Swift - Presenting multiple alerts at the same time

Question

I am making an app and want to create a custom alert. I have found the following way to do it:

1. Create a view controller in story board and set its identifier.
2. Set its background to clear.
3. Create a view in it and set all the buttons and labels.

4. Call it from the other controller like this:

   let alertViewController = self.storyboard.instantiateViewControllerWithIdentifier("alertViewController") as! AlertViewController
   
   self.presentViewController(alertViewController, animated: true, completion: nil)
   

But what I want to do is, presenting multiple alerts simultaneously like this:

I searched for this but only found ways in which second alert will be displayed when first alert is responded, but not at the same time. How can I achieve what is shown in the attached image?

Answer 1

It looks like this is a modal ViewController with a UIVisualEffectView for its background so its blurring the background. You need to create an array of alert messages then, for each message you add one alert view with that message to the view controller. Each message view should have constraints width constant, height constant, centerX to superview and centerY to superview. You can then set the transform of each view to scale it down and move it up based on its index in the message array. Something like yOffset = (messages.count - index) * spacing and scale = exp(0.95, (messages.count - index)). The message in front has the indentity matrix for its transform. As you dismiss the messages animate the transform change so they all scale up and slide down.

Answer 2

Is there a max number of the number of alerts shown at the same time? If yes, how many is it?

I would suggest making it not using UIViewController but easier: using UIView. And you may show them all on your current ViewController.

How to create a custom UIView: link.

Hope it helps.