Custom Activity Indicator with Swift - swift

Question

I am trying to create a custom activity indicator like one of these. There seems to be many approaches to animating the image, so I'm trying to figure out the best approach.
I found this tutorial with Photoshop + Aftereffects animation loop, but as the comment points out, it seems overly complex (and I don't own After Effects).
tldr: how can I take my existing image and animate it as a activity indicator (using either rotating/spinning animation or looping through an animation)

Answer 1

It's been a while since you posted this question, so I'm not sure if you've found the answer you're looking for.
You are right there are many ways to do what you are asking, and I don't think there's a "right way". I would make a UIView object which have a start and a stop method as the only public methods. I would also make it a singleton, so it's a shared object and not possible to put multiple instances on a UIViewController (imagine the mess it could make).
You can add a dataSource protocol which returns a UIViewController so the custom activity indicator could add itself to it's parent.
In the start method I would do whatever animations is needed (transform, rotate, GIF, etc.).
Here's an example:
import UIKit
protocol CustomActivityIndicatorDataSource {
func activityIndicatorParent() -> UIViewController
}
class CustomActivityIndicator: UIView {
private var activityIndicatorImageView: UIImageView
var dataSource: CustomActivityIndicatorDataSource? {
didSet {
self.setupView()
}
}
// Singleton
statice let sharedInstance = CustomActivityIndicator()
// MARK:- Initialiser
private init() {
var frame = CGRectMake(0,0,200,200)
self.activityIndicatorImageView = UIImageView(frame: frame)
self.activityIndicatorImageView.image = UIImage(named: "myImage")
super.init(frame: frame)
self.addSubview(self.activityIndicatorImageView)
self.hidden = true
}
internal required init?(coder aDecoder: NSCoder) {
self.activityIndicatorImageView = UIImageView(frame: CGRectMake(0, 0, 200, 200))
self.activityIndicatorImageView = UIImage(named: "myImage")
super.init(coder: aDecoder)
}
// MARK:- Helper methods
private func setupView() {
if self.dataSource != nil {
self.removeFromSuperview()
self.dataSource!.activityIndicatorParent().addSubview(self)
self.center = self.dataSource!.activityIndicatorParent().center
}
}
// MARK:- Animation methods
/**
Set active to true, and starts the animation
*/
func startAnimation() {
// A custom class which does thread handling. But you can use the dispatch methods.
ThreadController.performBlockOnMainQueue{
self.active = true
self.myAnimation
self.hidden = false
}
}
/**
This will set the 'active' boolean to false.
Remeber to remove the view from the superview manually
*/
func stopAnimation() {
ThreadController.performBlockOnMainQueue{
self.active = false
self.hidden = true
}
}
}
Mind that this is not fully tested and may need some tweaks to work 100%, but this is how I basically would handle it.