations: {
self.isPresenting ? transform() : identity()
}) { (_) in
transitionContext.completeTransition(!isCancelled)
}
}
}

Present UIViewController from frame

I am showing image slider as in this order.
UIViewController > UITableview > UITableviewCell > UICollectionview > UICollectionViewCell > UIImage
User can slide UICollectionview and view images.Problem is that I need to do animation. When user tap on my UICollectionviewCell, it should animate from that cell and show full screen as in this library.
https://github.com/suzuki-0000/SKPhotoBrowser
Problem is that I need to use MWPhotoBrowser and I can't present like that.
I am thinking to use hero animation library as well.
https://github.com/lkzhao/Hero
But my view hierachy and their example is different. How shall I do?
You have to use custom transition
Reference:
https://developer.apple.com/library/content/featuredarticles/ViewControllerPGforiPhoneOS/CustomizingtheTransitionAnimations.html
Code Work
On image selection
add in VC_A
var selectedImage: UIImageView?
let transition = PopAnimator()
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size, with: coordinator)
coordinator.animate(
alongsideTransition: {context in
self.bgImage.alpha = (size.width>size.height) ? 0.25 : 0.55
self.positionListItems()
},
completion: nil
)
}
//position all images inside the list
func positionListItems() {
let listHeight = listView.frame.height
let itemHeight: CGFloat = listHeight * 1.33
let aspectRatio = UIScreen.main.bounds.height / UIScreen.main.bounds.width
let itemWidth: CGFloat = itemHeight / aspectRatio
let horizontalPadding: CGFloat = 10.0
for i in herbs.indices {
let imageView = listView.viewWithTag(i) as! UIImageView
imageView.frame = CGRect(
x: CGFloat(i) * itemWidth + CGFloat(i+1) * horizontalPadding, y: 0.0,
width: itemWidth, height: itemHeight)
}
listView.contentSize = CGSize(
width: CGFloat(herbs.count) * (itemWidth + horizontalPadding) + horizontalPadding,
height: 0)
}
// On image selection
VC_B.transitioningDelegate = self
present(VC_B, animated: true, completion: nil)
// add extension
extension VC_A: UIViewControllerTransitioningDelegate {
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.originFrame = selectedImage!.superview!.convert(selectedImage!.frame, to: nil)
transition.presenting = true
selectedImage!.isHidden = true
return transition
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.presenting = false
return transition
}
}
and animation class
class PopAnimator: NSObject, UIViewControllerAnimatedTransitioning {
let duration = 1.0
var presenting = true
var originFrame = CGRect.zero
var dismissCompletion: (()->Void)?
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return duration
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let containerView = transitionContext.containerView
let toView = transitionContext.view(forKey: .to)!
let herbView = presenting ? toView : transitionContext.view(forKey: .from)!
let initialFrame = presenting ? originFrame : herbView.frame
let finalFrame = presenting ? herbView.frame : originFrame
let xScaleFactor = presenting ?
initialFrame.width / finalFrame.width :
finalFrame.width / initialFrame.width
let yScaleFactor = presenting ?
initialFrame.height / finalFrame.height :
finalFrame.height / initialFrame.height
let scaleTransform = CGAffineTransform(scaleX: xScaleFactor, y: yScaleFactor)
if presenting {
herbView.transform = scaleTransform
herbView.center = CGPoint(
x: initialFrame.midX,
y: initialFrame.midY)
herbView.clipsToBounds = true
}
containerView.addSubview(toView)
containerView.bringSubview(toFront: herbView)
UIView.animate(withDuration: duration, delay:0.0, usingSpringWithDamping: 0.4,
initialSpringVelocity: 0.0,
animations: {
herbView.transform = self.presenting ?
CGAffineTransform.identity : scaleTransform
herbView.center = CGPoint(x: finalFrame.midX,
y: finalFrame.midY)
},
completion:{_ in
if !self.presenting {
self.dismissCompletion?()
}
transitionContext.completeTransition(true)
}
)
}
}

Display 2 view controllers at the same time with animation

I'm following this awesome video to create a custom transition for my project, because I'm developing for the iPad, so instead of presenting destination view controller full screen, I want to have it occupy half of the screen like this:
My code of the custom transition class is:
class CircularTransition: NSObject {
var circle = UIView()
var startingPoint = CGPoint.zero {
didSet {
circle.center = startingPoint
}
}
var circleColor = UIColor.white
var duration = 0.4
enum circularTransitionMode: Int {
case present, dismiss
}
var transitionMode = circularTransitionMode.present
}
extension CircularTransition: UIViewControllerAnimatedTransitioning {
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return duration
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let containerView = transitionContext.containerView
if transitionMode == .present {
if let presentedView = transitionContext.view(forKey: UITransitionContextViewKey.to) {
var viewCenter = presentedView.center
var viewSize = presentedView.frame.size
if UIDevice.current.userInterfaceIdiom == .pad {
viewCenter = CGPoint(x: viewCenter.x, y: viewSize.height)
viewSize = CGSize(width: viewSize.width, height: viewSize.height)
}
circle = UIView()
circle.frame = frameForCircle(withViewCenter: viewCenter, size: viewSize, startPoint: startingPoint)
circle.layer.cornerRadius = circle.frame.size.width / 2
circle.center = startingPoint
circle.backgroundColor = circleColor
circle.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
containerView.addSubview(circle)
presentedView.center = startingPoint
presentedView.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
presentedView.alpha = 0
containerView.addSubview(presentedView)
UIView.animate(withDuration: duration, animations: {
self.circle.transform = CGAffineTransform.identity
presentedView.transform = CGAffineTransform.identity
presentedView.alpha = 1
presentedView.center = viewCenter
}, completion: {(sucess: Bool) in transitionContext.completeTransition(sucess)})
}
} else {
if let returningView = transitionContext.view(forKey: UITransitionContextViewKey.from) {
let viewCenter = returningView.center
let viewSize = returningView.frame.size
circle.frame = frameForCircle(withViewCenter: viewCenter, size: viewSize, startPoint: startingPoint)
circle.layer.cornerRadius = circle.frame.size.width / 2
circle.center = startingPoint
UIView.animate(withDuration: duration + 0.1, animations: {
self.circle.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
returningView.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
returningView.center = self.startingPoint
returningView.alpha = 0
}, completion: {(success: Bool) in
returningView.center = viewCenter
returningView.removeFromSuperview()
self.circle.removeFromSuperview()
transitionContext.completeTransition(success)
})
}
}
}
func frameForCircle(withViewCenter viewCenter: CGPoint, size viewSize: CGSize, startPoint: CGPoint) -> CGRect {
let xLength = fmax(startingPoint.x, viewSize.width - startingPoint.x)
let yLength = fmax(startingPoint.y, viewSize.height - startingPoint.y)
let offsetVector = sqrt(xLength * xLength + yLength * yLength) * 2
let size = CGSize(width: offsetVector, height: offsetVector)
return CGRect(origin: CGPoint.zero, size: size)
}
}
And the part of code in my view controller:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let secondVC = segue.destination as! ResultViewController
secondVC.transitioningDelegate = self
secondVC.modalPresentationStyle = .custom
}
// MARK: - Animation
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transtion.transitionMode = .dismiss
transtion.startingPoint = calculateButton.center
transtion.circleColor = calculateButton.backgroundColor!
return transtion
}
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transtion.transitionMode = .present
transtion.startingPoint = calculateButton.center
transtion.circleColor = calculateButton.backgroundColor!
return transtion
}
But the controller shows up full screen.
You may try the two different Container View for half of top and bottom.
then give animation on it...
So I have finished creating my answer, It takes a different approach than the other answers so bear with me.
Instead of adding a container view what I figured would be the best way was to create a UIViewController subclass (which I called CircleDisplayViewController). Then all your VCs that need to have this functionality could inherit from it (rather than from UIViewController).
This way all your logic for presenting and dismissing ResultViewController is handled in one place and can be used anywhere in your app.
The way your VCs can use it is like so:
class AnyViewController: CircleDisplayViewController {
/* Only inherit from CircleDisplayViewController,
otherwise you inherit from UIViewController twice */
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func showCircle(_ sender: UIButton) {
openCircle(withCenter: sender.center, radius: nil, resultDataSource: calculator!.iterateWPItems())
//I'll get to this stuff in just a minute
//Edit: from talking to Bright Future in chat I saw that resultViewController needs to be setup with calculator!.iterateWPItems()
}
}
Where showCircle will present your ResultViewController using the transitioning delegate with the circle center at the sending UIButtons center.
The CircleDisplayViewController subclass is this:
class CircleDisplayViewController: UIViewController, UIViewControllerTransitioningDelegate, ResultDelegate {
private enum CircleState {
case collapsed, visible
}
private var circleState: CircleState = .collapsed
private var resultViewController: ResultViewController!
private lazy var transition = CircularTransition()
func openCircle(withCenter center: CGPoint, radius: CGFloat?, resultDataSource: ([Items], Int, String)) {
let circleCollapsed = (circleState == .collapsed)
DispatchQueue.main.async { () -> Void in
if circleCollapsed {
self.addCircle(withCenter: center, radius: radius, resultDataSource: resultDataSource)
}
}
}
private func addCircle(withCenter circleCenter: CGPoint, radius: CGFloat?, resultDataSource: ([Items], Int, String])) {
var circleRadius: CGFloat!
if radius == nil {
circleRadius = view.frame.size.height/2.0
} else {
circleRadius = radius
}
//instantiate resultViewController here, and setup delegate etc.
resultViewController = UIStoryboard.resultViewController()
resultViewController.transitioningDelegate = self
resultViewController.delegate = self
resultViewController.modalPresentationStyle = .custom
//setup any values for resultViewController here
resultViewController.dataSource = resultDataSource
//then set the frame of resultViewController (while also setting endFrame)
let resultOrigin = CGPoint(x: 0.0, y: circleCenter.y - circleRadius)
let resultSize = CGSize(width: view.frame.size.width, height: (view.frame.size.height - circleCenter.y) + circleRadius)
resultViewController.view.frame = CGRect(origin: resultOrigin, size: resultSize)
resultViewController.endframe = CGRect(origin: resultOrigin, size: resultSize)
transition.circle = UIView()
transition.startingPoint = circleCenter
transition.radius = circleRadius
transition.circle.frame = circleFrame(radius: transition.radius, center: transition.startingPoint)
present(resultViewController, animated: true, completion: nil)
}
func collapseCircle() { //THIS IS THE RESULT DELEGATE FUNCTIONS
dismiss(animated: true) {
self.resultViewController = nil
}
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.transitionMode = .dismiss
transition.circleColor = UIColor.red
return transition
}
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.transitionMode = .present
transition.circleColor = UIColor.red
return transition
}
func circleFrame(radius: CGFloat, center: CGPoint) -> CGRect {
let circleOrigin = CGPoint(x: center.x - radius, y: center.y - radius)
let circleSize = CGSize(width: radius*2, height: radius*2)
return CGRect(origin: circleOrigin, size: circleSize)
}
}
public extension UIStoryboard {
class func mainStoryboard() -> UIStoryboard { return UIStoryboard(name: "Main", bundle: Bundle.main) }
}
private extension UIStoryboard {
class func resultViewController() -> ResultViewController {
return mainStoryboard().instantiateViewController(withIdentifier: "/* Your ID for ResultViewController */") as! ResultViewController
}
}
The only function that is called by the VCs that inherit from DisplayCircleViewController is openCircle, openCircle has a circleCenter argument (which should be your button center I'm guessing), an optional radius argument (if this is nil then a default value of half the view height is taken, and then whatever else you need to setup ResultViewController.
In the addCircle func there is some important stuff:
you setup ResultViewController however you have to before presenting (like you would in prepare for segue),
then setup the frame for it (I tried to make it the area of the circle that is visible but it is quite rough here, might be worth playing around with),
then this is where I reset the transition circle (rather than in the transition class), so that I could set the circle starting point, radius and frame here.
then just a normal present.
If you haven't set an identifier for ResultViewController you need to for this (see the UIStoryboard extensions)
I also changed the TransitioningDelegate functions so you don't set the circle center, this is because to keep it generic I put that responsibility to the ViewController that inherits from this one. (see top bit of code)
Finally I changed the CircularTransition class
I added a variable:
var radius: CGFloat = 0.0 //set in the addCircle function above
and changed animateTransition:
(removed the commented out lines):
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let containerView = transitionContext.containerView
if transitionMode == .present {
if let presentedView = transitionContext.view(forKey: UITransitionContextViewKey.to) {
...
// circle = UIView()
// circle.frame = frameForCircle(withViewCenter: viewCenter, size: viewSize, startPoint: startingPoint)
circle.layer.cornerRadius = radius
...
}
} else {
if let returningView = transitionContext.view(forKey: UITransitionContextViewKey.from) {
...
// circle.frame = frameForCircle(withViewCenter: viewCenter, size: viewSize, startPoint: startingPoint)
...
}
}
}
Finally I made a protocol so that ResultViewController could dismiss the circle
protocol ResultDelegate: class {
func collapseCircle()
}
class ResultViewController: UIViewController {
weak var delegate: ResultDelegate!
var endFrame: CGRect!
var dataSource: ([Items], Int, String)! // same as in Bright Future's case
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewDidLayoutSubviews() {
if endFrame != nil {
view.frame = endFrame
}
}
#IBAction func closeResult(_ sender: UIButton) {
delegate.collapseCircle()
}
}
This has turned out to be quite a huge answer, sorry about that, I wrote it in a bit a of rush so if anything is not clear just say.
Hope this helps!
Edit: I found the problem, iOS 10 has changed the way they layout views, so to fix this I added an endFrame property to ResultViewController and set it's views frame to that in viewDidLayoutSubviews. I also set both the frame and endFrame at the same time in addCircle. I changed the code above to reflect the changes. It's not ideal but I'll have another look later to see if there is a better fix.
Edit: this is what it looks like open for me
Thanks to everyone for the suggestions, I tried to use a container view, here's how I did it:
First I added a containerView property in CircularTransition class:
class CircularTransition: NSObject {
...
var containerView: UIView
init(containerView: UIView) {
self.containerView = containerView
}
...
}
Then commented out these code in its extension:
// let containerView = transitionContext.containerView
// if UIDevice.current.userInterfaceIdiom == .pad {
// viewCenter = CGPoint(x: viewCenter.x, y: viewSize.height)
// viewSize = CGSize(width: viewSize.width, height: viewSize.height)
// }
In my mainViewController, I added a method to add a container view:
func addContainerView() {
let containerView = UIView()
containerView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(containerView)
NSLayoutConstraint.activate([
containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10),
containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10),
containerView.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.5),
containerView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -10),
])
transtion.containerView = containerView
}
The reason I don't use story board is, if I put the animated view controller (ResultViewController) in the container view, it gets loaded whenever mainViewController is loaded, however, ResultViewController needs the data from prepareForSegue, thus it'll crash.
Then I changed a little bit in prepareForSegue:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
transtion.containerView = view
if UIDevice.current.userInterfaceIdiom == .pad {
addContainerView()
}
let secondVC = segue.destination as! ResultViewController
secondVC.transitioningDelegate = self
secondVC.modalPresentationStyle = .custom
secondVC.dataSource = calculator!.iterateWPItems().0
}
And created CircularTransition class this way in mainViewController:
let transtion = CircularTransition(containerView: UIView())
That's basically all I did, I could display the gorgeous dual vc view
on the iPad, however, the return transition doesn't work, I still
haven't figured out what caused that.
Hi i did some changes in your animateTransition method try this out. You might have to play a little bit with withRelativeStartTime of the animations and the frame and center to perfect the animation. But i guess this should get you started.
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let containerView = transitionContext.containerView
if transitionMode == .present {
if let presentedView = transitionContext.view(forKey: UITransitionContextViewKey.to) {
var viewCenter = presentedView.center
var viewSize = presentedView.frame.size
if UIDevice.current.userInterfaceIdiom == .pad {
viewCenter = CGPoint(x: viewCenter.x, y: viewSize.height)
viewSize = CGSize(width: viewSize.width, height: viewSize.height)
}
circle = UIView()
circle.frame = frameForCircle(withViewCenter: viewCenter, size: viewSize, startPoint: startingPoint)
circle.layer.cornerRadius = circle.frame.size.width / 2
circle.center = startingPoint
circle.backgroundColor = circleColor
circle.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
circle.layer.masksToBounds = true
containerView.addSubview(circle)
presentedView.center = startingPoint
presentedView.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
presentedView.alpha = 0
containerView.addSubview(presentedView)
UIView.animateKeyframes(withDuration: duration, delay: 0, options: .calculationModeLinear, animations: {
UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 1, animations: {
self.circle.transform = CGAffineTransform(scaleX: 0.5, y: 0.5)
presentedView.alpha = 1
})
UIView.addKeyframe(withRelativeStartTime: 0.19, relativeDuration: 1, animations: {
presentedView.transform = CGAffineTransform(scaleX: 1, y: 1)
presentedView.frame = CGRect(x: 0, y: (containerView.frame.size.height / 2)+10, width: containerView.frame.size.width, height: containerView.frame.size.height*0.5)
})
}, completion: { (sucess) in
transitionContext.completeTransition(sucess)
})
}
} else {
if let returningView = transitionContext.view(forKey: UITransitionContextViewKey.from) {
let viewCenter = returningView.center
let viewSize = returningView.frame.size
circle.frame = frameForCircle(withViewCenter: viewCenter, size: viewSize, startPoint: startingPoint)
circle.layer.cornerRadius = circle.frame.size.width / 2
circle.center = startingPoint
UIView.animate(withDuration: duration + 0.1, animations: {
self.circle.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
returningView.transform = CGAffineTransform(scaleX: 0.001, y: 0.001)
returningView.center = self.startingPoint
returningView.alpha = 0
}, completion: {(success: Bool) in
returningView.center = viewCenter
returningView.removeFromSuperview()
self.circle.removeFromSuperview()
transitionContext.completeTransition(success)
})
}
}
}
Hope this helps.

How to make a custom transition behave like a fall under the gravity?

The effect could be implemented like the following code in animateTransition method:
UIView.animateWithDuration(duration,
delay: 0,
usingSpringWithDamping: 0.3,
initialSpringVelocity: 0.0,
options: .CurveLinear,
animations: {
fromVC.view.alpha = 0.5
toVC.view.frame = finalFrame
},
completion: {_ -> () in
fromVC.view.alpha = 1.0
transitionContext.completeTransition(true)
})
But how could I implement it using gravity and collision behaviors(UIGravityBehavior, UICollisionBehavior)?
And a more general question may be "How to use the UIDynamicAnimator to customize the transitions between UIViewControllers?"
You can find the solution under the post Custom view controller transitions with UIDynamic behaviors by dasdom.
And the Swift code:
func transitionDuration(transitionContext: UIViewControllerContextTransitioning!) -> NSTimeInterval {
return 1.0
}
func animateTransition(transitionContext: UIViewControllerContextTransitioning!) {
// 1. Prepare for the required components
let toVC = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)
let finalFrame = transitionContext.finalFrameForViewController(toVC)
let containerView = transitionContext.containerView()
let screenBounds = UIScreen.mainScreen().bounds
// 2. Make toVC at the top of the screen
toVC.view.frame = CGRectOffset(finalFrame, 0, -1.0 * CGRectGetHeight(screenBounds))
containerView.addSubview(toVC.view)
// 3. Set the dynamic animators used by the view controller presentation
var animator: UIDynamicAnimator? = UIDynamicAnimator(referenceView: containerView)
let gravity = UIGravityBehavior(items: [toVC.view])
gravity.magnitude = 10
let collision = UICollisionBehavior(items: [toVC.view])
collision.addBoundaryWithIdentifier("GravityBoundary",
fromPoint: CGPoint(x: 0, y: screenBounds.height),
toPoint: CGPoint(x: screenBounds.width, y: screenBounds.height))
let animatorItem = UIDynamicItemBehavior(items: [toVC.view])
animatorItem.elasticity = 0.5
animator!.addBehavior(gravity)
animator!.addBehavior(collision)
animator!.addBehavior(animatorItem)
// 4. Complete the transition after the time of the duration
let nsecs = transitionDuration(transitionContext) * Double(NSEC_PER_SEC)
let delay = dispatch_time(DISPATCH_TIME_NOW, Int64(nsecs))
dispatch_after(delay, dispatch_get_main_queue()) {
animator = nil
transitionContext.completeTransition(true)
}
}
A little more complicated than using animateWithDuration:delay:usingSpringWithDamping:initialSpringVelocity:options:animations:completion: method.
EDIT: Fixed a bug when 'transitionDuration' is ≤1

Resources