Control Center view - ios

Am trying to create a view like control centre in iPhone. As per my requirement the view have to be at bottom when user swap up, View need to be present from bottom to top, while dismissing view need to be swap bottom.Exactly like control centre I need a view, Can Anyone help me?

You can achieve that by the following code:
class ViewController: UIViewController, UIGestureRecognizerDelegate {
var viewControlCenter : UIView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
createControlCenterView()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
// MARK: - Gesture Methods
#objc func respondToSwipeGesture(sender: UIGestureRecognizer? = nil) {
if let swipeGesture = sender as? UISwipeGestureRecognizer {
switch swipeGesture.direction {
case UISwipeGestureRecognizerDirection.up:
if self.viewControlCenter.frame.origin.y != 0 {
UIView.animate(withDuration: 0.5, animations: {
self.viewControlCenter.frame.origin.y = 0
}, completion: nil)
}
break
case UISwipeGestureRecognizerDirection.down:
if self.viewControlCenter.frame.origin.y == 0 {
UIView.animate(withDuration: 0.5, animations: {
self.viewControlCenter.frame.origin.y = self.view.frame.size.height
}, completion: nil)
}
break
default:
break
}
}
}
#objc func onViewTapped(sender: UITapGestureRecognizer? = nil) {
if self.viewControlCenter.frame.origin.y == 0 {
UIView.animate(withDuration: 0.5, animations: {
self.viewControlCenter.frame.origin.y = self.view.frame.size.height
}, completion: nil)
}
}
// MARK: - Custom Methods
func createControlCenterView() {
viewControlCenter = UIView.init(frame: self.view.bounds)
self.viewControlCenter.frame.origin.y = self.view.frame.size.height
let viewBG : UIView = UIView.init(frame: self.view.bounds)
viewBG.backgroundColor = UIColor.init(red: 0, green: 0, blue: 0, alpha: 0.6)
viewControlCenter.addSubview(viewBG)
self.view.addSubview(viewControlCenter)
let swipeUp = UISwipeGestureRecognizer(target: self, action: #selector(respondToSwipeGesture(sender:)))
swipeUp.direction = .up
self.view.addGestureRecognizer(swipeUp)
let swipeDown = UISwipeGestureRecognizer(target: self, action: #selector(respondToSwipeGesture(sender:)))
swipeDown.direction = .down
self.view.addGestureRecognizer(swipeDown)
let tap = UITapGestureRecognizer(target: self, action: #selector(onViewTapped(sender:)))
tap.delegate = self
viewControlCenter.addGestureRecognizer(tap)
}
}

Related

Animating UIButton configuration change

Modern UIButton configuration API allows for new way of setting button appearance. However the code below skips the animation entirely.
#IBAction func buttonTouched(_ sender: UIButton) {
sender.configuration?.background.backgroundColor = .green
UIView.animate(withDuration: 0.4, delay: 0.5) {
sender.configuration?.background.backgroundColor = .systemMint
}
}
Similar thing can be done like this:
#IBAction func buttonTouched(_ sender: UIButton) {
sender.backgroundColor = .red
UIView.animate(withDuration: 0.4, delay: 0.5) {
sender.backgroundColor = .systemMint
}
}
And this works. The question is how to animate UIButton's configuration changes.
After some quick searching, it appears configuration.background.backgroundColor is not animatable.
Depending on your needs, you can use a .customView for the button's background and then animate the color change for that view.
Quick example (assuming you've added the button as an #IBOutlet):
class TestVC: UIViewController {
#IBOutlet var button: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
let v = UIView()
v.backgroundColor = .red
button.configuration?.background.customView = v
}
#IBAction func buttonTouched(_ sender: UIButton) {
if let v = sender.configuration?.background.customView {
UIView.animate(withDuration: 0.4, delay: 0.5) {
v.backgroundColor = v.backgroundColor == .red ? .systemMint : .red
}
}
}
}
The way to achieve animated configuration change by using transitions is the only workaround I could find so far. Somewhat like this:
#IBAction func buttonTouched(_ sender: UIButton) {
UIView.transition(with: sender, duration: 0.3, options: .transitionCrossDissolve) {
sender.configuration?.background.backgroundColor = .red
} completion: { _ in
UIView.transition(with: sender, duration: 1.0, options: .transitionCrossDissolve) {
sender.configuration?.background.backgroundColor = .cyan
}
}
}
When I tried to optimize and reuse code, I ended with something like:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Another option is subclass `UIButton` and override its `configurationUpdateHandler`
view.subviews.compactMap({ $0 as? UIButton }).forEach {
$0.configurationUpdateHandler = { button in
guard let config = button.configuration else { return }
button.setConfiguration(config,duration: 2)
}
}
}
#IBAction func buttonTouched(_ sender: UIButton) {
// sender.configuration?.background.backgroundColor = .red
// sender.configuration?.baseForegroundColor = .white
// The above would work, but we should rather aggregate all changes at once.
if var config = sender.configuration {
config.background.backgroundColor = .red
config.baseForegroundColor = .white
sender.configuration = config
}
}
}
extension UIButton {
func setConfiguration(_ configuration: UIButton.Configuration, duration: Double = 0.25, completion: ((Bool) -> Void)? = nil) {
UIView.transition(with: self, duration: duration, options: .transitionCrossDissolve) {
self.configuration? = configuration
} completion: { completion?($0) }
}
}
I

Drag to dismiss a UIPresentationController

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

How do I get my backgroundImageView to be draggable instead of main view

class PhotoViewController: UIViewController {
override var prefersStatusBarHidden: Bool {
return true
}
private var backgroundImage: UIImage
init(image: UIImage) {
self.backgroundImage = image
super.init(nibName: nil, bundle: nil)
print(image)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = UIColor.gray
let backgroundImageView = UIImageView(frame: view.frame)
backgroundImageView.image = backgroundImage
backgroundImageView.isUserInteractionEnabled = true
let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(panGestureRecognizerAction(_:)))
backgroundImageView.addGestureRecognizer(panGestureRecognizer)
view.addSubview(backgroundImageView)
}
func panGestureRecognizerAction(_ gesture: UIPanGestureRecognizer){
let translation = gesture.translation(in: view)
view.frame.origin.y = translation.y
if gesture.state == .ended{
let velocity = gesture.velocity(in: view)
if velocity.y > 1500{
UIView.animate(withDuration: 0.5, animations: {
self.dismiss(animated: true, completion: nil)
})
} else{
UIView.animate(withDuration: 0.3, animations: {
self.view.frame.origin = CGPoint(x: 0, y: 0)
})
}
}
}
My entire view moves and reveals a black background behind it. How do i get the backgroundImageView to move instead? I am trying to display a view underneath. If any other info is required please let me know.
In your panGestureRecognizerAction you are asking it to move view, which is the view of your viewController. Instead, use the view assigned to the gestureRecognizer by saying:
if let bgImage = gesture.view {
bgImage.frame.origin.y = translation.y
}
gesture.view is an optional, which is why I check it first. You could also say gesture.view?.frame.origin.y = translation.y and that'd work just fine too.

Receive user input from UISwipeGestureRecognizer and UIScrollView

I am trying to create a UIScrollView that performs an action on scrollViewWillBeginDragging and also recognizes left and right swipes using UISwipeGestureRecognizer. When I use the scrollViewWillBeginDragging function, I get the desired result on a left swipe but my function cannot tell whether I am performing a right or left swipe. If I set detailScrollView.userInteractionEnabled = false, the gestureRecognizer performs correctly but the view no longer scrolls. Here is my code:
override func viewDidLoad() {
super.viewDidLoad()
var leftSwipe = UISwipeGestureRecognizer(target: self, action: Selector("handleSwipes:"))
var rightSwipe = UISwipeGestureRecognizer(target: self, action: Selector("handleSwipes:"))
leftSwipe.direction = .Left
rightSwipe.direction = .Right
view.addGestureRecognizer(leftSwipe)
view.addGestureRecognizer(rightSwipe) }
func gestureRecognizer(UIGestureRecognizer,
shouldRecognizeSimultaneouslyWithGestureRecognizer:UIGestureRecognizer) -> Bool {
return true
}
func scrollViewWillBeginDragging(scrollView: UIScrollView) {
if (counter < buttons.count) {
serialSelected(buttons[counter])
counter += 1
}
}
func handleSwipes(sender:UISwipeGestureRecognizer) {
if (sender.direction == .Left) {
println("Swipe Left")
var labelPosition = CGPointMake(self.contentView.frame.origin.x - 50.0, self.contentView.frame.origin.y);
contentView.frame = CGRectMake( labelPosition.x , labelPosition.y , self.contentView.frame.size.width, self.contentView.frame.size.height)
}
if (sender.direction == .Right) {
println("Swipe Right")
var labelPosition = CGPointMake(self.contentView.frame.origin.x + 50.0, self.contentView.frame.origin.y);
contentView.frame = CGRectMake( labelPosition.x , labelPosition.y , self.contentView.frame.size.width, self.contentView.frame.size.height)
}
}
According to your source code, the shouldRecognizeSimultaneouslyWithGestureRecognizer:UIGestureRecognizer is never invoked.
// Make yourself a delegate
class yourClass: parentClass, UIGestureRecognizerDelegate
// reference the delegate
leftSwipe.delegate = self
rightSwipe.delegate = self

In iOS, how to drag down to dismiss a modal?

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.

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