slide transition using UIView.transition() method - ios

Question

I have and table view and when the user clicks a button I want it to reload it's data and change numerous other things. Sadly, my users have not been satisfied with the available options for the transitions/animations, and wanted a sliding transition. I couldn't find anything online to do this, however. Here is my code:
UIView.transition(with: view, duration: 0.5,options: .transitionCurlUp,animations:
{ () -> Void in
self.schedule.reloadData()
self.formatter.dateFormat = "yyyy-MM-dd"
let dayOfWeek = self.week[self.getDayOfWeek(self.currentDate)!-1]
var forReturn = dayOfWeek.getCourseNumber()
if forReturn>3{
forReturn = forReturn + 1
self.refreshButton.isHidden = false
self.noClasses.isHidden = true
}else{
self.refreshButton.isHidden = true
self.noClasses.isHidden = false
}
self.changeWeek()
let startDate = self.formatter.string(from: self.startDateBase)
if self.currentDate == startDate{
self.other1.text = "Today's Schedule"
}else{
self.formatter.dateFormat = "yyyy-MM-dd"
self.currentDate = self.formatter.string(from: self.date)
self.other1.text = dayNames[self.getDayOfWeek(self.currentDate)!-1] + " Schedule"
}
}, completion: nil
);
Thank you.

Answer 1

You can go old school on this:
take a snapshot of the view;
add it to the view hierarchy;
apply offsetting transforms to the snapshot view and the view, itself;
animate the restoration of the main view's transform back to .identity; and
removing the snapshot view when done with the animation.
Thus:
let snapshotView = snapshot()
view.addSubview(snapshotView)
snapshotView.transform = CGAffineTransform(translationX: -view.bounds.size.width, y: 0)
view.transform = CGAffineTransform(translationX: view.frame.size.width, y: 0)
// do whatever updates to the views you want here
tableView.reloadData()
UIView.animate(withDuration: 0.5, animations: {
self.view.transform = .identity
}, completion: { _ in
snapshotView.removeFromSuperview()
})
For the snapshot, I used:
func snapshot() -> UIView {
UIGraphicsBeginImageContextWithOptions(view.bounds.size, true, 0)
view.drawHierarchy(in: view.bounds, afterScreenUpdates: false)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
let imageView = UIImageView(image: image)
imageView.frame = view.bounds
return imageView
}
By the way, you can also use snapshotView(afterScreenupdates:), which is faster than drawHierarchy, but it doesn't work in 7+ simulator for some reason (see https://forums.developer.apple.com/thread/63438), so I'm not 100% comfortable with it. But if you wanted to do that, you'd do replace the shapshotView declaration with:
let snapshotView = view.snapshotView(afterScreenUpdates: false)!