"Please wait" dialog in iOS8

Question

I used to have a "Please wait" dialog in my app for long time. It was quite simple thing using UIActivityIndicatorView and adding it to UIAlertView.

However iOS8 introduced UIAlertController. Is it possible to add anything to it to have similiar effect? Is there another way of doing such thing with iOS8?

I have searched a lot of sites and still have no idea how it can be done with the new API.

I would appreciate any answers - links to libs, tutorials etc., which could be helpful.

Regards,

Mateusz

Feininger

Answer is here #27033966 – Fault

Answer 1

Instead of using a UIAlertController, you can use a custom UIViewController that is presented modally. Here is what I use in Swift 2.0:

class ActivityViewController: UIViewController {

    private let activityView = ActivityView()

    init(message: String) {
        super.init(nibName: nil, bundle: nil)
        modalTransitionStyle = .CrossDissolve
        modalPresentationStyle = .OverFullScreen
        activityView.messageLabel.text = message
        view = activityView
    }

    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

private class ActivityView: UIView {

    let activityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: .WhiteLarge)
    let boundingBoxView = UIView(frame: CGRectZero)
    let messageLabel = UILabel(frame: CGRectZero)

    init() {
        super.init(frame: CGRectZero)

        backgroundColor = UIColor(white: 0.0, alpha: 0.5)

        boundingBoxView.backgroundColor = UIColor(white: 0.0, alpha: 0.5)
        boundingBoxView.layer.cornerRadius = 12.0

        activityIndicatorView.startAnimating()

        messageLabel.font = UIFont.boldSystemFontOfSize(UIFont.labelFontSize())
        messageLabel.textColor = UIColor.whiteColor()
        messageLabel.textAlignment = .Center
        messageLabel.shadowColor = UIColor.blackColor()
        messageLabel.shadowOffset = CGSizeMake(0.0, 1.0)
        messageLabel.numberOfLines = 0

        addSubview(boundingBoxView)
        addSubview(activityIndicatorView)
        addSubview(messageLabel)
    }

    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        boundingBoxView.frame.size.width = 160.0
        boundingBoxView.frame.size.height = 160.0
        boundingBoxView.frame.origin.x = ceil((bounds.width / 2.0) - (boundingBoxView.frame.width / 2.0))
        boundingBoxView.frame.origin.y = ceil((bounds.height / 2.0) - (boundingBoxView.frame.height / 2.0))

        activityIndicatorView.frame.origin.x = ceil((bounds.width / 2.0) - (activityIndicatorView.frame.width / 2.0))
        activityIndicatorView.frame.origin.y = ceil((bounds.height / 2.0) - (activityIndicatorView.frame.height / 2.0))

        let messageLabelSize = messageLabel.sizeThatFits(CGSizeMake(160.0 - 20.0 * 2.0, CGFloat.max))
        messageLabel.frame.size.width = messageLabelSize.width
        messageLabel.frame.size.height = messageLabelSize.height
        messageLabel.frame.origin.x = ceil((bounds.width / 2.0) - (messageLabel.frame.width / 2.0))
        messageLabel.frame.origin.y = ceil(activityIndicatorView.frame.origin.y + activityIndicatorView.frame.size.height + ((boundingBoxView.frame.height - activityIndicatorView.frame.height) / 4.0) - (messageLabel.frame.height / 2.0))
    }
}

You use it like this:

let activitiyViewController = ActivityViewController(message: "Loading...")
presentViewController(activitiyViewController, animated: true, completion: nil)

And it will look like this:

Presentation Controller and Animated Transitioning

See this answer for a sample implementation that recreates the UIAlertController animation using UIViewControllerAnimatedTransitioning.

Cadaver

The other solutions are quick and easy, but not very robust or future proof: You can not have message and spinner, you have to manually position the spinner (could break in the future), hack the strings with extra newlines, etc. This is the most elegant. – Steelworks

how do stop loading after some time loading? – Amateurish

if let view = view as? ActivityView { view.activityIndicatorView.stopAnimating } – Cadaver

activitiyViewController.dismiss(animated: true) will close the progress view controller – Maighdlin

This code is out of date for more recent versions of Swift – Aesop

Answer 2

Try this I done some trick...

Below code is working for me in iPod iOS8beta5 + XCode6

UIAlertController *alert = [UIAlertController alertControllerWithTitle:nil
                                        message:@"Please wait\n\n\n"
                                 preferredStyle:UIAlertControllerStyleAlert];

    UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    spinner.center = CGPointMake(130.5, 65.5);
    spinner.color = [UIColor blackColor];
    [spinner startAnimating];
    [alert.view addSubview:spinner];
    [self presentViewController:alert animated:NO completion:nil];

Uncleanly

Checked and in fact it works ;-) After some improvements it could be acceptable so answer accepted :) Thx for help. – Feininger

The only problem with this is you have to manually position the subview. Not ideal but it works and can't see another way around it – Hostelry

@Uncleanly I implemented this but I can't seem to get the alert view to exit. Would there be any way to implement this? – Tasimeter

you can add a button to the uialertcontroller, or follow @Uncleanly advice and hold reference of that file. I've done both and both work perfect. – Decahedron

Answer 3

Swift 3.0/4.1

To show the progress dialog:

let alertController = UIAlertController(title: nil, message: "Please wait\n\n", preferredStyle: .alert)

let spinnerIndicator = UIActivityIndicatorView(activityIndicatorStyle: .whiteLarge)

spinnerIndicator.center = CGPoint(x: 135.0, y: 65.5)
spinnerIndicator.color = UIColor.black
spinnerIndicator.startAnimating()

alertController.view.addSubview(spinnerIndicator)
self.present(alertController, animated: false, completion: nil)

To dismiss the progress dialog:

alertController.dismiss(animated: true, completion: nil);

Gemstone

Answer 4

Swift 2.0:

 override func viewDidAppear(animated: Bool)
 {

  let alertController = UIAlertController(title: nil, message: "Please wait\n\n", preferredStyle: UIAlertControllerStyle.Alert)

  let spinnerIndicator: UIActivityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.WhiteLarge)

  spinnerIndicator.center = CGPointMake(135.0, 65.5)
  spinnerIndicator.color = UIColor.blackColor()
  spinnerIndicator.startAnimating()

  alertController.view.addSubview(spinnerIndicator)
  self.presentViewController(alertController, animated: false, completion: nil)

}

After some point, we need to hide the alert.

alertController.dismissViewControllerAnimated(true, completion: nil)

Ypres

Answer 5

If you only want to display title and activity indicator and you feel adventurous, you can hack AlertController's view hierarchy. The code below works on 8.2. However this normally should not be in production.

As it's been noted in comments below, using this code in your app may get you rejected, here is the excerpt from documentation:

The UIAlertController class is intended to be used as-is and does not support subclassing. The view hierarchy for this class is private and must not be modified.

@implementation AlertControllerWithActivityIndicator

- (void)viewDidLayoutSubviews {
    [super viewDidLayoutSubviews];

    UIView *scrollView = [self findViewByClassPrefix:@"_UIAlertControllerShadowedScrollView" inView:self.view];
    UIView *containerView = [scrollView.subviews firstObject];
    UILabel *titleLabel = containerView.subviews.firstObject;

    if(!titleLabel) {
        return;
    }

    if(!self.indicatorView) {
        self.indicatorView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
        self.indicatorView.translatesAutoresizingMaskIntoConstraints = NO;
        [containerView addSubview:self.indicatorView];
        NSDictionary *views = @{ @"text": titleLabel, @"indicator": self.indicatorView };

        NSArray *constraints = [scrollView constraintsAffectingLayoutForAxis:UILayoutConstraintAxisVertical];
        for(NSLayoutConstraint *constraint in constraints) {
            if(constraint.firstItem == containerView && constraint.secondItem == titleLabel && constraint.firstAttribute == NSLayoutAttributeBottom) {
                constraint.active = NO;
            }
        }

        [containerView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[text]-[indicator]-24-|" options:0 metrics:nil views:views]];
        [containerView addConstraint:[NSLayoutConstraint constraintWithItem:self.indicatorView attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:containerView attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0]];

        [self.indicatorView startAnimating];
    }
}

- (UIView *)findViewByClassPrefix:(NSString *)prefix inView:(UIView *)view {
    for(UIView *subview in view.subviews) {
        if([NSStringFromClass(subview.class) hasPrefix:prefix]) {
            return subview;
        }

        UIView *child = [self findViewByClassPrefix:prefix inView:subview];
        if(child) {
            return child;
        }
    }
    return nil;
}

@end

Produces something like that:

Opaque

Please note that _UIAlertControllerShadowedScrollView is private and might cause a rejection of the app! – Granger

Answer 6

Same as @pheedsta but changed to work with Swift 4

import UIKit

class ActivityViewController: UIViewController {

    private let activityView = ActivityView()

    init(message: String) {
        super.init(nibName: nil, bundle: nil)
        modalTransitionStyle = .crossDissolve
        modalPresentationStyle = .overFullScreen
        activityView.messageLabel.text = message
        view = activityView
    }

    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

private class ActivityView: UIView {

    let activityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: .whiteLarge)
    let boundingBoxView = UIView(frame: CGRect.zero)
    let messageLabel = UILabel(frame: CGRect.zero)

    init() {
        super.init(frame: CGRect.zero)

        backgroundColor = UIColor(white: 0.0, alpha: 0.5)

        boundingBoxView.backgroundColor = UIColor(white: 0.0, alpha: 0.5)
        boundingBoxView.layer.cornerRadius = 12.0

        activityIndicatorView.startAnimating()

        messageLabel.font = UIFont.boldSystemFont(ofSize: UIFont.labelFontSize)
        messageLabel.textColor = UIColor.white
        messageLabel.textAlignment = .center
        messageLabel.shadowColor = UIColor.black
        messageLabel.shadowOffset = CGSize(width: 0.0, height: 1.0)
        messageLabel.numberOfLines = 0

        addSubview(boundingBoxView)
        addSubview(activityIndicatorView)
        addSubview(messageLabel)
    }

    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        boundingBoxView.frame.size.width = 160.0
        boundingBoxView.frame.size.height = 160.0
        boundingBoxView.frame.origin.x = ceil((bounds.width / 2.0) - (boundingBoxView.frame.width / 2.0))
        boundingBoxView.frame.origin.y = ceil((bounds.height / 2.0) - (boundingBoxView.frame.height / 2.0))

        activityIndicatorView.frame.origin.x = ceil((bounds.width / 2.0) - (activityIndicatorView.frame.width / 2.0))
        activityIndicatorView.frame.origin.y = ceil((bounds.height / 2.0) - (activityIndicatorView.frame.height / 2.0))

        let messageLabelSize = messageLabel.sizeThatFits(CGSize(width: 160.0 - 20.0 * 2.0, height: CGFloat.greatestFiniteMagnitude))
        messageLabel.frame.size.width = messageLabelSize.width
        messageLabel.frame.size.height = messageLabelSize.height
        messageLabel.frame.origin.x = ceil((bounds.width / 2.0) - (messageLabel.frame.width / 2.0))
        messageLabel.frame.origin.y = ceil(activityIndicatorView.frame.origin.y + activityIndicatorView.frame.size.height + ((boundingBoxView.frame.height - activityIndicatorView.frame.height) / 4.0) - (messageLabel.frame.height / 2.0))
    }
}

Usage:

// Initiate somewhere
let activitiyViewController = ActivityViewController(message: "Loading...")
// To start/show
present(activitiyViewController, animated: true, completion: nil)
// To stop/dissmiss
activitiyViewController.dismiss(animated: true)

Mehta

Answer 7

It seems to be impossible to do it plain old way using only basic API. I have decided to use DTAlertView which allows such modifications. It works as I wanted.

https://github.com/Darktt/DTAlertView

Feininger

how did they implement DTAlertView? without API! – Chumash

Answer 8

Swift 3.1 version of @darksinge code

import UIKit

class ActivityViewController: UIViewController {

    private let activityView = ActivityView()

    init(message: String) {
        super.init(nibName: nil, bundle: nil)
        modalTransitionStyle = .crossDissolve
        modalPresentationStyle = .overFullScreen
        activityView.messageLabel.text = message
        view = activityView
    }

    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

private class ActivityView: UIView {

    let activityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: .whiteLarge)
    let boundingBoxView = UIView(frame: CGRect.zero)
    let messageLabel = UILabel(frame: CGRect.zero)

    init() {
        super.init(frame: CGRect.zero)

        backgroundColor = UIColor(white: 0.0, alpha: 0.5)

        boundingBoxView.backgroundColor = UIColor(white: 0.0, alpha: 0.5)
        boundingBoxView.layer.cornerRadius = 12.0

        activityIndicatorView.startAnimating()

        messageLabel.font = UIFont.boldSystemFont(ofSize: UIFont.labelFontSize)
        messageLabel.textColor = UIColor.white
        messageLabel.textAlignment = .center
        messageLabel.shadowColor = UIColor.black
        messageLabel.shadowOffset = CGSize(width: 0.0, height: 1.0)
        messageLabel.numberOfLines = 0

        addSubview(boundingBoxView)
        addSubview(activityIndicatorView)
        addSubview(messageLabel)
    }

    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        boundingBoxView.frame.size.width = 160.0
        boundingBoxView.frame.size.height = 160.0
        boundingBoxView.frame.origin.x = ceil((bounds.width / 2.0) - (boundingBoxView.frame.width / 2.0))
        boundingBoxView.frame.origin.y = ceil((bounds.height / 2.0) - (boundingBoxView.frame.height / 2.0))

        activityIndicatorView.frame.origin.x = ceil((bounds.width / 2.0) - (activityIndicatorView.frame.width / 2.0))
        activityIndicatorView.frame.origin.y = ceil((bounds.height / 2.0) - (activityIndicatorView.frame.height / 2.0))

        let messageLabelSize = messageLabel.sizeThatFits(CGSize(width:160.0 - 20.0 * 2.0, height: CGFloat.greatestFiniteMagnitude))
        messageLabel.frame.size.width = messageLabelSize.width
        messageLabel.frame.size.height = messageLabelSize.height
        messageLabel.frame.origin.x = ceil((bounds.width / 2.0) - (messageLabel.frame.width / 2.0))
        messageLabel.frame.origin.y = ceil(activityIndicatorView.frame.origin.y + activityIndicatorView.frame.size.height + ((boundingBoxView.frame.height - activityIndicatorView.frame.height) / 4.0) - (messageLabel.frame.height / 2.0))
    }
}

Restrict