Snapchat-like swipe navigation between views in Xcode 6 and Swift)

Question

I've been trying to implement swipe navigation between View Controllers in my app using the Swipe Gesture Recognizer and embeded Navigation Controller, but it doesn't look even close to the Snapchat's nav.

What would be the most efficient and appropiate way to implement such functionality?

I'm quite a newbie to Swift and programming really, and I would appreciate every helpful comment.

Solution 1

The short version is to use a container view controller with a scrollview inside the controller. You then create separate view controllers for each screen you want in the application, and make those view controllers' parent the container view controller.

A github repo with sample code can be found, here.

Solution 2

You need a pageviewcontroller. This was originally for showing tutorials and stuff but you can put view controllers in there as well. There are tons of tutorials out there and essentially you have to apply a little bit of logic to tell the program what view controller to show it next.

This is a pretty advanced example, but it might be of help to you:

https://github.com/cwRichardKim/RKSwipeBetweenViewControllers

Solution 3

I'm not fond of the version given by lbrendanl because it does not use constraints. We can not custom it like we want. Here is the same version but with constraints :

scrollView is an IBOutlet pined to the controller with 4 constraints with a constant to 0 at each sides to the controller's view.

contentView is also an IBOutlet added as subview of scrollView pined to the scrollView with 4 constraints with a constant to 0 at each sides. It also has an equal height constraint and a width equal constraint. The width equal constraint is removed at runtime and only serves to calm down IB. This view represents the contentView of the scrollView.

UPDATE iOS 9

 func setupDetailViewControllers() {
    var previousController: UIViewController?
    for controller in self.controllers {
        addChildViewController(controller)
        addControllerInContentView(controller, previousController: previousController)
        controller.didMoveToParentViewController(self)
        previousController = controller
    }
}

func addControllerInContentView(controller: UIViewController, previousController: UIViewController?) {
    contentView.addSubview(controller.view)
    controller.view.translatesAutoresizingMaskIntoConstraints = false

    // top
    controller.view.topAnchor.constraintEqualToAnchor(contentView.topAnchor).active = true

    // bottom
    controller.view.bottomAnchor.constraintEqualToAnchor(contentView.bottomAnchor).active = true

    // trailing
    trailingContentViewConstraint?.active = false
    trailingContentViewConstraint = controller.view.trailingAnchor.constraintEqualToAnchor(contentView.trailingAnchor)
    trailingContentViewConstraint?.active = true

    // leading
    let leadingAnchor = previousController?.view.trailingAnchor ?? contentView.leadingAnchor
    controller.view.leadingAnchor.constraintEqualToAnchor(leadingAnchor).active = true

    // width
    controller.view.widthAnchor.constraintEqualToAnchor(scrollView.widthAnchor).active = true
}

PREVIOUS ANSWER

    class ContainerViewController: UIViewController {

    @IBOutlet var scrollView: UIScrollView!
    @IBOutlet var contentView: UIView!

    // A strong reference to the width contraint of the contentView
    var contentViewConstraint: NSLayoutConstraint!

    // A computed version of this reference
    var computedContentViewConstraint: NSLayoutConstraint {
        return NSLayoutConstraint(item: contentView, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: scrollView, attribute: .Width, multiplier: CGFloat(controllers.count + 1), constant: 0)
    }

    // The list of controllers currently present in the scrollView
    var controllers = [UIViewController]()

    override func viewDidLoad() {
        super.viewDidLoad()

        initScrollView()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()

    }

    func initScrollView(){
        contentView.setTranslatesAutoresizingMaskIntoConstraints(false)

        contentViewConstraint = computedContentViewConstraint
        view.addConstraint(contentViewConstraint)

        // Adding all the controllers you want in the scrollView
        let controller1 = storyboard!.instantiateViewControllerWithIdentifier("AStoryboardID") as! AnUIControllerViewSubclass
        addToScrollViewNewController(controller)
        let controller2 = storyboard!.instantiateViewControllerWithIdentifier("AnotherStoryboardID") as! AnotherUIControllerViewSubclass
        addToScrollViewNewController(controller2)
    }

    // The main method, adds the controller in the scrollView at the left of the previous controller added
    func addToScrollViewNewController(controller: UIViewController) {
        self.addChildViewController(controller)

        contentView.addSubview(controller.view)

        controller.view.setTranslatesAutoresizingMaskIntoConstraints(false)

        // Setting all the constraints 
        let bottomConstraint = NSLayoutConstraint(item: contentView, attribute: .Bottom, relatedBy: .Equal, toItem: controller.view, attribute: .Bottom, multiplier: 1.0, constant: 0)

        let topConstraint = NSLayoutConstraint(item: contentView, attribute: .Top, relatedBy: .Equal, toItem: controller.view, attribute: .Top, multiplier: 1.0, constant: 0)

        let widthConstraint = NSLayoutConstraint(item: controller.view, attribute: .Width, relatedBy: .Equal, toItem: scrollView, attribute: .Width, multiplier: 1.0, constant: 0)

        var trailingConstraint: NSLayoutConstraint!
        if controllers.isEmpty {
            // Since it's the first one, the trailing constraint is from the controller view to the contentView
            trailingConstraint = NSLayoutConstraint(item: contentView, attribute: .Trailing, relatedBy: .Equal, toItem: controller.view, attribute: .Trailing, multiplier: 1.0, constant: 0)
        }
        else {
            trailingConstraint = NSLayoutConstraint(item: controllers.last!.view, attribute: .Leading, relatedBy: .Equal, toItem: controller.view, attribute: .Trailing, multiplier: 1.0, constant: 0)
        }

        // Setting the new width constraint of the contentView
        view.removeConstraint(contentViewConstraint)
        contentViewConstraint = computedContentViewConstraint

        // Adding all the constraints to the view hierarchy
        view.addConstraint(contentViewConstraint)
        contentView.addConstraints([bottomConstraint, topConstraint, trailingConstraint])
        scrollView.addConstraints([widthConstraint])

        controller.didMoveToParentViewController(self)

        // Finally adding the controller in the list of controllers
        controllers.append(controller)
    }  
}

I've used the lbrendanl's version in the past. Now I prefer this one. Let me know what you think of it.

Solution 4

I suggest using UIPageViewController and hiding the dots bar by deleting these methods:

presentationCountForPageViewController
presentationIndexForPageViewController

Here is a good tutorial:

https://www.youtube.com/watch?v=8bltsDG2ENQ

Here is a great repo for this:

https://github.com/goktugyil/EZSwipeController

Solution 5

Paged Scroll View, not a PageViewController in the case of Snapchat.

View more solutions

Comments

[Steve Sahayadarlin]

If this helped you, please click the checkmark. Thanks!

[cud_programmer]

Tutorial helped me - thanks. However, your code no longer works (Xcode 6 beta 6, running iOS 8 beta 5) - compiles fine, but view controllers aren't instantiated properly. Instead I instantiated them directly from their nib using var AVc: AViewController = AViewController(nibName: "AViewController", bundle: nil). Hope this helps someone!

[lbrendanl]

Awesome, thank you. I haven't updated for beta6 yet, but I will add your change when I do.

[mircobabini]

EXACTLY what I was looking for, thank you so much dude. Thanks. Edit: even if he was asking for swift code!

[Jake Weso]

??? What does this do differently from Brendans code? Its the same thing. What do you mean directly from their nib? This isn't working for me and I don't know how to fix it... reason: '-[UIViewController _loadViewFromNibNamed:bundle:] loaded the "CViewController" nib but the view outlet was not set.'

[Jake Weso]

Hi, i finally got it to work... your tutorial is providing incorrect steps... but now i have a problem. I want to have 7 pages instead of 3, and I added code for 7 controllers, but only the first 3 pages work. The other 4 are blank. Any ideas??

[lbrendanl]

Dead link now, my apologies, I had to take this blog post down. Cannot edit/remove the answer unfortunately, but the github repo is still live if you need code samples.

[user3498976]

@lbrendani is there a way to programmatically scroll to a certain view by pressing a 'UIButton' ? I have tried with a protocol with delegate being set in 'ContainerViewController' 'viewDidLoad' but it keeps showing that the 'scrollView' is nil ... Thanks!

[lbrendanl]

@user3498976, check out my last comment here: github.com/lbrendanl/SwiftSwipeView/issues/7. That should answer your question.

[user3498976]

@lbrendanl thank you!! Anyone out there reading this, the "issues" section is incredibly helpful (as is the entire example/tutorial)

[applemavs]

I think this should get more attention. This helped a lot. Thank you!

[Nitin Nain]

I used this version; it works, but it isn't plug and play. I had to work a lot on adjusting the constraints.. they seemed to be a few pixels off all the time.

[Zorayr]

The only caveat here is that UIPagesViewController doesn't let you know transition progress without looking into private subviews, which means you can't have progress-based transitions in your view.

[L A]

What were the benefits in using a UICollectionView?