I have been trying for a while but I cannot figure out how to create a Compose animation seen in the iOS 10+ when you can drag the new composed email down, then it stays on the bottom and the rest of the app is normally accessed, then when you tap it, it re-shows.
I have created a sample project in which I have a UIViewController that presents another UIViewController which has a UIPanGestureRecognizer in it's UINavigationController that fires the pangesture state analyzer.
I can indeed drag to dismiss it , but I cannot find a way to keep it frame.
Bellow there's a print screen of what I'm trying to accomplish and then my used code to where I'm stuck at.
UIViewController that is the presentingViewController class
//
// ViewController.swift
// dismissLayerTest
//
// Created by Ivan Cantarino on 27/09/17.
// Copyright © 2017 Ivan Cantarino. All rights reserved.
//
import UIKit
class ViewController: UIViewController, UIViewControllerTransitioningDelegate {
#objc let interactor = Interactor()
lazy var presentButton: UIButton = {
let b = UIButton(type: .custom)
b.setTitle("Present", for: .normal)
b.setTitleColor(.black, for: .normal)
b.addTarget(self, action: #selector(didTapPresentButton), for: .touchUpInside)
return b
}()
lazy var testbutton: UIButton = {
let b = UIButton(type: .custom)
b.setTitle("test", for: .normal)
b.setTitleColor(.black, for: .normal)
b.addTarget(self, action: #selector(test), for: .touchUpInside)
return b
}()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
view.backgroundColor = .white
view.addSubview(presentButton)
presentButton.anchor(top: nil, left: nil, bottom: nil, right: nil, paddingTop: 0, paddinfLeft: 0, paddingBottom: 0, paddingRight: 0, width: 100, height: 100)
presentButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
presentButton.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
view.addSubview(testbutton)
testbutton.anchor(top: nil, left: nil, bottom: presentButton.topAnchor, right: nil, paddingTop: 0, paddinfLeft: 0, paddingBottom: 100, paddingRight: 0, width: 100, height: 100)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#objc func didTapPresentButton() {
let presentedVC = PresentedViewController()
let navController = UINavigationController(rootViewController: presentedVC)
navController.transitioningDelegate = self
presentedVC.interactor = interactor // new
navController.modalPresentationStyle = .custom
navController.view.layer.masksToBounds = true
present(navController, animated: true, completion: nil)
}
#objc func test() {
print("test")
}
// Handles the presenting animation
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
return CustomAnimationForPresentor()
}
// Handles the dismissing animation
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
return CustomAnimationForDismisser()
}
// interaction controller, only for dismissing the view;
func interactionControllerForDismissal(using animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
return interactor.hasStarted ? interactor : nil
}
// delegate do custom modal presentation style
func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
return CustomPresentationController(presentedViewController: presented, presenting: presenting)
}
}
UIViewController 2 that is the presentedViewController
import Foundation
import UIKit
class PresentedViewController: UIViewController, UIViewControllerTransitioningDelegate, UIGestureRecognizerDelegate {
#objc var interactor: Interactor? = nil
#objc var panGr = UIPanGestureRecognizer()
#objc var panTapRecon = UITapGestureRecognizer()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .green
let leftB = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action: #selector(didTapCancel))
navigationItem.leftBarButtonItem = leftB
panGr = UIPanGestureRecognizer(target: self, action: #selector(handleGesture))
navigationController?.navigationBar.addGestureRecognizer(panGr)
panTapRecon = UITapGestureRecognizer(target: self, action: #selector(handleNavControllerTapGR))
navigationController?.navigationBar.addGestureRecognizer(panTapRecon)
}
#objc func didTapCancel() {
guard let interactor = interactor else { return }
interactorFinish(interactor: interactor)
dismiss(animated: true, completion: nil)
}
#objc func handleNavControllerTapGR(_ sender: UITapGestureRecognizer) {
print("tap detected")
}
// Swipe gesture recognizer handler
#objc func handleGesture(_ sender: UIPanGestureRecognizer) {
//percentThreshold: This variable sets how far down the user has to drag
//in order to trigger the modal dismissal. In this case, it’s set to 40%.
let percentThreshold:CGFloat = 0.30
// convert y-position to downward pull progress (percentage)
let translation = sender.translation(in: view)
let verticalMovement = translation.y / view.bounds.height
let downwardMovement = fmaxf(Float(verticalMovement), 0.0)
let downwardMovementPercent = fminf(downwardMovement, 1.0)
let progress = CGFloat(downwardMovementPercent)
guard let interactor = interactor else { return }
switch sender.state {
case .began:
interactor.hasStarted = true
self.dismiss(animated: true, completion: nil)
case .changed:
// alterar se o tamanho do presentigViewController (MainTabBarController) for alterado no background
let scaleX = 0.95 + (progress * (1 - 0.95))
let scaleY = 0.95 + (progress * (1 - 0.95))
// Não deixa ultrapassar os 100% de scale (tamanho original)
if (scaleX > 1 && scaleY > 1) { return }
presentingViewController?.view.transform = CGAffineTransform.identity.scaledBy(x: scaleX, y: scaleY);
presentingViewController?.view.layer.masksToBounds = true
interactor.shouldFinish = progress > percentThreshold
interactor.update(progress)
case .cancelled:
interactor.hasStarted = false
interactor.cancel()
case .ended:
interactor.hasStarted = false
if (interactor.shouldFinish) {
interactorFinish(interactor: interactor)
} else {
// repõe o MainTabBarController na posição dele atrás do NewPostController
UIView.animate(withDuration: 0.5, animations: {
self.presentingViewController?.view.transform = CGAffineTransform.identity.scaledBy(x: 0.95, y: 0.95);
self.presentingViewController?.view.layer.masksToBounds = true
let c = UIColor.black.withAlphaComponent(0.4)
let shadowView = self.presentingViewController?.view.viewWithTag(999)
shadowView?.backgroundColor = c
})
interactor.cancel()
}
default: break
}
}
#objc func interactorFinish(interactor: Interactor) {
removeShadow()
interactor.finish()
}
// remove a shadow view
#objc func removeShadow() {
UIView.animate(withDuration: 0.2, animations: {
self.presentingViewController?.view.transform = CGAffineTransform.identity.scaledBy(x: 1.0, y: 1.0);
self.presentingViewController?.view.layer.masksToBounds = true
}) { _ in
}
}
}
Here's an Helper file that has the custom presentations:
//
// Helper.swift
// dismissLayerTest
//
// Created by Ivan Cantarino on 27/09/17.
// Copyright © 2017 Ivan Cantarino. All rights reserved.
//
import Foundation
import UIKit
class Interactor: UIPercentDrivenInteractiveTransition {
#objc var hasStarted = false
#objc var shouldFinish = false
}
extension UIView {
#objc func anchor(top: NSLayoutYAxisAnchor?, left: NSLayoutXAxisAnchor?, bottom: NSLayoutYAxisAnchor?, right: NSLayoutXAxisAnchor?, paddingTop: CGFloat, paddinfLeft: CGFloat, paddingBottom: CGFloat, paddingRight: CGFloat, width: CGFloat, height: CGFloat) {
translatesAutoresizingMaskIntoConstraints = false
if let top = top {
topAnchor.constraint(equalTo: top, constant: paddingTop).isActive = true
}
if let left = left {
leftAnchor.constraint(equalTo: left, constant: paddinfLeft).isActive = true
}
if let bottom = bottom {
bottomAnchor.constraint(equalTo: bottom, constant: -paddingBottom).isActive = true
}
if let right = right {
rightAnchor.constraint(equalTo: right, constant: -paddingRight).isActive = true
}
if width != 0 {
widthAnchor.constraint(equalToConstant: width).isActive = true
}
if height != 0 {
heightAnchor.constraint(equalToConstant: height).isActive = true
}
}
#objc func roundCorners(corners:UIRectCorner, radius: CGFloat) {
let path = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
let mask = CAShapeLayer()
mask.path = path.cgPath
self.layer.mask = mask
}
}
class CustomAnimationForDismisser: NSObject, UIViewControllerAnimatedTransitioning {
// Tempo da animação
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 0.27
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
// Get the set of relevant objects.
let containerView = transitionContext.containerView
guard let fromVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from) else {
print("Returning animateTransition VC")
return
}
// from view só existe no dismiss
guard let fromView = transitionContext.view(forKey: UITransitionContextViewKey.from) else {
print("Failed to instantiate fromView: CustomAnimationForDismisser()")
return
}
// Set up some variables for the animation.
let containerFrame: CGRect = containerView.frame
var fromViewFinalFrame: CGRect = transitionContext.finalFrame(for: fromVC)
fromViewFinalFrame = CGRect(x: 0, y: containerFrame.size.height, width: containerFrame.size.width, height: containerFrame.size.height)
// Animate using the animator's own duration value.
UIView.animate(withDuration: 0.4, delay: 0, options: .curveEaseOut, animations: {
fromView.frame = fromViewFinalFrame
}) { (finished) in
let success = !(transitionContext.transitionWasCancelled)
// Notify UIKit that the transition has finished
transitionContext.completeTransition(success)
}
}
}
class CustomAnimationForPresentor: NSObject, UIViewControllerAnimatedTransitioning {
// Tempo da animação
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 0.2
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
// Get the set of relevant objects.
let containerView = transitionContext.containerView
// obtém os VCs para não o perder na apresentação (default desaparece por trás)
guard let fromVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from) else {//, let toVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to) else {
print("Returning animateTransition VC")
return
}
// gets the view of the presented object
guard let toView = transitionContext.view(forKey: UITransitionContextViewKey.to) else { return }
// Set up animation parameters.
toView.transform = CGAffineTransform(translationX: 0, y: containerView.bounds.height)
// Always add the "to" view to the container.
containerView.addSubview(toView)
// Animate using the animator's own duration value.
UIView.animate(withDuration: 0.35, delay: 0, options: .curveEaseOut, animations: {
// Zooms out da MainTabBarController - o VC
fromVC.view.transform = CGAffineTransform(scaleX: 0.95, y: 0.95)
// propriedades declaradas no CustomPresentationController() // Anima o presented view
toView.transform = .identity
}, completion: { (finished) in
let success = !(transitionContext.transitionWasCancelled)
// So it avoids view stacks and overlap issues
if (!success) { toView.removeFromSuperview() }
// Notify UIKit that the transition has finished
transitionContext.completeTransition(success)
})
}
}
class CustomPresentationController: UIPresentationController {
override init(presentedViewController: UIViewController, presenting presentingViewController: UIViewController!) {
super.init(presentedViewController: presentedViewController, presenting: presentingViewController)
}
// Tamanho desejado para o NewPostController
override var frameOfPresentedViewInContainerView: CGRect {
guard let containerBounds = containerView?.bounds else {
print("Failed to instantiate container bounds: CustomPresentationController")
return .zero
}
return CGRect(x: 0.0, y: 0.0, width: containerBounds.width, height: containerBounds.height)
}
// Garante que o frame do view controller a mostrar, se mantém conforme desenhado na função frameOfPresentedViewInContainerView
override func containerViewWillLayoutSubviews() {
presentedView?.frame = frameOfPresentedViewInContainerView
}
}
This desired effect can also be seen in other apps, such like Music app, Stack Exchange/Overflow iOS App
Does anyone have a hint on how can this be accomplished? I feel like I'm really close to achieve it, but I can't find a way to keep the dismissed view with a layer on screen.
The project above can be found here
Thank you very much.
Regards.
I would suggest that Apple (in the animated screen gif you have so helpfully provided) is not using a presented view controller. If it were, the presenting view controller would not be able to shrink its view — and on dismissal, the presented view controller's view would completely disappear.
I would say that underlying this interface is a parent view controller with multiple child view controllers (or maybe just a normal view controller with two child views). Thus, we can display the two child views wherever and however we like. Your animated gif shows two possible arrangements of the two child views: overlapping, and one above the other with the second view just barely visible from the bottom of the screen.
Related
To me it looks like the safe area of a view is not updated after the owning view controller's .viewWillDisappear() method is called.
Is this intended or a bug in the framework?
The issue is easily visualised by creating a custom UIViewControllerTransitioningDelegate that animates a smaller view in one view controller, to full screen size in another (constrained to safe areas). Then the safe area will expand as the present animation goes on (as expected), but will not shrink as the dismiss animation goes on (not expected!). The expected behaviour would be that the safe area expands during the present animation, and shrinks during the dismiss animation.
The gif below shows the unexpected behaviour. The grey area of the presented view controller is the safe area.
Below is the code I used to visualise this problem. ViewController.swift presents MyViewController.swift using FullScreenTransitionManager.swift
//
// FullScreenTransitionManager.swift
//
import Foundation
import UIKit
// MARK: FullScreenPresentationController
final class FullScreenPresentationController: UIPresentationController {
private lazy var tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(onTap))
#objc private func onTap(_ gesture: UITapGestureRecognizer) {
presentedViewController.dismiss(animated: true)
}
}
// MARK: UIPresentationController
extension FullScreenPresentationController {
override func presentationTransitionWillBegin() {
guard let containerView = containerView else { return }
containerView.addGestureRecognizer(tapGestureRecognizer)
}
override func presentationTransitionDidEnd(_ completed: Bool) {
if !completed {
containerView?.removeGestureRecognizer(tapGestureRecognizer)
}
}
override func dismissalTransitionDidEnd(_ completed: Bool) {
if completed {
containerView?.removeGestureRecognizer(tapGestureRecognizer)
}
}
}
// MARK: FullScreenTransitionManager
final class FullScreenTransitionManager: NSObject, UIViewControllerTransitioningDelegate {
private weak var anchorView: UIView?
init(anchorView: UIView) {
self.anchorView = anchorView
}
func presentationController(forPresented presented: UIViewController,
presenting: UIViewController?,
source: UIViewController) -> UIPresentationController? {
FullScreenPresentationController(presentedViewController: presented, presenting: presenting)
}
func animationController(forPresented presented: UIViewController,
presenting: UIViewController,
source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
let anchorFrame = anchorView?.frame ?? CGRect(origin: presented.view.center, size: .zero)
return FullScreenAnimationController(animationType: .present,
anchorFrame: anchorFrame)
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
let anchorFrame = anchorView?.frame ?? CGRect(origin: dismissed.view.center, size: .zero)
return FullScreenAnimationController(animationType: .dismiss,
anchorFrame: anchorFrame)
}
}
// MARK: UIViewControllerAnimatedTransitioning
final class FullScreenAnimationController: NSObject, UIViewControllerAnimatedTransitioning {
enum AnimationType {
case present
case dismiss
}
private let animationType: AnimationType
private let anchorFrame: CGRect
private let animationDuration: TimeInterval
private var propertyAnimator: UIViewPropertyAnimator?
init(animationType: AnimationType, anchorFrame: CGRect, animationDuration: TimeInterval = 5) {
self.animationType = animationType
self.anchorFrame = anchorFrame
self.animationDuration = animationDuration
}
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
animationDuration
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
switch animationType {
case .present:
guard
let toViewController = transitionContext.viewController(forKey: .to)
else {
return transitionContext.completeTransition(false)
}
transitionContext.containerView.addSubview(toViewController.view)
propertyAnimator = presentAnimator(with: transitionContext, animating: toViewController)
case .dismiss:
guard
let fromViewController = transitionContext.viewController(forKey: .from)
else {
return transitionContext.completeTransition(false)
}
propertyAnimator = dismissAnimator(with: transitionContext, animating: fromViewController)
}
}
private func presentAnimator(with transitionContext: UIViewControllerContextTransitioning,
animating viewController: UIViewController) -> UIViewPropertyAnimator {
let finalFrame = transitionContext.finalFrame(for: viewController)
viewController.view.frame = anchorFrame
viewController.view.layoutIfNeeded()
return UIViewPropertyAnimator.runningPropertyAnimator(withDuration: transitionDuration(using: transitionContext),
delay: 0,
options: [.curveEaseInOut],
animations: {
viewController.view.frame = finalFrame
viewController.view.layoutIfNeeded()
}, completion: { _ in
transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
})
}
private func dismissAnimator(with transitionContext: UIViewControllerContextTransitioning,
animating viewController: UIViewController) -> UIViewPropertyAnimator {
return UIViewPropertyAnimator.runningPropertyAnimator(withDuration: transitionDuration(using: transitionContext),
delay: 0,
options: [.curveEaseInOut],
animations: {
viewController.view.frame = self.anchorFrame
viewController.view.layoutIfNeeded()
}, completion: { _ in
transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
})
}
}
//
// MyViewController.swift
//
import UIKit
class MyViewController: UIViewController {
private let square: UIView = {
let view = UIView()
view.backgroundColor = .white
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemGray
view.addSubview(square)
NSLayoutConstraint.activate([
square.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
square.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
square.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
square.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor)
])
}
}
//
// ViewController.swift
//
import UIKit
class ViewController: UIViewController {
private let button: UIButton = {
let button = UIButton(type: .system)
button.setTitle("Click Me!", for: .normal)
button.setTitleColor(.black, for: .normal)
button.backgroundColor = .white
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
private var fullScreenTransitionManager: FullScreenTransitionManager?
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemBackground
view.addSubview(button)
NSLayoutConstraint.activate([
button.widthAnchor.constraint(equalToConstant: 200),
button.heightAnchor.constraint(equalToConstant: 200),
button.centerXAnchor.constraint(equalTo: view.centerXAnchor),
button.centerYAnchor.constraint(equalTo: view.centerYAnchor)
])
button.addTarget(self, action: #selector(presentMyViewController), for: .primaryActionTriggered)
}
#objc private func presentMyViewController(_ button: UIButton) {
let fullScreenTransitionManager = FullScreenTransitionManager(anchorView: button)
let myViewController = MyViewController()
myViewController.modalPresentationStyle = .custom
myViewController.transitioningDelegate = fullScreenTransitionManager
present(myViewController, animated: true)
self.fullScreenTransitionManager = fullScreenTransitionManager
}
}
As confirmed by the answer on this post on the Apple Developer forums, this behaviour is expected. And safe areas is not updated if a view controller is not in the appearing state (between viewWillAppear and viewWillDisappear)
I have made a UIPresentationController that fits any view controller and shows up on half of the screen using this tutorial. Now I would love to add drag to dismiss to this. I'm trying to have the drag feel natural and responsive like the drag experience for "Top Stories" on the Apple iOS 13 stocks app. I thought the iOS 13 modal drag to dismiss would get carried over but it doesn't to this controller but it doesn't.
Every bit of code and tutorial I found had a bad dragging experience. Does anyone know how to do this? I've been trying / searching for the past week. Thank you in advance
Here's my code for the presentation controller
class SlideUpPresentationController: UIPresentationController {
// MARK: - Variables
private var dimmingView: UIView!
//MARK: - View functions
override init(presentedViewController: UIViewController, presenting presentingViewController: UIViewController?) {
super.init(presentedViewController: presentedViewController, presenting: presentingViewController)
setupDimmingView()
}
override func containerViewWillLayoutSubviews() {
presentedView?.frame = frameOfPresentedViewInContainerView
}
override var frameOfPresentedViewInContainerView: CGRect {
guard let container = containerView else { return super.frameOfPresentedViewInContainerView }
let width = container.bounds.size.width
let height : CGFloat = 300.0
return CGRect(x: 0, y: container.bounds.size.height - height, width: width, height: height)
}
override func presentationTransitionWillBegin() {
guard let dimmingView = dimmingView else { return }
containerView?.insertSubview(dimmingView, at: 0)
NSLayoutConstraint.activate(NSLayoutConstraint.constraints(withVisualFormat: "V:|[dimmingView]|",
options: [],
metrics: nil,
views: ["dimmingView": dimmingView]))
NSLayoutConstraint.activate(NSLayoutConstraint.constraints(withVisualFormat: "H:|[dimmingView]|",
options: [],
metrics: nil,
views: ["dimmingView": dimmingView]))
guard let coordinator = presentedViewController.transitionCoordinator else {
dimmingView.alpha = 1.0
return
}
coordinator.animate(alongsideTransition: { _ in
self.dimmingView.alpha = 1.0
})
}
override func dismissalTransitionWillBegin() {
guard let coordinator = presentedViewController.transitionCoordinator else {
dimmingView.alpha = 0.0
return
}
coordinator.animate(alongsideTransition: { _ in
self.dimmingView.alpha = 0.0
})
}
func setupDimmingView() {
dimmingView = UIView()
dimmingView.translatesAutoresizingMaskIntoConstraints = false
dimmingView.backgroundColor = UIColor(white: 0.0, alpha: 0.5)
dimmingView.alpha = 0.0
let recognizer = UITapGestureRecognizer(target: self,
action: #selector(handleTap(recognizer:)))
dimmingView.addGestureRecognizer(recognizer)
}
#objc func handleTap(recognizer: UITapGestureRecognizer) {
presentingViewController.dismiss(animated: true)
}
}
As your description about the dragging experience you wanted is not that clear, hope I didn't get you wrong.
I'm trying to have the drag feel natural and responsive like the drag experience for "Top Stories" on the Apple iOS 13 stocks app.
What I get is, you want to be able to drag the presented view, dismiss it if it reach certain point, else go back to its original position (and of coz you can bring the view to any position you wanted).
To achieve this, we can add a UIPanGesture to the presentedViewController, then
move the presentedView according to the gesture
dismiss / move back the presentedView
class SlideUpPresentationController: UIPresentationController {
// MARK: - Variables
private var dimmingView: UIView!
private var originalX: CGFloat = 0
//MARK: - View functions
override init(presentedViewController: UIViewController, presenting presentingViewController: UIViewController?) {
super.init(presentedViewController: presentedViewController, presenting: presentingViewController)
setupDimmingView()
}
override func containerViewWillLayoutSubviews() {
presentedView?.frame = frameOfPresentedViewInContainerView
}
override var frameOfPresentedViewInContainerView: CGRect {
guard let container = containerView else { return super.frameOfPresentedViewInContainerView }
let width = container.bounds.size.width
let height : CGFloat = 300.0
return CGRect(x: 0, y: container.bounds.size.height - height, width: width, height: height)
}
override func presentationTransitionWillBegin() {
guard let dimmingView = dimmingView else { return }
containerView?.insertSubview(dimmingView, at: 0)
// add PanGestureRecognizer for dragging the presented view controller
let viewPan = UIPanGestureRecognizer(target: self, action: #selector(viewPanned(_:)))
containerView?.addGestureRecognizer(viewPan)
NSLayoutConstraint.activate(NSLayoutConstraint.constraints(withVisualFormat: "V:|[dimmingView]|", options: [], metrics: nil, views: ["dimmingView": dimmingView]))
NSLayoutConstraint.activate(NSLayoutConstraint.constraints(withVisualFormat: "H:|[dimmingView]|", options: [], metrics: nil, views: ["dimmingView": dimmingView]))
guard let coordinator = presentedViewController.transitionCoordinator else {
dimmingView.alpha = 1.0
return
}
coordinator.animate(alongsideTransition: { _ in
self.dimmingView.alpha = 1.0
})
}
#objc private func viewPanned(_ sender: UIPanGestureRecognizer) {
// how far the pan gesture translated
let translate = sender.translation(in: self.presentedView)
switch sender.state {
case .began:
originalX = presentedViewController.view.frame.origin.x
case .changed:
// move the presentedView according to pan gesture
// prevent it from moving too far to the right
if originalX + translate.x < 0 {
presentedViewController.view.frame.origin.x = originalX + translate.x
}
case .ended:
let presentedViewWidth = presentedViewController.view.frame.width
let newX = presentedViewController.view.frame.origin.x
// if the presentedView move more than 0.75 of the presentedView's width, dimiss it, else bring it back to original position
if presentedViewWidth * 0.75 + newX > 0 {
setBackToOriginalPosition()
} else {
moveAndDismissPresentedView()
}
default:
break
}
}
private func setBackToOriginalPosition() {
// ensure no pending layout change in presentedView
presentedViewController.view.layoutIfNeeded()
UIView.animate(withDuration: 0.25, delay: 0.0, options: .curveEaseIn, animations: {
self.presentedViewController.view.frame.origin.x = self.originalX
self.presentedViewController.view.layoutIfNeeded()
}, completion: nil)
}
private func moveAndDismissPresentedView() {
// ensure no pending layout change in presentedView
presentedViewController.view.layoutIfNeeded()
UIView.animate(withDuration: 0.25, delay: 0.0, options: .curveEaseIn, animations: {
self.presentedViewController.view.frame.origin.x = -self.presentedViewController.view.frame.width
self.presentedViewController.view.layoutIfNeeded()
}, completion: { _ in
// dimiss when the view is completely move outside the screen
self.presentingViewController.dismiss(animated: true, completion: nil)
})
}
override func dismissalTransitionWillBegin() {
guard let coordinator = presentedViewController.transitionCoordinator else {
dimmingView.alpha = 0.0
return
}
coordinator.animate(alongsideTransition: { _ in
self.dimmingView.alpha = 0.0
})
}
func setupDimmingView() {
dimmingView = UIView()
dimmingView.translatesAutoresizingMaskIntoConstraints = false
dimmingView.backgroundColor = UIColor(white: 0.0, alpha: 0.5)
dimmingView.alpha = 0.0
let recognizer = UITapGestureRecognizer(target: self,
action: #selector(handleTap(recognizer:)))
dimmingView.addGestureRecognizer(recognizer)
}
#objc func handleTap(recognizer: UITapGestureRecognizer) {
presentingViewController.dismiss(animated: true)
}
}
The above code is just an example based on the code you provide, but I hope that explain what's happening under the hood of what you called a drag experience. Hope this helps ;)
Here is the example result:
via GIPHY
I was just looking at Context menu of Facebook and or slack and wanted to create something similar in my App.
I have tried two methods.
First method. Having a in View Table View and sliding it from bottom to create as if it is animated on to the view. But the problem with this is that The navigation controller and Tab bar controller are not hidden and a white patch is shown over the Black (Alpha 30 %).
The second method I tried was showing a new View controller over the current view controller and presenting as a Modal presentation.
let vc = CustomActionTableViewController(nibName: "CustomActionTableViewController", bundle: nil)
vc.modalPresentationStyle = .overFullScreen
self.present(vc, animated: false, completion: nil)
This works okay but the method is too slow as I have to work with lot of Notifications (To send selected index to my main View and then perform action). It is painfully slow.
Could anyone help me with how I can improve the implementation so that I can get the Action sheet similar to Facebook which is smooth and very very fluid
Check this example : Bottom pop Up
Currently I am using this in my app and it's work fine.
Since you mentioned Slack, they actually have open sourced their bottom sheet implementation, PanModal.
Using UIPresentationController and UIPanGestureRecognizer
1- create BottomMenu presentation Controller which will handle the height of your View Controller and blur
class BottomMenuPresentationController: UIPresentationController {
// MARK: - Properties
var blurEffectView: UIVisualEffectView?
var tapGestureRecognizer = UITapGestureRecognizer()
private var topHeightRatio: Float
private var bottomHeightRatio: Float
init(presentedViewController: UIViewController, presenting presentingViewController: UIViewController?, topHeightRatio: Float, bottomHeightRatio: Float) {
let blurEffect = UIBlurEffect(style: .systemThickMaterialDark)
blurEffectView = UIVisualEffectView(effect: blurEffect)
self.topHeightRatio = topHeightRatio
self.bottomHeightRatio = bottomHeightRatio
super.init(presentedViewController: presentedViewController, presenting: presentingViewController)
blurEffectView?.autoresizingMask = [.flexibleWidth, .flexibleHeight]
tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissController))
self.blurEffectView?.isUserInteractionEnabled = true
self.blurEffectView?.addGestureRecognizer(tapGestureRecognizer)
}
override var frameOfPresentedViewInContainerView: CGRect {
CGRect(origin: CGPoint(x: 0, y: self.containerView!.frame.height * CGFloat(topHeightRatio)),
size: CGSize(width: self.containerView!.frame.width, height: self.containerView!.frame.height * CGFloat(bottomHeightRatio)))
}
override func presentationTransitionWillBegin() {
self.blurEffectView?.alpha = 0
if let blurEffectView = blurEffectView {
self.containerView?.addSubview(blurEffectView)
}
self.presentedViewController.transitionCoordinator?.animate(alongsideTransition: { (_) in
self.blurEffectView?.alpha = 0.66
}, completion: { (_) in })
}
override func dismissalTransitionWillBegin() {
self.presentedViewController.transitionCoordinator?.animate(alongsideTransition: { (_) in
self.blurEffectView?.alpha = 0
}, completion: { (_) in
self.blurEffectView?.removeFromSuperview()
})
}
override func containerViewWillLayoutSubviews() {
super.containerViewWillLayoutSubviews()
presentedView!.roundCorners([.topLeft, .topRight], radius: 14)
}
override func containerViewDidLayoutSubviews() {
super.containerViewDidLayoutSubviews()
presentedView?.frame = frameOfPresentedViewInContainerView
blurEffectView?.frame = containerView!.bounds
}
#objc func dismissController() {
self.presentedViewController.dismiss(animated: true, completion: nil)
}
}
2- create Your ViewController
class BottomMenuVC: UIViewController {
// MARK: - Instances
var hasSetPointOrigin = false
var pointOrigin: CGPoint?
// MARK: - Properties
let topDarkLine: UIView = {
let view = UIView()
view.backgroundColor = UIColor(hexString: "#E1E1E1")
view.layer.cornerRadius = 2
return view
}()
let cancelButn: UIButton = {
let button = UIButton(type: .custom)
button.setAttributedTitle(NSAttributedString(string: "Cancel", attributes: [NSAttributedString.Key.font: UIFont.LatoMedium(size: 17),
NSAttributedString.Key.foregroundColor: UIColor(hexString: "#515151")
]), for: .normal)
button.backgroundColor = UIColor(hexString: "#F1F3F4")
button.layer.cornerRadius = 5.0
button.addTarget(self, action: #selector(cancelButnPressed), for: .touchUpInside)
return button
}()
// MARK: - viewLifeCycle
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
view.isUserInteractionEnabled = true
setupMenuView()
}
override func viewDidLayoutSubviews() {
if !hasSetPointOrigin {
hasSetPointOrigin = true
pointOrigin = self.view.frame.origin
}
}
// MARK: - SetupView
func setupMenuView() {
self.view.addSubview(topDarkLine)
self.view.addSubview(cancelButn)
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(panGestureRecognizerAction(_:)))
view.addGestureRecognizer(panGesture)
topDarkLine.constrainHeight(constant: 4)
topDarkLine.constrainWidth(constant: view.frame.size.width * 0.10)
topDarkLine.centerXInSuperview()
topDarkLine.anchor(top: view.topAnchor, leading: nil, bottom: nil, trailing: nil, padding: .init(top: 8, left: 0, bottom: 0, right: 0))
cancelButn.anchor(top:view.topAnchor, leading: view.leadingAnchor, bottom: nil, trailing: view.trailingAnchor,
padding: .init(top: 16, left: 16, bottom: 0, right: 16))
cancelButn.constrainHeight(constant: 44)
}
// MARK: - Actions
#objc func panGestureRecognizerAction(_ sender: UIPanGestureRecognizer) {
let translation = sender.translation(in: view)
// Not allowing the user to drag the view upward
guard translation.y >= 0 else { return }
// setting x as 0 because we don't want users to move the frame side ways!! Only want straight up or down in the y-axis
view.frame.origin = CGPoint(x: 0, y: self.pointOrigin!.y + translation.y)
if sender.state == .ended {
let dragVelocity = sender.velocity(in: view)
if dragVelocity.y >= 1300 {
// Velocity fast enough to dismiss the uiview
self.dismiss(animated: true, completion: nil)
} else {
// If the dragging isn’t too fast, resetting the view back to it’s original point
UIView.animate(withDuration: 0.3) {
self.view.frame.origin = self.pointOrigin ?? CGPoint(x: 0, y: 400)
}
}
}
}
#objc func cancelButnPressed() {
dismiss(animated: true, completion: nil)
}
}
3- make the viewController that contain the button that will present your menu conforms to UIViewControllerTransitioningDelegate
extension viewController: UIViewControllerTransitioningDelegate {
func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
BottomMenuPresentationController(presentedViewController: presented, presenting: presenting, topHeightRatio: 0.6, bottomHeightRatio: 0.4)
}
}
4- set the transitioning delegate to self and present your custom presentation Controller
func showBottomMenu() {
let menu = BottomMenuVC()
menu.coordinator = self
menu.modalPresentationStyle = .custom
menu.transitioningDelegate = self
present(menu, animated: true, completion: nil)
}
check this PanGesture Slidable View article
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.
A common way to dismiss a modal is to swipe down - How do we allows the user to drag the modal down, if it's far enough, the modal's dismissed, otherwise it animates back to the original position?
For example, we can find this used on the Twitter app's photo views, or Snapchat's "discover" mode.
Similar threads point out that we can use a UISwipeGestureRecognizer and [self dismissViewControllerAnimated...] to dismiss a modal VC when a user swipes down. But this only handles a single swipe, not letting the user drag the modal around.
I just created a tutorial for interactively dragging down a modal to dismiss it.
http://www.thorntech.com/2016/02/ios-tutorial-close-modal-dragging/
I found this topic to be confusing at first, so the tutorial builds this out step-by-step.
If you just want to run the code yourself, this is the repo:
https://github.com/ThornTechPublic/InteractiveModal
This is the approach I used:
View Controller
You override the dismiss animation with a custom one. If the user is dragging the modal, the interactor kicks in.
import UIKit
class ViewController: UIViewController {
let interactor = Interactor()
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if let destinationViewController = segue.destinationViewController as? ModalViewController {
destinationViewController.transitioningDelegate = self
destinationViewController.interactor = interactor
}
}
}
extension ViewController: UIViewControllerTransitioningDelegate {
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
DismissAnimator()
}
func interactionControllerForDismissal(animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
interactor.hasStarted ? interactor : .none
}
}
Dismiss Animator
You create a custom animator. This is a custom animation that you package inside a UIViewControllerAnimatedTransitioning protocol.
import UIKit
class DismissAnimator : NSObject {
let transitionDuration = 0.6
}
extension DismissAnimator : UIViewControllerAnimatedTransitioning {
func transitionDuration(transitionContext: UIViewControllerContextTransitioning?) -> NSTimeInterval {
transitionDuration
}
func animateTransition(transitionContext: UIViewControllerContextTransitioning) {
guard
let fromVC = transitionContext.viewControllerForKey(UITransitionContextFromViewControllerKey),
let toVC = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey),
let containerView = transitionContext.containerView()
else {
return
}
if transitionContext.transitionWasCancelled {
containerView.insertSubview(toVC.view, belowSubview: fromVC.view)
}
let screenBounds = UIScreen.mainScreen().bounds
let bottomLeftCorner = CGPoint(x: 0, y: screenBounds.height)
let finalFrame = CGRect(origin: bottomLeftCorner, size: screenBounds.size)
UIView.animateWithDuration(
transitionDuration(transitionContext),
animations: {
fromVC.view.frame = finalFrame
},
completion: { _ in
transitionContext.completeTransition(!transitionContext.transitionWasCancelled())
}
)
}
}
Interactor
You subclass UIPercentDrivenInteractiveTransition so that it can act as your state machine. Since the interactor object is accessed by both VCs, use it to keep track of the panning progress.
import UIKit
class Interactor: UIPercentDrivenInteractiveTransition {
var hasStarted = false
var shouldFinish = false
}
Modal View Controller
This maps the pan gesture state to interactor method calls. The translationInView() y value determines whether the user crossed a threshold. When the pan gesture is .Ended, the interactor either finishes or cancels.
import UIKit
class ModalViewController: UIViewController {
var interactor:Interactor? = nil
#IBAction func close(sender: UIButton) {
dismiss(animated: true)
}
#IBAction func handleGesture(sender: UIPanGestureRecognizer) {
let percentThreshold:CGFloat = 0.3
let translation = sender.translation(in: view)
let verticalMovement = translation.y / view.bounds.height
let downwardMovement = fmaxf(Float(verticalMovement), 0.0)
let downwardMovementPercent = fminf(downwardMovement, 1.0)
let progress = CGFloat(downwardMovementPercent)
guard interactor = interactor else { return }
switch sender.state {
case .began:
interactor.hasStarted = true
dismiss(animated: true)
case .changed:
interactor.shouldFinish = progress > percentThreshold
interactor.update(progress)
case .cancelled:
interactor.hasStarted = false
interactor.cancel()
case .ended:
interactor.hasStarted = false
interactor.shouldFinish ? interactor.finish() :
interactor.cancel()
default:
break
}
}
}
I'll share how I did it in Swift 3 :
Result
Implementation
class MainViewController: UIViewController {
#IBAction func click() {
performSegue(withIdentifier: "showModalOne", sender: nil)
}
}
class ModalOneViewController: ViewControllerPannable {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .yellow
}
#IBAction func click() {
performSegue(withIdentifier: "showModalTwo", sender: nil)
}
}
class ModalTwoViewController: ViewControllerPannable {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .green
}
}
Where the Modals View Controllers inherit from a class that I've built (ViewControllerPannable) to make them draggable and dismissible when reach certain velocity.
ViewControllerPannable class
class ViewControllerPannable: UIViewController {
var panGestureRecognizer: UIPanGestureRecognizer?
var originalPosition: CGPoint?
var currentPositionTouched: CGPoint?
override func viewDidLoad() {
super.viewDidLoad()
panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(panGestureAction(_:)))
view.addGestureRecognizer(panGestureRecognizer!)
}
#objc func panGestureAction(_ panGesture: UIPanGestureRecognizer) {
let translation = panGesture.translation(in: view)
if panGesture.state == .began {
originalPosition = view.center
currentPositionTouched = panGesture.location(in: view)
} else if panGesture.state == .changed {
view.frame.origin = CGPoint(
x: translation.x,
y: translation.y
)
} else if panGesture.state == .ended {
let velocity = panGesture.velocity(in: view)
if velocity.y >= 1500 {
UIView.animate(withDuration: 0.2
, animations: {
self.view.frame.origin = CGPoint(
x: self.view.frame.origin.x,
y: self.view.frame.size.height
)
}, completion: { (isCompleted) in
if isCompleted {
self.dismiss(animated: false, completion: nil)
}
})
} else {
UIView.animate(withDuration: 0.2, animations: {
self.view.center = self.originalPosition!
})
}
}
}
}
Here is a one-file solution based on #wilson's answer (thanks 👍 ) with the following improvements:
List of Improvements from previous solution
Limit panning so that the view only goes down:
Avoid horizontal translation by only updating the y coordinate of view.frame.origin
Avoid panning out of the screen when swiping up with let y = max(0, translation.y)
Also dismiss the view controller based on where the finger is released (defaults to the bottom half of the screen) and not just based on the velocity of the swipe
Show view controller as modal to ensure the previous viewcontroller appears behind and avoid a black background (should answer your question #nguyễn-anh-việt)
Remove unneeded currentPositionTouched and originalPosition
Expose the following parameters:
minimumVelocityToHide: what speed is enough to hide (defaults to 1500)
minimumScreenRatioToHide: how low is enough to hide (defaults to 0.5)
animationDuration : how fast do we hide/show (defaults to 0.2s)
Solution
Swift 3 & Swift 4 :
//
// PannableViewController.swift
//
import UIKit
class PannableViewController: UIViewController {
public var minimumVelocityToHide: CGFloat = 1500
public var minimumScreenRatioToHide: CGFloat = 0.5
public var animationDuration: TimeInterval = 0.2
override func viewDidLoad() {
super.viewDidLoad()
// Listen for pan gesture
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(onPan(_:)))
view.addGestureRecognizer(panGesture)
}
#objc func onPan(_ panGesture: UIPanGestureRecognizer) {
func slideViewVerticallyTo(_ y: CGFloat) {
self.view.frame.origin = CGPoint(x: 0, y: y)
}
switch panGesture.state {
case .began, .changed:
// If pan started or is ongoing then
// slide the view to follow the finger
let translation = panGesture.translation(in: view)
let y = max(0, translation.y)
slideViewVerticallyTo(y)
case .ended:
// If pan ended, decide it we should close or reset the view
// based on the final position and the speed of the gesture
let translation = panGesture.translation(in: view)
let velocity = panGesture.velocity(in: view)
let closing = (translation.y > self.view.frame.size.height * minimumScreenRatioToHide) ||
(velocity.y > minimumVelocityToHide)
if closing {
UIView.animate(withDuration: animationDuration, animations: {
// If closing, animate to the bottom of the view
self.slideViewVerticallyTo(self.view.frame.size.height)
}, completion: { (isCompleted) in
if isCompleted {
// Dismiss the view when it dissapeared
dismiss(animated: false, completion: nil)
}
})
} else {
// If not closing, reset the view to the top
UIView.animate(withDuration: animationDuration, animations: {
slideViewVerticallyTo(0)
})
}
default:
// If gesture state is undefined, reset the view to the top
UIView.animate(withDuration: animationDuration, animations: {
slideViewVerticallyTo(0)
})
}
}
override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
super.init(nibName: nil, bundle: nil)
modalPresentationStyle = .overFullScreen;
modalTransitionStyle = .coverVertical;
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
modalPresentationStyle = .overFullScreen;
modalTransitionStyle = .coverVertical;
}
}
I figured out super simple way to do this. Just put the following code into your view controller:
Swift 4
override func viewDidLoad() {
super.viewDidLoad()
let gestureRecognizer = UIPanGestureRecognizer(target: self,
action: #selector(panGestureRecognizerHandler(_:)))
view.addGestureRecognizer(gestureRecognizer)
}
#IBAction func panGestureRecognizerHandler(_ sender: UIPanGestureRecognizer) {
let touchPoint = sender.location(in: view?.window)
var initialTouchPoint = CGPoint.zero
switch sender.state {
case .began:
initialTouchPoint = touchPoint
case .changed:
if touchPoint.y > initialTouchPoint.y {
view.frame.origin.y = touchPoint.y - initialTouchPoint.y
}
case .ended, .cancelled:
if touchPoint.y - initialTouchPoint.y > 200 {
dismiss(animated: true, completion: nil)
} else {
UIView.animate(withDuration: 0.2, animations: {
self.view.frame = CGRect(x: 0,
y: 0,
width: self.view.frame.size.width,
height: self.view.frame.size.height)
})
}
case .failed, .possible:
break
}
}
created a demo for interactively dragging down to dismiss view controller like snapchat's discover mode. Check this github for sample project.
Swift 4.x, Using Pangesture
Simple way
Horizontal
class ViewConrtoller: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.addGestureRecognizer(UIPanGestureRecognizer(target: self, action: #selector(onDrage(_:))))
}
#objc func onDrage(_ sender:UIPanGestureRecognizer) {
let percentThreshold:CGFloat = 0.3
let translation = sender.translation(in: view)
let newX = ensureRange(value: view.frame.minX + translation.x, minimum: 0, maximum: view.frame.maxX)
let progress = progressAlongAxis(newX, view.bounds.width)
view.frame.origin.x = newX //Move view to new position
if sender.state == .ended {
let velocity = sender.velocity(in: view)
if velocity.x >= 300 || progress > percentThreshold {
self.dismiss(animated: true) //Perform dismiss
} else {
UIView.animate(withDuration: 0.2, animations: {
self.view.frame.origin.x = 0 // Revert animation
})
}
}
sender.setTranslation(.zero, in: view)
}
}
Helper function
func progressAlongAxis(_ pointOnAxis: CGFloat, _ axisLength: CGFloat) -> CGFloat {
let movementOnAxis = pointOnAxis / axisLength
let positiveMovementOnAxis = fmaxf(Float(movementOnAxis), 0.0)
let positiveMovementOnAxisPercent = fminf(positiveMovementOnAxis, 1.0)
return CGFloat(positiveMovementOnAxisPercent)
}
func ensureRange<T>(value: T, minimum: T, maximum: T) -> T where T : Comparable {
return min(max(value, minimum), maximum)
}
#Hard way
Refer this -> https://github.com/satishVekariya/DraggableViewController
Massively updates the repo for Swift 4.
For Swift 3, I have created the following to present a UIViewController from right to left and dismiss it by pan gesture. I have uploaded this as a GitHub repository.
DismissOnPanGesture.swift file:
// Created by David Seek on 11/21/16.
// Copyright © 2016 David Seek. All rights reserved.
import UIKit
class DismissAnimator : NSObject {
}
extension DismissAnimator : UIViewControllerAnimatedTransitioning {
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 0.6
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
let screenBounds = UIScreen.main.bounds
let fromVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)
let toVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)
var x:CGFloat = toVC!.view.bounds.origin.x - screenBounds.width
let y:CGFloat = toVC!.view.bounds.origin.y
let width:CGFloat = toVC!.view.bounds.width
let height:CGFloat = toVC!.view.bounds.height
var frame:CGRect = CGRect(x: x, y: y, width: width, height: height)
toVC?.view.alpha = 0.2
toVC?.view.frame = frame
let containerView = transitionContext.containerView
containerView.insertSubview(toVC!.view, belowSubview: fromVC!.view)
let bottomLeftCorner = CGPoint(x: screenBounds.width, y: 0)
let finalFrame = CGRect(origin: bottomLeftCorner, size: screenBounds.size)
UIView.animate(
withDuration: transitionDuration(using: transitionContext),
animations: {
fromVC!.view.frame = finalFrame
toVC?.view.alpha = 1
x = toVC!.view.bounds.origin.x
frame = CGRect(x: x, y: y, width: width, height: height)
toVC?.view.frame = frame
},
completion: { _ in
transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
}
)
}
}
class Interactor: UIPercentDrivenInteractiveTransition {
var hasStarted = false
var shouldFinish = false
}
let transition: CATransition = CATransition()
func presentVCRightToLeft(_ fromVC: UIViewController, _ toVC: UIViewController) {
transition.duration = 0.5
transition.type = kCATransitionPush
transition.subtype = kCATransitionFromRight
fromVC.view.window!.layer.add(transition, forKey: kCATransition)
fromVC.present(toVC, animated: false, completion: nil)
}
func dismissVCLeftToRight(_ vc: UIViewController) {
transition.duration = 0.5
transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.type = kCATransitionPush
transition.subtype = kCATransitionFromLeft
vc.view.window!.layer.add(transition, forKey: nil)
vc.dismiss(animated: false, completion: nil)
}
func instantiatePanGestureRecognizer(_ vc: UIViewController, _ selector: Selector) {
var edgeRecognizer: UIScreenEdgePanGestureRecognizer!
edgeRecognizer = UIScreenEdgePanGestureRecognizer(target: vc, action: selector)
edgeRecognizer.edges = .left
vc.view.addGestureRecognizer(edgeRecognizer)
}
func dismissVCOnPanGesture(_ vc: UIViewController, _ sender: UIScreenEdgePanGestureRecognizer, _ interactor: Interactor) {
let percentThreshold:CGFloat = 0.3
let translation = sender.translation(in: vc.view)
let fingerMovement = translation.x / vc.view.bounds.width
let rightMovement = fmaxf(Float(fingerMovement), 0.0)
let rightMovementPercent = fminf(rightMovement, 1.0)
let progress = CGFloat(rightMovementPercent)
switch sender.state {
case .began:
interactor.hasStarted = true
vc.dismiss(animated: true, completion: nil)
case .changed:
interactor.shouldFinish = progress > percentThreshold
interactor.update(progress)
case .cancelled:
interactor.hasStarted = false
interactor.cancel()
case .ended:
interactor.hasStarted = false
interactor.shouldFinish
? interactor.finish()
: interactor.cancel()
default:
break
}
}
Easy usage:
import UIKit
class VC1: UIViewController, UIViewControllerTransitioningDelegate {
let interactor = Interactor()
#IBAction func present(_ sender: Any) {
let vc = self.storyboard?.instantiateViewController(withIdentifier: "VC2") as! VC2
vc.transitioningDelegate = self
vc.interactor = interactor
presentVCRightToLeft(self, vc)
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
return DismissAnimator()
}
func interactionControllerForDismissal(using animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
return interactor.hasStarted ? interactor : nil
}
}
class VC2: UIViewController {
var interactor:Interactor? = nil
override func viewDidLoad() {
super.viewDidLoad()
instantiatePanGestureRecognizer(self, #selector(gesture))
}
#IBAction func dismiss(_ sender: Any) {
dismissVCLeftToRight(self)
}
func gesture(_ sender: UIScreenEdgePanGestureRecognizer) {
dismissVCOnPanGesture(self, sender, interactor!)
}
}
Only vertical dismiss
func panGestureAction(_ panGesture: UIPanGestureRecognizer) {
let translation = panGesture.translation(in: view)
if panGesture.state == .began {
originalPosition = view.center
currentPositionTouched = panGesture.location(in: view)
} else if panGesture.state == .changed {
view.frame.origin = CGPoint(
x: view.frame.origin.x,
y: view.frame.origin.y + translation.y
)
panGesture.setTranslation(CGPoint.zero, in: self.view)
} else if panGesture.state == .ended {
let velocity = panGesture.velocity(in: view)
if velocity.y >= 150 {
UIView.animate(withDuration: 0.2
, animations: {
self.view.frame.origin = CGPoint(
x: self.view.frame.origin.x,
y: self.view.frame.size.height
)
}, completion: { (isCompleted) in
if isCompleted {
self.dismiss(animated: false, completion: nil)
}
})
} else {
UIView.animate(withDuration: 0.2, animations: {
self.view.center = self.originalPosition!
})
}
}
I've created an easy to use extension.
Just inherent Your UIViewController with InteractiveViewController and you are done
InteractiveViewController
call method showInteractive() from your controller to show as Interactive.
What you're describing is an interactive custom transition animation. You are customizing both the animation and the driving gesture of a transition, i.e. the dismissal (or not) of a presented view controller. The easiest way to implement it is by combining a UIPanGestureRecognizer with a UIPercentDrivenInteractiveTransition.
My book explains how to do this, and I have posted examples (from the book). This particular example is a different situation - the transition is sideways, not down, and it is for a tab bar controller, not a presented controller - but the basic idea is exactly the same:
https://github.com/mattneub/Programming-iOS-Book-Examples/blob/master/bk2ch06p300customAnimation3/ch19p620customAnimation1/Animator.swift
If you download that project and run it, you will see that what is happening is exactly what you are describing, except that it is sideways: if the drag is more than half, we transition, but if not, we cancel and snap back into place.
In Objective C :
Here's the code
inviewDidLoad
UISwipeGestureRecognizer *swipeRecognizer = [[UISwipeGestureRecognizer alloc]
initWithTarget:self action:#selector(swipeDown:)];
swipeRecognizer.direction = UISwipeGestureRecognizerDirectionDown;
[self.view addGestureRecognizer:swipeRecognizer];
//Swipe Down Method
- (void)swipeDown:(UIGestureRecognizer *)sender{
[self dismissViewControllerAnimated:YES completion:nil];
}
For those who really wanna dive a little deeper into Custom UIViewController Transition, I recommend this great tutorial from raywenderlich.com.
The original final sample project contains bug. So I fixed it and upload it to Github repo. The proj is in Swift 5, so you can easily run and play it.
Here is a preview:
And it's interactive too!
Happy hacking!
This my simple class for Drag ViewController from axis. Just herited your class from DraggableViewController.
MyCustomClass: DraggableViewController
Work only for presented ViewController.
// MARK: - DraggableViewController
public class DraggableViewController: UIViewController {
public let percentThresholdDismiss: CGFloat = 0.3
public var velocityDismiss: CGFloat = 300
public var axis: NSLayoutConstraint.Axis = .horizontal
public var backgroundDismissColor: UIColor = .black {
didSet {
navigationController?.view.backgroundColor = backgroundDismissColor
}
}
// MARK: LifeCycle
override func viewDidLoad() {
super.viewDidLoad()
view.addGestureRecognizer(UIPanGestureRecognizer(target: self, action: #selector(onDrag(_:))))
}
// MARK: Private methods
#objc fileprivate func onDrag(_ sender: UIPanGestureRecognizer) {
let translation = sender.translation(in: view)
// Movement indication index
let movementOnAxis: CGFloat
// Move view to new position
switch axis {
case .vertical:
let newY = min(max(view.frame.minY + translation.y, 0), view.frame.maxY)
movementOnAxis = newY / view.bounds.height
view.frame.origin.y = newY
case .horizontal:
let newX = min(max(view.frame.minX + translation.x, 0), view.frame.maxX)
movementOnAxis = newX / view.bounds.width
view.frame.origin.x = newX
}
let positiveMovementOnAxis = fmaxf(Float(movementOnAxis), 0.0)
let positiveMovementOnAxisPercent = fminf(positiveMovementOnAxis, 1.0)
let progress = CGFloat(positiveMovementOnAxisPercent)
navigationController?.view.backgroundColor = UIColor.black.withAlphaComponent(1 - progress)
switch sender.state {
case .ended where sender.velocity(in: view).y >= velocityDismiss || progress > percentThresholdDismiss:
// After animate, user made the conditions to leave
UIView.animate(withDuration: 0.2, animations: {
switch self.axis {
case .vertical:
self.view.frame.origin.y = self.view.bounds.height
case .horizontal:
self.view.frame.origin.x = self.view.bounds.width
}
self.navigationController?.view.backgroundColor = UIColor.black.withAlphaComponent(0)
}, completion: { finish in
self.dismiss(animated: true) //Perform dismiss
})
case .ended:
// Revert animation
UIView.animate(withDuration: 0.2, animations: {
switch self.axis {
case .vertical:
self.view.frame.origin.y = 0
case .horizontal:
self.view.frame.origin.x = 0
}
})
default:
break
}
sender.setTranslation(.zero, in: view)
}
}
Here is an extension I made based on #Wilson answer :
// MARK: IMPORT STATEMENTS
import UIKit
// MARK: EXTENSION
extension UIViewController {
// MARK: IS SWIPABLE - FUNCTION
func isSwipable() {
let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture(_:)))
self.view.addGestureRecognizer(panGestureRecognizer)
}
// MARK: HANDLE PAN GESTURE - FUNCTION
#objc func handlePanGesture(_ panGesture: UIPanGestureRecognizer) {
let translation = panGesture.translation(in: view)
let minX = view.frame.width * 0.135
var originalPosition = CGPoint.zero
if panGesture.state == .began {
originalPosition = view.center
} else if panGesture.state == .changed {
view.frame.origin = CGPoint(x: translation.x, y: 0.0)
if panGesture.location(in: view).x > minX {
view.frame.origin = originalPosition
}
if view.frame.origin.x <= 0.0 {
view.frame.origin.x = 0.0
}
} else if panGesture.state == .ended {
if view.frame.origin.x >= view.frame.width * 0.5 {
UIView.animate(withDuration: 0.2
, animations: {
self.view.frame.origin = CGPoint(
x: self.view.frame.size.width,
y: self.view.frame.origin.y
)
}, completion: { (isCompleted) in
if isCompleted {
self.dismiss(animated: false, completion: nil)
}
})
} else {
UIView.animate(withDuration: 0.2, animations: {
self.view.frame.origin = originalPosition
})
}
}
}
}
USAGE
Inside your view controller you want to be swipable :
override func viewDidLoad() {
super.viewDidLoad()
self.isSwipable()
}
and it will be dismissible by swiping from the extreme left side of the view controller, as a navigation controller.
For Swift 4 + Swift 5, using UIPanGestureRecognizer. Based on #SPatel 's answer above.
Add these two helper functions:
func progressAlongAxis(_ pointOnAxis: CGFloat, _ axisLength: CGFloat) -> CGFloat {
let movementOnAxis = pointOnAxis / axisLength
let positiveMovementOnAxis = fmaxf(Float(movementOnAxis), 0.0)
let positiveMovementOnAxisPercent = fminf(positiveMovementOnAxis, 1.0)
return CGFloat(positiveMovementOnAxisPercent)
}
func ensureRange<T>(value: T, minimum: T, maximum: T) -> T where T: Comparable {
return min(max(value, minimum), maximum)
}
To dismiss by dragging down:
class SwipeDownViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// dismiss dragging vertically:
view.addGestureRecognizer(UIPanGestureRecognizer(target: self, action: #selector(onDragY(_:))))
}
#objc func onDragY(_ sender: UIPanGestureRecognizer) {
let percentThreshold: CGFloat = 0.3
let translation = sender.translation(in: view)
let newY = ensureRange(value: view.frame.minY + translation.y, minimum: 0, maximum: view.frame.maxY)
let progress = progressAlongAxis(newY, view.bounds.height)
view.frame.origin.y = newY // Move view to new position
if sender.state == .ended {
let velocity = sender.velocity(in: view)
if velocity.y >= 300 || progress > percentThreshold {
dismiss(animated: true) // Perform dismiss
} else {
UIView.animate(withDuration: 0.2, animations: {
self.view.frame.origin.y = 0 // Revert animation
})
}
}
sender.setTranslation(.zero, in: view)
}
}
To dismiss by dragging right:
class SwipeRightViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// dismiss dragging horizontally:
view.addGestureRecognizer(UIPanGestureRecognizer(target: self, action: #selector(onDragX(_:))))
}
#objc func onDragX(_ sender: UIPanGestureRecognizer) {
let percentThreshold: CGFloat = 0.3
let translation = sender.translation(in: view)
let newX = ensureRange(value: view.frame.minX + translation.x, minimum: 0, maximum: view.frame.maxX)
let progress = progressAlongAxis(newX, view.bounds.width)
view.frame.origin.x = newX // Move view to new position
if sender.state == .ended {
let velocity = sender.velocity(in: view)
if velocity.x >= 300 || progress > percentThreshold {
dismiss(animated: true) // Perform dismiss
} else {
UIView.animate(withDuration: 0.2, animations: {
self.view.frame.origin.x = 0 // Revert animation
})
}
}
sender.setTranslation(.zero, in: view)
}
}
You can use a UIPanGestureRecognizer to detect the user's drag and move the modal view with it. If the ending position is far enough down, the view can be dismissed, or otherwise animated back to its original position.
Check out this answer for more information on how to implement something like this.